1 /*-
2 * Copyright (c) 1982, 1986 The Regents of the University of California.
3 * Copyright (c) 1989, 1990 William Jolitz
4 * Copyright (c) 1994 John Dyson
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * the Systems Programming Group of the University of Utah Computer
9 * Science Department, and William Jolitz.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the University of
22 * California, Berkeley and its contributors.
23 * 4. Neither the name of the University nor the names of its contributors
24 * may be used to endorse or promote products derived from this software
25 * without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 *
39 * from: @(#)vm_machdep.c 7.3 (Berkeley) 5/13/91
40 * Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
41 */
42
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD: releng/6.3/sys/i386/i386/vm_machdep.c 173886 2007-11-24 19:45:58Z cvs2svn $");
45
46 #include "opt_isa.h"
47 #include "opt_npx.h"
48 #include "opt_reset.h"
49 #include "opt_cpu.h"
50 #include "opt_xbox.h"
51
52 #include <sys/param.h>
53 #include <sys/systm.h>
54 #include <sys/bio.h>
55 #include <sys/buf.h>
56 #include <sys/kse.h>
57 #include <sys/kernel.h>
58 #include <sys/ktr.h>
59 #include <sys/lock.h>
60 #include <sys/malloc.h>
61 #include <sys/mbuf.h>
62 #include <sys/mutex.h>
63 #include <sys/pioctl.h>
64 #include <sys/proc.h>
65 #include <sys/sf_buf.h>
66 #include <sys/smp.h>
67 #include <sys/sched.h>
68 #include <sys/sysctl.h>
69 #include <sys/unistd.h>
70 #include <sys/vnode.h>
71 #include <sys/vmmeter.h>
72
73 #include <machine/cpu.h>
74 #include <machine/cputypes.h>
75 #include <machine/md_var.h>
76 #include <machine/pcb.h>
77 #include <machine/pcb_ext.h>
78 #include <machine/smp.h>
79 #include <machine/vm86.h>
80
81 #ifdef CPU_ELAN
82 #include <machine/elan_mmcr.h>
83 #endif
84
85 #include <vm/vm.h>
86 #include <vm/vm_extern.h>
87 #include <vm/vm_kern.h>
88 #include <vm/vm_page.h>
89 #include <vm/vm_map.h>
90 #include <vm/vm_param.h>
91
92 #ifdef PC98
93 #include <pc98/cbus/cbus.h>
94 #else
95 #include <i386/isa/isa.h>
96 #endif
97
98 #ifdef XBOX
99 #include <machine/xbox.h>
100 #endif
101
102 #ifndef NSFBUFS
103 #define NSFBUFS (512 + maxusers * 16)
104 #endif
105
106 static void cpu_reset_real(void);
107 #ifdef SMP
108 static void cpu_reset_proxy(void);
109 static u_int cpu_reset_proxyid;
110 static volatile u_int cpu_reset_proxy_active;
111 #endif
112 static void sf_buf_init(void *arg);
113 SYSINIT(sock_sf, SI_SUB_MBUF, SI_ORDER_ANY, sf_buf_init, NULL)
114
115 LIST_HEAD(sf_head, sf_buf);
116
117 /*
118 * A hash table of active sendfile(2) buffers
119 */
120 static struct sf_head *sf_buf_active;
121 static u_long sf_buf_hashmask;
122
123 #define SF_BUF_HASH(m) (((m) - vm_page_array) & sf_buf_hashmask)
124
125 static TAILQ_HEAD(, sf_buf) sf_buf_freelist;
126 static u_int sf_buf_alloc_want;
127
128 /*
129 * A lock used to synchronize access to the hash table and free list
130 */
131 static struct mtx sf_buf_lock;
132
133 extern int _ucodesel, _udatasel;
134
135 /*
136 * Finish a fork operation, with process p2 nearly set up.
137 * Copy and update the pcb, set up the stack so that the child
138 * ready to run and return to user mode.
139 */
140 void
141 cpu_fork(td1, p2, td2, flags)
142 register struct thread *td1;
143 register struct proc *p2;
144 struct thread *td2;
145 int flags;
146 {
147 register struct proc *p1;
148 struct pcb *pcb2;
149 struct mdproc *mdp2;
150 #ifdef DEV_NPX
151 register_t savecrit;
152 #endif
153
154 p1 = td1->td_proc;
155 if ((flags & RFPROC) == 0) {
156 if ((flags & RFMEM) == 0) {
157 /* unshare user LDT */
158 struct mdproc *mdp1 = &p1->p_md;
159 struct proc_ldt *pldt;
160
161 pldt = mdp1->md_ldt;
162 if (pldt && pldt->ldt_refcnt > 1) {
163 pldt = user_ldt_alloc(mdp1, pldt->ldt_len);
164 if (pldt == NULL)
165 panic("could not copy LDT");
166 mdp1->md_ldt = pldt;
167 set_user_ldt(mdp1);
168 user_ldt_free(td1);
169 }
170 }
171 return;
172 }
173
174 /* Ensure that p1's pcb is up to date. */
175 #ifdef DEV_NPX
176 if (td1 == curthread)
177 td1->td_pcb->pcb_gs = rgs();
178 savecrit = intr_disable();
179 if (PCPU_GET(fpcurthread) == td1)
180 npxsave(&td1->td_pcb->pcb_save);
181 intr_restore(savecrit);
182 #endif
183
184 /* Point the pcb to the top of the stack */
185 pcb2 = (struct pcb *)(td2->td_kstack +
186 td2->td_kstack_pages * PAGE_SIZE) - 1;
187 td2->td_pcb = pcb2;
188
189 /* Copy p1's pcb */
190 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2));
191
192 /* Point mdproc and then copy over td1's contents */
193 mdp2 = &p2->p_md;
194 bcopy(&p1->p_md, mdp2, sizeof(*mdp2));
195
196 /*
197 * Create a new fresh stack for the new process.
198 * Copy the trap frame for the return to user mode as if from a
199 * syscall. This copies most of the user mode register values.
200 * The -16 is so we can expand the trapframe if we go to vm86.
201 */
202 td2->td_frame = (struct trapframe *)((caddr_t)td2->td_pcb - 16) - 1;
203 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe));
204
205 td2->td_frame->tf_eax = 0; /* Child returns zero */
206 td2->td_frame->tf_eflags &= ~PSL_C; /* success */
207 td2->td_frame->tf_edx = 1;
208
209 /*
210 * If the parent process has the trap bit set (i.e. a debugger had
211 * single stepped the process to the system call), we need to clear
212 * the trap flag from the new frame unless the debugger had set PF_FORK
213 * on the parent. Otherwise, the child will receive a (likely
214 * unexpected) SIGTRAP when it executes the first instruction after
215 * returning to userland.
216 */
217 if ((p1->p_pfsflags & PF_FORK) == 0)
218 td2->td_frame->tf_eflags &= ~PSL_T;
219
220 /*
221 * Set registers for trampoline to user mode. Leave space for the
222 * return address on stack. These are the kernel mode register values.
223 */
224 #ifdef PAE
225 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdpt);
226 #else
227 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdir);
228 #endif
229 pcb2->pcb_edi = 0;
230 pcb2->pcb_esi = (int)fork_return; /* fork_trampoline argument */
231 pcb2->pcb_ebp = 0;
232 pcb2->pcb_esp = (int)td2->td_frame - sizeof(void *);
233 pcb2->pcb_ebx = (int)td2; /* fork_trampoline argument */
234 pcb2->pcb_eip = (int)fork_trampoline;
235 pcb2->pcb_psl = PSL_KERNEL; /* ints disabled */
236 pcb2->pcb_gs = rgs();
237 /*-
238 * pcb2->pcb_dr*: cloned above.
239 * pcb2->pcb_savefpu: cloned above.
240 * pcb2->pcb_flags: cloned above.
241 * pcb2->pcb_onfault: cloned above (always NULL here?).
242 * pcb2->pcb_gs: cloned above.
243 * pcb2->pcb_ext: cleared below.
244 */
245
246 /*
247 * XXX don't copy the i/o pages. this should probably be fixed.
248 */
249 pcb2->pcb_ext = 0;
250
251 /* Copy the LDT, if necessary. */
252 mtx_lock_spin(&sched_lock);
253 if (mdp2->md_ldt != NULL) {
254 if (flags & RFMEM) {
255 mdp2->md_ldt->ldt_refcnt++;
256 } else {
257 mdp2->md_ldt = user_ldt_alloc(mdp2,
258 mdp2->md_ldt->ldt_len);
259 if (mdp2->md_ldt == NULL)
260 panic("could not copy LDT");
261 }
262 }
263 mtx_unlock_spin(&sched_lock);
264
265 /* Setup to release sched_lock in fork_exit(). */
266 td2->td_md.md_spinlock_count = 1;
267 td2->td_md.md_saved_flags = PSL_KERNEL | PSL_I;
268
269 /*
270 * Now, cpu_switch() can schedule the new process.
271 * pcb_esp is loaded pointing to the cpu_switch() stack frame
272 * containing the return address when exiting cpu_switch.
273 * This will normally be to fork_trampoline(), which will have
274 * %ebx loaded with the new proc's pointer. fork_trampoline()
275 * will set up a stack to call fork_return(p, frame); to complete
276 * the return to user-mode.
277 */
278 }
279
280 /*
281 * Intercept the return address from a freshly forked process that has NOT
282 * been scheduled yet.
283 *
284 * This is needed to make kernel threads stay in kernel mode.
285 */
286 void
287 cpu_set_fork_handler(td, func, arg)
288 struct thread *td;
289 void (*func)(void *);
290 void *arg;
291 {
292 /*
293 * Note that the trap frame follows the args, so the function
294 * is really called like this: func(arg, frame);
295 */
296 td->td_pcb->pcb_esi = (int) func; /* function */
297 td->td_pcb->pcb_ebx = (int) arg; /* first arg */
298 }
299
300 void
301 cpu_exit(struct thread *td)
302 {
303
304 /*
305 * If this process has a custom LDT, release it. Reset pc->pcb_gs
306 * and %gs before we free it in case they refer to an LDT entry.
307 */
308 if (td->td_proc->p_md.md_ldt) {
309 td->td_pcb->pcb_gs = _udatasel;
310 load_gs(_udatasel);
311 user_ldt_free(td);
312 }
313 }
314
315 void
316 cpu_thread_exit(struct thread *td)
317 {
318
319 #ifdef DEV_NPX
320 if (td == PCPU_GET(fpcurthread))
321 npxdrop();
322 #endif
323
324 /* Disable any hardware breakpoints. */
325 if (td->td_pcb->pcb_flags & PCB_DBREGS) {
326 reset_dbregs();
327 td->td_pcb->pcb_flags &= ~PCB_DBREGS;
328 }
329 }
330
331 void
332 cpu_thread_clean(struct thread *td)
333 {
334 struct pcb *pcb;
335
336 pcb = td->td_pcb;
337 if (pcb->pcb_ext != NULL) {
338 /* XXXKSE XXXSMP not SMP SAFE.. what locks do we have? */
339 /* if (pcb->pcb_ext->ext_refcount-- == 1) ?? */
340 /*
341 * XXX do we need to move the TSS off the allocated pages
342 * before freeing them? (not done here)
343 */
344 kmem_free(kernel_map, (vm_offset_t)pcb->pcb_ext,
345 ctob(IOPAGES + 1));
346 pcb->pcb_ext = NULL;
347 }
348 }
349
350 void
351 cpu_thread_swapin(struct thread *td)
352 {
353 }
354
355 void
356 cpu_thread_swapout(struct thread *td)
357 {
358 }
359
360 void
361 cpu_thread_setup(struct thread *td)
362 {
363
364 td->td_pcb = (struct pcb *)(td->td_kstack +
365 td->td_kstack_pages * PAGE_SIZE) - 1;
366 td->td_frame = (struct trapframe *)((caddr_t)td->td_pcb - 16) - 1;
367 td->td_pcb->pcb_ext = NULL;
368 }
369
370 /*
371 * Initialize machine state (pcb and trap frame) for a new thread about to
372 * upcall. Put enough state in the new thread's PCB to get it to go back
373 * userret(), where we can intercept it again to set the return (upcall)
374 * Address and stack, along with those from upcals that are from other sources
375 * such as those generated in thread_userret() itself.
376 */
377 void
378 cpu_set_upcall(struct thread *td, struct thread *td0)
379 {
380 struct pcb *pcb2;
381
382 /* Point the pcb to the top of the stack. */
383 pcb2 = td->td_pcb;
384
385 /*
386 * Copy the upcall pcb. This loads kernel regs.
387 * Those not loaded individually below get their default
388 * values here.
389 *
390 * XXXKSE It might be a good idea to simply skip this as
391 * the values of the other registers may be unimportant.
392 * This would remove any requirement for knowing the KSE
393 * at this time (see the matching comment below for
394 * more analysis) (need a good safe default).
395 */
396 bcopy(td0->td_pcb, pcb2, sizeof(*pcb2));
397 pcb2->pcb_flags &= ~(PCB_NPXTRAP|PCB_NPXINITDONE);
398
399 /*
400 * Create a new fresh stack for the new thread.
401 * The -16 is so we can expand the trapframe if we go to vm86.
402 * Don't forget to set this stack value into whatever supplies
403 * the address for the fault handlers.
404 * The contexts are filled in at the time we actually DO the
405 * upcall as only then do we know which KSE we got.
406 */
407 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe));
408
409 /*
410 * Set registers for trampoline to user mode. Leave space for the
411 * return address on stack. These are the kernel mode register values.
412 */
413 #ifdef PAE
414 pcb2->pcb_cr3 = vtophys(vmspace_pmap(td->td_proc->p_vmspace)->pm_pdpt);
415 #else
416 pcb2->pcb_cr3 = vtophys(vmspace_pmap(td->td_proc->p_vmspace)->pm_pdir);
417 #endif
418 pcb2->pcb_edi = 0;
419 pcb2->pcb_esi = (int)fork_return; /* trampoline arg */
420 pcb2->pcb_ebp = 0;
421 pcb2->pcb_esp = (int)td->td_frame - sizeof(void *); /* trampoline arg */
422 pcb2->pcb_ebx = (int)td; /* trampoline arg */
423 pcb2->pcb_eip = (int)fork_trampoline;
424 pcb2->pcb_psl &= ~(PSL_I); /* interrupts must be disabled */
425 pcb2->pcb_gs = rgs();
426 /*
427 * If we didn't copy the pcb, we'd need to do the following registers:
428 * pcb2->pcb_dr*: cloned above.
429 * pcb2->pcb_savefpu: cloned above.
430 * pcb2->pcb_flags: cloned above.
431 * pcb2->pcb_onfault: cloned above (always NULL here?).
432 * pcb2->pcb_gs: cloned above. XXXKSE ???
433 * pcb2->pcb_ext: cleared below.
434 */
435 pcb2->pcb_ext = NULL;
436
437 /* Setup to release sched_lock in fork_exit(). */
438 td->td_md.md_spinlock_count = 1;
439 td->td_md.md_saved_flags = PSL_KERNEL | PSL_I;
440 }
441
442 /*
443 * Set that machine state for performing an upcall that has to
444 * be done in thread_userret() so that those upcalls generated
445 * in thread_userret() itself can be done as well.
446 */
447 void
448 cpu_set_upcall_kse(struct thread *td, void (*entry)(void *), void *arg,
449 stack_t *stack)
450 {
451
452 /*
453 * Do any extra cleaning that needs to be done.
454 * The thread may have optional components
455 * that are not present in a fresh thread.
456 * This may be a recycled thread so make it look
457 * as though it's newly allocated.
458 */
459 cpu_thread_clean(td);
460
461 /*
462 * Set the trap frame to point at the beginning of the uts
463 * function.
464 */
465 td->td_frame->tf_ebp = 0;
466 td->td_frame->tf_esp =
467 (((int)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4;
468 td->td_frame->tf_eip = (int)entry;
469
470 /*
471 * Pass the address of the mailbox for this kse to the uts
472 * function as a parameter on the stack.
473 */
474 suword((void *)(td->td_frame->tf_esp + sizeof(void *)),
475 (int)arg);
476 }
477
478 int
479 cpu_set_user_tls(struct thread *td, void *tls_base)
480 {
481 struct segment_descriptor sd;
482 uint32_t base;
483
484 /*
485 * Construct a descriptor and store it in the pcb for
486 * the next context switch. Also store it in the gdt
487 * so that the load of tf_fs into %fs will activate it
488 * at return to userland.
489 */
490 base = (uint32_t)tls_base;
491 sd.sd_lobase = base & 0xffffff;
492 sd.sd_hibase = (base >> 24) & 0xff;
493 sd.sd_lolimit = 0xffff; /* 4GB limit, wraps around */
494 sd.sd_hilimit = 0xf;
495 sd.sd_type = SDT_MEMRWA;
496 sd.sd_dpl = SEL_UPL;
497 sd.sd_p = 1;
498 sd.sd_xx = 0;
499 sd.sd_def32 = 1;
500 sd.sd_gran = 1;
501 critical_enter();
502 /* set %gs */
503 td->td_pcb->pcb_gsd = sd;
504 if (td == curthread) {
505 PCPU_GET(fsgs_gdt)[1] = sd;
506 load_gs(GSEL(GUGS_SEL, SEL_UPL));
507 }
508 critical_exit();
509 return (0);
510 }
511
512 /*
513 * Convert kernel VA to physical address
514 */
515 vm_paddr_t
516 kvtop(void *addr)
517 {
518 vm_paddr_t pa;
519
520 pa = pmap_kextract((vm_offset_t)addr);
521 if (pa == 0)
522 panic("kvtop: zero page frame");
523 return (pa);
524 }
525
526 #ifdef SMP
527 static void
528 cpu_reset_proxy()
529 {
530
531 cpu_reset_proxy_active = 1;
532 while (cpu_reset_proxy_active == 1)
533 ; /* Wait for other cpu to see that we've started */
534 stop_cpus((1<<cpu_reset_proxyid));
535 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid);
536 DELAY(1000000);
537 cpu_reset_real();
538 }
539 #endif
540
541 void
542 cpu_reset()
543 {
544 #ifdef XBOX
545 if (arch_i386_is_xbox) {
546 /* Kick the PIC16L, it can reboot the box */
547 pic16l_reboot();
548 for (;;);
549 }
550 #endif
551
552 #ifdef SMP
553 u_int cnt, map;
554
555 if (smp_active) {
556 map = PCPU_GET(other_cpus) & ~stopped_cpus;
557 if (map != 0) {
558 printf("cpu_reset: Stopping other CPUs\n");
559 stop_cpus(map);
560 }
561
562 if (PCPU_GET(cpuid) != 0) {
563 cpu_reset_proxyid = PCPU_GET(cpuid);
564 cpustop_restartfunc = cpu_reset_proxy;
565 cpu_reset_proxy_active = 0;
566 printf("cpu_reset: Restarting BSP\n");
567 started_cpus = (1<<0); /* Restart CPU #0 */
568
569 cnt = 0;
570 while (cpu_reset_proxy_active == 0 && cnt < 10000000)
571 cnt++; /* Wait for BSP to announce restart */
572 if (cpu_reset_proxy_active == 0)
573 printf("cpu_reset: Failed to restart BSP\n");
574 enable_intr();
575 cpu_reset_proxy_active = 2;
576
577 while (1);
578 /* NOTREACHED */
579 }
580
581 DELAY(1000000);
582 }
583 #endif
584 cpu_reset_real();
585 /* NOTREACHED */
586 }
587
588 static void
589 cpu_reset_real()
590 {
591 struct region_descriptor null_idt;
592 #ifndef PC98
593 int b;
594 #endif
595
596 disable_intr();
597 #ifdef CPU_ELAN
598 if (elan_mmcr != NULL)
599 elan_mmcr->RESCFG = 1;
600 #endif
601
602 if (cpu == CPU_GEODE1100) {
603 /* Attempt Geode's own reset */
604 outl(0xcf8, 0x80009044ul);
605 outl(0xcfc, 0xf);
606 }
607
608 #ifdef PC98
609 /*
610 * Attempt to do a CPU reset via CPU reset port.
611 */
612 if ((inb(0x35) & 0xa0) != 0xa0) {
613 outb(0x37, 0x0f); /* SHUT0 = 0. */
614 outb(0x37, 0x0b); /* SHUT1 = 0. */
615 }
616 outb(0xf0, 0x00); /* Reset. */
617 #else
618 #if !defined(BROKEN_KEYBOARD_RESET)
619 /*
620 * Attempt to do a CPU reset via the keyboard controller,
621 * do not turn off GateA20, as any machine that fails
622 * to do the reset here would then end up in no man's land.
623 */
624 outb(IO_KBD + 4, 0xFE);
625 DELAY(500000); /* wait 0.5 sec to see if that did it */
626 #endif
627
628 /*
629 * Attempt to force a reset via the Reset Control register at
630 * I/O port 0xcf9. Bit 2 forces a system reset when it is
631 * written as 1. Bit 1 selects the type of reset to attempt:
632 * 0 selects a "soft" reset, and 1 selects a "hard" reset. We
633 * try to do a "soft" reset first, and then a "hard" reset.
634 */
635 outb(0xcf9, 0x2);
636 outb(0xcf9, 0x6);
637 DELAY(500000); /* wait 0.5 sec to see if that did it */
638
639 /*
640 * Attempt to force a reset via the Fast A20 and Init register
641 * at I/O port 0x92. Bit 1 serves as an alternate A20 gate.
642 * Bit 0 asserts INIT# when set to 1. We are careful to only
643 * preserve bit 1 while setting bit 0. We also must clear bit
644 * 0 before setting it if it isn't already clear.
645 */
646 b = inb(0x92);
647 if (b != 0xff) {
648 if ((b & 0x1) != 0)
649 outb(0x92, b & 0xfe);
650 outb(0x92, b | 0x1);
651 DELAY(500000); /* wait 0.5 sec to see if that did it */
652 }
653 #endif /* PC98 */
654
655 printf("No known reset method worked, attempting CPU shutdown\n");
656 DELAY(1000000); /* wait 1 sec for printf to complete */
657
658 /* Wipe the IDT. */
659 null_idt.rd_limit = 0;
660 null_idt.rd_base = 0;
661 lidt(&null_idt);
662
663 /* "good night, sweet prince .... <THUNK!>" */
664 breakpoint();
665
666 /* NOTREACHED */
667 while(1);
668 }
669
670 /*
671 * Allocate a pool of sf_bufs (sendfile(2) or "super-fast" if you prefer. :-))
672 */
673 static void
674 sf_buf_init(void *arg)
675 {
676 struct sf_buf *sf_bufs;
677 vm_offset_t sf_base;
678 int i;
679
680 nsfbufs = NSFBUFS;
681 TUNABLE_INT_FETCH("kern.ipc.nsfbufs", &nsfbufs);
682
683 sf_buf_active = hashinit(nsfbufs, M_TEMP, &sf_buf_hashmask);
684 TAILQ_INIT(&sf_buf_freelist);
685 sf_base = kmem_alloc_nofault(kernel_map, nsfbufs * PAGE_SIZE);
686 sf_bufs = malloc(nsfbufs * sizeof(struct sf_buf), M_TEMP,
687 M_NOWAIT | M_ZERO);
688 for (i = 0; i < nsfbufs; i++) {
689 sf_bufs[i].kva = sf_base + i * PAGE_SIZE;
690 TAILQ_INSERT_TAIL(&sf_buf_freelist, &sf_bufs[i], free_entry);
691 }
692 sf_buf_alloc_want = 0;
693 mtx_init(&sf_buf_lock, "sf_buf", NULL, MTX_DEF);
694 }
695
696 /*
697 * Get an sf_buf from the freelist. Will block if none are available.
698 */
699 struct sf_buf *
700 sf_buf_alloc(struct vm_page *m, int flags)
701 {
702 pt_entry_t opte, *ptep;
703 struct sf_head *hash_list;
704 struct sf_buf *sf;
705 #ifdef SMP
706 cpumask_t cpumask, other_cpus;
707 #endif
708 int error;
709
710 KASSERT(curthread->td_pinned > 0 || (flags & SFB_CPUPRIVATE) == 0,
711 ("sf_buf_alloc(SFB_CPUPRIVATE): curthread not pinned"));
712 hash_list = &sf_buf_active[SF_BUF_HASH(m)];
713 mtx_lock(&sf_buf_lock);
714 LIST_FOREACH(sf, hash_list, list_entry) {
715 if (sf->m == m) {
716 sf->ref_count++;
717 if (sf->ref_count == 1) {
718 TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry);
719 nsfbufsused++;
720 nsfbufspeak = imax(nsfbufspeak, nsfbufsused);
721 }
722 #ifdef SMP
723 goto shootdown;
724 #else
725 goto done;
726 #endif
727 }
728 }
729 while ((sf = TAILQ_FIRST(&sf_buf_freelist)) == NULL) {
730 if (flags & SFB_NOWAIT)
731 goto done;
732 sf_buf_alloc_want++;
733 mbstat.sf_allocwait++;
734 error = msleep(&sf_buf_freelist, &sf_buf_lock,
735 (flags & SFB_CATCH) ? PCATCH | PVM : PVM, "sfbufa", 0);
736 sf_buf_alloc_want--;
737
738 /*
739 * If we got a signal, don't risk going back to sleep.
740 */
741 if (error)
742 goto done;
743 }
744 TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry);
745 if (sf->m != NULL)
746 LIST_REMOVE(sf, list_entry);
747 LIST_INSERT_HEAD(hash_list, sf, list_entry);
748 sf->ref_count = 1;
749 sf->m = m;
750 nsfbufsused++;
751 nsfbufspeak = imax(nsfbufspeak, nsfbufsused);
752
753 /*
754 * Update the sf_buf's virtual-to-physical mapping, flushing the
755 * virtual address from the TLB. Since the reference count for
756 * the sf_buf's old mapping was zero, that mapping is not
757 * currently in use. Consequently, there is no need to exchange
758 * the old and new PTEs atomically, even under PAE.
759 */
760 ptep = vtopte(sf->kva);
761 opte = *ptep;
762 *ptep = VM_PAGE_TO_PHYS(m) | pgeflag | PG_RW | PG_V;
763
764 /*
765 * Avoid unnecessary TLB invalidations: If the sf_buf's old
766 * virtual-to-physical mapping was not used, then any processor
767 * that has invalidated the sf_buf's virtual address from its TLB
768 * since the last used mapping need not invalidate again.
769 */
770 #ifdef SMP
771 if ((opte & (PG_V | PG_A)) == (PG_V | PG_A))
772 sf->cpumask = 0;
773 shootdown:
774 sched_pin();
775 cpumask = PCPU_GET(cpumask);
776 if ((sf->cpumask & cpumask) == 0) {
777 sf->cpumask |= cpumask;
778 invlpg(sf->kva);
779 }
780 if ((flags & SFB_CPUPRIVATE) == 0) {
781 other_cpus = PCPU_GET(other_cpus) & ~sf->cpumask;
782 if (other_cpus != 0) {
783 sf->cpumask |= other_cpus;
784 smp_masked_invlpg(other_cpus, sf->kva);
785 }
786 }
787 sched_unpin();
788 #else
789 if ((opte & (PG_V | PG_A)) == (PG_V | PG_A))
790 pmap_invalidate_page(kernel_pmap, sf->kva);
791 #endif
792 done:
793 mtx_unlock(&sf_buf_lock);
794 return (sf);
795 }
796
797 /*
798 * Remove a reference from the given sf_buf, adding it to the free
799 * list when its reference count reaches zero. A freed sf_buf still,
800 * however, retains its virtual-to-physical mapping until it is
801 * recycled or reactivated by sf_buf_alloc(9).
802 */
803 void
804 sf_buf_free(struct sf_buf *sf)
805 {
806
807 mtx_lock(&sf_buf_lock);
808 sf->ref_count--;
809 if (sf->ref_count == 0) {
810 TAILQ_INSERT_TAIL(&sf_buf_freelist, sf, free_entry);
811 nsfbufsused--;
812 if (sf_buf_alloc_want > 0)
813 wakeup_one(&sf_buf_freelist);
814 }
815 mtx_unlock(&sf_buf_lock);
816 }
817
818 /*
819 * Software interrupt handler for queued VM system processing.
820 */
821 void
822 swi_vm(void *dummy)
823 {
824 if (busdma_swi_pending != 0)
825 busdma_swi();
826 }
827
828 /*
829 * Tell whether this address is in some physical memory region.
830 * Currently used by the kernel coredump code in order to avoid
831 * dumping the ``ISA memory hole'' which could cause indefinite hangs,
832 * or other unpredictable behaviour.
833 */
834
835 int
836 is_physical_memory(vm_paddr_t addr)
837 {
838
839 #ifdef DEV_ISA
840 /* The ISA ``memory hole''. */
841 if (addr >= 0xa0000 && addr < 0x100000)
842 return 0;
843 #endif
844
845 /*
846 * stuff other tests for known memory-mapped devices (PCI?)
847 * here
848 */
849
850 return 1;
851 }
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