FreeBSD/Linux Kernel Cross Reference
sys/i386/i386/pmap.c
1 /*-
2 * Copyright (c) 1991 Regents of the University of California.
3 * All rights reserved.
4 * Copyright (c) 1994 John S. Dyson
5 * All rights reserved.
6 * Copyright (c) 1994 David Greenman
7 * All rights reserved.
8 * Copyright (c) 2005-2008 Alan L. Cox <alc@cs.rice.edu>
9 * All rights reserved.
10 *
11 * This code is derived from software contributed to Berkeley by
12 * the Systems Programming Group of the University of Utah Computer
13 * Science Department and William Jolitz of UUNET Technologies Inc.
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
17 * are met:
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
23 * 3. All advertising materials mentioning features or use of this software
24 * must display the following acknowledgement:
25 * This product includes software developed by the University of
26 * California, Berkeley and its contributors.
27 * 4. Neither the name of the University nor the names of its contributors
28 * may be used to endorse or promote products derived from this software
29 * without specific prior written permission.
30 *
31 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
32 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
33 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
34 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
35 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
39 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
40 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
41 * SUCH DAMAGE.
42 *
43 * from: @(#)pmap.c 7.7 (Berkeley) 5/12/91
44 */
45 /*-
46 * Copyright (c) 2003 Networks Associates Technology, Inc.
47 * All rights reserved.
48 *
49 * This software was developed for the FreeBSD Project by Jake Burkholder,
50 * Safeport Network Services, and Network Associates Laboratories, the
51 * Security Research Division of Network Associates, Inc. under
52 * DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA
53 * CHATS research program.
54 *
55 * Redistribution and use in source and binary forms, with or without
56 * modification, are permitted provided that the following conditions
57 * are met:
58 * 1. Redistributions of source code must retain the above copyright
59 * notice, this list of conditions and the following disclaimer.
60 * 2. Redistributions in binary form must reproduce the above copyright
61 * notice, this list of conditions and the following disclaimer in the
62 * documentation and/or other materials provided with the distribution.
63 *
64 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
65 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
66 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
67 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
68 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
69 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
70 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
71 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
72 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
73 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
74 * SUCH DAMAGE.
75 */
76
77 #include <sys/cdefs.h>
78 __FBSDID("$FreeBSD: releng/8.0/sys/i386/i386/pmap.c 198991 2009-11-06 17:09:04Z attilio $");
79
80 /*
81 * Manages physical address maps.
82 *
83 * In addition to hardware address maps, this
84 * module is called upon to provide software-use-only
85 * maps which may or may not be stored in the same
86 * form as hardware maps. These pseudo-maps are
87 * used to store intermediate results from copy
88 * operations to and from address spaces.
89 *
90 * Since the information managed by this module is
91 * also stored by the logical address mapping module,
92 * this module may throw away valid virtual-to-physical
93 * mappings at almost any time. However, invalidations
94 * of virtual-to-physical mappings must be done as
95 * requested.
96 *
97 * In order to cope with hardware architectures which
98 * make virtual-to-physical map invalidates expensive,
99 * this module may delay invalidate or reduced protection
100 * operations until such time as they are actually
101 * necessary. This module is given full information as
102 * to which processors are currently using which maps,
103 * and to when physical maps must be made correct.
104 */
105
106 #include "opt_cpu.h"
107 #include "opt_pmap.h"
108 #include "opt_msgbuf.h"
109 #include "opt_smp.h"
110 #include "opt_xbox.h"
111
112 #include <sys/param.h>
113 #include <sys/systm.h>
114 #include <sys/kernel.h>
115 #include <sys/ktr.h>
116 #include <sys/lock.h>
117 #include <sys/malloc.h>
118 #include <sys/mman.h>
119 #include <sys/msgbuf.h>
120 #include <sys/mutex.h>
121 #include <sys/proc.h>
122 #include <sys/sf_buf.h>
123 #include <sys/sx.h>
124 #include <sys/vmmeter.h>
125 #include <sys/sched.h>
126 #include <sys/sysctl.h>
127 #ifdef SMP
128 #include <sys/smp.h>
129 #endif
130
131 #include <vm/vm.h>
132 #include <vm/vm_param.h>
133 #include <vm/vm_kern.h>
134 #include <vm/vm_page.h>
135 #include <vm/vm_map.h>
136 #include <vm/vm_object.h>
137 #include <vm/vm_extern.h>
138 #include <vm/vm_pageout.h>
139 #include <vm/vm_pager.h>
140 #include <vm/vm_reserv.h>
141 #include <vm/uma.h>
142
143 #include <machine/cpu.h>
144 #include <machine/cputypes.h>
145 #include <machine/md_var.h>
146 #include <machine/pcb.h>
147 #include <machine/specialreg.h>
148 #ifdef SMP
149 #include <machine/smp.h>
150 #endif
151
152 #ifdef XBOX
153 #include <machine/xbox.h>
154 #endif
155
156 #if !defined(CPU_DISABLE_SSE) && defined(I686_CPU)
157 #define CPU_ENABLE_SSE
158 #endif
159
160 #ifndef PMAP_SHPGPERPROC
161 #define PMAP_SHPGPERPROC 200
162 #endif
163
164 #if !defined(DIAGNOSTIC)
165 #define PMAP_INLINE __gnu89_inline
166 #else
167 #define PMAP_INLINE
168 #endif
169
170 #define PV_STATS
171 #ifdef PV_STATS
172 #define PV_STAT(x) do { x ; } while (0)
173 #else
174 #define PV_STAT(x) do { } while (0)
175 #endif
176
177 #define pa_index(pa) ((pa) >> PDRSHIFT)
178 #define pa_to_pvh(pa) (&pv_table[pa_index(pa)])
179
180 /*
181 * Get PDEs and PTEs for user/kernel address space
182 */
183 #define pmap_pde(m, v) (&((m)->pm_pdir[(vm_offset_t)(v) >> PDRSHIFT]))
184 #define pdir_pde(m, v) (m[(vm_offset_t)(v) >> PDRSHIFT])
185
186 #define pmap_pde_v(pte) ((*(int *)pte & PG_V) != 0)
187 #define pmap_pte_w(pte) ((*(int *)pte & PG_W) != 0)
188 #define pmap_pte_m(pte) ((*(int *)pte & PG_M) != 0)
189 #define pmap_pte_u(pte) ((*(int *)pte & PG_A) != 0)
190 #define pmap_pte_v(pte) ((*(int *)pte & PG_V) != 0)
191
192 #define pmap_pte_set_w(pte, v) ((v) ? atomic_set_int((u_int *)(pte), PG_W) : \
193 atomic_clear_int((u_int *)(pte), PG_W))
194 #define pmap_pte_set_prot(pte, v) ((*(int *)pte &= ~PG_PROT), (*(int *)pte |= (v)))
195
196 struct pmap kernel_pmap_store;
197 LIST_HEAD(pmaplist, pmap);
198 static struct pmaplist allpmaps;
199 static struct mtx allpmaps_lock;
200
201 vm_offset_t virtual_avail; /* VA of first avail page (after kernel bss) */
202 vm_offset_t virtual_end; /* VA of last avail page (end of kernel AS) */
203 int pgeflag = 0; /* PG_G or-in */
204 int pseflag = 0; /* PG_PS or-in */
205
206 static int nkpt;
207 vm_offset_t kernel_vm_end;
208 extern u_int32_t KERNend;
209
210 #ifdef PAE
211 pt_entry_t pg_nx;
212 static uma_zone_t pdptzone;
213 #endif
214
215 static int pat_works; /* Is page attribute table sane? */
216
217 SYSCTL_NODE(_vm, OID_AUTO, pmap, CTLFLAG_RD, 0, "VM/pmap parameters");
218
219 static int pg_ps_enabled;
220 SYSCTL_INT(_vm_pmap, OID_AUTO, pg_ps_enabled, CTLFLAG_RD, &pg_ps_enabled, 0,
221 "Are large page mappings enabled?");
222
223 /*
224 * Data for the pv entry allocation mechanism
225 */
226 static int pv_entry_count = 0, pv_entry_max = 0, pv_entry_high_water = 0;
227 static struct md_page *pv_table;
228 static int shpgperproc = PMAP_SHPGPERPROC;
229
230 struct pv_chunk *pv_chunkbase; /* KVA block for pv_chunks */
231 int pv_maxchunks; /* How many chunks we have KVA for */
232 vm_offset_t pv_vafree; /* freelist stored in the PTE */
233
234 /*
235 * All those kernel PT submaps that BSD is so fond of
236 */
237 struct sysmaps {
238 struct mtx lock;
239 pt_entry_t *CMAP1;
240 pt_entry_t *CMAP2;
241 caddr_t CADDR1;
242 caddr_t CADDR2;
243 };
244 static struct sysmaps sysmaps_pcpu[MAXCPU];
245 pt_entry_t *CMAP1 = 0;
246 static pt_entry_t *CMAP3;
247 caddr_t CADDR1 = 0, ptvmmap = 0;
248 static caddr_t CADDR3;
249 struct msgbuf *msgbufp = 0;
250
251 /*
252 * Crashdump maps.
253 */
254 static caddr_t crashdumpmap;
255
256 static pt_entry_t *PMAP1 = 0, *PMAP2;
257 static pt_entry_t *PADDR1 = 0, *PADDR2;
258 #ifdef SMP
259 static int PMAP1cpu;
260 static int PMAP1changedcpu;
261 SYSCTL_INT(_debug, OID_AUTO, PMAP1changedcpu, CTLFLAG_RD,
262 &PMAP1changedcpu, 0,
263 "Number of times pmap_pte_quick changed CPU with same PMAP1");
264 #endif
265 static int PMAP1changed;
266 SYSCTL_INT(_debug, OID_AUTO, PMAP1changed, CTLFLAG_RD,
267 &PMAP1changed, 0,
268 "Number of times pmap_pte_quick changed PMAP1");
269 static int PMAP1unchanged;
270 SYSCTL_INT(_debug, OID_AUTO, PMAP1unchanged, CTLFLAG_RD,
271 &PMAP1unchanged, 0,
272 "Number of times pmap_pte_quick didn't change PMAP1");
273 static struct mtx PMAP2mutex;
274
275 static void free_pv_entry(pmap_t pmap, pv_entry_t pv);
276 static pv_entry_t get_pv_entry(pmap_t locked_pmap, int try);
277 static void pmap_pv_demote_pde(pmap_t pmap, vm_offset_t va, vm_paddr_t pa);
278 static boolean_t pmap_pv_insert_pde(pmap_t pmap, vm_offset_t va, vm_paddr_t pa);
279 static void pmap_pv_promote_pde(pmap_t pmap, vm_offset_t va, vm_paddr_t pa);
280 static void pmap_pvh_free(struct md_page *pvh, pmap_t pmap, vm_offset_t va);
281 static pv_entry_t pmap_pvh_remove(struct md_page *pvh, pmap_t pmap,
282 vm_offset_t va);
283 static int pmap_pvh_wired_mappings(struct md_page *pvh, int count);
284
285 static boolean_t pmap_demote_pde(pmap_t pmap, pd_entry_t *pde, vm_offset_t va);
286 static boolean_t pmap_enter_pde(pmap_t pmap, vm_offset_t va, vm_page_t m,
287 vm_prot_t prot);
288 static vm_page_t pmap_enter_quick_locked(pmap_t pmap, vm_offset_t va,
289 vm_page_t m, vm_prot_t prot, vm_page_t mpte);
290 static void pmap_insert_pt_page(pmap_t pmap, vm_page_t mpte);
291 static void pmap_fill_ptp(pt_entry_t *firstpte, pt_entry_t newpte);
292 static boolean_t pmap_is_modified_pvh(struct md_page *pvh);
293 static void pmap_kenter_attr(vm_offset_t va, vm_paddr_t pa, int mode);
294 static vm_page_t pmap_lookup_pt_page(pmap_t pmap, vm_offset_t va);
295 static void pmap_pde_attr(pd_entry_t *pde, int cache_bits);
296 static void pmap_promote_pde(pmap_t pmap, pd_entry_t *pde, vm_offset_t va);
297 static boolean_t pmap_protect_pde(pmap_t pmap, pd_entry_t *pde, vm_offset_t sva,
298 vm_prot_t prot);
299 static void pmap_pte_attr(pt_entry_t *pte, int cache_bits);
300 static void pmap_remove_pde(pmap_t pmap, pd_entry_t *pdq, vm_offset_t sva,
301 vm_page_t *free);
302 static int pmap_remove_pte(pmap_t pmap, pt_entry_t *ptq, vm_offset_t sva,
303 vm_page_t *free);
304 static void pmap_remove_pt_page(pmap_t pmap, vm_page_t mpte);
305 static void pmap_remove_page(struct pmap *pmap, vm_offset_t va,
306 vm_page_t *free);
307 static void pmap_remove_entry(struct pmap *pmap, vm_page_t m,
308 vm_offset_t va);
309 static void pmap_insert_entry(pmap_t pmap, vm_offset_t va, vm_page_t m);
310 static boolean_t pmap_try_insert_pv_entry(pmap_t pmap, vm_offset_t va,
311 vm_page_t m);
312
313 static vm_page_t pmap_allocpte(pmap_t pmap, vm_offset_t va, int flags);
314
315 static vm_page_t _pmap_allocpte(pmap_t pmap, unsigned ptepindex, int flags);
316 static int _pmap_unwire_pte_hold(pmap_t pmap, vm_page_t m, vm_page_t *free);
317 static pt_entry_t *pmap_pte_quick(pmap_t pmap, vm_offset_t va);
318 static void pmap_pte_release(pt_entry_t *pte);
319 static int pmap_unuse_pt(pmap_t, vm_offset_t, vm_page_t *);
320 static vm_offset_t pmap_kmem_choose(vm_offset_t addr);
321 #ifdef PAE
322 static void *pmap_pdpt_allocf(uma_zone_t zone, int bytes, u_int8_t *flags, int wait);
323 #endif
324
325 CTASSERT(1 << PDESHIFT == sizeof(pd_entry_t));
326 CTASSERT(1 << PTESHIFT == sizeof(pt_entry_t));
327
328 /*
329 * If you get an error here, then you set KVA_PAGES wrong! See the
330 * description of KVA_PAGES in sys/i386/include/pmap.h. It must be
331 * multiple of 4 for a normal kernel, or a multiple of 8 for a PAE.
332 */
333 CTASSERT(KERNBASE % (1 << 24) == 0);
334
335 /*
336 * Move the kernel virtual free pointer to the next
337 * 4MB. This is used to help improve performance
338 * by using a large (4MB) page for much of the kernel
339 * (.text, .data, .bss)
340 */
341 static vm_offset_t
342 pmap_kmem_choose(vm_offset_t addr)
343 {
344 vm_offset_t newaddr = addr;
345
346 #ifndef DISABLE_PSE
347 if (cpu_feature & CPUID_PSE)
348 newaddr = (addr + PDRMASK) & ~PDRMASK;
349 #endif
350 return newaddr;
351 }
352
353 /*
354 * Bootstrap the system enough to run with virtual memory.
355 *
356 * On the i386 this is called after mapping has already been enabled
357 * and just syncs the pmap module with what has already been done.
358 * [We can't call it easily with mapping off since the kernel is not
359 * mapped with PA == VA, hence we would have to relocate every address
360 * from the linked base (virtual) address "KERNBASE" to the actual
361 * (physical) address starting relative to 0]
362 */
363 void
364 pmap_bootstrap(vm_paddr_t firstaddr)
365 {
366 vm_offset_t va;
367 pt_entry_t *pte, *unused;
368 struct sysmaps *sysmaps;
369 int i;
370
371 /*
372 * XXX The calculation of virtual_avail is wrong. It's NKPT*PAGE_SIZE too
373 * large. It should instead be correctly calculated in locore.s and
374 * not based on 'first' (which is a physical address, not a virtual
375 * address, for the start of unused physical memory). The kernel
376 * page tables are NOT double mapped and thus should not be included
377 * in this calculation.
378 */
379 virtual_avail = (vm_offset_t) KERNBASE + firstaddr;
380 virtual_avail = pmap_kmem_choose(virtual_avail);
381
382 virtual_end = VM_MAX_KERNEL_ADDRESS;
383
384 /*
385 * Initialize the kernel pmap (which is statically allocated).
386 */
387 PMAP_LOCK_INIT(kernel_pmap);
388 kernel_pmap->pm_pdir = (pd_entry_t *) (KERNBASE + (u_int)IdlePTD);
389 #ifdef PAE
390 kernel_pmap->pm_pdpt = (pdpt_entry_t *) (KERNBASE + (u_int)IdlePDPT);
391 #endif
392 kernel_pmap->pm_root = NULL;
393 kernel_pmap->pm_active = -1; /* don't allow deactivation */
394 TAILQ_INIT(&kernel_pmap->pm_pvchunk);
395 LIST_INIT(&allpmaps);
396 mtx_init(&allpmaps_lock, "allpmaps", NULL, MTX_SPIN);
397 mtx_lock_spin(&allpmaps_lock);
398 LIST_INSERT_HEAD(&allpmaps, kernel_pmap, pm_list);
399 mtx_unlock_spin(&allpmaps_lock);
400 nkpt = NKPT;
401
402 /*
403 * Reserve some special page table entries/VA space for temporary
404 * mapping of pages.
405 */
406 #define SYSMAP(c, p, v, n) \
407 v = (c)va; va += ((n)*PAGE_SIZE); p = pte; pte += (n);
408
409 va = virtual_avail;
410 pte = vtopte(va);
411
412 /*
413 * CMAP1/CMAP2 are used for zeroing and copying pages.
414 * CMAP3 is used for the idle process page zeroing.
415 */
416 for (i = 0; i < MAXCPU; i++) {
417 sysmaps = &sysmaps_pcpu[i];
418 mtx_init(&sysmaps->lock, "SYSMAPS", NULL, MTX_DEF);
419 SYSMAP(caddr_t, sysmaps->CMAP1, sysmaps->CADDR1, 1)
420 SYSMAP(caddr_t, sysmaps->CMAP2, sysmaps->CADDR2, 1)
421 }
422 SYSMAP(caddr_t, CMAP1, CADDR1, 1)
423 SYSMAP(caddr_t, CMAP3, CADDR3, 1)
424 *CMAP3 = 0;
425
426 /*
427 * Crashdump maps.
428 */
429 SYSMAP(caddr_t, unused, crashdumpmap, MAXDUMPPGS)
430
431 /*
432 * ptvmmap is used for reading arbitrary physical pages via /dev/mem.
433 */
434 SYSMAP(caddr_t, unused, ptvmmap, 1)
435
436 /*
437 * msgbufp is used to map the system message buffer.
438 */
439 SYSMAP(struct msgbuf *, unused, msgbufp, atop(round_page(MSGBUF_SIZE)))
440
441 /*
442 * ptemap is used for pmap_pte_quick
443 */
444 SYSMAP(pt_entry_t *, PMAP1, PADDR1, 1);
445 SYSMAP(pt_entry_t *, PMAP2, PADDR2, 1);
446
447 mtx_init(&PMAP2mutex, "PMAP2", NULL, MTX_DEF);
448
449 virtual_avail = va;
450
451 *CMAP1 = 0;
452
453 /*
454 * Leave in place an identity mapping (virt == phys) for the low 1 MB
455 * physical memory region that is used by the ACPI wakeup code. This
456 * mapping must not have PG_G set.
457 */
458 #ifdef XBOX
459 /* FIXME: This is gross, but needed for the XBOX. Since we are in such
460 * an early stadium, we cannot yet neatly map video memory ... :-(
461 * Better fixes are very welcome! */
462 if (!arch_i386_is_xbox)
463 #endif
464 for (i = 1; i < NKPT; i++)
465 PTD[i] = 0;
466
467 /* Initialize the PAT MSR if present. */
468 pmap_init_pat();
469
470 /* Turn on PG_G on kernel page(s) */
471 pmap_set_pg();
472 }
473
474 /*
475 * Setup the PAT MSR.
476 */
477 void
478 pmap_init_pat(void)
479 {
480 uint64_t pat_msr;
481
482 /* Bail if this CPU doesn't implement PAT. */
483 if (!(cpu_feature & CPUID_PAT))
484 return;
485
486 if (cpu_vendor_id != CPU_VENDOR_INTEL ||
487 (CPUID_TO_FAMILY(cpu_id) == 6 && CPUID_TO_MODEL(cpu_id) >= 0xe)) {
488 /*
489 * Leave the indices 0-3 at the default of WB, WT, UC, and UC-.
490 * Program 4 and 5 as WP and WC.
491 * Leave 6 and 7 as UC and UC-.
492 */
493 pat_msr = rdmsr(MSR_PAT);
494 pat_msr &= ~(PAT_MASK(4) | PAT_MASK(5));
495 pat_msr |= PAT_VALUE(4, PAT_WRITE_PROTECTED) |
496 PAT_VALUE(5, PAT_WRITE_COMBINING);
497 pat_works = 1;
498 } else {
499 /*
500 * Due to some Intel errata, we can only safely use the lower 4
501 * PAT entries. Thus, just replace PAT Index 2 with WC instead
502 * of UC-.
503 *
504 * Intel Pentium III Processor Specification Update
505 * Errata E.27 (Upper Four PAT Entries Not Usable With Mode B
506 * or Mode C Paging)
507 *
508 * Intel Pentium IV Processor Specification Update
509 * Errata N46 (PAT Index MSB May Be Calculated Incorrectly)
510 */
511 pat_msr = rdmsr(MSR_PAT);
512 pat_msr &= ~PAT_MASK(2);
513 pat_msr |= PAT_VALUE(2, PAT_WRITE_COMBINING);
514 pat_works = 0;
515 }
516 wrmsr(MSR_PAT, pat_msr);
517 }
518
519 /*
520 * Set PG_G on kernel pages. Only the BSP calls this when SMP is turned on.
521 */
522 void
523 pmap_set_pg(void)
524 {
525 pd_entry_t pdir;
526 pt_entry_t *pte;
527 vm_offset_t va, endva;
528 int i;
529
530 if (pgeflag == 0)
531 return;
532
533 i = KERNLOAD/NBPDR;
534 endva = KERNBASE + KERNend;
535
536 if (pseflag) {
537 va = KERNBASE + KERNLOAD;
538 while (va < endva) {
539 pdir = kernel_pmap->pm_pdir[KPTDI+i];
540 pdir |= pgeflag;
541 kernel_pmap->pm_pdir[KPTDI+i] = PTD[KPTDI+i] = pdir;
542 invltlb(); /* Play it safe, invltlb() every time */
543 i++;
544 va += NBPDR;
545 }
546 } else {
547 va = (vm_offset_t)btext;
548 while (va < endva) {
549 pte = vtopte(va);
550 if (*pte)
551 *pte |= pgeflag;
552 invltlb(); /* Play it safe, invltlb() every time */
553 va += PAGE_SIZE;
554 }
555 }
556 }
557
558 /*
559 * Initialize a vm_page's machine-dependent fields.
560 */
561 void
562 pmap_page_init(vm_page_t m)
563 {
564
565 TAILQ_INIT(&m->md.pv_list);
566 m->md.pat_mode = PAT_WRITE_BACK;
567 }
568
569 #ifdef PAE
570 static void *
571 pmap_pdpt_allocf(uma_zone_t zone, int bytes, u_int8_t *flags, int wait)
572 {
573
574 /* Inform UMA that this allocator uses kernel_map/object. */
575 *flags = UMA_SLAB_KERNEL;
576 return ((void *)kmem_alloc_contig(kernel_map, bytes, wait, 0x0ULL,
577 0xffffffffULL, 1, 0, VM_MEMATTR_DEFAULT));
578 }
579 #endif
580
581 /*
582 * ABuse the pte nodes for unmapped kva to thread a kva freelist through.
583 * Requirements:
584 * - Must deal with pages in order to ensure that none of the PG_* bits
585 * are ever set, PG_V in particular.
586 * - Assumes we can write to ptes without pte_store() atomic ops, even
587 * on PAE systems. This should be ok.
588 * - Assumes nothing will ever test these addresses for 0 to indicate
589 * no mapping instead of correctly checking PG_V.
590 * - Assumes a vm_offset_t will fit in a pte (true for i386).
591 * Because PG_V is never set, there can be no mappings to invalidate.
592 */
593 static vm_offset_t
594 pmap_ptelist_alloc(vm_offset_t *head)
595 {
596 pt_entry_t *pte;
597 vm_offset_t va;
598
599 va = *head;
600 if (va == 0)
601 return (va); /* Out of memory */
602 pte = vtopte(va);
603 *head = *pte;
604 if (*head & PG_V)
605 panic("pmap_ptelist_alloc: va with PG_V set!");
606 *pte = 0;
607 return (va);
608 }
609
610 static void
611 pmap_ptelist_free(vm_offset_t *head, vm_offset_t va)
612 {
613 pt_entry_t *pte;
614
615 if (va & PG_V)
616 panic("pmap_ptelist_free: freeing va with PG_V set!");
617 pte = vtopte(va);
618 *pte = *head; /* virtual! PG_V is 0 though */
619 *head = va;
620 }
621
622 static void
623 pmap_ptelist_init(vm_offset_t *head, void *base, int npages)
624 {
625 int i;
626 vm_offset_t va;
627
628 *head = 0;
629 for (i = npages - 1; i >= 0; i--) {
630 va = (vm_offset_t)base + i * PAGE_SIZE;
631 pmap_ptelist_free(head, va);
632 }
633 }
634
635
636 /*
637 * Initialize the pmap module.
638 * Called by vm_init, to initialize any structures that the pmap
639 * system needs to map virtual memory.
640 */
641 void
642 pmap_init(void)
643 {
644 vm_page_t mpte;
645 vm_size_t s;
646 int i, pv_npg;
647
648 /*
649 * Initialize the vm page array entries for the kernel pmap's
650 * page table pages.
651 */
652 for (i = 0; i < nkpt; i++) {
653 mpte = PHYS_TO_VM_PAGE(PTD[i + KPTDI] & PG_FRAME);
654 KASSERT(mpte >= vm_page_array &&
655 mpte < &vm_page_array[vm_page_array_size],
656 ("pmap_init: page table page is out of range"));
657 mpte->pindex = i + KPTDI;
658 mpte->phys_addr = PTD[i + KPTDI] & PG_FRAME;
659 }
660
661 /*
662 * Initialize the address space (zone) for the pv entries. Set a
663 * high water mark so that the system can recover from excessive
664 * numbers of pv entries.
665 */
666 TUNABLE_INT_FETCH("vm.pmap.shpgperproc", &shpgperproc);
667 pv_entry_max = shpgperproc * maxproc + cnt.v_page_count;
668 TUNABLE_INT_FETCH("vm.pmap.pv_entries", &pv_entry_max);
669 pv_entry_max = roundup(pv_entry_max, _NPCPV);
670 pv_entry_high_water = 9 * (pv_entry_max / 10);
671
672 /*
673 * Are large page mappings enabled?
674 */
675 TUNABLE_INT_FETCH("vm.pmap.pg_ps_enabled", &pg_ps_enabled);
676
677 /*
678 * Calculate the size of the pv head table for superpages.
679 */
680 for (i = 0; phys_avail[i + 1]; i += 2);
681 pv_npg = round_4mpage(phys_avail[(i - 2) + 1]) / NBPDR;
682
683 /*
684 * Allocate memory for the pv head table for superpages.
685 */
686 s = (vm_size_t)(pv_npg * sizeof(struct md_page));
687 s = round_page(s);
688 pv_table = (struct md_page *)kmem_alloc(kernel_map, s);
689 for (i = 0; i < pv_npg; i++)
690 TAILQ_INIT(&pv_table[i].pv_list);
691
692 pv_maxchunks = MAX(pv_entry_max / _NPCPV, maxproc);
693 pv_chunkbase = (struct pv_chunk *)kmem_alloc_nofault(kernel_map,
694 PAGE_SIZE * pv_maxchunks);
695 if (pv_chunkbase == NULL)
696 panic("pmap_init: not enough kvm for pv chunks");
697 pmap_ptelist_init(&pv_vafree, pv_chunkbase, pv_maxchunks);
698 #ifdef PAE
699 pdptzone = uma_zcreate("PDPT", NPGPTD * sizeof(pdpt_entry_t), NULL,
700 NULL, NULL, NULL, (NPGPTD * sizeof(pdpt_entry_t)) - 1,
701 UMA_ZONE_VM | UMA_ZONE_NOFREE);
702 uma_zone_set_allocf(pdptzone, pmap_pdpt_allocf);
703 #endif
704 }
705
706
707 SYSCTL_INT(_vm_pmap, OID_AUTO, pv_entry_max, CTLFLAG_RD, &pv_entry_max, 0,
708 "Max number of PV entries");
709 SYSCTL_INT(_vm_pmap, OID_AUTO, shpgperproc, CTLFLAG_RD, &shpgperproc, 0,
710 "Page share factor per proc");
711
712 SYSCTL_NODE(_vm_pmap, OID_AUTO, pde, CTLFLAG_RD, 0,
713 "2/4MB page mapping counters");
714
715 static u_long pmap_pde_demotions;
716 SYSCTL_ULONG(_vm_pmap_pde, OID_AUTO, demotions, CTLFLAG_RD,
717 &pmap_pde_demotions, 0, "2/4MB page demotions");
718
719 static u_long pmap_pde_mappings;
720 SYSCTL_ULONG(_vm_pmap_pde, OID_AUTO, mappings, CTLFLAG_RD,
721 &pmap_pde_mappings, 0, "2/4MB page mappings");
722
723 static u_long pmap_pde_p_failures;
724 SYSCTL_ULONG(_vm_pmap_pde, OID_AUTO, p_failures, CTLFLAG_RD,
725 &pmap_pde_p_failures, 0, "2/4MB page promotion failures");
726
727 static u_long pmap_pde_promotions;
728 SYSCTL_ULONG(_vm_pmap_pde, OID_AUTO, promotions, CTLFLAG_RD,
729 &pmap_pde_promotions, 0, "2/4MB page promotions");
730
731 /***************************************************
732 * Low level helper routines.....
733 ***************************************************/
734
735 /*
736 * Determine the appropriate bits to set in a PTE or PDE for a specified
737 * caching mode.
738 */
739 int
740 pmap_cache_bits(int mode, boolean_t is_pde)
741 {
742 int pat_flag, pat_index, cache_bits;
743
744 /* The PAT bit is different for PTE's and PDE's. */
745 pat_flag = is_pde ? PG_PDE_PAT : PG_PTE_PAT;
746
747 /* If we don't support PAT, map extended modes to older ones. */
748 if (!(cpu_feature & CPUID_PAT)) {
749 switch (mode) {
750 case PAT_UNCACHEABLE:
751 case PAT_WRITE_THROUGH:
752 case PAT_WRITE_BACK:
753 break;
754 case PAT_UNCACHED:
755 case PAT_WRITE_COMBINING:
756 case PAT_WRITE_PROTECTED:
757 mode = PAT_UNCACHEABLE;
758 break;
759 }
760 }
761
762 /* Map the caching mode to a PAT index. */
763 if (pat_works) {
764 switch (mode) {
765 case PAT_UNCACHEABLE:
766 pat_index = 3;
767 break;
768 case PAT_WRITE_THROUGH:
769 pat_index = 1;
770 break;
771 case PAT_WRITE_BACK:
772 pat_index = 0;
773 break;
774 case PAT_UNCACHED:
775 pat_index = 2;
776 break;
777 case PAT_WRITE_COMBINING:
778 pat_index = 5;
779 break;
780 case PAT_WRITE_PROTECTED:
781 pat_index = 4;
782 break;
783 default:
784 panic("Unknown caching mode %d\n", mode);
785 }
786 } else {
787 switch (mode) {
788 case PAT_UNCACHED:
789 case PAT_UNCACHEABLE:
790 case PAT_WRITE_PROTECTED:
791 pat_index = 3;
792 break;
793 case PAT_WRITE_THROUGH:
794 pat_index = 1;
795 break;
796 case PAT_WRITE_BACK:
797 pat_index = 0;
798 break;
799 case PAT_WRITE_COMBINING:
800 pat_index = 2;
801 break;
802 default:
803 panic("Unknown caching mode %d\n", mode);
804 }
805 }
806
807 /* Map the 3-bit index value into the PAT, PCD, and PWT bits. */
808 cache_bits = 0;
809 if (pat_index & 0x4)
810 cache_bits |= pat_flag;
811 if (pat_index & 0x2)
812 cache_bits |= PG_NC_PCD;
813 if (pat_index & 0x1)
814 cache_bits |= PG_NC_PWT;
815 return (cache_bits);
816 }
817 #ifdef SMP
818 /*
819 * For SMP, these functions have to use the IPI mechanism for coherence.
820 *
821 * N.B.: Before calling any of the following TLB invalidation functions,
822 * the calling processor must ensure that all stores updating a non-
823 * kernel page table are globally performed. Otherwise, another
824 * processor could cache an old, pre-update entry without being
825 * invalidated. This can happen one of two ways: (1) The pmap becomes
826 * active on another processor after its pm_active field is checked by
827 * one of the following functions but before a store updating the page
828 * table is globally performed. (2) The pmap becomes active on another
829 * processor before its pm_active field is checked but due to
830 * speculative loads one of the following functions stills reads the
831 * pmap as inactive on the other processor.
832 *
833 * The kernel page table is exempt because its pm_active field is
834 * immutable. The kernel page table is always active on every
835 * processor.
836 */
837 void
838 pmap_invalidate_page(pmap_t pmap, vm_offset_t va)
839 {
840 u_int cpumask;
841 u_int other_cpus;
842
843 sched_pin();
844 if (pmap == kernel_pmap || pmap->pm_active == all_cpus) {
845 invlpg(va);
846 smp_invlpg(va);
847 } else {
848 cpumask = PCPU_GET(cpumask);
849 other_cpus = PCPU_GET(other_cpus);
850 if (pmap->pm_active & cpumask)
851 invlpg(va);
852 if (pmap->pm_active & other_cpus)
853 smp_masked_invlpg(pmap->pm_active & other_cpus, va);
854 }
855 sched_unpin();
856 }
857
858 void
859 pmap_invalidate_range(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
860 {
861 u_int cpumask;
862 u_int other_cpus;
863 vm_offset_t addr;
864
865 sched_pin();
866 if (pmap == kernel_pmap || pmap->pm_active == all_cpus) {
867 for (addr = sva; addr < eva; addr += PAGE_SIZE)
868 invlpg(addr);
869 smp_invlpg_range(sva, eva);
870 } else {
871 cpumask = PCPU_GET(cpumask);
872 other_cpus = PCPU_GET(other_cpus);
873 if (pmap->pm_active & cpumask)
874 for (addr = sva; addr < eva; addr += PAGE_SIZE)
875 invlpg(addr);
876 if (pmap->pm_active & other_cpus)
877 smp_masked_invlpg_range(pmap->pm_active & other_cpus,
878 sva, eva);
879 }
880 sched_unpin();
881 }
882
883 void
884 pmap_invalidate_all(pmap_t pmap)
885 {
886 u_int cpumask;
887 u_int other_cpus;
888
889 sched_pin();
890 if (pmap == kernel_pmap || pmap->pm_active == all_cpus) {
891 invltlb();
892 smp_invltlb();
893 } else {
894 cpumask = PCPU_GET(cpumask);
895 other_cpus = PCPU_GET(other_cpus);
896 if (pmap->pm_active & cpumask)
897 invltlb();
898 if (pmap->pm_active & other_cpus)
899 smp_masked_invltlb(pmap->pm_active & other_cpus);
900 }
901 sched_unpin();
902 }
903
904 void
905 pmap_invalidate_cache(void)
906 {
907
908 sched_pin();
909 wbinvd();
910 smp_cache_flush();
911 sched_unpin();
912 }
913 #else /* !SMP */
914 /*
915 * Normal, non-SMP, 486+ invalidation functions.
916 * We inline these within pmap.c for speed.
917 */
918 PMAP_INLINE void
919 pmap_invalidate_page(pmap_t pmap, vm_offset_t va)
920 {
921
922 if (pmap == kernel_pmap || pmap->pm_active)
923 invlpg(va);
924 }
925
926 PMAP_INLINE void
927 pmap_invalidate_range(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
928 {
929 vm_offset_t addr;
930
931 if (pmap == kernel_pmap || pmap->pm_active)
932 for (addr = sva; addr < eva; addr += PAGE_SIZE)
933 invlpg(addr);
934 }
935
936 PMAP_INLINE void
937 pmap_invalidate_all(pmap_t pmap)
938 {
939
940 if (pmap == kernel_pmap || pmap->pm_active)
941 invltlb();
942 }
943
944 PMAP_INLINE void
945 pmap_invalidate_cache(void)
946 {
947
948 wbinvd();
949 }
950 #endif /* !SMP */
951
952 void
953 pmap_invalidate_cache_range(vm_offset_t sva, vm_offset_t eva)
954 {
955
956 KASSERT((sva & PAGE_MASK) == 0,
957 ("pmap_invalidate_cache_range: sva not page-aligned"));
958 KASSERT((eva & PAGE_MASK) == 0,
959 ("pmap_invalidate_cache_range: eva not page-aligned"));
960
961 if (cpu_feature & CPUID_SS)
962 ; /* If "Self Snoop" is supported, do nothing. */
963 else if (cpu_feature & CPUID_CLFSH) {
964
965 /*
966 * Otherwise, do per-cache line flush. Use the mfence
967 * instruction to insure that previous stores are
968 * included in the write-back. The processor
969 * propagates flush to other processors in the cache
970 * coherence domain.
971 */
972 mfence();
973 for (; sva < eva; sva += cpu_clflush_line_size)
974 clflush(sva);
975 mfence();
976 } else {
977
978 /*
979 * No targeted cache flush methods are supported by CPU,
980 * globally invalidate cache as a last resort.
981 */
982 pmap_invalidate_cache();
983 }
984 }
985
986 /*
987 * Are we current address space or kernel? N.B. We return FALSE when
988 * a pmap's page table is in use because a kernel thread is borrowing
989 * it. The borrowed page table can change spontaneously, making any
990 * dependence on its continued use subject to a race condition.
991 */
992 static __inline int
993 pmap_is_current(pmap_t pmap)
994 {
995
996 return (pmap == kernel_pmap ||
997 (pmap == vmspace_pmap(curthread->td_proc->p_vmspace) &&
998 (pmap->pm_pdir[PTDPTDI] & PG_FRAME) == (PTDpde[0] & PG_FRAME)));
999 }
1000
1001 /*
1002 * If the given pmap is not the current or kernel pmap, the returned pte must
1003 * be released by passing it to pmap_pte_release().
1004 */
1005 pt_entry_t *
1006 pmap_pte(pmap_t pmap, vm_offset_t va)
1007 {
1008 pd_entry_t newpf;
1009 pd_entry_t *pde;
1010
1011 pde = pmap_pde(pmap, va);
1012 if (*pde & PG_PS)
1013 return (pde);
1014 if (*pde != 0) {
1015 /* are we current address space or kernel? */
1016 if (pmap_is_current(pmap))
1017 return (vtopte(va));
1018 mtx_lock(&PMAP2mutex);
1019 newpf = *pde & PG_FRAME;
1020 if ((*PMAP2 & PG_FRAME) != newpf) {
1021 *PMAP2 = newpf | PG_RW | PG_V | PG_A | PG_M;
1022 pmap_invalidate_page(kernel_pmap, (vm_offset_t)PADDR2);
1023 }
1024 return (PADDR2 + (i386_btop(va) & (NPTEPG - 1)));
1025 }
1026 return (0);
1027 }
1028
1029 /*
1030 * Releases a pte that was obtained from pmap_pte(). Be prepared for the pte
1031 * being NULL.
1032 */
1033 static __inline void
1034 pmap_pte_release(pt_entry_t *pte)
1035 {
1036
1037 if ((pt_entry_t *)((vm_offset_t)pte & ~PAGE_MASK) == PADDR2)
1038 mtx_unlock(&PMAP2mutex);
1039 }
1040
1041 static __inline void
1042 invlcaddr(void *caddr)
1043 {
1044
1045 invlpg((u_int)caddr);
1046 }
1047
1048 /*
1049 * Super fast pmap_pte routine best used when scanning
1050 * the pv lists. This eliminates many coarse-grained
1051 * invltlb calls. Note that many of the pv list
1052 * scans are across different pmaps. It is very wasteful
1053 * to do an entire invltlb for checking a single mapping.
1054 *
1055 * If the given pmap is not the current pmap, vm_page_queue_mtx
1056 * must be held and curthread pinned to a CPU.
1057 */
1058 static pt_entry_t *
1059 pmap_pte_quick(pmap_t pmap, vm_offset_t va)
1060 {
1061 pd_entry_t newpf;
1062 pd_entry_t *pde;
1063
1064 pde = pmap_pde(pmap, va);
1065 if (*pde & PG_PS)
1066 return (pde);
1067 if (*pde != 0) {
1068 /* are we current address space or kernel? */
1069 if (pmap_is_current(pmap))
1070 return (vtopte(va));
1071 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
1072 KASSERT(curthread->td_pinned > 0, ("curthread not pinned"));
1073 newpf = *pde & PG_FRAME;
1074 if ((*PMAP1 & PG_FRAME) != newpf) {
1075 *PMAP1 = newpf | PG_RW | PG_V | PG_A | PG_M;
1076 #ifdef SMP
1077 PMAP1cpu = PCPU_GET(cpuid);
1078 #endif
1079 invlcaddr(PADDR1);
1080 PMAP1changed++;
1081 } else
1082 #ifdef SMP
1083 if (PMAP1cpu != PCPU_GET(cpuid)) {
1084 PMAP1cpu = PCPU_GET(cpuid);
1085 invlcaddr(PADDR1);
1086 PMAP1changedcpu++;
1087 } else
1088 #endif
1089 PMAP1unchanged++;
1090 return (PADDR1 + (i386_btop(va) & (NPTEPG - 1)));
1091 }
1092 return (0);
1093 }
1094
1095 /*
1096 * Routine: pmap_extract
1097 * Function:
1098 * Extract the physical page address associated
1099 * with the given map/virtual_address pair.
1100 */
1101 vm_paddr_t
1102 pmap_extract(pmap_t pmap, vm_offset_t va)
1103 {
1104 vm_paddr_t rtval;
1105 pt_entry_t *pte;
1106 pd_entry_t pde;
1107
1108 rtval = 0;
1109 PMAP_LOCK(pmap);
1110 pde = pmap->pm_pdir[va >> PDRSHIFT];
1111 if (pde != 0) {
1112 if ((pde & PG_PS) != 0)
1113 rtval = (pde & PG_PS_FRAME) | (va & PDRMASK);
1114 else {
1115 pte = pmap_pte(pmap, va);
1116 rtval = (*pte & PG_FRAME) | (va & PAGE_MASK);
1117 pmap_pte_release(pte);
1118 }
1119 }
1120 PMAP_UNLOCK(pmap);
1121 return (rtval);
1122 }
1123
1124 /*
1125 * Routine: pmap_extract_and_hold
1126 * Function:
1127 * Atomically extract and hold the physical page
1128 * with the given pmap and virtual address pair
1129 * if that mapping permits the given protection.
1130 */
1131 vm_page_t
1132 pmap_extract_and_hold(pmap_t pmap, vm_offset_t va, vm_prot_t prot)
1133 {
1134 pd_entry_t pde;
1135 pt_entry_t pte;
1136 vm_page_t m;
1137
1138 m = NULL;
1139 vm_page_lock_queues();
1140 PMAP_LOCK(pmap);
1141 pde = *pmap_pde(pmap, va);
1142 if (pde != 0) {
1143 if (pde & PG_PS) {
1144 if ((pde & PG_RW) || (prot & VM_PROT_WRITE) == 0) {
1145 m = PHYS_TO_VM_PAGE((pde & PG_PS_FRAME) |
1146 (va & PDRMASK));
1147 vm_page_hold(m);
1148 }
1149 } else {
1150 sched_pin();
1151 pte = *pmap_pte_quick(pmap, va);
1152 if (pte != 0 &&
1153 ((pte & PG_RW) || (prot & VM_PROT_WRITE) == 0)) {
1154 m = PHYS_TO_VM_PAGE(pte & PG_FRAME);
1155 vm_page_hold(m);
1156 }
1157 sched_unpin();
1158 }
1159 }
1160 vm_page_unlock_queues();
1161 PMAP_UNLOCK(pmap);
1162 return (m);
1163 }
1164
1165 /***************************************************
1166 * Low level mapping routines.....
1167 ***************************************************/
1168
1169 /*
1170 * Add a wired page to the kva.
1171 * Note: not SMP coherent.
1172 */
1173 PMAP_INLINE void
1174 pmap_kenter(vm_offset_t va, vm_paddr_t pa)
1175 {
1176 pt_entry_t *pte;
1177
1178 pte = vtopte(va);
1179 pte_store(pte, pa | PG_RW | PG_V | pgeflag);
1180 }
1181
1182 static __inline void
1183 pmap_kenter_attr(vm_offset_t va, vm_paddr_t pa, int mode)
1184 {
1185 pt_entry_t *pte;
1186
1187 pte = vtopte(va);
1188 pte_store(pte, pa | PG_RW | PG_V | pgeflag | pmap_cache_bits(mode, 0));
1189 }
1190
1191 /*
1192 * Remove a page from the kernel pagetables.
1193 * Note: not SMP coherent.
1194 */
1195 PMAP_INLINE void
1196 pmap_kremove(vm_offset_t va)
1197 {
1198 pt_entry_t *pte;
1199
1200 pte = vtopte(va);
1201 pte_clear(pte);
1202 }
1203
1204 /*
1205 * Used to map a range of physical addresses into kernel
1206 * virtual address space.
1207 *
1208 * The value passed in '*virt' is a suggested virtual address for
1209 * the mapping. Architectures which can support a direct-mapped
1210 * physical to virtual region can return the appropriate address
1211 * within that region, leaving '*virt' unchanged. Other
1212 * architectures should map the pages starting at '*virt' and
1213 * update '*virt' with the first usable address after the mapped
1214 * region.
1215 */
1216 vm_offset_t
1217 pmap_map(vm_offset_t *virt, vm_paddr_t start, vm_paddr_t end, int prot)
1218 {
1219 vm_offset_t va, sva;
1220
1221 va = sva = *virt;
1222 while (start < end) {
1223 pmap_kenter(va, start);
1224 va += PAGE_SIZE;
1225 start += PAGE_SIZE;
1226 }
1227 pmap_invalidate_range(kernel_pmap, sva, va);
1228 *virt = va;
1229 return (sva);
1230 }
1231
1232
1233 /*
1234 * Add a list of wired pages to the kva
1235 * this routine is only used for temporary
1236 * kernel mappings that do not need to have
1237 * page modification or references recorded.
1238 * Note that old mappings are simply written
1239 * over. The page *must* be wired.
1240 * Note: SMP coherent. Uses a ranged shootdown IPI.
1241 */
1242 void
1243 pmap_qenter(vm_offset_t sva, vm_page_t *ma, int count)
1244 {
1245 pt_entry_t *endpte, oldpte, *pte;
1246
1247 oldpte = 0;
1248 pte = vtopte(sva);
1249 endpte = pte + count;
1250 while (pte < endpte) {
1251 oldpte |= *pte;
1252 pte_store(pte, VM_PAGE_TO_PHYS(*ma) | pgeflag |
1253 pmap_cache_bits((*ma)->md.pat_mode, 0) | PG_RW | PG_V);
1254 pte++;
1255 ma++;
1256 }
1257 if ((oldpte & PG_V) != 0)
1258 pmap_invalidate_range(kernel_pmap, sva, sva + count *
1259 PAGE_SIZE);
1260 }
1261
1262 /*
1263 * This routine tears out page mappings from the
1264 * kernel -- it is meant only for temporary mappings.
1265 * Note: SMP coherent. Uses a ranged shootdown IPI.
1266 */
1267 void
1268 pmap_qremove(vm_offset_t sva, int count)
1269 {
1270 vm_offset_t va;
1271
1272 va = sva;
1273 while (count-- > 0) {
1274 pmap_kremove(va);
1275 va += PAGE_SIZE;
1276 }
1277 pmap_invalidate_range(kernel_pmap, sva, va);
1278 }
1279
1280 /***************************************************
1281 * Page table page management routines.....
1282 ***************************************************/
1283 static __inline void
1284 pmap_free_zero_pages(vm_page_t free)
1285 {
1286 vm_page_t m;
1287
1288 while (free != NULL) {
1289 m = free;
1290 free = m->right;
1291 /* Preserve the page's PG_ZERO setting. */
1292 vm_page_free_toq(m);
1293 }
1294 }
1295
1296 /*
1297 * Schedule the specified unused page table page to be freed. Specifically,
1298 * add the page to the specified list of pages that will be released to the
1299 * physical memory manager after the TLB has been updated.
1300 */
1301 static __inline void
1302 pmap_add_delayed_free_list(vm_page_t m, vm_page_t *free, boolean_t set_PG_ZERO)
1303 {
1304
1305 if (set_PG_ZERO)
1306 m->flags |= PG_ZERO;
1307 else
1308 m->flags &= ~PG_ZERO;
1309 m->right = *free;
1310 *free = m;
1311 }
1312
1313 /*
1314 * Inserts the specified page table page into the specified pmap's collection
1315 * of idle page table pages. Each of a pmap's page table pages is responsible
1316 * for mapping a distinct range of virtual addresses. The pmap's collection is
1317 * ordered by this virtual address range.
1318 */
1319 static void
1320 pmap_insert_pt_page(pmap_t pmap, vm_page_t mpte)
1321 {
1322 vm_page_t root;
1323
1324 PMAP_LOCK_ASSERT(pmap, MA_OWNED);
1325 root = pmap->pm_root;
1326 if (root == NULL) {
1327 mpte->left = NULL;
1328 mpte->right = NULL;
1329 } else {
1330 root = vm_page_splay(mpte->pindex, root);
1331 if (mpte->pindex < root->pindex) {
1332 mpte->left = root->left;
1333 mpte->right = root;
1334 root->left = NULL;
1335 } else if (mpte->pindex == root->pindex)
1336 panic("pmap_insert_pt_page: pindex already inserted");
1337 else {
1338 mpte->right = root->right;
1339 mpte->left = root;
1340 root->right = NULL;
1341 }
1342 }
1343 pmap->pm_root = mpte;
1344 }
1345
1346 /*
1347 * Looks for a page table page mapping the specified virtual address in the
1348 * specified pmap's collection of idle page table pages. Returns NULL if there
1349 * is no page table page corresponding to the specified virtual address.
1350 */
1351 static vm_page_t
1352 pmap_lookup_pt_page(pmap_t pmap, vm_offset_t va)
1353 {
1354 vm_page_t mpte;
1355 vm_pindex_t pindex = va >> PDRSHIFT;
1356
1357 PMAP_LOCK_ASSERT(pmap, MA_OWNED);
1358 if ((mpte = pmap->pm_root) != NULL && mpte->pindex != pindex) {
1359 mpte = vm_page_splay(pindex, mpte);
1360 if ((pmap->pm_root = mpte)->pindex != pindex)
1361 mpte = NULL;
1362 }
1363 return (mpte);
1364 }
1365
1366 /*
1367 * Removes the specified page table page from the specified pmap's collection
1368 * of idle page table pages. The specified page table page must be a member of
1369 * the pmap's collection.
1370 */
1371 static void
1372 pmap_remove_pt_page(pmap_t pmap, vm_page_t mpte)
1373 {
1374 vm_page_t root;
1375
1376 PMAP_LOCK_ASSERT(pmap, MA_OWNED);
1377 if (mpte != pmap->pm_root)
1378 vm_page_splay(mpte->pindex, pmap->pm_root);
1379 if (mpte->left == NULL)
1380 root = mpte->right;
1381 else {
1382 root = vm_page_splay(mpte->pindex, mpte->left);
1383 root->right = mpte->right;
1384 }
1385 pmap->pm_root = root;
1386 }
1387
1388 /*
1389 * This routine unholds page table pages, and if the hold count
1390 * drops to zero, then it decrements the wire count.
1391 */
1392 static __inline int
1393 pmap_unwire_pte_hold(pmap_t pmap, vm_page_t m, vm_page_t *free)
1394 {
1395
1396 --m->wire_count;
1397 if (m->wire_count == 0)
1398 return _pmap_unwire_pte_hold(pmap, m, free);
1399 else
1400 return 0;
1401 }
1402
1403 static int
1404 _pmap_unwire_pte_hold(pmap_t pmap, vm_page_t m, vm_page_t *free)
1405 {
1406 vm_offset_t pteva;
1407
1408 /*
1409 * unmap the page table page
1410 */
1411 pmap->pm_pdir[m->pindex] = 0;
1412 --pmap->pm_stats.resident_count;
1413
1414 /*
1415 * This is a release store so that the ordinary store unmapping
1416 * the page table page is globally performed before TLB shoot-
1417 * down is begun.
1418 */
1419 atomic_subtract_rel_int(&cnt.v_wire_count, 1);
1420
1421 /*
1422 * Do an invltlb to make the invalidated mapping
1423 * take effect immediately.
1424 */
1425 pteva = VM_MAXUSER_ADDRESS + i386_ptob(m->pindex);
1426 pmap_invalidate_page(pmap, pteva);
1427
1428 /*
1429 * Put page on a list so that it is released after
1430 * *ALL* TLB shootdown is done
1431 */
1432 pmap_add_delayed_free_list(m, free, TRUE);
1433
1434 return 1;
1435 }
1436
1437 /*
1438 * After removing a page table entry, this routine is used to
1439 * conditionally free the page, and manage the hold/wire counts.
1440 */
1441 static int
1442 pmap_unuse_pt(pmap_t pmap, vm_offset_t va, vm_page_t *free)
1443 {
1444 pd_entry_t ptepde;
1445 vm_page_t mpte;
1446
1447 if (va >= VM_MAXUSER_ADDRESS)
1448 return 0;
1449 ptepde = *pmap_pde(pmap, va);
1450 mpte = PHYS_TO_VM_PAGE(ptepde & PG_FRAME);
1451 return pmap_unwire_pte_hold(pmap, mpte, free);
1452 }
1453
1454 void
1455 pmap_pinit0(pmap_t pmap)
1456 {
1457
1458 PMAP_LOCK_INIT(pmap);
1459 pmap->pm_pdir = (pd_entry_t *)(KERNBASE + (vm_offset_t)IdlePTD);
1460 #ifdef PAE
1461 pmap->pm_pdpt = (pdpt_entry_t *)(KERNBASE + (vm_offset_t)IdlePDPT);
1462 #endif
1463 pmap->pm_root = NULL;
1464 pmap->pm_active = 0;
1465 PCPU_SET(curpmap, pmap);
1466 TAILQ_INIT(&pmap->pm_pvchunk);
1467 bzero(&pmap->pm_stats, sizeof pmap->pm_stats);
1468 mtx_lock_spin(&allpmaps_lock);
1469 LIST_INSERT_HEAD(&allpmaps, pmap, pm_list);
1470 mtx_unlock_spin(&allpmaps_lock);
1471 }
1472
1473 /*
1474 * Initialize a preallocated and zeroed pmap structure,
1475 * such as one in a vmspace structure.
1476 */
1477 int
1478 pmap_pinit(pmap_t pmap)
1479 {
1480 vm_page_t m, ptdpg[NPGPTD];
1481 vm_paddr_t pa;
1482 static int color;
1483 int i;
1484
1485 PMAP_LOCK_INIT(pmap);
1486
1487 /*
1488 * No need to allocate page table space yet but we do need a valid
1489 * page directory table.
1490 */
1491 if (pmap->pm_pdir == NULL) {
1492 pmap->pm_pdir = (pd_entry_t *)kmem_alloc_nofault(kernel_map,
1493 NBPTD);
1494
1495 if (pmap->pm_pdir == NULL) {
1496 PMAP_LOCK_DESTROY(pmap);
1497 return (0);
1498 }
1499 #ifdef PAE
1500 pmap->pm_pdpt = uma_zalloc(pdptzone, M_WAITOK | M_ZERO);
1501 KASSERT(((vm_offset_t)pmap->pm_pdpt &
1502 ((NPGPTD * sizeof(pdpt_entry_t)) - 1)) == 0,
1503 ("pmap_pinit: pdpt misaligned"));
1504 KASSERT(pmap_kextract((vm_offset_t)pmap->pm_pdpt) < (4ULL<<30),
1505 ("pmap_pinit: pdpt above 4g"));
1506 #endif
1507 pmap->pm_root = NULL;
1508 }
1509 KASSERT(pmap->pm_root == NULL,
1510 ("pmap_pinit: pmap has reserved page table page(s)"));
1511
1512 /*
1513 * allocate the page directory page(s)
1514 */
1515 for (i = 0; i < NPGPTD;) {
1516 m = vm_page_alloc(NULL, color++,
1517 VM_ALLOC_NORMAL | VM_ALLOC_NOOBJ | VM_ALLOC_WIRED |
1518 VM_ALLOC_ZERO);
1519 if (m == NULL)
1520 VM_WAIT;
1521 else {
1522 ptdpg[i++] = m;
1523 }
1524 }
1525
1526 pmap_qenter((vm_offset_t)pmap->pm_pdir, ptdpg, NPGPTD);
1527
1528 for (i = 0; i < NPGPTD; i++) {
1529 if ((ptdpg[i]->flags & PG_ZERO) == 0)
1530 bzero(pmap->pm_pdir + (i * NPDEPG), PAGE_SIZE);
1531 }
1532
1533 mtx_lock_spin(&allpmaps_lock);
1534 LIST_INSERT_HEAD(&allpmaps, pmap, pm_list);
1535 mtx_unlock_spin(&allpmaps_lock);
1536 /* Wire in kernel global address entries. */
1537 bcopy(PTD + KPTDI, pmap->pm_pdir + KPTDI, nkpt * sizeof(pd_entry_t));
1538
1539 /* install self-referential address mapping entry(s) */
1540 for (i = 0; i < NPGPTD; i++) {
1541 pa = VM_PAGE_TO_PHYS(ptdpg[i]);
1542 pmap->pm_pdir[PTDPTDI + i] = pa | PG_V | PG_RW | PG_A | PG_M;
1543 #ifdef PAE
1544 pmap->pm_pdpt[i] = pa | PG_V;
1545 #endif
1546 }
1547
1548 pmap->pm_active = 0;
1549 TAILQ_INIT(&pmap->pm_pvchunk);
1550 bzero(&pmap->pm_stats, sizeof pmap->pm_stats);
1551
1552 return (1);
1553 }
1554
1555 /*
1556 * this routine is called if the page table page is not
1557 * mapped correctly.
1558 */
1559 static vm_page_t
1560 _pmap_allocpte(pmap_t pmap, unsigned ptepindex, int flags)
1561 {
1562 vm_paddr_t ptepa;
1563 vm_page_t m;
1564
1565 KASSERT((flags & (M_NOWAIT | M_WAITOK)) == M_NOWAIT ||
1566 (flags & (M_NOWAIT | M_WAITOK)) == M_WAITOK,
1567 ("_pmap_allocpte: flags is neither M_NOWAIT nor M_WAITOK"));
1568
1569 /*
1570 * Allocate a page table page.
1571 */
1572 if ((m = vm_page_alloc(NULL, ptepindex, VM_ALLOC_NOOBJ |
1573 VM_ALLOC_WIRED | VM_ALLOC_ZERO)) == NULL) {
1574 if (flags & M_WAITOK) {
1575 PMAP_UNLOCK(pmap);
1576 vm_page_unlock_queues();
1577 VM_WAIT;
1578 vm_page_lock_queues();
1579 PMAP_LOCK(pmap);
1580 }
1581
1582 /*
1583 * Indicate the need to retry. While waiting, the page table
1584 * page may have been allocated.
1585 */
1586 return (NULL);
1587 }
1588 if ((m->flags & PG_ZERO) == 0)
1589 pmap_zero_page(m);
1590
1591 /*
1592 * Map the pagetable page into the process address space, if
1593 * it isn't already there.
1594 */
1595
1596 pmap->pm_stats.resident_count++;
1597
1598 ptepa = VM_PAGE_TO_PHYS(m);
1599 pmap->pm_pdir[ptepindex] =
1600 (pd_entry_t) (ptepa | PG_U | PG_RW | PG_V | PG_A | PG_M);
1601
1602 return m;
1603 }
1604
1605 static vm_page_t
1606 pmap_allocpte(pmap_t pmap, vm_offset_t va, int flags)
1607 {
1608 unsigned ptepindex;
1609 pd_entry_t ptepa;
1610 vm_page_t m;
1611
1612 KASSERT((flags & (M_NOWAIT | M_WAITOK)) == M_NOWAIT ||
1613 (flags & (M_NOWAIT | M_WAITOK)) == M_WAITOK,
1614 ("pmap_allocpte: flags is neither M_NOWAIT nor M_WAITOK"));
1615
1616 /*
1617 * Calculate pagetable page index
1618 */
1619 ptepindex = va >> PDRSHIFT;
1620 retry:
1621 /*
1622 * Get the page directory entry
1623 */
1624 ptepa = pmap->pm_pdir[ptepindex];
1625
1626 /*
1627 * This supports switching from a 4MB page to a
1628 * normal 4K page.
1629 */
1630 if (ptepa & PG_PS) {
1631 (void)pmap_demote_pde(pmap, &pmap->pm_pdir[ptepindex], va);
1632 ptepa = pmap->pm_pdir[ptepindex];
1633 }
1634
1635 /*
1636 * If the page table page is mapped, we just increment the
1637 * hold count, and activate it.
1638 */
1639 if (ptepa) {
1640 m = PHYS_TO_VM_PAGE(ptepa & PG_FRAME);
1641 m->wire_count++;
1642 } else {
1643 /*
1644 * Here if the pte page isn't mapped, or if it has
1645 * been deallocated.
1646 */
1647 m = _pmap_allocpte(pmap, ptepindex, flags);
1648 if (m == NULL && (flags & M_WAITOK))
1649 goto retry;
1650 }
1651 return (m);
1652 }
1653
1654
1655 /***************************************************
1656 * Pmap allocation/deallocation routines.
1657 ***************************************************/
1658
1659 #ifdef SMP
1660 /*
1661 * Deal with a SMP shootdown of other users of the pmap that we are
1662 * trying to dispose of. This can be a bit hairy.
1663 */
1664 static cpumask_t *lazymask;
1665 static u_int lazyptd;
1666 static volatile u_int lazywait;
1667
1668 void pmap_lazyfix_action(void);
1669
1670 void
1671 pmap_lazyfix_action(void)
1672 {
1673 cpumask_t mymask = PCPU_GET(cpumask);
1674
1675 #ifdef COUNT_IPIS
1676 (*ipi_lazypmap_counts[PCPU_GET(cpuid)])++;
1677 #endif
1678 if (rcr3() == lazyptd)
1679 load_cr3(PCPU_GET(curpcb)->pcb_cr3);
1680 atomic_clear_int(lazymask, mymask);
1681 atomic_store_rel_int(&lazywait, 1);
1682 }
1683
1684 static void
1685 pmap_lazyfix_self(cpumask_t mymask)
1686 {
1687
1688 if (rcr3() == lazyptd)
1689 load_cr3(PCPU_GET(curpcb)->pcb_cr3);
1690 atomic_clear_int(lazymask, mymask);
1691 }
1692
1693
1694 static void
1695 pmap_lazyfix(pmap_t pmap)
1696 {
1697 cpumask_t mymask, mask;
1698 u_int spins;
1699
1700 while ((mask = pmap->pm_active) != 0) {
1701 spins = 50000000;
1702 mask = mask & -mask; /* Find least significant set bit */
1703 mtx_lock_spin(&smp_ipi_mtx);
1704 #ifdef PAE
1705 lazyptd = vtophys(pmap->pm_pdpt);
1706 #else
1707 lazyptd = vtophys(pmap->pm_pdir);
1708 #endif
1709 mymask = PCPU_GET(cpumask);
1710 if (mask == mymask) {
1711 lazymask = &pmap->pm_active;
1712 pmap_lazyfix_self(mymask);
1713 } else {
1714 atomic_store_rel_int((u_int *)&lazymask,
1715 (u_int)&pmap->pm_active);
1716 atomic_store_rel_int(&lazywait, 0);
1717 ipi_selected(mask, IPI_LAZYPMAP);
1718 while (lazywait == 0) {
1719 ia32_pause();
1720 if (--spins == 0)
1721 break;
1722 }
1723 }
1724 mtx_unlock_spin(&smp_ipi_mtx);
1725 if (spins == 0)
1726 printf("pmap_lazyfix: spun for 50000000\n");
1727 }
1728 }
1729
1730 #else /* SMP */
1731
1732 /*
1733 * Cleaning up on uniprocessor is easy. For various reasons, we're
1734 * unlikely to have to even execute this code, including the fact
1735 * that the cleanup is deferred until the parent does a wait(2), which
1736 * means that another userland process has run.
1737 */
1738 static void
1739 pmap_lazyfix(pmap_t pmap)
1740 {
1741 u_int cr3;
1742
1743 cr3 = vtophys(pmap->pm_pdir);
1744 if (cr3 == rcr3()) {
1745 load_cr3(PCPU_GET(curpcb)->pcb_cr3);
1746 pmap->pm_active &= ~(PCPU_GET(cpumask));
1747 }
1748 }
1749 #endif /* SMP */
1750
1751 /*
1752 * Release any resources held by the given physical map.
1753 * Called when a pmap initialized by pmap_pinit is being released.
1754 * Should only be called if the map contains no valid mappings.
1755 */
1756 void
1757 pmap_release(pmap_t pmap)
1758 {
1759 vm_page_t m, ptdpg[NPGPTD];
1760 int i;
1761
1762 KASSERT(pmap->pm_stats.resident_count == 0,
1763 ("pmap_release: pmap resident count %ld != 0",
1764 pmap->pm_stats.resident_count));
1765 KASSERT(pmap->pm_root == NULL,
1766 ("pmap_release: pmap has reserved page table page(s)"));
1767
1768 pmap_lazyfix(pmap);
1769 mtx_lock_spin(&allpmaps_lock);
1770 LIST_REMOVE(pmap, pm_list);
1771 mtx_unlock_spin(&allpmaps_lock);
1772
1773 for (i = 0; i < NPGPTD; i++)
1774 ptdpg[i] = PHYS_TO_VM_PAGE(pmap->pm_pdir[PTDPTDI + i] &
1775 PG_FRAME);
1776
1777 bzero(pmap->pm_pdir + PTDPTDI, (nkpt + NPGPTD) *
1778 sizeof(*pmap->pm_pdir));
1779
1780 pmap_qremove((vm_offset_t)pmap->pm_pdir, NPGPTD);
1781
1782 for (i = 0; i < NPGPTD; i++) {
1783 m = ptdpg[i];
1784 #ifdef PAE
1785 KASSERT(VM_PAGE_TO_PHYS(m) == (pmap->pm_pdpt[i] & PG_FRAME),
1786 ("pmap_release: got wrong ptd page"));
1787 #endif
1788 m->wire_count--;
1789 atomic_subtract_int(&cnt.v_wire_count, 1);
1790 vm_page_free_zero(m);
1791 }
1792 PMAP_LOCK_DESTROY(pmap);
1793 }
1794
1795 static int
1796 kvm_size(SYSCTL_HANDLER_ARGS)
1797 {
1798 unsigned long ksize = VM_MAX_KERNEL_ADDRESS - KERNBASE;
1799
1800 return sysctl_handle_long(oidp, &ksize, 0, req);
1801 }
1802 SYSCTL_PROC(_vm, OID_AUTO, kvm_size, CTLTYPE_LONG|CTLFLAG_RD,
1803 0, 0, kvm_size, "IU", "Size of KVM");
1804
1805 static int
1806 kvm_free(SYSCTL_HANDLER_ARGS)
1807 {
1808 unsigned long kfree = VM_MAX_KERNEL_ADDRESS - kernel_vm_end;
1809
1810 return sysctl_handle_long(oidp, &kfree, 0, req);
1811 }
1812 SYSCTL_PROC(_vm, OID_AUTO, kvm_free, CTLTYPE_LONG|CTLFLAG_RD,
1813 0, 0, kvm_free, "IU", "Amount of KVM free");
1814
1815 /*
1816 * grow the number of kernel page table entries, if needed
1817 */
1818 void
1819 pmap_growkernel(vm_offset_t addr)
1820 {
1821 struct pmap *pmap;
1822 vm_paddr_t ptppaddr;
1823 vm_page_t nkpg;
1824 pd_entry_t newpdir;
1825 pt_entry_t *pde;
1826
1827 mtx_assert(&kernel_map->system_mtx, MA_OWNED);
1828 if (kernel_vm_end == 0) {
1829 kernel_vm_end = KERNBASE;
1830 nkpt = 0;
1831 while (pdir_pde(PTD, kernel_vm_end)) {
1832 kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1);
1833 nkpt++;
1834 if (kernel_vm_end - 1 >= kernel_map->max_offset) {
1835 kernel_vm_end = kernel_map->max_offset;
1836 break;
1837 }
1838 }
1839 }
1840 addr = roundup2(addr, PAGE_SIZE * NPTEPG);
1841 if (addr - 1 >= kernel_map->max_offset)
1842 addr = kernel_map->max_offset;
1843 while (kernel_vm_end < addr) {
1844 if (pdir_pde(PTD, kernel_vm_end)) {
1845 kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1);
1846 if (kernel_vm_end - 1 >= kernel_map->max_offset) {
1847 kernel_vm_end = kernel_map->max_offset;
1848 break;
1849 }
1850 continue;
1851 }
1852
1853 nkpg = vm_page_alloc(NULL, kernel_vm_end >> PDRSHIFT,
1854 VM_ALLOC_INTERRUPT | VM_ALLOC_NOOBJ | VM_ALLOC_WIRED |
1855 VM_ALLOC_ZERO);
1856 if (nkpg == NULL)
1857 panic("pmap_growkernel: no memory to grow kernel");
1858
1859 nkpt++;
1860
1861 if ((nkpg->flags & PG_ZERO) == 0)
1862 pmap_zero_page(nkpg);
1863 ptppaddr = VM_PAGE_TO_PHYS(nkpg);
1864 newpdir = (pd_entry_t) (ptppaddr | PG_V | PG_RW | PG_A | PG_M);
1865 pdir_pde(PTD, kernel_vm_end) = newpdir;
1866
1867 mtx_lock_spin(&allpmaps_lock);
1868 LIST_FOREACH(pmap, &allpmaps, pm_list) {
1869 pde = pmap_pde(pmap, kernel_vm_end);
1870 pde_store(pde, newpdir);
1871 }
1872 mtx_unlock_spin(&allpmaps_lock);
1873 kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1);
1874 if (kernel_vm_end - 1 >= kernel_map->max_offset) {
1875 kernel_vm_end = kernel_map->max_offset;
1876 break;
1877 }
1878 }
1879 }
1880
1881
1882 /***************************************************
1883 * page management routines.
1884 ***************************************************/
1885
1886 CTASSERT(sizeof(struct pv_chunk) == PAGE_SIZE);
1887 CTASSERT(_NPCM == 11);
1888
1889 static __inline struct pv_chunk *
1890 pv_to_chunk(pv_entry_t pv)
1891 {
1892
1893 return (struct pv_chunk *)((uintptr_t)pv & ~(uintptr_t)PAGE_MASK);
1894 }
1895
1896 #define PV_PMAP(pv) (pv_to_chunk(pv)->pc_pmap)
1897
1898 #define PC_FREE0_9 0xfffffffful /* Free values for index 0 through 9 */
1899 #define PC_FREE10 0x0000fffful /* Free values for index 10 */
1900
1901 static uint32_t pc_freemask[11] = {
1902 PC_FREE0_9, PC_FREE0_9, PC_FREE0_9,
1903 PC_FREE0_9, PC_FREE0_9, PC_FREE0_9,
1904 PC_FREE0_9, PC_FREE0_9, PC_FREE0_9,
1905 PC_FREE0_9, PC_FREE10
1906 };
1907
1908 SYSCTL_INT(_vm_pmap, OID_AUTO, pv_entry_count, CTLFLAG_RD, &pv_entry_count, 0,
1909 "Current number of pv entries");
1910
1911 #ifdef PV_STATS
1912 static int pc_chunk_count, pc_chunk_allocs, pc_chunk_frees, pc_chunk_tryfail;
1913
1914 SYSCTL_INT(_vm_pmap, OID_AUTO, pc_chunk_count, CTLFLAG_RD, &pc_chunk_count, 0,
1915 "Current number of pv entry chunks");
1916 SYSCTL_INT(_vm_pmap, OID_AUTO, pc_chunk_allocs, CTLFLAG_RD, &pc_chunk_allocs, 0,
1917 "Current number of pv entry chunks allocated");
1918 SYSCTL_INT(_vm_pmap, OID_AUTO, pc_chunk_frees, CTLFLAG_RD, &pc_chunk_frees, 0,
1919 "Current number of pv entry chunks frees");
1920 SYSCTL_INT(_vm_pmap, OID_AUTO, pc_chunk_tryfail, CTLFLAG_RD, &pc_chunk_tryfail, 0,
1921 "Number of times tried to get a chunk page but failed.");
1922
1923 static long pv_entry_frees, pv_entry_allocs;
1924 static int pv_entry_spare;
1925
1926 SYSCTL_LONG(_vm_pmap, OID_AUTO, pv_entry_frees, CTLFLAG_RD, &pv_entry_frees, 0,
1927 "Current number of pv entry frees");
1928 SYSCTL_LONG(_vm_pmap, OID_AUTO, pv_entry_allocs, CTLFLAG_RD, &pv_entry_allocs, 0,
1929 "Current number of pv entry allocs");
1930 SYSCTL_INT(_vm_pmap, OID_AUTO, pv_entry_spare, CTLFLAG_RD, &pv_entry_spare, 0,
1931 "Current number of spare pv entries");
1932
1933 static int pmap_collect_inactive, pmap_collect_active;
1934
1935 SYSCTL_INT(_vm_pmap, OID_AUTO, pmap_collect_inactive, CTLFLAG_RD, &pmap_collect_inactive, 0,
1936 "Current number times pmap_collect called on inactive queue");
1937 SYSCTL_INT(_vm_pmap, OID_AUTO, pmap_collect_active, CTLFLAG_RD, &pmap_collect_active, 0,
1938 "Current number times pmap_collect called on active queue");
1939 #endif
1940
1941 /*
1942 * We are in a serious low memory condition. Resort to
1943 * drastic measures to free some pages so we can allocate
1944 * another pv entry chunk. This is normally called to
1945 * unmap inactive pages, and if necessary, active pages.
1946 */
1947 static void
1948 pmap_collect(pmap_t locked_pmap, struct vpgqueues *vpq)
1949 {
1950 struct md_page *pvh;
1951 pd_entry_t *pde;
1952 pmap_t pmap;
1953 pt_entry_t *pte, tpte;
1954 pv_entry_t next_pv, pv;
1955 vm_offset_t va;
1956 vm_page_t m, free;
1957
1958 sched_pin();
1959 TAILQ_FOREACH(m, &vpq->pl, pageq) {
1960 if (m->hold_count || m->busy)
1961 continue;
1962 TAILQ_FOREACH_SAFE(pv, &m->md.pv_list, pv_list, next_pv) {
1963 va = pv->pv_va;
1964 pmap = PV_PMAP(pv);
1965 /* Avoid deadlock and lock recursion. */
1966 if (pmap > locked_pmap)
1967 PMAP_LOCK(pmap);
1968 else if (pmap != locked_pmap && !PMAP_TRYLOCK(pmap))
1969 continue;
1970 pmap->pm_stats.resident_count--;
1971 pde = pmap_pde(pmap, va);
1972 KASSERT((*pde & PG_PS) == 0, ("pmap_collect: found"
1973 " a 4mpage in page %p's pv list", m));
1974 pte = pmap_pte_quick(pmap, va);
1975 tpte = pte_load_clear(pte);
1976 KASSERT((tpte & PG_W) == 0,
1977 ("pmap_collect: wired pte %#jx", (uintmax_t)tpte));
1978 if (tpte & PG_A)
1979 vm_page_flag_set(m, PG_REFERENCED);
1980 if ((tpte & (PG_M | PG_RW)) == (PG_M | PG_RW))
1981 vm_page_dirty(m);
1982 free = NULL;
1983 pmap_unuse_pt(pmap, va, &free);
1984 pmap_invalidate_page(pmap, va);
1985 pmap_free_zero_pages(free);
1986 TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
1987 if (TAILQ_EMPTY(&m->md.pv_list)) {
1988 pvh = pa_to_pvh(VM_PAGE_TO_PHYS(m));
1989 if (TAILQ_EMPTY(&pvh->pv_list))
1990 vm_page_flag_clear(m, PG_WRITEABLE);
1991 }
1992 free_pv_entry(pmap, pv);
1993 if (pmap != locked_pmap)
1994 PMAP_UNLOCK(pmap);
1995 }
1996 }
1997 sched_unpin();
1998 }
1999
2000
2001 /*
2002 * free the pv_entry back to the free list
2003 */
2004 static void
2005 free_pv_entry(pmap_t pmap, pv_entry_t pv)
2006 {
2007 vm_page_t m;
2008 struct pv_chunk *pc;
2009 int idx, field, bit;
2010
2011 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
2012 PMAP_LOCK_ASSERT(pmap, MA_OWNED);
2013 PV_STAT(pv_entry_frees++);
2014 PV_STAT(pv_entry_spare++);
2015 pv_entry_count--;
2016 pc = pv_to_chunk(pv);
2017 idx = pv - &pc->pc_pventry[0];
2018 field = idx / 32;
2019 bit = idx % 32;
2020 pc->pc_map[field] |= 1ul << bit;
2021 /* move to head of list */
2022 TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list);
2023 for (idx = 0; idx < _NPCM; idx++)
2024 if (pc->pc_map[idx] != pc_freemask[idx]) {
2025 TAILQ_INSERT_HEAD(&pmap->pm_pvchunk, pc, pc_list);
2026 return;
2027 }
2028 PV_STAT(pv_entry_spare -= _NPCPV);
2029 PV_STAT(pc_chunk_count--);
2030 PV_STAT(pc_chunk_frees++);
2031 /* entire chunk is free, return it */
2032 m = PHYS_TO_VM_PAGE(pmap_kextract((vm_offset_t)pc));
2033 pmap_qremove((vm_offset_t)pc, 1);
2034 vm_page_unwire(m, 0);
2035 vm_page_free(m);
2036 pmap_ptelist_free(&pv_vafree, (vm_offset_t)pc);
2037 }
2038
2039 /*
2040 * get a new pv_entry, allocating a block from the system
2041 * when needed.
2042 */
2043 static pv_entry_t
2044 get_pv_entry(pmap_t pmap, int try)
2045 {
2046 static const struct timeval printinterval = { 60, 0 };
2047 static struct timeval lastprint;
2048 static vm_pindex_t colour;
2049 struct vpgqueues *pq;
2050 int bit, field;
2051 pv_entry_t pv;
2052 struct pv_chunk *pc;
2053 vm_page_t m;
2054
2055 PMAP_LOCK_ASSERT(pmap, MA_OWNED);
2056 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
2057 PV_STAT(pv_entry_allocs++);
2058 pv_entry_count++;
2059 if (pv_entry_count > pv_entry_high_water)
2060 if (ratecheck(&lastprint, &printinterval))
2061 printf("Approaching the limit on PV entries, consider "
2062 "increasing either the vm.pmap.shpgperproc or the "
2063 "vm.pmap.pv_entry_max tunable.\n");
2064 pq = NULL;
2065 retry:
2066 pc = TAILQ_FIRST(&pmap->pm_pvchunk);
2067 if (pc != NULL) {
2068 for (field = 0; field < _NPCM; field++) {
2069 if (pc->pc_map[field]) {
2070 bit = bsfl(pc->pc_map[field]);
2071 break;
2072 }
2073 }
2074 if (field < _NPCM) {
2075 pv = &pc->pc_pventry[field * 32 + bit];
2076 pc->pc_map[field] &= ~(1ul << bit);
2077 /* If this was the last item, move it to tail */
2078 for (field = 0; field < _NPCM; field++)
2079 if (pc->pc_map[field] != 0) {
2080 PV_STAT(pv_entry_spare--);
2081 return (pv); /* not full, return */
2082 }
2083 TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list);
2084 TAILQ_INSERT_TAIL(&pmap->pm_pvchunk, pc, pc_list);
2085 PV_STAT(pv_entry_spare--);
2086 return (pv);
2087 }
2088 }
2089 /*
2090 * Access to the ptelist "pv_vafree" is synchronized by the page
2091 * queues lock. If "pv_vafree" is currently non-empty, it will
2092 * remain non-empty until pmap_ptelist_alloc() completes.
2093 */
2094 if (pv_vafree == 0 || (m = vm_page_alloc(NULL, colour, (pq ==
2095 &vm_page_queues[PQ_ACTIVE] ? VM_ALLOC_SYSTEM : VM_ALLOC_NORMAL) |
2096 VM_ALLOC_NOOBJ | VM_ALLOC_WIRED)) == NULL) {
2097 if (try) {
2098 pv_entry_count--;
2099 PV_STAT(pc_chunk_tryfail++);
2100 return (NULL);
2101 }
2102 /*
2103 * Reclaim pv entries: At first, destroy mappings to
2104 * inactive pages. After that, if a pv chunk entry
2105 * is still needed, destroy mappings to active pages.
2106 */
2107 if (pq == NULL) {
2108 PV_STAT(pmap_collect_inactive++);
2109 pq = &vm_page_queues[PQ_INACTIVE];
2110 } else if (pq == &vm_page_queues[PQ_INACTIVE]) {
2111 PV_STAT(pmap_collect_active++);
2112 pq = &vm_page_queues[PQ_ACTIVE];
2113 } else
2114 panic("get_pv_entry: increase vm.pmap.shpgperproc");
2115 pmap_collect(pmap, pq);
2116 goto retry;
2117 }
2118 PV_STAT(pc_chunk_count++);
2119 PV_STAT(pc_chunk_allocs++);
2120 colour++;
2121 pc = (struct pv_chunk *)pmap_ptelist_alloc(&pv_vafree);
2122 pmap_qenter((vm_offset_t)pc, &m, 1);
2123 pc->pc_pmap = pmap;
2124 pc->pc_map[0] = pc_freemask[0] & ~1ul; /* preallocated bit 0 */
2125 for (field = 1; field < _NPCM; field++)
2126 pc->pc_map[field] = pc_freemask[field];
2127 pv = &pc->pc_pventry[0];
2128 TAILQ_INSERT_HEAD(&pmap->pm_pvchunk, pc, pc_list);
2129 PV_STAT(pv_entry_spare += _NPCPV - 1);
2130 return (pv);
2131 }
2132
2133 static __inline pv_entry_t
2134 pmap_pvh_remove(struct md_page *pvh, pmap_t pmap, vm_offset_t va)
2135 {
2136 pv_entry_t pv;
2137
2138 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
2139 TAILQ_FOREACH(pv, &pvh->pv_list, pv_list) {
2140 if (pmap == PV_PMAP(pv) && va == pv->pv_va) {
2141 TAILQ_REMOVE(&pvh->pv_list, pv, pv_list);
2142 break;
2143 }
2144 }
2145 return (pv);
2146 }
2147
2148 static void
2149 pmap_pv_demote_pde(pmap_t pmap, vm_offset_t va, vm_paddr_t pa)
2150 {
2151 struct md_page *pvh;
2152 pv_entry_t pv;
2153 vm_offset_t va_last;
2154 vm_page_t m;
2155
2156 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
2157 KASSERT((pa & PDRMASK) == 0,
2158 ("pmap_pv_demote_pde: pa is not 4mpage aligned"));
2159
2160 /*
2161 * Transfer the 4mpage's pv entry for this mapping to the first
2162 * page's pv list.
2163 */
2164 pvh = pa_to_pvh(pa);
2165 va = trunc_4mpage(va);
2166 pv = pmap_pvh_remove(pvh, pmap, va);
2167 KASSERT(pv != NULL, ("pmap_pv_demote_pde: pv not found"));
2168 m = PHYS_TO_VM_PAGE(pa);
2169 TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list);
2170 /* Instantiate the remaining NPTEPG - 1 pv entries. */
2171 va_last = va + NBPDR - PAGE_SIZE;
2172 do {
2173 m++;
2174 KASSERT((m->flags & (PG_FICTITIOUS | PG_UNMANAGED)) == 0,
2175 ("pmap_pv_demote_pde: page %p is not managed", m));
2176 va += PAGE_SIZE;
2177 pmap_insert_entry(pmap, va, m);
2178 } while (va < va_last);
2179 }
2180
2181 static void
2182 pmap_pv_promote_pde(pmap_t pmap, vm_offset_t va, vm_paddr_t pa)
2183 {
2184 struct md_page *pvh;
2185 pv_entry_t pv;
2186 vm_offset_t va_last;
2187 vm_page_t m;
2188
2189 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
2190 KASSERT((pa & PDRMASK) == 0,
2191 ("pmap_pv_promote_pde: pa is not 4mpage aligned"));
2192
2193 /*
2194 * Transfer the first page's pv entry for this mapping to the
2195 * 4mpage's pv list. Aside from avoiding the cost of a call
2196 * to get_pv_entry(), a transfer avoids the possibility that
2197 * get_pv_entry() calls pmap_collect() and that pmap_collect()
2198 * removes one of the mappings that is being promoted.
2199 */
2200 m = PHYS_TO_VM_PAGE(pa);
2201 va = trunc_4mpage(va);
2202 pv = pmap_pvh_remove(&m->md, pmap, va);
2203 KASSERT(pv != NULL, ("pmap_pv_promote_pde: pv not found"));
2204 pvh = pa_to_pvh(pa);
2205 TAILQ_INSERT_TAIL(&pvh->pv_list, pv, pv_list);
2206 /* Free the remaining NPTEPG - 1 pv entries. */
2207 va_last = va + NBPDR - PAGE_SIZE;
2208 do {
2209 m++;
2210 va += PAGE_SIZE;
2211 pmap_pvh_free(&m->md, pmap, va);
2212 } while (va < va_last);
2213 }
2214
2215 static void
2216 pmap_pvh_free(struct md_page *pvh, pmap_t pmap, vm_offset_t va)
2217 {
2218 pv_entry_t pv;
2219
2220 pv = pmap_pvh_remove(pvh, pmap, va);
2221 KASSERT(pv != NULL, ("pmap_pvh_free: pv not found"));
2222 free_pv_entry(pmap, pv);
2223 }
2224
2225 static void
2226 pmap_remove_entry(pmap_t pmap, vm_page_t m, vm_offset_t va)
2227 {
2228 struct md_page *pvh;
2229
2230 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
2231 pmap_pvh_free(&m->md, pmap, va);
2232 if (TAILQ_EMPTY(&m->md.pv_list)) {
2233 pvh = pa_to_pvh(VM_PAGE_TO_PHYS(m));
2234 if (TAILQ_EMPTY(&pvh->pv_list))
2235 vm_page_flag_clear(m, PG_WRITEABLE);
2236 }
2237 }
2238
2239 /*
2240 * Create a pv entry for page at pa for
2241 * (pmap, va).
2242 */
2243 static void
2244 pmap_insert_entry(pmap_t pmap, vm_offset_t va, vm_page_t m)
2245 {
2246 pv_entry_t pv;
2247
2248 PMAP_LOCK_ASSERT(pmap, MA_OWNED);
2249 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
2250 pv = get_pv_entry(pmap, FALSE);
2251 pv->pv_va = va;
2252 TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list);
2253 }
2254
2255 /*
2256 * Conditionally create a pv entry.
2257 */
2258 static boolean_t
2259 pmap_try_insert_pv_entry(pmap_t pmap, vm_offset_t va, vm_page_t m)
2260 {
2261 pv_entry_t pv;
2262
2263 PMAP_LOCK_ASSERT(pmap, MA_OWNED);
2264 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
2265 if (pv_entry_count < pv_entry_high_water &&
2266 (pv = get_pv_entry(pmap, TRUE)) != NULL) {
2267 pv->pv_va = va;
2268 TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list);
2269 return (TRUE);
2270 } else
2271 return (FALSE);
2272 }
2273
2274 /*
2275 * Create the pv entries for each of the pages within a superpage.
2276 */
2277 static boolean_t
2278 pmap_pv_insert_pde(pmap_t pmap, vm_offset_t va, vm_paddr_t pa)
2279 {
2280 struct md_page *pvh;
2281 pv_entry_t pv;
2282
2283 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
2284 if (pv_entry_count < pv_entry_high_water &&
2285 (pv = get_pv_entry(pmap, TRUE)) != NULL) {
2286 pv->pv_va = va;
2287 pvh = pa_to_pvh(pa);
2288 TAILQ_INSERT_TAIL(&pvh->pv_list, pv, pv_list);
2289 return (TRUE);
2290 } else
2291 return (FALSE);
2292 }
2293
2294 /*
2295 * Fills a page table page with mappings to consecutive physical pages.
2296 */
2297 static void
2298 pmap_fill_ptp(pt_entry_t *firstpte, pt_entry_t newpte)
2299 {
2300 pt_entry_t *pte;
2301
2302 for (pte = firstpte; pte < firstpte + NPTEPG; pte++) {
2303 *pte = newpte;
2304 newpte += PAGE_SIZE;
2305 }
2306 }
2307
2308 /*
2309 * Tries to demote a 2- or 4MB page mapping. If demotion fails, the
2310 * 2- or 4MB page mapping is invalidated.
2311 */
2312 static boolean_t
2313 pmap_demote_pde(pmap_t pmap, pd_entry_t *pde, vm_offset_t va)
2314 {
2315 pd_entry_t newpde, oldpde;
2316 pmap_t allpmaps_entry;
2317 pt_entry_t *firstpte, newpte;
2318 vm_paddr_t mptepa;
2319 vm_page_t free, mpte;
2320
2321 PMAP_LOCK_ASSERT(pmap, MA_OWNED);
2322 oldpde = *pde;
2323 KASSERT((oldpde & (PG_PS | PG_V)) == (PG_PS | PG_V),
2324 ("pmap_demote_pde: oldpde is missing PG_PS and/or PG_V"));
2325 mpte = pmap_lookup_pt_page(pmap, va);
2326 if (mpte != NULL)
2327 pmap_remove_pt_page(pmap, mpte);
2328 else {
2329 KASSERT((oldpde & PG_W) == 0,
2330 ("pmap_demote_pde: page table page for a wired mapping"
2331 " is missing"));
2332
2333 /*
2334 * Invalidate the 2- or 4MB page mapping and return
2335 * "failure" if the mapping was never accessed or the
2336 * allocation of the new page table page fails.
2337 */
2338 if ((oldpde & PG_A) == 0 || (mpte = vm_page_alloc(NULL,
2339 va >> PDRSHIFT, VM_ALLOC_NOOBJ | VM_ALLOC_NORMAL |
2340 VM_ALLOC_WIRED)) == NULL) {
2341 free = NULL;
2342 pmap_remove_pde(pmap, pde, trunc_4mpage(va), &free);
2343 pmap_invalidate_page(pmap, trunc_4mpage(va));
2344 pmap_free_zero_pages(free);
2345 CTR2(KTR_PMAP, "pmap_demote_pde: failure for va %#x"
2346 " in pmap %p", va, pmap);
2347 return (FALSE);
2348 }
2349 if (va < VM_MAXUSER_ADDRESS)
2350 pmap->pm_stats.resident_count++;
2351 }
2352 mptepa = VM_PAGE_TO_PHYS(mpte);
2353
2354 /*
2355 * Temporarily map the page table page (mpte) into the kernel's
2356 * address space at either PADDR1 or PADDR2.
2357 */
2358 if (curthread->td_pinned > 0 && mtx_owned(&vm_page_queue_mtx)) {
2359 if ((*PMAP1 & PG_FRAME) != mptepa) {
2360 *PMAP1 = mptepa | PG_RW | PG_V | PG_A | PG_M;
2361 #ifdef SMP
2362 PMAP1cpu = PCPU_GET(cpuid);
2363 #endif
2364 invlcaddr(PADDR1);
2365 PMAP1changed++;
2366 } else
2367 #ifdef SMP
2368 if (PMAP1cpu != PCPU_GET(cpuid)) {
2369 PMAP1cpu = PCPU_GET(cpuid);
2370 invlcaddr(PADDR1);
2371 PMAP1changedcpu++;
2372 } else
2373 #endif
2374 PMAP1unchanged++;
2375 firstpte = PADDR1;
2376 } else {
2377 mtx_lock(&PMAP2mutex);
2378 if ((*PMAP2 & PG_FRAME) != mptepa) {
2379 *PMAP2 = mptepa | PG_RW | PG_V | PG_A | PG_M;
2380 pmap_invalidate_page(kernel_pmap, (vm_offset_t)PADDR2);
2381 }
2382 firstpte = PADDR2;
2383 }
2384 newpde = mptepa | PG_M | PG_A | (oldpde & PG_U) | PG_RW | PG_V;
2385 KASSERT((oldpde & PG_A) != 0,
2386 ("pmap_demote_pde: oldpde is missing PG_A"));
2387 KASSERT((oldpde & (PG_M | PG_RW)) != PG_RW,
2388 ("pmap_demote_pde: oldpde is missing PG_M"));
2389 newpte = oldpde & ~PG_PS;
2390 if ((newpte & PG_PDE_PAT) != 0)
2391 newpte ^= PG_PDE_PAT | PG_PTE_PAT;
2392
2393 /*
2394 * If the page table page is new, initialize it.
2395 */
2396 if (mpte->wire_count == 1) {
2397 mpte->wire_count = NPTEPG;
2398 pmap_fill_ptp(firstpte, newpte);
2399 }
2400 KASSERT((*firstpte & PG_FRAME) == (newpte & PG_FRAME),
2401 ("pmap_demote_pde: firstpte and newpte map different physical"
2402 " addresses"));
2403
2404 /*
2405 * If the mapping has changed attributes, update the page table
2406 * entries.
2407 */
2408 if ((*firstpte & PG_PTE_PROMOTE) != (newpte & PG_PTE_PROMOTE))
2409 pmap_fill_ptp(firstpte, newpte);
2410
2411 /*
2412 * Demote the mapping. This pmap is locked. The old PDE has
2413 * PG_A set. If the old PDE has PG_RW set, it also has PG_M
2414 * set. Thus, there is no danger of a race with another
2415 * processor changing the setting of PG_A and/or PG_M between
2416 * the read above and the store below.
2417 */
2418 if (pmap == kernel_pmap) {
2419 /*
2420 * A harmless race exists between this loop and the bcopy()
2421 * in pmap_pinit() that initializes the kernel segment of
2422 * the new page table. Specifically, that bcopy() may copy
2423 * the new PDE from the PTD, which is first in allpmaps, to
2424 * the new page table before this loop updates that new
2425 * page table.
2426 */
2427 mtx_lock_spin(&allpmaps_lock);
2428 LIST_FOREACH(allpmaps_entry, &allpmaps, pm_list) {
2429 pde = pmap_pde(allpmaps_entry, va);
2430 KASSERT(*pde == newpde || (*pde & PG_PTE_PROMOTE) ==
2431 (oldpde & PG_PTE_PROMOTE),
2432 ("pmap_demote_pde: pde was %#jx, expected %#jx",
2433 (uintmax_t)*pde, (uintmax_t)oldpde));
2434 pde_store(pde, newpde);
2435 }
2436 mtx_unlock_spin(&allpmaps_lock);
2437 } else
2438 pde_store(pde, newpde);
2439 if (firstpte == PADDR2)
2440 mtx_unlock(&PMAP2mutex);
2441
2442 /*
2443 * Invalidate the recursive mapping of the page table page.
2444 */
2445 pmap_invalidate_page(pmap, (vm_offset_t)vtopte(va));
2446
2447 /*
2448 * Demote the pv entry. This depends on the earlier demotion
2449 * of the mapping. Specifically, the (re)creation of a per-
2450 * page pv entry might trigger the execution of pmap_collect(),
2451 * which might reclaim a newly (re)created per-page pv entry
2452 * and destroy the associated mapping. In order to destroy
2453 * the mapping, the PDE must have already changed from mapping
2454 * the 2mpage to referencing the page table page.
2455 */
2456 if ((oldpde & PG_MANAGED) != 0)
2457 pmap_pv_demote_pde(pmap, va, oldpde & PG_PS_FRAME);
2458
2459 pmap_pde_demotions++;
2460 CTR2(KTR_PMAP, "pmap_demote_pde: success for va %#x"
2461 " in pmap %p", va, pmap);
2462 return (TRUE);
2463 }
2464
2465 /*
2466 * pmap_remove_pde: do the things to unmap a superpage in a process
2467 */
2468 static void
2469 pmap_remove_pde(pmap_t pmap, pd_entry_t *pdq, vm_offset_t sva,
2470 vm_page_t *free)
2471 {
2472 struct md_page *pvh;
2473 pd_entry_t oldpde;
2474 vm_offset_t eva, va;
2475 vm_page_t m, mpte;
2476
2477 PMAP_LOCK_ASSERT(pmap, MA_OWNED);
2478 KASSERT((sva & PDRMASK) == 0,
2479 ("pmap_remove_pde: sva is not 4mpage aligned"));
2480 oldpde = pte_load_clear(pdq);
2481 if (oldpde & PG_W)
2482 pmap->pm_stats.wired_count -= NBPDR / PAGE_SIZE;
2483
2484 /*
2485 * Machines that don't support invlpg, also don't support
2486 * PG_G.
2487 */
2488 if (oldpde & PG_G)
2489 pmap_invalidate_page(kernel_pmap, sva);
2490 pmap->pm_stats.resident_count -= NBPDR / PAGE_SIZE;
2491 if (oldpde & PG_MANAGED) {
2492 pvh = pa_to_pvh(oldpde & PG_PS_FRAME);
2493 pmap_pvh_free(pvh, pmap, sva);
2494 eva = sva + NBPDR;
2495 for (va = sva, m = PHYS_TO_VM_PAGE(oldpde & PG_PS_FRAME);
2496 va < eva; va += PAGE_SIZE, m++) {
2497 if ((oldpde & (PG_M | PG_RW)) == (PG_M | PG_RW))
2498 vm_page_dirty(m);
2499 if (oldpde & PG_A)
2500 vm_page_flag_set(m, PG_REFERENCED);
2501 if (TAILQ_EMPTY(&m->md.pv_list) &&
2502 TAILQ_EMPTY(&pvh->pv_list))
2503 vm_page_flag_clear(m, PG_WRITEABLE);
2504 }
2505 }
2506 if (pmap == kernel_pmap) {
2507 if (!pmap_demote_pde(pmap, pdq, sva))
2508 panic("pmap_remove_pde: failed demotion");
2509 } else {
2510 mpte = pmap_lookup_pt_page(pmap, sva);
2511 if (mpte != NULL) {
2512 pmap_remove_pt_page(pmap, mpte);
2513 pmap->pm_stats.resident_count--;
2514 KASSERT(mpte->wire_count == NPTEPG,
2515 ("pmap_remove_pde: pte page wire count error"));
2516 mpte->wire_count = 0;
2517 pmap_add_delayed_free_list(mpte, free, FALSE);
2518 atomic_subtract_int(&cnt.v_wire_count, 1);
2519 }
2520 }
2521 }
2522
2523 /*
2524 * pmap_remove_pte: do the things to unmap a page in a process
2525 */
2526 static int
2527 pmap_remove_pte(pmap_t pmap, pt_entry_t *ptq, vm_offset_t va, vm_page_t *free)
2528 {
2529 pt_entry_t oldpte;
2530 vm_page_t m;
2531
2532 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
2533 PMAP_LOCK_ASSERT(pmap, MA_OWNED);
2534 oldpte = pte_load_clear(ptq);
2535 if (oldpte & PG_W)
2536 pmap->pm_stats.wired_count -= 1;
2537 /*
2538 * Machines that don't support invlpg, also don't support
2539 * PG_G.
2540 */
2541 if (oldpte & PG_G)
2542 pmap_invalidate_page(kernel_pmap, va);
2543 pmap->pm_stats.resident_count -= 1;
2544 if (oldpte & PG_MANAGED) {
2545 m = PHYS_TO_VM_PAGE(oldpte & PG_FRAME);
2546 if ((oldpte & (PG_M | PG_RW)) == (PG_M | PG_RW))
2547 vm_page_dirty(m);
2548 if (oldpte & PG_A)
2549 vm_page_flag_set(m, PG_REFERENCED);
2550 pmap_remove_entry(pmap, m, va);
2551 }
2552 return (pmap_unuse_pt(pmap, va, free));
2553 }
2554
2555 /*
2556 * Remove a single page from a process address space
2557 */
2558 static void
2559 pmap_remove_page(pmap_t pmap, vm_offset_t va, vm_page_t *free)
2560 {
2561 pt_entry_t *pte;
2562
2563 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
2564 KASSERT(curthread->td_pinned > 0, ("curthread not pinned"));
2565 PMAP_LOCK_ASSERT(pmap, MA_OWNED);
2566 if ((pte = pmap_pte_quick(pmap, va)) == NULL || *pte == 0)
2567 return;
2568 pmap_remove_pte(pmap, pte, va, free);
2569 pmap_invalidate_page(pmap, va);
2570 }
2571
2572 /*
2573 * Remove the given range of addresses from the specified map.
2574 *
2575 * It is assumed that the start and end are properly
2576 * rounded to the page size.
2577 */
2578 void
2579 pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
2580 {
2581 vm_offset_t pdnxt;
2582 pd_entry_t ptpaddr;
2583 pt_entry_t *pte;
2584 vm_page_t free = NULL;
2585 int anyvalid;
2586
2587 /*
2588 * Perform an unsynchronized read. This is, however, safe.
2589 */
2590 if (pmap->pm_stats.resident_count == 0)
2591 return;
2592
2593 anyvalid = 0;
2594
2595 vm_page_lock_queues();
2596 sched_pin();
2597 PMAP_LOCK(pmap);
2598
2599 /*
2600 * special handling of removing one page. a very
2601 * common operation and easy to short circuit some
2602 * code.
2603 */
2604 if ((sva + PAGE_SIZE == eva) &&
2605 ((pmap->pm_pdir[(sva >> PDRSHIFT)] & PG_PS) == 0)) {
2606 pmap_remove_page(pmap, sva, &free);
2607 goto out;
2608 }
2609
2610 for (; sva < eva; sva = pdnxt) {
2611 unsigned pdirindex;
2612
2613 /*
2614 * Calculate index for next page table.
2615 */
2616 pdnxt = (sva + NBPDR) & ~PDRMASK;
2617 if (pdnxt < sva)
2618 pdnxt = eva;
2619 if (pmap->pm_stats.resident_count == 0)
2620 break;
2621
2622 pdirindex = sva >> PDRSHIFT;
2623 ptpaddr = pmap->pm_pdir[pdirindex];
2624
2625 /*
2626 * Weed out invalid mappings. Note: we assume that the page
2627 * directory table is always allocated, and in kernel virtual.
2628 */
2629 if (ptpaddr == 0)
2630 continue;
2631
2632 /*
2633 * Check for large page.
2634 */
2635 if ((ptpaddr & PG_PS) != 0) {
2636 /*
2637 * Are we removing the entire large page? If not,
2638 * demote the mapping and fall through.
2639 */
2640 if (sva + NBPDR == pdnxt && eva >= pdnxt) {
2641 /*
2642 * The TLB entry for a PG_G mapping is
2643 * invalidated by pmap_remove_pde().
2644 */
2645 if ((ptpaddr & PG_G) == 0)
2646 anyvalid = 1;
2647 pmap_remove_pde(pmap,
2648 &pmap->pm_pdir[pdirindex], sva, &free);
2649 continue;
2650 } else if (!pmap_demote_pde(pmap,
2651 &pmap->pm_pdir[pdirindex], sva)) {
2652 /* The large page mapping was destroyed. */
2653 continue;
2654 }
2655 }
2656
2657 /*
2658 * Limit our scan to either the end of the va represented
2659 * by the current page table page, or to the end of the
2660 * range being removed.
2661 */
2662 if (pdnxt > eva)
2663 pdnxt = eva;
2664
2665 for (pte = pmap_pte_quick(pmap, sva); sva != pdnxt; pte++,
2666 sva += PAGE_SIZE) {
2667 if (*pte == 0)
2668 continue;
2669
2670 /*
2671 * The TLB entry for a PG_G mapping is invalidated
2672 * by pmap_remove_pte().
2673 */
2674 if ((*pte & PG_G) == 0)
2675 anyvalid = 1;
2676 if (pmap_remove_pte(pmap, pte, sva, &free))
2677 break;
2678 }
2679 }
2680 out:
2681 sched_unpin();
2682 if (anyvalid)
2683 pmap_invalidate_all(pmap);
2684 vm_page_unlock_queues();
2685 PMAP_UNLOCK(pmap);
2686 pmap_free_zero_pages(free);
2687 }
2688
2689 /*
2690 * Routine: pmap_remove_all
2691 * Function:
2692 * Removes this physical page from
2693 * all physical maps in which it resides.
2694 * Reflects back modify bits to the pager.
2695 *
2696 * Notes:
2697 * Original versions of this routine were very
2698 * inefficient because they iteratively called
2699 * pmap_remove (slow...)
2700 */
2701
2702 void
2703 pmap_remove_all(vm_page_t m)
2704 {
2705 struct md_page *pvh;
2706 pv_entry_t pv;
2707 pmap_t pmap;
2708 pt_entry_t *pte, tpte;
2709 pd_entry_t *pde;
2710 vm_offset_t va;
2711 vm_page_t free;
2712
2713 KASSERT((m->flags & PG_FICTITIOUS) == 0,
2714 ("pmap_remove_all: page %p is fictitious", m));
2715 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
2716 sched_pin();
2717 pvh = pa_to_pvh(VM_PAGE_TO_PHYS(m));
2718 while ((pv = TAILQ_FIRST(&pvh->pv_list)) != NULL) {
2719 va = pv->pv_va;
2720 pmap = PV_PMAP(pv);
2721 PMAP_LOCK(pmap);
2722 pde = pmap_pde(pmap, va);
2723 (void)pmap_demote_pde(pmap, pde, va);
2724 PMAP_UNLOCK(pmap);
2725 }
2726 while ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) {
2727 pmap = PV_PMAP(pv);
2728 PMAP_LOCK(pmap);
2729 pmap->pm_stats.resident_count--;
2730 pde = pmap_pde(pmap, pv->pv_va);
2731 KASSERT((*pde & PG_PS) == 0, ("pmap_remove_all: found"
2732 " a 4mpage in page %p's pv list", m));
2733 pte = pmap_pte_quick(pmap, pv->pv_va);
2734 tpte = pte_load_clear(pte);
2735 if (tpte & PG_W)
2736 pmap->pm_stats.wired_count--;
2737 if (tpte & PG_A)
2738 vm_page_flag_set(m, PG_REFERENCED);
2739
2740 /*
2741 * Update the vm_page_t clean and reference bits.
2742 */
2743 if ((tpte & (PG_M | PG_RW)) == (PG_M | PG_RW))
2744 vm_page_dirty(m);
2745 free = NULL;
2746 pmap_unuse_pt(pmap, pv->pv_va, &free);
2747 pmap_invalidate_page(pmap, pv->pv_va);
2748 pmap_free_zero_pages(free);
2749 TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
2750 free_pv_entry(pmap, pv);
2751 PMAP_UNLOCK(pmap);
2752 }
2753 vm_page_flag_clear(m, PG_WRITEABLE);
2754 sched_unpin();
2755 }
2756
2757 /*
2758 * pmap_protect_pde: do the things to protect a 4mpage in a process
2759 */
2760 static boolean_t
2761 pmap_protect_pde(pmap_t pmap, pd_entry_t *pde, vm_offset_t sva, vm_prot_t prot)
2762 {
2763 pd_entry_t newpde, oldpde;
2764 vm_offset_t eva, va;
2765 vm_page_t m;
2766 boolean_t anychanged;
2767
2768 PMAP_LOCK_ASSERT(pmap, MA_OWNED);
2769 KASSERT((sva & PDRMASK) == 0,
2770 ("pmap_protect_pde: sva is not 4mpage aligned"));
2771 anychanged = FALSE;
2772 retry:
2773 oldpde = newpde = *pde;
2774 if (oldpde & PG_MANAGED) {
2775 eva = sva + NBPDR;
2776 for (va = sva, m = PHYS_TO_VM_PAGE(oldpde & PG_PS_FRAME);
2777 va < eva; va += PAGE_SIZE, m++) {
2778 /*
2779 * In contrast to the analogous operation on a 4KB page
2780 * mapping, the mapping's PG_A flag is not cleared and
2781 * the page's PG_REFERENCED flag is not set. The
2782 * reason is that pmap_demote_pde() expects that a 2/4MB
2783 * page mapping with a stored page table page has PG_A
2784 * set.
2785 */
2786 if ((oldpde & (PG_M | PG_RW)) == (PG_M | PG_RW))
2787 vm_page_dirty(m);
2788 }
2789 }
2790 if ((prot & VM_PROT_WRITE) == 0)
2791 newpde &= ~(PG_RW | PG_M);
2792 #ifdef PAE
2793 if ((prot & VM_PROT_EXECUTE) == 0)
2794 newpde |= pg_nx;
2795 #endif
2796 if (newpde != oldpde) {
2797 if (!pde_cmpset(pde, oldpde, newpde))
2798 goto retry;
2799 if (oldpde & PG_G)
2800 pmap_invalidate_page(pmap, sva);
2801 else
2802 anychanged = TRUE;
2803 }
2804 return (anychanged);
2805 }
2806
2807 /*
2808 * Set the physical protection on the
2809 * specified range of this map as requested.
2810 */
2811 void
2812 pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
2813 {
2814 vm_offset_t pdnxt;
2815 pd_entry_t ptpaddr;
2816 pt_entry_t *pte;
2817 int anychanged;
2818
2819 if ((prot & VM_PROT_READ) == VM_PROT_NONE) {
2820 pmap_remove(pmap, sva, eva);
2821 return;
2822 }
2823
2824 #ifdef PAE
2825 if ((prot & (VM_PROT_WRITE|VM_PROT_EXECUTE)) ==
2826 (VM_PROT_WRITE|VM_PROT_EXECUTE))
2827 return;
2828 #else
2829 if (prot & VM_PROT_WRITE)
2830 return;
2831 #endif
2832
2833 anychanged = 0;
2834
2835 vm_page_lock_queues();
2836 sched_pin();
2837 PMAP_LOCK(pmap);
2838 for (; sva < eva; sva = pdnxt) {
2839 pt_entry_t obits, pbits;
2840 unsigned pdirindex;
2841
2842 pdnxt = (sva + NBPDR) & ~PDRMASK;
2843 if (pdnxt < sva)
2844 pdnxt = eva;
2845
2846 pdirindex = sva >> PDRSHIFT;
2847 ptpaddr = pmap->pm_pdir[pdirindex];
2848
2849 /*
2850 * Weed out invalid mappings. Note: we assume that the page
2851 * directory table is always allocated, and in kernel virtual.
2852 */
2853 if (ptpaddr == 0)
2854 continue;
2855
2856 /*
2857 * Check for large page.
2858 */
2859 if ((ptpaddr & PG_PS) != 0) {
2860 /*
2861 * Are we protecting the entire large page? If not,
2862 * demote the mapping and fall through.
2863 */
2864 if (sva + NBPDR == pdnxt && eva >= pdnxt) {
2865 /*
2866 * The TLB entry for a PG_G mapping is
2867 * invalidated by pmap_protect_pde().
2868 */
2869 if (pmap_protect_pde(pmap,
2870 &pmap->pm_pdir[pdirindex], sva, prot))
2871 anychanged = 1;
2872 continue;
2873 } else if (!pmap_demote_pde(pmap,
2874 &pmap->pm_pdir[pdirindex], sva)) {
2875 /* The large page mapping was destroyed. */
2876 continue;
2877 }
2878 }
2879
2880 if (pdnxt > eva)
2881 pdnxt = eva;
2882
2883 for (pte = pmap_pte_quick(pmap, sva); sva != pdnxt; pte++,
2884 sva += PAGE_SIZE) {
2885 vm_page_t m;
2886
2887 retry:
2888 /*
2889 * Regardless of whether a pte is 32 or 64 bits in
2890 * size, PG_RW, PG_A, and PG_M are among the least
2891 * significant 32 bits.
2892 */
2893 obits = pbits = *pte;
2894 if ((pbits & PG_V) == 0)
2895 continue;
2896 if (pbits & PG_MANAGED) {
2897 m = NULL;
2898 if (pbits & PG_A) {
2899 m = PHYS_TO_VM_PAGE(pbits & PG_FRAME);
2900 vm_page_flag_set(m, PG_REFERENCED);
2901 pbits &= ~PG_A;
2902 }
2903 if ((pbits & (PG_M | PG_RW)) == (PG_M | PG_RW)) {
2904 if (m == NULL)
2905 m = PHYS_TO_VM_PAGE(pbits & PG_FRAME);
2906 vm_page_dirty(m);
2907 }
2908 }
2909
2910 if ((prot & VM_PROT_WRITE) == 0)
2911 pbits &= ~(PG_RW | PG_M);
2912 #ifdef PAE
2913 if ((prot & VM_PROT_EXECUTE) == 0)
2914 pbits |= pg_nx;
2915 #endif
2916
2917 if (pbits != obits) {
2918 #ifdef PAE
2919 if (!atomic_cmpset_64(pte, obits, pbits))
2920 goto retry;
2921 #else
2922 if (!atomic_cmpset_int((u_int *)pte, obits,
2923 pbits))
2924 goto retry;
2925 #endif
2926 if (obits & PG_G)
2927 pmap_invalidate_page(pmap, sva);
2928 else
2929 anychanged = 1;
2930 }
2931 }
2932 }
2933 sched_unpin();
2934 if (anychanged)
2935 pmap_invalidate_all(pmap);
2936 vm_page_unlock_queues();
2937 PMAP_UNLOCK(pmap);
2938 }
2939
2940 /*
2941 * Tries to promote the 512 or 1024, contiguous 4KB page mappings that are
2942 * within a single page table page (PTP) to a single 2- or 4MB page mapping.
2943 * For promotion to occur, two conditions must be met: (1) the 4KB page
2944 * mappings must map aligned, contiguous physical memory and (2) the 4KB page
2945 * mappings must have identical characteristics.
2946 *
2947 * Managed (PG_MANAGED) mappings within the kernel address space are not
2948 * promoted. The reason is that kernel PDEs are replicated in each pmap but
2949 * pmap_clear_ptes() and pmap_ts_referenced() only read the PDE from the kernel
2950 * pmap.
2951 */
2952 static void
2953 pmap_promote_pde(pmap_t pmap, pd_entry_t *pde, vm_offset_t va)
2954 {
2955 pd_entry_t newpde;
2956 pmap_t allpmaps_entry;
2957 pt_entry_t *firstpte, oldpte, pa, *pte;
2958 vm_offset_t oldpteva;
2959 vm_page_t mpte;
2960
2961 PMAP_LOCK_ASSERT(pmap, MA_OWNED);
2962
2963 /*
2964 * Examine the first PTE in the specified PTP. Abort if this PTE is
2965 * either invalid, unused, or does not map the first 4KB physical page
2966 * within a 2- or 4MB page.
2967 */
2968 firstpte = vtopte(trunc_4mpage(va));
2969 setpde:
2970 newpde = *firstpte;
2971 if ((newpde & ((PG_FRAME & PDRMASK) | PG_A | PG_V)) != (PG_A | PG_V)) {
2972 pmap_pde_p_failures++;
2973 CTR2(KTR_PMAP, "pmap_promote_pde: failure for va %#x"
2974 " in pmap %p", va, pmap);
2975 return;
2976 }
2977 if ((*firstpte & PG_MANAGED) != 0 && pmap == kernel_pmap) {
2978 pmap_pde_p_failures++;
2979 CTR2(KTR_PMAP, "pmap_promote_pde: failure for va %#x"
2980 " in pmap %p", va, pmap);
2981 return;
2982 }
2983 if ((newpde & (PG_M | PG_RW)) == PG_RW) {
2984 /*
2985 * When PG_M is already clear, PG_RW can be cleared without
2986 * a TLB invalidation.
2987 */
2988 if (!atomic_cmpset_int((u_int *)firstpte, newpde, newpde &
2989 ~PG_RW))
2990 goto setpde;
2991 newpde &= ~PG_RW;
2992 }
2993
2994 /*
2995 * Examine each of the other PTEs in the specified PTP. Abort if this
2996 * PTE maps an unexpected 4KB physical page or does not have identical
2997 * characteristics to the first PTE.
2998 */
2999 pa = (newpde & (PG_PS_FRAME | PG_A | PG_V)) + NBPDR - PAGE_SIZE;
3000 for (pte = firstpte + NPTEPG - 1; pte > firstpte; pte--) {
3001 setpte:
3002 oldpte = *pte;
3003 if ((oldpte & (PG_FRAME | PG_A | PG_V)) != pa) {
3004 pmap_pde_p_failures++;
3005 CTR2(KTR_PMAP, "pmap_promote_pde: failure for va %#x"
3006 " in pmap %p", va, pmap);
3007 return;
3008 }
3009 if ((oldpte & (PG_M | PG_RW)) == PG_RW) {
3010 /*
3011 * When PG_M is already clear, PG_RW can be cleared
3012 * without a TLB invalidation.
3013 */
3014 if (!atomic_cmpset_int((u_int *)pte, oldpte,
3015 oldpte & ~PG_RW))
3016 goto setpte;
3017 oldpte &= ~PG_RW;
3018 oldpteva = (oldpte & PG_FRAME & PDRMASK) |
3019 (va & ~PDRMASK);
3020 CTR2(KTR_PMAP, "pmap_promote_pde: protect for va %#x"
3021 " in pmap %p", oldpteva, pmap);
3022 }
3023 if ((oldpte & PG_PTE_PROMOTE) != (newpde & PG_PTE_PROMOTE)) {
3024 pmap_pde_p_failures++;
3025 CTR2(KTR_PMAP, "pmap_promote_pde: failure for va %#x"
3026 " in pmap %p", va, pmap);
3027 return;
3028 }
3029 pa -= PAGE_SIZE;
3030 }
3031
3032 /*
3033 * Save the page table page in its current state until the PDE
3034 * mapping the superpage is demoted by pmap_demote_pde() or
3035 * destroyed by pmap_remove_pde().
3036 */
3037 mpte = PHYS_TO_VM_PAGE(*pde & PG_FRAME);
3038 KASSERT(mpte >= vm_page_array &&
3039 mpte < &vm_page_array[vm_page_array_size],
3040 ("pmap_promote_pde: page table page is out of range"));
3041 KASSERT(mpte->pindex == va >> PDRSHIFT,
3042 ("pmap_promote_pde: page table page's pindex is wrong"));
3043 pmap_insert_pt_page(pmap, mpte);
3044
3045 /*
3046 * Promote the pv entries.
3047 */
3048 if ((newpde & PG_MANAGED) != 0)
3049 pmap_pv_promote_pde(pmap, va, newpde & PG_PS_FRAME);
3050
3051 /*
3052 * Propagate the PAT index to its proper position.
3053 */
3054 if ((newpde & PG_PTE_PAT) != 0)
3055 newpde ^= PG_PDE_PAT | PG_PTE_PAT;
3056
3057 /*
3058 * Map the superpage.
3059 */
3060 if (pmap == kernel_pmap) {
3061 mtx_lock_spin(&allpmaps_lock);
3062 LIST_FOREACH(allpmaps_entry, &allpmaps, pm_list) {
3063 pde = pmap_pde(allpmaps_entry, va);
3064 pde_store(pde, PG_PS | newpde);
3065 }
3066 mtx_unlock_spin(&allpmaps_lock);
3067 } else
3068 pde_store(pde, PG_PS | newpde);
3069
3070 pmap_pde_promotions++;
3071 CTR2(KTR_PMAP, "pmap_promote_pde: success for va %#x"
3072 " in pmap %p", va, pmap);
3073 }
3074
3075 /*
3076 * Insert the given physical page (p) at
3077 * the specified virtual address (v) in the
3078 * target physical map with the protection requested.
3079 *
3080 * If specified, the page will be wired down, meaning
3081 * that the related pte can not be reclaimed.
3082 *
3083 * NB: This is the only routine which MAY NOT lazy-evaluate
3084 * or lose information. That is, this routine must actually
3085 * insert this page into the given map NOW.
3086 */
3087 void
3088 pmap_enter(pmap_t pmap, vm_offset_t va, vm_prot_t access, vm_page_t m,
3089 vm_prot_t prot, boolean_t wired)
3090 {
3091 vm_paddr_t pa;
3092 pd_entry_t *pde;
3093 pt_entry_t *pte;
3094 vm_paddr_t opa;
3095 pt_entry_t origpte, newpte;
3096 vm_page_t mpte, om;
3097 boolean_t invlva;
3098
3099 va = trunc_page(va);
3100 KASSERT(va <= VM_MAX_KERNEL_ADDRESS, ("pmap_enter: toobig"));
3101 KASSERT(va < UPT_MIN_ADDRESS || va >= UPT_MAX_ADDRESS,
3102 ("pmap_enter: invalid to pmap_enter page table pages (va: 0x%x)", va));
3103
3104 mpte = NULL;
3105
3106 vm_page_lock_queues();
3107 PMAP_LOCK(pmap);
3108 sched_pin();
3109
3110 /*
3111 * In the case that a page table page is not
3112 * resident, we are creating it here.
3113 */
3114 if (va < VM_MAXUSER_ADDRESS) {
3115 mpte = pmap_allocpte(pmap, va, M_WAITOK);
3116 }
3117
3118 pde = pmap_pde(pmap, va);
3119 if ((*pde & PG_PS) != 0)
3120 panic("pmap_enter: attempted pmap_enter on 4MB page");
3121 pte = pmap_pte_quick(pmap, va);
3122
3123 /*
3124 * Page Directory table entry not valid, we need a new PT page
3125 */
3126 if (pte == NULL) {
3127 panic("pmap_enter: invalid page directory pdir=%#jx, va=%#x",
3128 (uintmax_t)pmap->pm_pdir[PTDPTDI], va);
3129 }
3130
3131 pa = VM_PAGE_TO_PHYS(m);
3132 om = NULL;
3133 origpte = *pte;
3134 opa = origpte & PG_FRAME;
3135
3136 /*
3137 * Mapping has not changed, must be protection or wiring change.
3138 */
3139 if (origpte && (opa == pa)) {
3140 /*
3141 * Wiring change, just update stats. We don't worry about
3142 * wiring PT pages as they remain resident as long as there
3143 * are valid mappings in them. Hence, if a user page is wired,
3144 * the PT page will be also.
3145 */
3146 if (wired && ((origpte & PG_W) == 0))
3147 pmap->pm_stats.wired_count++;
3148 else if (!wired && (origpte & PG_W))
3149 pmap->pm_stats.wired_count--;
3150
3151 /*
3152 * Remove extra pte reference
3153 */
3154 if (mpte)
3155 mpte->wire_count--;
3156
3157 /*
3158 * We might be turning off write access to the page,
3159 * so we go ahead and sense modify status.
3160 */
3161 if (origpte & PG_MANAGED) {
3162 om = m;
3163 pa |= PG_MANAGED;
3164 }
3165 goto validate;
3166 }
3167 /*
3168 * Mapping has changed, invalidate old range and fall through to
3169 * handle validating new mapping.
3170 */
3171 if (opa) {
3172 if (origpte & PG_W)
3173 pmap->pm_stats.wired_count--;
3174 if (origpte & PG_MANAGED) {
3175 om = PHYS_TO_VM_PAGE(opa);
3176 pmap_remove_entry(pmap, om, va);
3177 }
3178 if (mpte != NULL) {
3179 mpte->wire_count--;
3180 KASSERT(mpte->wire_count > 0,
3181 ("pmap_enter: missing reference to page table page,"
3182 " va: 0x%x", va));
3183 }
3184 } else
3185 pmap->pm_stats.resident_count++;
3186
3187 /*
3188 * Enter on the PV list if part of our managed memory.
3189 */
3190 if ((m->flags & (PG_FICTITIOUS | PG_UNMANAGED)) == 0) {
3191 KASSERT(va < kmi.clean_sva || va >= kmi.clean_eva,
3192 ("pmap_enter: managed mapping within the clean submap"));
3193 pmap_insert_entry(pmap, va, m);
3194 pa |= PG_MANAGED;
3195 }
3196
3197 /*
3198 * Increment counters
3199 */
3200 if (wired)
3201 pmap->pm_stats.wired_count++;
3202
3203 validate:
3204 /*
3205 * Now validate mapping with desired protection/wiring.
3206 */
3207 newpte = (pt_entry_t)(pa | pmap_cache_bits(m->md.pat_mode, 0) | PG_V);
3208 if ((prot & VM_PROT_WRITE) != 0) {
3209 newpte |= PG_RW;
3210 vm_page_flag_set(m, PG_WRITEABLE);
3211 }
3212 #ifdef PAE
3213 if ((prot & VM_PROT_EXECUTE) == 0)
3214 newpte |= pg_nx;
3215 #endif
3216 if (wired)
3217 newpte |= PG_W;
3218 if (va < VM_MAXUSER_ADDRESS)
3219 newpte |= PG_U;
3220 if (pmap == kernel_pmap)
3221 newpte |= pgeflag;
3222
3223 /*
3224 * if the mapping or permission bits are different, we need
3225 * to update the pte.
3226 */
3227 if ((origpte & ~(PG_M|PG_A)) != newpte) {
3228 newpte |= PG_A;
3229 if ((access & VM_PROT_WRITE) != 0)
3230 newpte |= PG_M;
3231 if (origpte & PG_V) {
3232 invlva = FALSE;
3233 origpte = pte_load_store(pte, newpte);
3234 if (origpte & PG_A) {
3235 if (origpte & PG_MANAGED)
3236 vm_page_flag_set(om, PG_REFERENCED);
3237 if (opa != VM_PAGE_TO_PHYS(m))
3238 invlva = TRUE;
3239 #ifdef PAE
3240 if ((origpte & PG_NX) == 0 &&
3241 (newpte & PG_NX) != 0)
3242 invlva = TRUE;
3243 #endif
3244 }
3245 if ((origpte & (PG_M | PG_RW)) == (PG_M | PG_RW)) {
3246 if ((origpte & PG_MANAGED) != 0)
3247 vm_page_dirty(om);
3248 if ((prot & VM_PROT_WRITE) == 0)
3249 invlva = TRUE;
3250 }
3251 if (invlva)
3252 pmap_invalidate_page(pmap, va);
3253 } else
3254 pte_store(pte, newpte);
3255 }
3256
3257 /*
3258 * If both the page table page and the reservation are fully
3259 * populated, then attempt promotion.
3260 */
3261 if ((mpte == NULL || mpte->wire_count == NPTEPG) &&
3262 pg_ps_enabled && vm_reserv_level_iffullpop(m) == 0)
3263 pmap_promote_pde(pmap, pde, va);
3264
3265 sched_unpin();
3266 vm_page_unlock_queues();
3267 PMAP_UNLOCK(pmap);
3268 }
3269
3270 /*
3271 * Tries to create a 2- or 4MB page mapping. Returns TRUE if successful and
3272 * FALSE otherwise. Fails if (1) a page table page cannot be allocated without
3273 * blocking, (2) a mapping already exists at the specified virtual address, or
3274 * (3) a pv entry cannot be allocated without reclaiming another pv entry.
3275 */
3276 static boolean_t
3277 pmap_enter_pde(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot)
3278 {
3279 pd_entry_t *pde, newpde;
3280
3281 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
3282 PMAP_LOCK_ASSERT(pmap, MA_OWNED);
3283 pde = pmap_pde(pmap, va);
3284 if (*pde != 0) {
3285 CTR2(KTR_PMAP, "pmap_enter_pde: failure for va %#lx"
3286 " in pmap %p", va, pmap);
3287 return (FALSE);
3288 }
3289 newpde = VM_PAGE_TO_PHYS(m) | pmap_cache_bits(m->md.pat_mode, 1) |
3290 PG_PS | PG_V;
3291 if ((m->flags & (PG_FICTITIOUS | PG_UNMANAGED)) == 0) {
3292 newpde |= PG_MANAGED;
3293
3294 /*
3295 * Abort this mapping if its PV entry could not be created.
3296 */
3297 if (!pmap_pv_insert_pde(pmap, va, VM_PAGE_TO_PHYS(m))) {
3298 CTR2(KTR_PMAP, "pmap_enter_pde: failure for va %#lx"
3299 " in pmap %p", va, pmap);
3300 return (FALSE);
3301 }
3302 }
3303 #ifdef PAE
3304 if ((prot & VM_PROT_EXECUTE) == 0)
3305 newpde |= pg_nx;
3306 #endif
3307 if (va < VM_MAXUSER_ADDRESS)
3308 newpde |= PG_U;
3309
3310 /*
3311 * Increment counters.
3312 */
3313 pmap->pm_stats.resident_count += NBPDR / PAGE_SIZE;
3314
3315 /*
3316 * Map the superpage.
3317 */
3318 pde_store(pde, newpde);
3319
3320 pmap_pde_mappings++;
3321 CTR2(KTR_PMAP, "pmap_enter_pde: success for va %#lx"
3322 " in pmap %p", va, pmap);
3323 return (TRUE);
3324 }
3325
3326 /*
3327 * Maps a sequence of resident pages belonging to the same object.
3328 * The sequence begins with the given page m_start. This page is
3329 * mapped at the given virtual address start. Each subsequent page is
3330 * mapped at a virtual address that is offset from start by the same
3331 * amount as the page is offset from m_start within the object. The
3332 * last page in the sequence is the page with the largest offset from
3333 * m_start that can be mapped at a virtual address less than the given
3334 * virtual address end. Not every virtual page between start and end
3335 * is mapped; only those for which a resident page exists with the
3336 * corresponding offset from m_start are mapped.
3337 */
3338 void
3339 pmap_enter_object(pmap_t pmap, vm_offset_t start, vm_offset_t end,
3340 vm_page_t m_start, vm_prot_t prot)
3341 {
3342 vm_offset_t va;
3343 vm_page_t m, mpte;
3344 vm_pindex_t diff, psize;
3345
3346 VM_OBJECT_LOCK_ASSERT(m_start->object, MA_OWNED);
3347 psize = atop(end - start);
3348 mpte = NULL;
3349 m = m_start;
3350 PMAP_LOCK(pmap);
3351 while (m != NULL && (diff = m->pindex - m_start->pindex) < psize) {
3352 va = start + ptoa(diff);
3353 if ((va & PDRMASK) == 0 && va + NBPDR <= end &&
3354 (VM_PAGE_TO_PHYS(m) & PDRMASK) == 0 &&
3355 pg_ps_enabled && vm_reserv_level_iffullpop(m) == 0 &&
3356 pmap_enter_pde(pmap, va, m, prot))
3357 m = &m[NBPDR / PAGE_SIZE - 1];
3358 else
3359 mpte = pmap_enter_quick_locked(pmap, va, m, prot,
3360 mpte);
3361 m = TAILQ_NEXT(m, listq);
3362 }
3363 PMAP_UNLOCK(pmap);
3364 }
3365
3366 /*
3367 * this code makes some *MAJOR* assumptions:
3368 * 1. Current pmap & pmap exists.
3369 * 2. Not wired.
3370 * 3. Read access.
3371 * 4. No page table pages.
3372 * but is *MUCH* faster than pmap_enter...
3373 */
3374
3375 void
3376 pmap_enter_quick(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot)
3377 {
3378
3379 PMAP_LOCK(pmap);
3380 (void) pmap_enter_quick_locked(pmap, va, m, prot, NULL);
3381 PMAP_UNLOCK(pmap);
3382 }
3383
3384 static vm_page_t
3385 pmap_enter_quick_locked(pmap_t pmap, vm_offset_t va, vm_page_t m,
3386 vm_prot_t prot, vm_page_t mpte)
3387 {
3388 pt_entry_t *pte;
3389 vm_paddr_t pa;
3390 vm_page_t free;
3391
3392 KASSERT(va < kmi.clean_sva || va >= kmi.clean_eva ||
3393 (m->flags & (PG_FICTITIOUS | PG_UNMANAGED)) != 0,
3394 ("pmap_enter_quick_locked: managed mapping within the clean submap"));
3395 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
3396 PMAP_LOCK_ASSERT(pmap, MA_OWNED);
3397
3398 /*
3399 * In the case that a page table page is not
3400 * resident, we are creating it here.
3401 */
3402 if (va < VM_MAXUSER_ADDRESS) {
3403 unsigned ptepindex;
3404 pd_entry_t ptepa;
3405
3406 /*
3407 * Calculate pagetable page index
3408 */
3409 ptepindex = va >> PDRSHIFT;
3410 if (mpte && (mpte->pindex == ptepindex)) {
3411 mpte->wire_count++;
3412 } else {
3413 /*
3414 * Get the page directory entry
3415 */
3416 ptepa = pmap->pm_pdir[ptepindex];
3417
3418 /*
3419 * If the page table page is mapped, we just increment
3420 * the hold count, and activate it.
3421 */
3422 if (ptepa) {
3423 if (ptepa & PG_PS)
3424 return (NULL);
3425 mpte = PHYS_TO_VM_PAGE(ptepa & PG_FRAME);
3426 mpte->wire_count++;
3427 } else {
3428 mpte = _pmap_allocpte(pmap, ptepindex,
3429 M_NOWAIT);
3430 if (mpte == NULL)
3431 return (mpte);
3432 }
3433 }
3434 } else {
3435 mpte = NULL;
3436 }
3437
3438 /*
3439 * This call to vtopte makes the assumption that we are
3440 * entering the page into the current pmap. In order to support
3441 * quick entry into any pmap, one would likely use pmap_pte_quick.
3442 * But that isn't as quick as vtopte.
3443 */
3444 pte = vtopte(va);
3445 if (*pte) {
3446 if (mpte != NULL) {
3447 mpte->wire_count--;
3448 mpte = NULL;
3449 }
3450 return (mpte);
3451 }
3452
3453 /*
3454 * Enter on the PV list if part of our managed memory.
3455 */
3456 if ((m->flags & (PG_FICTITIOUS | PG_UNMANAGED)) == 0 &&
3457 !pmap_try_insert_pv_entry(pmap, va, m)) {
3458 if (mpte != NULL) {
3459 free = NULL;
3460 if (pmap_unwire_pte_hold(pmap, mpte, &free)) {
3461 pmap_invalidate_page(pmap, va);
3462 pmap_free_zero_pages(free);
3463 }
3464
3465 mpte = NULL;
3466 }
3467 return (mpte);
3468 }
3469
3470 /*
3471 * Increment counters
3472 */
3473 pmap->pm_stats.resident_count++;
3474
3475 pa = VM_PAGE_TO_PHYS(m) | pmap_cache_bits(m->md.pat_mode, 0);
3476 #ifdef PAE
3477 if ((prot & VM_PROT_EXECUTE) == 0)
3478 pa |= pg_nx;
3479 #endif
3480
3481 /*
3482 * Now validate mapping with RO protection
3483 */
3484 if (m->flags & (PG_FICTITIOUS|PG_UNMANAGED))
3485 pte_store(pte, pa | PG_V | PG_U);
3486 else
3487 pte_store(pte, pa | PG_V | PG_U | PG_MANAGED);
3488 return mpte;
3489 }
3490
3491 /*
3492 * Make a temporary mapping for a physical address. This is only intended
3493 * to be used for panic dumps.
3494 */
3495 void *
3496 pmap_kenter_temporary(vm_paddr_t pa, int i)
3497 {
3498 vm_offset_t va;
3499
3500 va = (vm_offset_t)crashdumpmap + (i * PAGE_SIZE);
3501 pmap_kenter(va, pa);
3502 invlpg(va);
3503 return ((void *)crashdumpmap);
3504 }
3505
3506 /*
3507 * This code maps large physical mmap regions into the
3508 * processor address space. Note that some shortcuts
3509 * are taken, but the code works.
3510 */
3511 void
3512 pmap_object_init_pt(pmap_t pmap, vm_offset_t addr, vm_object_t object,
3513 vm_pindex_t pindex, vm_size_t size)
3514 {
3515 pd_entry_t *pde;
3516 vm_paddr_t pa, ptepa;
3517 vm_page_t p;
3518 int pat_mode;
3519
3520 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
3521 KASSERT(object->type == OBJT_DEVICE || object->type == OBJT_SG,
3522 ("pmap_object_init_pt: non-device object"));
3523 if (pseflag &&
3524 (addr & (NBPDR - 1)) == 0 && (size & (NBPDR - 1)) == 0) {
3525 if (!vm_object_populate(object, pindex, pindex + atop(size)))
3526 return;
3527 p = vm_page_lookup(object, pindex);
3528 KASSERT(p->valid == VM_PAGE_BITS_ALL,
3529 ("pmap_object_init_pt: invalid page %p", p));
3530 pat_mode = p->md.pat_mode;
3531
3532 /*
3533 * Abort the mapping if the first page is not physically
3534 * aligned to a 2/4MB page boundary.
3535 */
3536 ptepa = VM_PAGE_TO_PHYS(p);
3537 if (ptepa & (NBPDR - 1))
3538 return;
3539
3540 /*
3541 * Skip the first page. Abort the mapping if the rest of
3542 * the pages are not physically contiguous or have differing
3543 * memory attributes.
3544 */
3545 p = TAILQ_NEXT(p, listq);
3546 for (pa = ptepa + PAGE_SIZE; pa < ptepa + size;
3547 pa += PAGE_SIZE) {
3548 KASSERT(p->valid == VM_PAGE_BITS_ALL,
3549 ("pmap_object_init_pt: invalid page %p", p));
3550 if (pa != VM_PAGE_TO_PHYS(p) ||
3551 pat_mode != p->md.pat_mode)
3552 return;
3553 p = TAILQ_NEXT(p, listq);
3554 }
3555
3556 /*
3557 * Map using 2/4MB pages. Since "ptepa" is 2/4M aligned and
3558 * "size" is a multiple of 2/4M, adding the PAT setting to
3559 * "pa" will not affect the termination of this loop.
3560 */
3561 PMAP_LOCK(pmap);
3562 for (pa = ptepa | pmap_cache_bits(pat_mode, 1); pa < ptepa +
3563 size; pa += NBPDR) {
3564 pde = pmap_pde(pmap, addr);
3565 if (*pde == 0) {
3566 pde_store(pde, pa | PG_PS | PG_M | PG_A |
3567 PG_U | PG_RW | PG_V);
3568 pmap->pm_stats.resident_count += NBPDR /
3569 PAGE_SIZE;
3570 pmap_pde_mappings++;
3571 }
3572 /* Else continue on if the PDE is already valid. */
3573 addr += NBPDR;
3574 }
3575 PMAP_UNLOCK(pmap);
3576 }
3577 }
3578
3579 /*
3580 * Routine: pmap_change_wiring
3581 * Function: Change the wiring attribute for a map/virtual-address
3582 * pair.
3583 * In/out conditions:
3584 * The mapping must already exist in the pmap.
3585 */
3586 void
3587 pmap_change_wiring(pmap_t pmap, vm_offset_t va, boolean_t wired)
3588 {
3589 pd_entry_t *pde;
3590 pt_entry_t *pte;
3591 boolean_t are_queues_locked;
3592
3593 are_queues_locked = FALSE;
3594 retry:
3595 PMAP_LOCK(pmap);
3596 pde = pmap_pde(pmap, va);
3597 if ((*pde & PG_PS) != 0) {
3598 if (!wired != ((*pde & PG_W) == 0)) {
3599 if (!are_queues_locked) {
3600 are_queues_locked = TRUE;
3601 if (!mtx_trylock(&vm_page_queue_mtx)) {
3602 PMAP_UNLOCK(pmap);
3603 vm_page_lock_queues();
3604 goto retry;
3605 }
3606 }
3607 if (!pmap_demote_pde(pmap, pde, va))
3608 panic("pmap_change_wiring: demotion failed");
3609 } else
3610 goto out;
3611 }
3612 pte = pmap_pte(pmap, va);
3613
3614 if (wired && !pmap_pte_w(pte))
3615 pmap->pm_stats.wired_count++;
3616 else if (!wired && pmap_pte_w(pte))
3617 pmap->pm_stats.wired_count--;
3618
3619 /*
3620 * Wiring is not a hardware characteristic so there is no need to
3621 * invalidate TLB.
3622 */
3623 pmap_pte_set_w(pte, wired);
3624 pmap_pte_release(pte);
3625 out:
3626 if (are_queues_locked)
3627 vm_page_unlock_queues();
3628 PMAP_UNLOCK(pmap);
3629 }
3630
3631
3632
3633 /*
3634 * Copy the range specified by src_addr/len
3635 * from the source map to the range dst_addr/len
3636 * in the destination map.
3637 *
3638 * This routine is only advisory and need not do anything.
3639 */
3640
3641 void
3642 pmap_copy(pmap_t dst_pmap, pmap_t src_pmap, vm_offset_t dst_addr, vm_size_t len,
3643 vm_offset_t src_addr)
3644 {
3645 vm_page_t free;
3646 vm_offset_t addr;
3647 vm_offset_t end_addr = src_addr + len;
3648 vm_offset_t pdnxt;
3649
3650 if (dst_addr != src_addr)
3651 return;
3652
3653 if (!pmap_is_current(src_pmap))
3654 return;
3655
3656 vm_page_lock_queues();
3657 if (dst_pmap < src_pmap) {
3658 PMAP_LOCK(dst_pmap);
3659 PMAP_LOCK(src_pmap);
3660 } else {
3661 PMAP_LOCK(src_pmap);
3662 PMAP_LOCK(dst_pmap);
3663 }
3664 sched_pin();
3665 for (addr = src_addr; addr < end_addr; addr = pdnxt) {
3666 pt_entry_t *src_pte, *dst_pte;
3667 vm_page_t dstmpte, srcmpte;
3668 pd_entry_t srcptepaddr;
3669 unsigned ptepindex;
3670
3671 KASSERT(addr < UPT_MIN_ADDRESS,
3672 ("pmap_copy: invalid to pmap_copy page tables"));
3673
3674 pdnxt = (addr + NBPDR) & ~PDRMASK;
3675 if (pdnxt < addr)
3676 pdnxt = end_addr;
3677 ptepindex = addr >> PDRSHIFT;
3678
3679 srcptepaddr = src_pmap->pm_pdir[ptepindex];
3680 if (srcptepaddr == 0)
3681 continue;
3682
3683 if (srcptepaddr & PG_PS) {
3684 if (dst_pmap->pm_pdir[ptepindex] == 0 &&
3685 ((srcptepaddr & PG_MANAGED) == 0 ||
3686 pmap_pv_insert_pde(dst_pmap, addr, srcptepaddr &
3687 PG_PS_FRAME))) {
3688 dst_pmap->pm_pdir[ptepindex] = srcptepaddr &
3689 ~PG_W;
3690 dst_pmap->pm_stats.resident_count +=
3691 NBPDR / PAGE_SIZE;
3692 }
3693 continue;
3694 }
3695
3696 srcmpte = PHYS_TO_VM_PAGE(srcptepaddr & PG_FRAME);
3697 KASSERT(srcmpte->wire_count > 0,
3698 ("pmap_copy: source page table page is unused"));
3699
3700 if (pdnxt > end_addr)
3701 pdnxt = end_addr;
3702
3703 src_pte = vtopte(addr);
3704 while (addr < pdnxt) {
3705 pt_entry_t ptetemp;
3706 ptetemp = *src_pte;
3707 /*
3708 * we only virtual copy managed pages
3709 */
3710 if ((ptetemp & PG_MANAGED) != 0) {
3711 dstmpte = pmap_allocpte(dst_pmap, addr,
3712 M_NOWAIT);
3713 if (dstmpte == NULL)
3714 goto out;
3715 dst_pte = pmap_pte_quick(dst_pmap, addr);
3716 if (*dst_pte == 0 &&
3717 pmap_try_insert_pv_entry(dst_pmap, addr,
3718 PHYS_TO_VM_PAGE(ptetemp & PG_FRAME))) {
3719 /*
3720 * Clear the wired, modified, and
3721 * accessed (referenced) bits
3722 * during the copy.
3723 */
3724 *dst_pte = ptetemp & ~(PG_W | PG_M |
3725 PG_A);
3726 dst_pmap->pm_stats.resident_count++;
3727 } else {
3728 free = NULL;
3729 if (pmap_unwire_pte_hold(dst_pmap,
3730 dstmpte, &free)) {
3731 pmap_invalidate_page(dst_pmap,
3732 addr);
3733 pmap_free_zero_pages(free);
3734 }
3735 goto out;
3736 }
3737 if (dstmpte->wire_count >= srcmpte->wire_count)
3738 break;
3739 }
3740 addr += PAGE_SIZE;
3741 src_pte++;
3742 }
3743 }
3744 out:
3745 sched_unpin();
3746 vm_page_unlock_queues();
3747 PMAP_UNLOCK(src_pmap);
3748 PMAP_UNLOCK(dst_pmap);
3749 }
3750
3751 static __inline void
3752 pagezero(void *page)
3753 {
3754 #if defined(I686_CPU)
3755 if (cpu_class == CPUCLASS_686) {
3756 #if defined(CPU_ENABLE_SSE)
3757 if (cpu_feature & CPUID_SSE2)
3758 sse2_pagezero(page);
3759 else
3760 #endif
3761 i686_pagezero(page);
3762 } else
3763 #endif
3764 bzero(page, PAGE_SIZE);
3765 }
3766
3767 /*
3768 * pmap_zero_page zeros the specified hardware page by mapping
3769 * the page into KVM and using bzero to clear its contents.
3770 */
3771 void
3772 pmap_zero_page(vm_page_t m)
3773 {
3774 struct sysmaps *sysmaps;
3775
3776 sysmaps = &sysmaps_pcpu[PCPU_GET(cpuid)];
3777 mtx_lock(&sysmaps->lock);
3778 if (*sysmaps->CMAP2)
3779 panic("pmap_zero_page: CMAP2 busy");
3780 sched_pin();
3781 *sysmaps->CMAP2 = PG_V | PG_RW | VM_PAGE_TO_PHYS(m) | PG_A | PG_M |
3782 pmap_cache_bits(m->md.pat_mode, 0);
3783 invlcaddr(sysmaps->CADDR2);
3784 pagezero(sysmaps->CADDR2);
3785 *sysmaps->CMAP2 = 0;
3786 sched_unpin();
3787 mtx_unlock(&sysmaps->lock);
3788 }
3789
3790 /*
3791 * pmap_zero_page_area zeros the specified hardware page by mapping
3792 * the page into KVM and using bzero to clear its contents.
3793 *
3794 * off and size may not cover an area beyond a single hardware page.
3795 */
3796 void
3797 pmap_zero_page_area(vm_page_t m, int off, int size)
3798 {
3799 struct sysmaps *sysmaps;
3800
3801 sysmaps = &sysmaps_pcpu[PCPU_GET(cpuid)];
3802 mtx_lock(&sysmaps->lock);
3803 if (*sysmaps->CMAP2)
3804 panic("pmap_zero_page_area: CMAP2 busy");
3805 sched_pin();
3806 *sysmaps->CMAP2 = PG_V | PG_RW | VM_PAGE_TO_PHYS(m) | PG_A | PG_M |
3807 pmap_cache_bits(m->md.pat_mode, 0);
3808 invlcaddr(sysmaps->CADDR2);
3809 if (off == 0 && size == PAGE_SIZE)
3810 pagezero(sysmaps->CADDR2);
3811 else
3812 bzero((char *)sysmaps->CADDR2 + off, size);
3813 *sysmaps->CMAP2 = 0;
3814 sched_unpin();
3815 mtx_unlock(&sysmaps->lock);
3816 }
3817
3818 /*
3819 * pmap_zero_page_idle zeros the specified hardware page by mapping
3820 * the page into KVM and using bzero to clear its contents. This
3821 * is intended to be called from the vm_pagezero process only and
3822 * outside of Giant.
3823 */
3824 void
3825 pmap_zero_page_idle(vm_page_t m)
3826 {
3827
3828 if (*CMAP3)
3829 panic("pmap_zero_page_idle: CMAP3 busy");
3830 sched_pin();
3831 *CMAP3 = PG_V | PG_RW | VM_PAGE_TO_PHYS(m) | PG_A | PG_M |
3832 pmap_cache_bits(m->md.pat_mode, 0);
3833 invlcaddr(CADDR3);
3834 pagezero(CADDR3);
3835 *CMAP3 = 0;
3836 sched_unpin();
3837 }
3838
3839 /*
3840 * pmap_copy_page copies the specified (machine independent)
3841 * page by mapping the page into virtual memory and using
3842 * bcopy to copy the page, one machine dependent page at a
3843 * time.
3844 */
3845 void
3846 pmap_copy_page(vm_page_t src, vm_page_t dst)
3847 {
3848 struct sysmaps *sysmaps;
3849
3850 sysmaps = &sysmaps_pcpu[PCPU_GET(cpuid)];
3851 mtx_lock(&sysmaps->lock);
3852 if (*sysmaps->CMAP1)
3853 panic("pmap_copy_page: CMAP1 busy");
3854 if (*sysmaps->CMAP2)
3855 panic("pmap_copy_page: CMAP2 busy");
3856 sched_pin();
3857 invlpg((u_int)sysmaps->CADDR1);
3858 invlpg((u_int)sysmaps->CADDR2);
3859 *sysmaps->CMAP1 = PG_V | VM_PAGE_TO_PHYS(src) | PG_A |
3860 pmap_cache_bits(src->md.pat_mode, 0);
3861 *sysmaps->CMAP2 = PG_V | PG_RW | VM_PAGE_TO_PHYS(dst) | PG_A | PG_M |
3862 pmap_cache_bits(dst->md.pat_mode, 0);
3863 bcopy(sysmaps->CADDR1, sysmaps->CADDR2, PAGE_SIZE);
3864 *sysmaps->CMAP1 = 0;
3865 *sysmaps->CMAP2 = 0;
3866 sched_unpin();
3867 mtx_unlock(&sysmaps->lock);
3868 }
3869
3870 /*
3871 * Returns true if the pmap's pv is one of the first
3872 * 16 pvs linked to from this page. This count may
3873 * be changed upwards or downwards in the future; it
3874 * is only necessary that true be returned for a small
3875 * subset of pmaps for proper page aging.
3876 */
3877 boolean_t
3878 pmap_page_exists_quick(pmap_t pmap, vm_page_t m)
3879 {
3880 struct md_page *pvh;
3881 pv_entry_t pv;
3882 int loops = 0;
3883
3884 if (m->flags & PG_FICTITIOUS)
3885 return FALSE;
3886
3887 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
3888 TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
3889 if (PV_PMAP(pv) == pmap) {
3890 return TRUE;
3891 }
3892 loops++;
3893 if (loops >= 16)
3894 break;
3895 }
3896 if (loops < 16) {
3897 pvh = pa_to_pvh(VM_PAGE_TO_PHYS(m));
3898 TAILQ_FOREACH(pv, &pvh->pv_list, pv_list) {
3899 if (PV_PMAP(pv) == pmap)
3900 return (TRUE);
3901 loops++;
3902 if (loops >= 16)
3903 break;
3904 }
3905 }
3906 return (FALSE);
3907 }
3908
3909 /*
3910 * pmap_page_wired_mappings:
3911 *
3912 * Return the number of managed mappings to the given physical page
3913 * that are wired.
3914 */
3915 int
3916 pmap_page_wired_mappings(vm_page_t m)
3917 {
3918 int count;
3919
3920 count = 0;
3921 if ((m->flags & PG_FICTITIOUS) != 0)
3922 return (count);
3923 count = pmap_pvh_wired_mappings(&m->md, count);
3924 return (pmap_pvh_wired_mappings(pa_to_pvh(VM_PAGE_TO_PHYS(m)), count));
3925 }
3926
3927 /*
3928 * pmap_pvh_wired_mappings:
3929 *
3930 * Return the updated number "count" of managed mappings that are wired.
3931 */
3932 static int
3933 pmap_pvh_wired_mappings(struct md_page *pvh, int count)
3934 {
3935 pmap_t pmap;
3936 pt_entry_t *pte;
3937 pv_entry_t pv;
3938
3939 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
3940 sched_pin();
3941 TAILQ_FOREACH(pv, &pvh->pv_list, pv_list) {
3942 pmap = PV_PMAP(pv);
3943 PMAP_LOCK(pmap);
3944 pte = pmap_pte_quick(pmap, pv->pv_va);
3945 if ((*pte & PG_W) != 0)
3946 count++;
3947 PMAP_UNLOCK(pmap);
3948 }
3949 sched_unpin();
3950 return (count);
3951 }
3952
3953 /*
3954 * Returns TRUE if the given page is mapped individually or as part of
3955 * a 4mpage. Otherwise, returns FALSE.
3956 */
3957 boolean_t
3958 pmap_page_is_mapped(vm_page_t m)
3959 {
3960 struct md_page *pvh;
3961
3962 if ((m->flags & (PG_FICTITIOUS | PG_UNMANAGED)) != 0)
3963 return (FALSE);
3964 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
3965 if (TAILQ_EMPTY(&m->md.pv_list)) {
3966 pvh = pa_to_pvh(VM_PAGE_TO_PHYS(m));
3967 return (!TAILQ_EMPTY(&pvh->pv_list));
3968 } else
3969 return (TRUE);
3970 }
3971
3972 /*
3973 * Remove all pages from specified address space
3974 * this aids process exit speeds. Also, this code
3975 * is special cased for current process only, but
3976 * can have the more generic (and slightly slower)
3977 * mode enabled. This is much faster than pmap_remove
3978 * in the case of running down an entire address space.
3979 */
3980 void
3981 pmap_remove_pages(pmap_t pmap)
3982 {
3983 pt_entry_t *pte, tpte;
3984 vm_page_t free = NULL;
3985 vm_page_t m, mpte, mt;
3986 pv_entry_t pv;
3987 struct md_page *pvh;
3988 struct pv_chunk *pc, *npc;
3989 int field, idx;
3990 int32_t bit;
3991 uint32_t inuse, bitmask;
3992 int allfree;
3993
3994 if (pmap != vmspace_pmap(curthread->td_proc->p_vmspace)) {
3995 printf("warning: pmap_remove_pages called with non-current pmap\n");
3996 return;
3997 }
3998 vm_page_lock_queues();
3999 PMAP_LOCK(pmap);
4000 sched_pin();
4001 TAILQ_FOREACH_SAFE(pc, &pmap->pm_pvchunk, pc_list, npc) {
4002 allfree = 1;
4003 for (field = 0; field < _NPCM; field++) {
4004 inuse = (~(pc->pc_map[field])) & pc_freemask[field];
4005 while (inuse != 0) {
4006 bit = bsfl(inuse);
4007 bitmask = 1UL << bit;
4008 idx = field * 32 + bit;
4009 pv = &pc->pc_pventry[idx];
4010 inuse &= ~bitmask;
4011
4012 pte = pmap_pde(pmap, pv->pv_va);
4013 tpte = *pte;
4014 if ((tpte & PG_PS) == 0) {
4015 pte = vtopte(pv->pv_va);
4016 tpte = *pte & ~PG_PTE_PAT;
4017 }
4018
4019 if (tpte == 0) {
4020 printf(
4021 "TPTE at %p IS ZERO @ VA %08x\n",
4022 pte, pv->pv_va);
4023 panic("bad pte");
4024 }
4025
4026 /*
4027 * We cannot remove wired pages from a process' mapping at this time
4028 */
4029 if (tpte & PG_W) {
4030 allfree = 0;
4031 continue;
4032 }
4033
4034 m = PHYS_TO_VM_PAGE(tpte & PG_FRAME);
4035 KASSERT(m->phys_addr == (tpte & PG_FRAME),
4036 ("vm_page_t %p phys_addr mismatch %016jx %016jx",
4037 m, (uintmax_t)m->phys_addr,
4038 (uintmax_t)tpte));
4039
4040 KASSERT(m < &vm_page_array[vm_page_array_size],
4041 ("pmap_remove_pages: bad tpte %#jx",
4042 (uintmax_t)tpte));
4043
4044 pte_clear(pte);
4045
4046 /*
4047 * Update the vm_page_t clean/reference bits.
4048 */
4049 if ((tpte & (PG_M | PG_RW)) == (PG_M | PG_RW)) {
4050 if ((tpte & PG_PS) != 0) {
4051 for (mt = m; mt < &m[NBPDR / PAGE_SIZE]; mt++)
4052 vm_page_dirty(mt);
4053 } else
4054 vm_page_dirty(m);
4055 }
4056
4057 /* Mark free */
4058 PV_STAT(pv_entry_frees++);
4059 PV_STAT(pv_entry_spare++);
4060 pv_entry_count--;
4061 pc->pc_map[field] |= bitmask;
4062 if ((tpte & PG_PS) != 0) {
4063 pmap->pm_stats.resident_count -= NBPDR / PAGE_SIZE;
4064 pvh = pa_to_pvh(tpte & PG_PS_FRAME);
4065 TAILQ_REMOVE(&pvh->pv_list, pv, pv_list);
4066 if (TAILQ_EMPTY(&pvh->pv_list)) {
4067 for (mt = m; mt < &m[NBPDR / PAGE_SIZE]; mt++)
4068 if (TAILQ_EMPTY(&mt->md.pv_list))
4069 vm_page_flag_clear(mt, PG_WRITEABLE);
4070 }
4071 mpte = pmap_lookup_pt_page(pmap, pv->pv_va);
4072 if (mpte != NULL) {
4073 pmap_remove_pt_page(pmap, mpte);
4074 pmap->pm_stats.resident_count--;
4075 KASSERT(mpte->wire_count == NPTEPG,
4076 ("pmap_remove_pages: pte page wire count error"));
4077 mpte->wire_count = 0;
4078 pmap_add_delayed_free_list(mpte, &free, FALSE);
4079 atomic_subtract_int(&cnt.v_wire_count, 1);
4080 }
4081 } else {
4082 pmap->pm_stats.resident_count--;
4083 TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
4084 if (TAILQ_EMPTY(&m->md.pv_list)) {
4085 pvh = pa_to_pvh(VM_PAGE_TO_PHYS(m));
4086 if (TAILQ_EMPTY(&pvh->pv_list))
4087 vm_page_flag_clear(m, PG_WRITEABLE);
4088 }
4089 pmap_unuse_pt(pmap, pv->pv_va, &free);
4090 }
4091 }
4092 }
4093 if (allfree) {
4094 PV_STAT(pv_entry_spare -= _NPCPV);
4095 PV_STAT(pc_chunk_count--);
4096 PV_STAT(pc_chunk_frees++);
4097 TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list);
4098 m = PHYS_TO_VM_PAGE(pmap_kextract((vm_offset_t)pc));
4099 pmap_qremove((vm_offset_t)pc, 1);
4100 vm_page_unwire(m, 0);
4101 vm_page_free(m);
4102 pmap_ptelist_free(&pv_vafree, (vm_offset_t)pc);
4103 }
4104 }
4105 sched_unpin();
4106 pmap_invalidate_all(pmap);
4107 vm_page_unlock_queues();
4108 PMAP_UNLOCK(pmap);
4109 pmap_free_zero_pages(free);
4110 }
4111
4112 /*
4113 * pmap_is_modified:
4114 *
4115 * Return whether or not the specified physical page was modified
4116 * in any physical maps.
4117 */
4118 boolean_t
4119 pmap_is_modified(vm_page_t m)
4120 {
4121
4122 if (m->flags & PG_FICTITIOUS)
4123 return (FALSE);
4124 if (pmap_is_modified_pvh(&m->md))
4125 return (TRUE);
4126 return (pmap_is_modified_pvh(pa_to_pvh(VM_PAGE_TO_PHYS(m))));
4127 }
4128
4129 /*
4130 * Returns TRUE if any of the given mappings were used to modify
4131 * physical memory. Otherwise, returns FALSE. Both page and 2mpage
4132 * mappings are supported.
4133 */
4134 static boolean_t
4135 pmap_is_modified_pvh(struct md_page *pvh)
4136 {
4137 pv_entry_t pv;
4138 pt_entry_t *pte;
4139 pmap_t pmap;
4140 boolean_t rv;
4141
4142 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
4143 rv = FALSE;
4144 sched_pin();
4145 TAILQ_FOREACH(pv, &pvh->pv_list, pv_list) {
4146 pmap = PV_PMAP(pv);
4147 PMAP_LOCK(pmap);
4148 pte = pmap_pte_quick(pmap, pv->pv_va);
4149 rv = (*pte & (PG_M | PG_RW)) == (PG_M | PG_RW);
4150 PMAP_UNLOCK(pmap);
4151 if (rv)
4152 break;
4153 }
4154 sched_unpin();
4155 return (rv);
4156 }
4157
4158 /*
4159 * pmap_is_prefaultable:
4160 *
4161 * Return whether or not the specified virtual address is elgible
4162 * for prefault.
4163 */
4164 boolean_t
4165 pmap_is_prefaultable(pmap_t pmap, vm_offset_t addr)
4166 {
4167 pd_entry_t *pde;
4168 pt_entry_t *pte;
4169 boolean_t rv;
4170
4171 rv = FALSE;
4172 PMAP_LOCK(pmap);
4173 pde = pmap_pde(pmap, addr);
4174 if (*pde != 0 && (*pde & PG_PS) == 0) {
4175 pte = vtopte(addr);
4176 rv = *pte == 0;
4177 }
4178 PMAP_UNLOCK(pmap);
4179 return (rv);
4180 }
4181
4182 /*
4183 * Clear the write and modified bits in each of the given page's mappings.
4184 */
4185 void
4186 pmap_remove_write(vm_page_t m)
4187 {
4188 struct md_page *pvh;
4189 pv_entry_t next_pv, pv;
4190 pmap_t pmap;
4191 pd_entry_t *pde;
4192 pt_entry_t oldpte, *pte;
4193 vm_offset_t va;
4194
4195 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
4196 if ((m->flags & PG_FICTITIOUS) != 0 ||
4197 (m->flags & PG_WRITEABLE) == 0)
4198 return;
4199 sched_pin();
4200 pvh = pa_to_pvh(VM_PAGE_TO_PHYS(m));
4201 TAILQ_FOREACH_SAFE(pv, &pvh->pv_list, pv_list, next_pv) {
4202 va = pv->pv_va;
4203 pmap = PV_PMAP(pv);
4204 PMAP_LOCK(pmap);
4205 pde = pmap_pde(pmap, va);
4206 if ((*pde & PG_RW) != 0)
4207 (void)pmap_demote_pde(pmap, pde, va);
4208 PMAP_UNLOCK(pmap);
4209 }
4210 TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
4211 pmap = PV_PMAP(pv);
4212 PMAP_LOCK(pmap);
4213 pde = pmap_pde(pmap, pv->pv_va);
4214 KASSERT((*pde & PG_PS) == 0, ("pmap_clear_write: found"
4215 " a 4mpage in page %p's pv list", m));
4216 pte = pmap_pte_quick(pmap, pv->pv_va);
4217 retry:
4218 oldpte = *pte;
4219 if ((oldpte & PG_RW) != 0) {
4220 /*
4221 * Regardless of whether a pte is 32 or 64 bits
4222 * in size, PG_RW and PG_M are among the least
4223 * significant 32 bits.
4224 */
4225 if (!atomic_cmpset_int((u_int *)pte, oldpte,
4226 oldpte & ~(PG_RW | PG_M)))
4227 goto retry;
4228 if ((oldpte & PG_M) != 0)
4229 vm_page_dirty(m);
4230 pmap_invalidate_page(pmap, pv->pv_va);
4231 }
4232 PMAP_UNLOCK(pmap);
4233 }
4234 vm_page_flag_clear(m, PG_WRITEABLE);
4235 sched_unpin();
4236 }
4237
4238 /*
4239 * pmap_ts_referenced:
4240 *
4241 * Return a count of reference bits for a page, clearing those bits.
4242 * It is not necessary for every reference bit to be cleared, but it
4243 * is necessary that 0 only be returned when there are truly no
4244 * reference bits set.
4245 *
4246 * XXX: The exact number of bits to check and clear is a matter that
4247 * should be tested and standardized at some point in the future for
4248 * optimal aging of shared pages.
4249 */
4250 int
4251 pmap_ts_referenced(vm_page_t m)
4252 {
4253 struct md_page *pvh;
4254 pv_entry_t pv, pvf, pvn;
4255 pmap_t pmap;
4256 pd_entry_t oldpde, *pde;
4257 pt_entry_t *pte;
4258 vm_offset_t va;
4259 int rtval = 0;
4260
4261 if (m->flags & PG_FICTITIOUS)
4262 return (rtval);
4263 sched_pin();
4264 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
4265 pvh = pa_to_pvh(VM_PAGE_TO_PHYS(m));
4266 TAILQ_FOREACH_SAFE(pv, &pvh->pv_list, pv_list, pvn) {
4267 va = pv->pv_va;
4268 pmap = PV_PMAP(pv);
4269 PMAP_LOCK(pmap);
4270 pde = pmap_pde(pmap, va);
4271 oldpde = *pde;
4272 if ((oldpde & PG_A) != 0) {
4273 if (pmap_demote_pde(pmap, pde, va)) {
4274 if ((oldpde & PG_W) == 0) {
4275 /*
4276 * Remove the mapping to a single page
4277 * so that a subsequent access may
4278 * repromote. Since the underlying
4279 * page table page is fully populated,
4280 * this removal never frees a page
4281 * table page.
4282 */
4283 va += VM_PAGE_TO_PHYS(m) - (oldpde &
4284 PG_PS_FRAME);
4285 pmap_remove_page(pmap, va, NULL);
4286 rtval++;
4287 if (rtval > 4) {
4288 PMAP_UNLOCK(pmap);
4289 return (rtval);
4290 }
4291 }
4292 }
4293 }
4294 PMAP_UNLOCK(pmap);
4295 }
4296 if ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) {
4297 pvf = pv;
4298 do {
4299 pvn = TAILQ_NEXT(pv, pv_list);
4300 TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
4301 TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list);
4302 pmap = PV_PMAP(pv);
4303 PMAP_LOCK(pmap);
4304 pde = pmap_pde(pmap, pv->pv_va);
4305 KASSERT((*pde & PG_PS) == 0, ("pmap_ts_referenced:"
4306 " found a 4mpage in page %p's pv list", m));
4307 pte = pmap_pte_quick(pmap, pv->pv_va);
4308 if ((*pte & PG_A) != 0) {
4309 atomic_clear_int((u_int *)pte, PG_A);
4310 pmap_invalidate_page(pmap, pv->pv_va);
4311 rtval++;
4312 if (rtval > 4)
4313 pvn = NULL;
4314 }
4315 PMAP_UNLOCK(pmap);
4316 } while ((pv = pvn) != NULL && pv != pvf);
4317 }
4318 sched_unpin();
4319 return (rtval);
4320 }
4321
4322 /*
4323 * Clear the modify bits on the specified physical page.
4324 */
4325 void
4326 pmap_clear_modify(vm_page_t m)
4327 {
4328 struct md_page *pvh;
4329 pv_entry_t next_pv, pv;
4330 pmap_t pmap;
4331 pd_entry_t oldpde, *pde;
4332 pt_entry_t oldpte, *pte;
4333 vm_offset_t va;
4334
4335 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
4336 if ((m->flags & PG_FICTITIOUS) != 0)
4337 return;
4338 sched_pin();
4339 pvh = pa_to_pvh(VM_PAGE_TO_PHYS(m));
4340 TAILQ_FOREACH_SAFE(pv, &pvh->pv_list, pv_list, next_pv) {
4341 va = pv->pv_va;
4342 pmap = PV_PMAP(pv);
4343 PMAP_LOCK(pmap);
4344 pde = pmap_pde(pmap, va);
4345 oldpde = *pde;
4346 if ((oldpde & PG_RW) != 0) {
4347 if (pmap_demote_pde(pmap, pde, va)) {
4348 if ((oldpde & PG_W) == 0) {
4349 /*
4350 * Write protect the mapping to a
4351 * single page so that a subsequent
4352 * write access may repromote.
4353 */
4354 va += VM_PAGE_TO_PHYS(m) - (oldpde &
4355 PG_PS_FRAME);
4356 pte = pmap_pte_quick(pmap, va);
4357 oldpte = *pte;
4358 if ((oldpte & PG_V) != 0) {
4359 /*
4360 * Regardless of whether a pte is 32 or 64 bits
4361 * in size, PG_RW and PG_M are among the least
4362 * significant 32 bits.
4363 */
4364 while (!atomic_cmpset_int((u_int *)pte,
4365 oldpte,
4366 oldpte & ~(PG_M | PG_RW)))
4367 oldpte = *pte;
4368 vm_page_dirty(m);
4369 pmap_invalidate_page(pmap, va);
4370 }
4371 }
4372 }
4373 }
4374 PMAP_UNLOCK(pmap);
4375 }
4376 TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
4377 pmap = PV_PMAP(pv);
4378 PMAP_LOCK(pmap);
4379 pde = pmap_pde(pmap, pv->pv_va);
4380 KASSERT((*pde & PG_PS) == 0, ("pmap_clear_modify: found"
4381 " a 4mpage in page %p's pv list", m));
4382 pte = pmap_pte_quick(pmap, pv->pv_va);
4383 if ((*pte & (PG_M | PG_RW)) == (PG_M | PG_RW)) {
4384 /*
4385 * Regardless of whether a pte is 32 or 64 bits
4386 * in size, PG_M is among the least significant
4387 * 32 bits.
4388 */
4389 atomic_clear_int((u_int *)pte, PG_M);
4390 pmap_invalidate_page(pmap, pv->pv_va);
4391 }
4392 PMAP_UNLOCK(pmap);
4393 }
4394 sched_unpin();
4395 }
4396
4397 /*
4398 * pmap_clear_reference:
4399 *
4400 * Clear the reference bit on the specified physical page.
4401 */
4402 void
4403 pmap_clear_reference(vm_page_t m)
4404 {
4405 struct md_page *pvh;
4406 pv_entry_t next_pv, pv;
4407 pmap_t pmap;
4408 pd_entry_t oldpde, *pde;
4409 pt_entry_t *pte;
4410 vm_offset_t va;
4411
4412 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
4413 if ((m->flags & PG_FICTITIOUS) != 0)
4414 return;
4415 sched_pin();
4416 pvh = pa_to_pvh(VM_PAGE_TO_PHYS(m));
4417 TAILQ_FOREACH_SAFE(pv, &pvh->pv_list, pv_list, next_pv) {
4418 va = pv->pv_va;
4419 pmap = PV_PMAP(pv);
4420 PMAP_LOCK(pmap);
4421 pde = pmap_pde(pmap, va);
4422 oldpde = *pde;
4423 if ((oldpde & PG_A) != 0) {
4424 if (pmap_demote_pde(pmap, pde, va)) {
4425 /*
4426 * Remove the mapping to a single page so
4427 * that a subsequent access may repromote.
4428 * Since the underlying page table page is
4429 * fully populated, this removal never frees
4430 * a page table page.
4431 */
4432 va += VM_PAGE_TO_PHYS(m) - (oldpde &
4433 PG_PS_FRAME);
4434 pmap_remove_page(pmap, va, NULL);
4435 }
4436 }
4437 PMAP_UNLOCK(pmap);
4438 }
4439 TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
4440 pmap = PV_PMAP(pv);
4441 PMAP_LOCK(pmap);
4442 pde = pmap_pde(pmap, pv->pv_va);
4443 KASSERT((*pde & PG_PS) == 0, ("pmap_clear_reference: found"
4444 " a 4mpage in page %p's pv list", m));
4445 pte = pmap_pte_quick(pmap, pv->pv_va);
4446 if ((*pte & PG_A) != 0) {
4447 /*
4448 * Regardless of whether a pte is 32 or 64 bits
4449 * in size, PG_A is among the least significant
4450 * 32 bits.
4451 */
4452 atomic_clear_int((u_int *)pte, PG_A);
4453 pmap_invalidate_page(pmap, pv->pv_va);
4454 }
4455 PMAP_UNLOCK(pmap);
4456 }
4457 sched_unpin();
4458 }
4459
4460 /*
4461 * Miscellaneous support routines follow
4462 */
4463
4464 /* Adjust the cache mode for a 4KB page mapped via a PTE. */
4465 static __inline void
4466 pmap_pte_attr(pt_entry_t *pte, int cache_bits)
4467 {
4468 u_int opte, npte;
4469
4470 /*
4471 * The cache mode bits are all in the low 32-bits of the
4472 * PTE, so we can just spin on updating the low 32-bits.
4473 */
4474 do {
4475 opte = *(u_int *)pte;
4476 npte = opte & ~PG_PTE_CACHE;
4477 npte |= cache_bits;
4478 } while (npte != opte && !atomic_cmpset_int((u_int *)pte, opte, npte));
4479 }
4480
4481 /* Adjust the cache mode for a 2/4MB page mapped via a PDE. */
4482 static __inline void
4483 pmap_pde_attr(pd_entry_t *pde, int cache_bits)
4484 {
4485 u_int opde, npde;
4486
4487 /*
4488 * The cache mode bits are all in the low 32-bits of the
4489 * PDE, so we can just spin on updating the low 32-bits.
4490 */
4491 do {
4492 opde = *(u_int *)pde;
4493 npde = opde & ~PG_PDE_CACHE;
4494 npde |= cache_bits;
4495 } while (npde != opde && !atomic_cmpset_int((u_int *)pde, opde, npde));
4496 }
4497
4498 /*
4499 * Map a set of physical memory pages into the kernel virtual
4500 * address space. Return a pointer to where it is mapped. This
4501 * routine is intended to be used for mapping device memory,
4502 * NOT real memory.
4503 */
4504 void *
4505 pmap_mapdev_attr(vm_paddr_t pa, vm_size_t size, int mode)
4506 {
4507 vm_offset_t va, offset;
4508 vm_size_t tmpsize;
4509
4510 offset = pa & PAGE_MASK;
4511 size = roundup(offset + size, PAGE_SIZE);
4512 pa = pa & PG_FRAME;
4513
4514 if (pa < KERNLOAD && pa + size <= KERNLOAD)
4515 va = KERNBASE + pa;
4516 else
4517 va = kmem_alloc_nofault(kernel_map, size);
4518 if (!va)
4519 panic("pmap_mapdev: Couldn't alloc kernel virtual memory");
4520
4521 for (tmpsize = 0; tmpsize < size; tmpsize += PAGE_SIZE)
4522 pmap_kenter_attr(va + tmpsize, pa + tmpsize, mode);
4523 pmap_invalidate_range(kernel_pmap, va, va + tmpsize);
4524 pmap_invalidate_cache_range(va, va + size);
4525 return ((void *)(va + offset));
4526 }
4527
4528 void *
4529 pmap_mapdev(vm_paddr_t pa, vm_size_t size)
4530 {
4531
4532 return (pmap_mapdev_attr(pa, size, PAT_UNCACHEABLE));
4533 }
4534
4535 void *
4536 pmap_mapbios(vm_paddr_t pa, vm_size_t size)
4537 {
4538
4539 return (pmap_mapdev_attr(pa, size, PAT_WRITE_BACK));
4540 }
4541
4542 void
4543 pmap_unmapdev(vm_offset_t va, vm_size_t size)
4544 {
4545 vm_offset_t base, offset, tmpva;
4546
4547 if (va >= KERNBASE && va + size <= KERNBASE + KERNLOAD)
4548 return;
4549 base = trunc_page(va);
4550 offset = va & PAGE_MASK;
4551 size = roundup(offset + size, PAGE_SIZE);
4552 for (tmpva = base; tmpva < (base + size); tmpva += PAGE_SIZE)
4553 pmap_kremove(tmpva);
4554 pmap_invalidate_range(kernel_pmap, va, tmpva);
4555 kmem_free(kernel_map, base, size);
4556 }
4557
4558 /*
4559 * Sets the memory attribute for the specified page.
4560 */
4561 void
4562 pmap_page_set_memattr(vm_page_t m, vm_memattr_t ma)
4563 {
4564 struct sysmaps *sysmaps;
4565 vm_offset_t sva, eva;
4566
4567 m->md.pat_mode = ma;
4568 if ((m->flags & PG_FICTITIOUS) != 0)
4569 return;
4570
4571 /*
4572 * If "m" is a normal page, flush it from the cache.
4573 * See pmap_invalidate_cache_range().
4574 *
4575 * First, try to find an existing mapping of the page by sf
4576 * buffer. sf_buf_invalidate_cache() modifies mapping and
4577 * flushes the cache.
4578 */
4579 if (sf_buf_invalidate_cache(m))
4580 return;
4581
4582 /*
4583 * If page is not mapped by sf buffer, but CPU does not
4584 * support self snoop, map the page transient and do
4585 * invalidation. In the worst case, whole cache is flushed by
4586 * pmap_invalidate_cache_range().
4587 */
4588 if ((cpu_feature & (CPUID_SS|CPUID_CLFSH)) == CPUID_CLFSH) {
4589 sysmaps = &sysmaps_pcpu[PCPU_GET(cpuid)];
4590 mtx_lock(&sysmaps->lock);
4591 if (*sysmaps->CMAP2)
4592 panic("pmap_page_set_memattr: CMAP2 busy");
4593 sched_pin();
4594 *sysmaps->CMAP2 = PG_V | PG_RW | VM_PAGE_TO_PHYS(m) |
4595 PG_A | PG_M | pmap_cache_bits(m->md.pat_mode, 0);
4596 invlcaddr(sysmaps->CADDR2);
4597 sva = (vm_offset_t)sysmaps->CADDR2;
4598 eva = sva + PAGE_SIZE;
4599 } else
4600 sva = eva = 0; /* gcc */
4601 pmap_invalidate_cache_range(sva, eva);
4602 if (sva != 0) {
4603 *sysmaps->CMAP2 = 0;
4604 sched_unpin();
4605 mtx_unlock(&sysmaps->lock);
4606 }
4607 }
4608
4609 /*
4610 * Changes the specified virtual address range's memory type to that given by
4611 * the parameter "mode". The specified virtual address range must be
4612 * completely contained within either the kernel map.
4613 *
4614 * Returns zero if the change completed successfully, and either EINVAL or
4615 * ENOMEM if the change failed. Specifically, EINVAL is returned if some part
4616 * of the virtual address range was not mapped, and ENOMEM is returned if
4617 * there was insufficient memory available to complete the change.
4618 */
4619 int
4620 pmap_change_attr(vm_offset_t va, vm_size_t size, int mode)
4621 {
4622 vm_offset_t base, offset, tmpva;
4623 pd_entry_t *pde;
4624 pt_entry_t *pte;
4625 int cache_bits_pte, cache_bits_pde;
4626 boolean_t changed;
4627
4628 base = trunc_page(va);
4629 offset = va & PAGE_MASK;
4630 size = roundup(offset + size, PAGE_SIZE);
4631
4632 /*
4633 * Only supported on kernel virtual addresses above the recursive map.
4634 */
4635 if (base < VM_MIN_KERNEL_ADDRESS)
4636 return (EINVAL);
4637
4638 cache_bits_pde = pmap_cache_bits(mode, 1);
4639 cache_bits_pte = pmap_cache_bits(mode, 0);
4640 changed = FALSE;
4641
4642 /*
4643 * Pages that aren't mapped aren't supported. Also break down
4644 * 2/4MB pages into 4KB pages if required.
4645 */
4646 PMAP_LOCK(kernel_pmap);
4647 for (tmpva = base; tmpva < base + size; ) {
4648 pde = pmap_pde(kernel_pmap, tmpva);
4649 if (*pde == 0) {
4650 PMAP_UNLOCK(kernel_pmap);
4651 return (EINVAL);
4652 }
4653 if (*pde & PG_PS) {
4654 /*
4655 * If the current 2/4MB page already has
4656 * the required memory type, then we need not
4657 * demote this page. Just increment tmpva to
4658 * the next 2/4MB page frame.
4659 */
4660 if ((*pde & PG_PDE_CACHE) == cache_bits_pde) {
4661 tmpva = trunc_4mpage(tmpva) + NBPDR;
4662 continue;
4663 }
4664
4665 /*
4666 * If the current offset aligns with a 2/4MB
4667 * page frame and there is at least 2/4MB left
4668 * within the range, then we need not break
4669 * down this page into 4KB pages.
4670 */
4671 if ((tmpva & PDRMASK) == 0 &&
4672 tmpva + PDRMASK < base + size) {
4673 tmpva += NBPDR;
4674 continue;
4675 }
4676 if (!pmap_demote_pde(kernel_pmap, pde, tmpva)) {
4677 PMAP_UNLOCK(kernel_pmap);
4678 return (ENOMEM);
4679 }
4680 }
4681 pte = vtopte(tmpva);
4682 if (*pte == 0) {
4683 PMAP_UNLOCK(kernel_pmap);
4684 return (EINVAL);
4685 }
4686 tmpva += PAGE_SIZE;
4687 }
4688 PMAP_UNLOCK(kernel_pmap);
4689
4690 /*
4691 * Ok, all the pages exist, so run through them updating their
4692 * cache mode if required.
4693 */
4694 for (tmpva = base; tmpva < base + size; ) {
4695 pde = pmap_pde(kernel_pmap, tmpva);
4696 if (*pde & PG_PS) {
4697 if ((*pde & PG_PDE_CACHE) != cache_bits_pde) {
4698 pmap_pde_attr(pde, cache_bits_pde);
4699 changed = TRUE;
4700 }
4701 tmpva = trunc_4mpage(tmpva) + NBPDR;
4702 } else {
4703 pte = vtopte(tmpva);
4704 if ((*pte & PG_PTE_CACHE) != cache_bits_pte) {
4705 pmap_pte_attr(pte, cache_bits_pte);
4706 changed = TRUE;
4707 }
4708 tmpva += PAGE_SIZE;
4709 }
4710 }
4711
4712 /*
4713 * Flush CPU caches to make sure any data isn't cached that
4714 * shouldn't be, etc.
4715 */
4716 if (changed) {
4717 pmap_invalidate_range(kernel_pmap, base, tmpva);
4718 pmap_invalidate_cache_range(base, tmpva);
4719 }
4720 return (0);
4721 }
4722
4723 /*
4724 * perform the pmap work for mincore
4725 */
4726 int
4727 pmap_mincore(pmap_t pmap, vm_offset_t addr)
4728 {
4729 pd_entry_t *pdep;
4730 pt_entry_t *ptep, pte;
4731 vm_paddr_t pa;
4732 vm_page_t m;
4733 int val = 0;
4734
4735 PMAP_LOCK(pmap);
4736 pdep = pmap_pde(pmap, addr);
4737 if (*pdep != 0) {
4738 if (*pdep & PG_PS) {
4739 pte = *pdep;
4740 val = MINCORE_SUPER;
4741 /* Compute the physical address of the 4KB page. */
4742 pa = ((*pdep & PG_PS_FRAME) | (addr & PDRMASK)) &
4743 PG_FRAME;
4744 } else {
4745 ptep = pmap_pte(pmap, addr);
4746 pte = *ptep;
4747 pmap_pte_release(ptep);
4748 pa = pte & PG_FRAME;
4749 }
4750 } else {
4751 pte = 0;
4752 pa = 0;
4753 }
4754 PMAP_UNLOCK(pmap);
4755
4756 if (pte != 0) {
4757 val |= MINCORE_INCORE;
4758 if ((pte & PG_MANAGED) == 0)
4759 return val;
4760
4761 m = PHYS_TO_VM_PAGE(pa);
4762
4763 /*
4764 * Modified by us
4765 */
4766 if ((pte & (PG_M | PG_RW)) == (PG_M | PG_RW))
4767 val |= MINCORE_MODIFIED|MINCORE_MODIFIED_OTHER;
4768 else {
4769 /*
4770 * Modified by someone else
4771 */
4772 vm_page_lock_queues();
4773 if (m->dirty || pmap_is_modified(m))
4774 val |= MINCORE_MODIFIED_OTHER;
4775 vm_page_unlock_queues();
4776 }
4777 /*
4778 * Referenced by us
4779 */
4780 if (pte & PG_A)
4781 val |= MINCORE_REFERENCED|MINCORE_REFERENCED_OTHER;
4782 else {
4783 /*
4784 * Referenced by someone else
4785 */
4786 vm_page_lock_queues();
4787 if ((m->flags & PG_REFERENCED) ||
4788 pmap_ts_referenced(m)) {
4789 val |= MINCORE_REFERENCED_OTHER;
4790 vm_page_flag_set(m, PG_REFERENCED);
4791 }
4792 vm_page_unlock_queues();
4793 }
4794 }
4795 return val;
4796 }
4797
4798 void
4799 pmap_activate(struct thread *td)
4800 {
4801 pmap_t pmap, oldpmap;
4802 u_int32_t cr3;
4803
4804 critical_enter();
4805 pmap = vmspace_pmap(td->td_proc->p_vmspace);
4806 oldpmap = PCPU_GET(curpmap);
4807 #if defined(SMP)
4808 atomic_clear_int(&oldpmap->pm_active, PCPU_GET(cpumask));
4809 atomic_set_int(&pmap->pm_active, PCPU_GET(cpumask));
4810 #else
4811 oldpmap->pm_active &= ~1;
4812 pmap->pm_active |= 1;
4813 #endif
4814 #ifdef PAE
4815 cr3 = vtophys(pmap->pm_pdpt);
4816 #else
4817 cr3 = vtophys(pmap->pm_pdir);
4818 #endif
4819 /*
4820 * pmap_activate is for the current thread on the current cpu
4821 */
4822 td->td_pcb->pcb_cr3 = cr3;
4823 load_cr3(cr3);
4824 PCPU_SET(curpmap, pmap);
4825 critical_exit();
4826 }
4827
4828 /*
4829 * Increase the starting virtual address of the given mapping if a
4830 * different alignment might result in more superpage mappings.
4831 */
4832 void
4833 pmap_align_superpage(vm_object_t object, vm_ooffset_t offset,
4834 vm_offset_t *addr, vm_size_t size)
4835 {
4836 vm_offset_t superpage_offset;
4837
4838 if (size < NBPDR)
4839 return;
4840 if (object != NULL && (object->flags & OBJ_COLORED) != 0)
4841 offset += ptoa(object->pg_color);
4842 superpage_offset = offset & PDRMASK;
4843 if (size - ((NBPDR - superpage_offset) & PDRMASK) < NBPDR ||
4844 (*addr & PDRMASK) == superpage_offset)
4845 return;
4846 if ((*addr & PDRMASK) < superpage_offset)
4847 *addr = (*addr & ~PDRMASK) + superpage_offset;
4848 else
4849 *addr = ((*addr + PDRMASK) & ~PDRMASK) + superpage_offset;
4850 }
4851
4852
4853 #if defined(PMAP_DEBUG)
4854 pmap_pid_dump(int pid)
4855 {
4856 pmap_t pmap;
4857 struct proc *p;
4858 int npte = 0;
4859 int index;
4860
4861 sx_slock(&allproc_lock);
4862 FOREACH_PROC_IN_SYSTEM(p) {
4863 if (p->p_pid != pid)
4864 continue;
4865
4866 if (p->p_vmspace) {
4867 int i,j;
4868 index = 0;
4869 pmap = vmspace_pmap(p->p_vmspace);
4870 for (i = 0; i < NPDEPTD; i++) {
4871 pd_entry_t *pde;
4872 pt_entry_t *pte;
4873 vm_offset_t base = i << PDRSHIFT;
4874
4875 pde = &pmap->pm_pdir[i];
4876 if (pde && pmap_pde_v(pde)) {
4877 for (j = 0; j < NPTEPG; j++) {
4878 vm_offset_t va = base + (j << PAGE_SHIFT);
4879 if (va >= (vm_offset_t) VM_MIN_KERNEL_ADDRESS) {
4880 if (index) {
4881 index = 0;
4882 printf("\n");
4883 }
4884 sx_sunlock(&allproc_lock);
4885 return npte;
4886 }
4887 pte = pmap_pte(pmap, va);
4888 if (pte && pmap_pte_v(pte)) {
4889 pt_entry_t pa;
4890 vm_page_t m;
4891 pa = *pte;
4892 m = PHYS_TO_VM_PAGE(pa & PG_FRAME);
4893 printf("va: 0x%x, pt: 0x%x, h: %d, w: %d, f: 0x%x",
4894 va, pa, m->hold_count, m->wire_count, m->flags);
4895 npte++;
4896 index++;
4897 if (index >= 2) {
4898 index = 0;
4899 printf("\n");
4900 } else {
4901 printf(" ");
4902 }
4903 }
4904 }
4905 }
4906 }
4907 }
4908 }
4909 sx_sunlock(&allproc_lock);
4910 return npte;
4911 }
4912 #endif
4913
4914 #if defined(DEBUG)
4915
4916 static void pads(pmap_t pm);
4917 void pmap_pvdump(vm_offset_t pa);
4918
4919 /* print address space of pmap*/
4920 static void
4921 pads(pmap_t pm)
4922 {
4923 int i, j;
4924 vm_paddr_t va;
4925 pt_entry_t *ptep;
4926
4927 if (pm == kernel_pmap)
4928 return;
4929 for (i = 0; i < NPDEPTD; i++)
4930 if (pm->pm_pdir[i])
4931 for (j = 0; j < NPTEPG; j++) {
4932 va = (i << PDRSHIFT) + (j << PAGE_SHIFT);
4933 if (pm == kernel_pmap && va < KERNBASE)
4934 continue;
4935 if (pm != kernel_pmap && va > UPT_MAX_ADDRESS)
4936 continue;
4937 ptep = pmap_pte(pm, va);
4938 if (pmap_pte_v(ptep))
4939 printf("%x:%x ", va, *ptep);
4940 };
4941
4942 }
4943
4944 void
4945 pmap_pvdump(vm_paddr_t pa)
4946 {
4947 pv_entry_t pv;
4948 pmap_t pmap;
4949 vm_page_t m;
4950
4951 printf("pa %x", pa);
4952 m = PHYS_TO_VM_PAGE(pa);
4953 TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
4954 pmap = PV_PMAP(pv);
4955 printf(" -> pmap %p, va %x", (void *)pmap, pv->pv_va);
4956 pads(pmap);
4957 }
4958 printf(" ");
4959 }
4960 #endif
Cache object: 85af363e8a8b52b42c0627e365b947bc
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