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/9.0/sys/i386/i386/vm_machdep.c 223758 2011-07-04 12:04:52Z attilio $");
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/kernel.h>
57 #include <sys/ktr.h>
58 #include <sys/lock.h>
59 #include <sys/malloc.h>
60 #include <sys/mbuf.h>
61 #include <sys/mutex.h>
62 #include <sys/pioctl.h>
63 #include <sys/proc.h>
64 #include <sys/sysent.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 XEN
93 #include <xen/hypervisor.h>
94 #endif
95 #ifdef PC98
96 #include <pc98/cbus/cbus.h>
97 #else
98 #include <x86/isa/isa.h>
99 #endif
100
101 #ifdef XBOX
102 #include <machine/xbox.h>
103 #endif
104
105 #ifndef NSFBUFS
106 #define NSFBUFS (512 + maxusers * 16)
107 #endif
108
109 static void cpu_reset_real(void);
110 #ifdef SMP
111 static void cpu_reset_proxy(void);
112 static u_int cpu_reset_proxyid;
113 static volatile u_int cpu_reset_proxy_active;
114 #endif
115 static void sf_buf_init(void *arg);
116 SYSINIT(sock_sf, SI_SUB_MBUF, SI_ORDER_ANY, sf_buf_init, NULL);
117
118 LIST_HEAD(sf_head, sf_buf);
119
120 /*
121 * A hash table of active sendfile(2) buffers
122 */
123 static struct sf_head *sf_buf_active;
124 static u_long sf_buf_hashmask;
125
126 #define SF_BUF_HASH(m) (((m) - vm_page_array) & sf_buf_hashmask)
127
128 static TAILQ_HEAD(, sf_buf) sf_buf_freelist;
129 static u_int sf_buf_alloc_want;
130
131 /*
132 * A lock used to synchronize access to the hash table and free list
133 */
134 static struct mtx sf_buf_lock;
135
136 extern int _ucodesel, _udatasel;
137
138 /*
139 * Finish a fork operation, with process p2 nearly set up.
140 * Copy and update the pcb, set up the stack so that the child
141 * ready to run and return to user mode.
142 */
143 void
144 cpu_fork(td1, p2, td2, flags)
145 register struct thread *td1;
146 register struct proc *p2;
147 struct thread *td2;
148 int flags;
149 {
150 register struct proc *p1;
151 struct pcb *pcb2;
152 struct mdproc *mdp2;
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, *pldt1;
160
161 mtx_lock_spin(&dt_lock);
162 if ((pldt1 = mdp1->md_ldt) != NULL &&
163 pldt1->ldt_refcnt > 1) {
164 pldt = user_ldt_alloc(mdp1, pldt1->ldt_len);
165 if (pldt == NULL)
166 panic("could not copy LDT");
167 mdp1->md_ldt = pldt;
168 set_user_ldt(mdp1);
169 user_ldt_deref(pldt1);
170 } else
171 mtx_unlock_spin(&dt_lock);
172 }
173 return;
174 }
175
176 /* Ensure that td1's pcb is up to date. */
177 if (td1 == curthread)
178 td1->td_pcb->pcb_gs = rgs();
179 #ifdef DEV_NPX
180 critical_enter();
181 if (PCPU_GET(fpcurthread) == td1)
182 npxsave(td1->td_pcb->pcb_save);
183 critical_exit();
184 #endif
185
186 /* Point the pcb to the top of the stack */
187 pcb2 = (struct pcb *)(td2->td_kstack +
188 td2->td_kstack_pages * PAGE_SIZE) - 1;
189 td2->td_pcb = pcb2;
190
191 /* Copy td1's pcb */
192 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2));
193
194 /* Properly initialize pcb_save */
195 pcb2->pcb_save = &pcb2->pcb_user_save;
196
197 /* Point mdproc and then copy over td1's contents */
198 mdp2 = &p2->p_md;
199 bcopy(&p1->p_md, mdp2, sizeof(*mdp2));
200
201 /*
202 * Create a new fresh stack for the new process.
203 * Copy the trap frame for the return to user mode as if from a
204 * syscall. This copies most of the user mode register values.
205 * The -16 is so we can expand the trapframe if we go to vm86.
206 */
207 td2->td_frame = (struct trapframe *)((caddr_t)td2->td_pcb - 16) - 1;
208 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe));
209
210 td2->td_frame->tf_eax = 0; /* Child returns zero */
211 td2->td_frame->tf_eflags &= ~PSL_C; /* success */
212 td2->td_frame->tf_edx = 1;
213
214 /*
215 * If the parent process has the trap bit set (i.e. a debugger had
216 * single stepped the process to the system call), we need to clear
217 * the trap flag from the new frame unless the debugger had set PF_FORK
218 * on the parent. Otherwise, the child will receive a (likely
219 * unexpected) SIGTRAP when it executes the first instruction after
220 * returning to userland.
221 */
222 if ((p1->p_pfsflags & PF_FORK) == 0)
223 td2->td_frame->tf_eflags &= ~PSL_T;
224
225 /*
226 * Set registers for trampoline to user mode. Leave space for the
227 * return address on stack. These are the kernel mode register values.
228 */
229 #ifdef PAE
230 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdpt);
231 #else
232 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdir);
233 #endif
234 pcb2->pcb_edi = 0;
235 pcb2->pcb_esi = (int)fork_return; /* fork_trampoline argument */
236 pcb2->pcb_ebp = 0;
237 pcb2->pcb_esp = (int)td2->td_frame - sizeof(void *);
238 pcb2->pcb_ebx = (int)td2; /* fork_trampoline argument */
239 pcb2->pcb_eip = (int)fork_trampoline;
240 pcb2->pcb_psl = PSL_KERNEL; /* ints disabled */
241 /*-
242 * pcb2->pcb_dr*: cloned above.
243 * pcb2->pcb_savefpu: cloned above.
244 * pcb2->pcb_flags: cloned above.
245 * pcb2->pcb_onfault: cloned above (always NULL here?).
246 * pcb2->pcb_gs: cloned above.
247 * pcb2->pcb_ext: cleared below.
248 */
249
250 /*
251 * XXX don't copy the i/o pages. this should probably be fixed.
252 */
253 pcb2->pcb_ext = 0;
254
255 /* Copy the LDT, if necessary. */
256 mtx_lock_spin(&dt_lock);
257 if (mdp2->md_ldt != NULL) {
258 if (flags & RFMEM) {
259 mdp2->md_ldt->ldt_refcnt++;
260 } else {
261 mdp2->md_ldt = user_ldt_alloc(mdp2,
262 mdp2->md_ldt->ldt_len);
263 if (mdp2->md_ldt == NULL)
264 panic("could not copy LDT");
265 }
266 }
267 mtx_unlock_spin(&dt_lock);
268
269 /* Setup to release spin count in fork_exit(). */
270 td2->td_md.md_spinlock_count = 1;
271 /*
272 * XXX XEN need to check on PSL_USER is handled
273 */
274 td2->td_md.md_saved_flags = PSL_KERNEL | PSL_I;
275 /*
276 * Now, cpu_switch() can schedule the new process.
277 * pcb_esp is loaded pointing to the cpu_switch() stack frame
278 * containing the return address when exiting cpu_switch.
279 * This will normally be to fork_trampoline(), which will have
280 * %ebx loaded with the new proc's pointer. fork_trampoline()
281 * will set up a stack to call fork_return(p, frame); to complete
282 * the return to user-mode.
283 */
284 }
285
286 /*
287 * Intercept the return address from a freshly forked process that has NOT
288 * been scheduled yet.
289 *
290 * This is needed to make kernel threads stay in kernel mode.
291 */
292 void
293 cpu_set_fork_handler(td, func, arg)
294 struct thread *td;
295 void (*func)(void *);
296 void *arg;
297 {
298 /*
299 * Note that the trap frame follows the args, so the function
300 * is really called like this: func(arg, frame);
301 */
302 td->td_pcb->pcb_esi = (int) func; /* function */
303 td->td_pcb->pcb_ebx = (int) arg; /* first arg */
304 }
305
306 void
307 cpu_exit(struct thread *td)
308 {
309
310 /*
311 * If this process has a custom LDT, release it. Reset pc->pcb_gs
312 * and %gs before we free it in case they refer to an LDT entry.
313 */
314 mtx_lock_spin(&dt_lock);
315 if (td->td_proc->p_md.md_ldt) {
316 td->td_pcb->pcb_gs = _udatasel;
317 load_gs(_udatasel);
318 user_ldt_free(td);
319 } else
320 mtx_unlock_spin(&dt_lock);
321 }
322
323 void
324 cpu_thread_exit(struct thread *td)
325 {
326
327 #ifdef DEV_NPX
328 critical_enter();
329 if (td == PCPU_GET(fpcurthread))
330 npxdrop();
331 critical_exit();
332 #endif
333
334 /* Disable any hardware breakpoints. */
335 if (td->td_pcb->pcb_flags & PCB_DBREGS) {
336 reset_dbregs();
337 td->td_pcb->pcb_flags &= ~PCB_DBREGS;
338 }
339 }
340
341 void
342 cpu_thread_clean(struct thread *td)
343 {
344 struct pcb *pcb;
345
346 pcb = td->td_pcb;
347 if (pcb->pcb_ext != NULL) {
348 /* if (pcb->pcb_ext->ext_refcount-- == 1) ?? */
349 /*
350 * XXX do we need to move the TSS off the allocated pages
351 * before freeing them? (not done here)
352 */
353 kmem_free(kernel_map, (vm_offset_t)pcb->pcb_ext,
354 ctob(IOPAGES + 1));
355 pcb->pcb_ext = NULL;
356 }
357 }
358
359 void
360 cpu_thread_swapin(struct thread *td)
361 {
362 }
363
364 void
365 cpu_thread_swapout(struct thread *td)
366 {
367 }
368
369 void
370 cpu_thread_alloc(struct thread *td)
371 {
372
373 td->td_pcb = (struct pcb *)(td->td_kstack +
374 td->td_kstack_pages * PAGE_SIZE) - 1;
375 td->td_frame = (struct trapframe *)((caddr_t)td->td_pcb - 16) - 1;
376 td->td_pcb->pcb_ext = NULL;
377 td->td_pcb->pcb_save = &td->td_pcb->pcb_user_save;
378 }
379
380 void
381 cpu_thread_free(struct thread *td)
382 {
383
384 cpu_thread_clean(td);
385 }
386
387 void
388 cpu_set_syscall_retval(struct thread *td, int error)
389 {
390
391 switch (error) {
392 case 0:
393 td->td_frame->tf_eax = td->td_retval[0];
394 td->td_frame->tf_edx = td->td_retval[1];
395 td->td_frame->tf_eflags &= ~PSL_C;
396 break;
397
398 case ERESTART:
399 /*
400 * Reconstruct pc, assuming lcall $X,y is 7 bytes, int
401 * 0x80 is 2 bytes. We saved this in tf_err.
402 */
403 td->td_frame->tf_eip -= td->td_frame->tf_err;
404 break;
405
406 case EJUSTRETURN:
407 break;
408
409 default:
410 if (td->td_proc->p_sysent->sv_errsize) {
411 if (error >= td->td_proc->p_sysent->sv_errsize)
412 error = -1; /* XXX */
413 else
414 error = td->td_proc->p_sysent->sv_errtbl[error];
415 }
416 td->td_frame->tf_eax = error;
417 td->td_frame->tf_eflags |= PSL_C;
418 break;
419 }
420 }
421
422 /*
423 * Initialize machine state (pcb and trap frame) for a new thread about to
424 * upcall. Put enough state in the new thread's PCB to get it to go back
425 * userret(), where we can intercept it again to set the return (upcall)
426 * Address and stack, along with those from upcals that are from other sources
427 * such as those generated in thread_userret() itself.
428 */
429 void
430 cpu_set_upcall(struct thread *td, struct thread *td0)
431 {
432 struct pcb *pcb2;
433
434 /* Point the pcb to the top of the stack. */
435 pcb2 = td->td_pcb;
436
437 /*
438 * Copy the upcall pcb. This loads kernel regs.
439 * Those not loaded individually below get their default
440 * values here.
441 */
442 bcopy(td0->td_pcb, pcb2, sizeof(*pcb2));
443 pcb2->pcb_flags &= ~(PCB_NPXINITDONE | PCB_NPXUSERINITDONE);
444 pcb2->pcb_save = &pcb2->pcb_user_save;
445
446 /*
447 * Create a new fresh stack for the new thread.
448 */
449 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe));
450
451 /* If the current thread has the trap bit set (i.e. a debugger had
452 * single stepped the process to the system call), we need to clear
453 * the trap flag from the new frame. Otherwise, the new thread will
454 * receive a (likely unexpected) SIGTRAP when it executes the first
455 * instruction after returning to userland.
456 */
457 td->td_frame->tf_eflags &= ~PSL_T;
458
459 /*
460 * Set registers for trampoline to user mode. Leave space for the
461 * return address on stack. These are the kernel mode register values.
462 */
463 pcb2->pcb_edi = 0;
464 pcb2->pcb_esi = (int)fork_return; /* trampoline arg */
465 pcb2->pcb_ebp = 0;
466 pcb2->pcb_esp = (int)td->td_frame - sizeof(void *); /* trampoline arg */
467 pcb2->pcb_ebx = (int)td; /* trampoline arg */
468 pcb2->pcb_eip = (int)fork_trampoline;
469 pcb2->pcb_psl &= ~(PSL_I); /* interrupts must be disabled */
470 pcb2->pcb_gs = rgs();
471 /*
472 * If we didn't copy the pcb, we'd need to do the following registers:
473 * pcb2->pcb_cr3: cloned above.
474 * pcb2->pcb_dr*: cloned above.
475 * pcb2->pcb_savefpu: cloned above.
476 * pcb2->pcb_flags: cloned above.
477 * pcb2->pcb_onfault: cloned above (always NULL here?).
478 * pcb2->pcb_gs: cloned above.
479 * pcb2->pcb_ext: cleared below.
480 */
481 pcb2->pcb_ext = NULL;
482
483 /* Setup to release spin count in fork_exit(). */
484 td->td_md.md_spinlock_count = 1;
485 td->td_md.md_saved_flags = PSL_KERNEL | PSL_I;
486 }
487
488 /*
489 * Set that machine state for performing an upcall that has to
490 * be done in thread_userret() so that those upcalls generated
491 * in thread_userret() itself can be done as well.
492 */
493 void
494 cpu_set_upcall_kse(struct thread *td, void (*entry)(void *), void *arg,
495 stack_t *stack)
496 {
497
498 /*
499 * Do any extra cleaning that needs to be done.
500 * The thread may have optional components
501 * that are not present in a fresh thread.
502 * This may be a recycled thread so make it look
503 * as though it's newly allocated.
504 */
505 cpu_thread_clean(td);
506
507 /*
508 * Set the trap frame to point at the beginning of the uts
509 * function.
510 */
511 td->td_frame->tf_ebp = 0;
512 td->td_frame->tf_esp =
513 (((int)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4;
514 td->td_frame->tf_eip = (int)entry;
515
516 /*
517 * Pass the address of the mailbox for this kse to the uts
518 * function as a parameter on the stack.
519 */
520 suword((void *)(td->td_frame->tf_esp + sizeof(void *)),
521 (int)arg);
522 }
523
524 int
525 cpu_set_user_tls(struct thread *td, void *tls_base)
526 {
527 struct segment_descriptor sd;
528 uint32_t base;
529
530 /*
531 * Construct a descriptor and store it in the pcb for
532 * the next context switch. Also store it in the gdt
533 * so that the load of tf_fs into %fs will activate it
534 * at return to userland.
535 */
536 base = (uint32_t)tls_base;
537 sd.sd_lobase = base & 0xffffff;
538 sd.sd_hibase = (base >> 24) & 0xff;
539 sd.sd_lolimit = 0xffff; /* 4GB limit, wraps around */
540 sd.sd_hilimit = 0xf;
541 sd.sd_type = SDT_MEMRWA;
542 sd.sd_dpl = SEL_UPL;
543 sd.sd_p = 1;
544 sd.sd_xx = 0;
545 sd.sd_def32 = 1;
546 sd.sd_gran = 1;
547 critical_enter();
548 /* set %gs */
549 td->td_pcb->pcb_gsd = sd;
550 if (td == curthread) {
551 PCPU_GET(fsgs_gdt)[1] = sd;
552 load_gs(GSEL(GUGS_SEL, SEL_UPL));
553 }
554 critical_exit();
555 return (0);
556 }
557
558 /*
559 * Convert kernel VA to physical address
560 */
561 vm_paddr_t
562 kvtop(void *addr)
563 {
564 vm_paddr_t pa;
565
566 pa = pmap_kextract((vm_offset_t)addr);
567 if (pa == 0)
568 panic("kvtop: zero page frame");
569 return (pa);
570 }
571
572 #ifdef SMP
573 static void
574 cpu_reset_proxy()
575 {
576 cpuset_t tcrp;
577
578 cpu_reset_proxy_active = 1;
579 while (cpu_reset_proxy_active == 1)
580 ; /* Wait for other cpu to see that we've started */
581 CPU_SETOF(cpu_reset_proxyid, &tcrp);
582 stop_cpus(tcrp);
583 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid);
584 DELAY(1000000);
585 cpu_reset_real();
586 }
587 #endif
588
589 void
590 cpu_reset()
591 {
592 #ifdef XBOX
593 if (arch_i386_is_xbox) {
594 /* Kick the PIC16L, it can reboot the box */
595 pic16l_reboot();
596 for (;;);
597 }
598 #endif
599
600 #ifdef SMP
601 cpuset_t map;
602 u_int cnt;
603
604 if (smp_active) {
605 map = all_cpus;
606 CPU_CLR(PCPU_GET(cpuid), &map);
607 CPU_NAND(&map, &stopped_cpus);
608 if (!CPU_EMPTY(&map)) {
609 printf("cpu_reset: Stopping other CPUs\n");
610 stop_cpus(map);
611 }
612
613 if (PCPU_GET(cpuid) != 0) {
614 cpu_reset_proxyid = PCPU_GET(cpuid);
615 cpustop_restartfunc = cpu_reset_proxy;
616 cpu_reset_proxy_active = 0;
617 printf("cpu_reset: Restarting BSP\n");
618
619 /* Restart CPU #0. */
620 /* XXX: restart_cpus(1 << 0); */
621 CPU_SETOF(0, &started_cpus);
622 wmb();
623
624 cnt = 0;
625 while (cpu_reset_proxy_active == 0 && cnt < 10000000)
626 cnt++; /* Wait for BSP to announce restart */
627 if (cpu_reset_proxy_active == 0)
628 printf("cpu_reset: Failed to restart BSP\n");
629 enable_intr();
630 cpu_reset_proxy_active = 2;
631
632 while (1);
633 /* NOTREACHED */
634 }
635
636 DELAY(1000000);
637 }
638 #endif
639 cpu_reset_real();
640 /* NOTREACHED */
641 }
642
643 static void
644 cpu_reset_real()
645 {
646 struct region_descriptor null_idt;
647 #ifndef PC98
648 int b;
649 #endif
650
651 disable_intr();
652 #ifdef XEN
653 if (smp_processor_id() == 0)
654 HYPERVISOR_shutdown(SHUTDOWN_reboot);
655 else
656 HYPERVISOR_shutdown(SHUTDOWN_poweroff);
657 #endif
658 #ifdef CPU_ELAN
659 if (elan_mmcr != NULL)
660 elan_mmcr->RESCFG = 1;
661 #endif
662
663 if (cpu == CPU_GEODE1100) {
664 /* Attempt Geode's own reset */
665 outl(0xcf8, 0x80009044ul);
666 outl(0xcfc, 0xf);
667 }
668
669 #ifdef PC98
670 /*
671 * Attempt to do a CPU reset via CPU reset port.
672 */
673 if ((inb(0x35) & 0xa0) != 0xa0) {
674 outb(0x37, 0x0f); /* SHUT0 = 0. */
675 outb(0x37, 0x0b); /* SHUT1 = 0. */
676 }
677 outb(0xf0, 0x00); /* Reset. */
678 #else
679 #if !defined(BROKEN_KEYBOARD_RESET)
680 /*
681 * Attempt to do a CPU reset via the keyboard controller,
682 * do not turn off GateA20, as any machine that fails
683 * to do the reset here would then end up in no man's land.
684 */
685 outb(IO_KBD + 4, 0xFE);
686 DELAY(500000); /* wait 0.5 sec to see if that did it */
687 #endif
688
689 /*
690 * Attempt to force a reset via the Reset Control register at
691 * I/O port 0xcf9. Bit 2 forces a system reset when it
692 * transitions from 0 to 1. Bit 1 selects the type of reset
693 * to attempt: 0 selects a "soft" reset, and 1 selects a
694 * "hard" reset. We try a "hard" reset. The first write sets
695 * bit 1 to select a "hard" reset and clears bit 2. The
696 * second write forces a 0 -> 1 transition in bit 2 to trigger
697 * a reset.
698 */
699 outb(0xcf9, 0x2);
700 outb(0xcf9, 0x6);
701 DELAY(500000); /* wait 0.5 sec to see if that did it */
702
703 /*
704 * Attempt to force a reset via the Fast A20 and Init register
705 * at I/O port 0x92. Bit 1 serves as an alternate A20 gate.
706 * Bit 0 asserts INIT# when set to 1. We are careful to only
707 * preserve bit 1 while setting bit 0. We also must clear bit
708 * 0 before setting it if it isn't already clear.
709 */
710 b = inb(0x92);
711 if (b != 0xff) {
712 if ((b & 0x1) != 0)
713 outb(0x92, b & 0xfe);
714 outb(0x92, b | 0x1);
715 DELAY(500000); /* wait 0.5 sec to see if that did it */
716 }
717 #endif /* PC98 */
718
719 printf("No known reset method worked, attempting CPU shutdown\n");
720 DELAY(1000000); /* wait 1 sec for printf to complete */
721
722 /* Wipe the IDT. */
723 null_idt.rd_limit = 0;
724 null_idt.rd_base = 0;
725 lidt(&null_idt);
726
727 /* "good night, sweet prince .... <THUNK!>" */
728 breakpoint();
729
730 /* NOTREACHED */
731 while(1);
732 }
733
734 /*
735 * Allocate a pool of sf_bufs (sendfile(2) or "super-fast" if you prefer. :-))
736 */
737 static void
738 sf_buf_init(void *arg)
739 {
740 struct sf_buf *sf_bufs;
741 vm_offset_t sf_base;
742 int i;
743
744 nsfbufs = NSFBUFS;
745 TUNABLE_INT_FETCH("kern.ipc.nsfbufs", &nsfbufs);
746
747 sf_buf_active = hashinit(nsfbufs, M_TEMP, &sf_buf_hashmask);
748 TAILQ_INIT(&sf_buf_freelist);
749 sf_base = kmem_alloc_nofault(kernel_map, nsfbufs * PAGE_SIZE);
750 sf_bufs = malloc(nsfbufs * sizeof(struct sf_buf), M_TEMP,
751 M_NOWAIT | M_ZERO);
752 for (i = 0; i < nsfbufs; i++) {
753 sf_bufs[i].kva = sf_base + i * PAGE_SIZE;
754 TAILQ_INSERT_TAIL(&sf_buf_freelist, &sf_bufs[i], free_entry);
755 }
756 sf_buf_alloc_want = 0;
757 mtx_init(&sf_buf_lock, "sf_buf", NULL, MTX_DEF);
758 }
759
760 /*
761 * Invalidate the cache lines that may belong to the page, if
762 * (possibly old) mapping of the page by sf buffer exists. Returns
763 * TRUE when mapping was found and cache invalidated.
764 */
765 boolean_t
766 sf_buf_invalidate_cache(vm_page_t m)
767 {
768 struct sf_head *hash_list;
769 struct sf_buf *sf;
770 boolean_t ret;
771
772 hash_list = &sf_buf_active[SF_BUF_HASH(m)];
773 ret = FALSE;
774 mtx_lock(&sf_buf_lock);
775 LIST_FOREACH(sf, hash_list, list_entry) {
776 if (sf->m == m) {
777 /*
778 * Use pmap_qenter to update the pte for
779 * existing mapping, in particular, the PAT
780 * settings are recalculated.
781 */
782 pmap_qenter(sf->kva, &m, 1);
783 pmap_invalidate_cache_range(sf->kva, sf->kva +
784 PAGE_SIZE);
785 ret = TRUE;
786 break;
787 }
788 }
789 mtx_unlock(&sf_buf_lock);
790 return (ret);
791 }
792
793 /*
794 * Get an sf_buf from the freelist. May block if none are available.
795 */
796 struct sf_buf *
797 sf_buf_alloc(struct vm_page *m, int flags)
798 {
799 pt_entry_t opte, *ptep;
800 struct sf_head *hash_list;
801 struct sf_buf *sf;
802 #ifdef SMP
803 cpuset_t other_cpus;
804 u_int cpuid;
805 #endif
806 int error;
807
808 KASSERT(curthread->td_pinned > 0 || (flags & SFB_CPUPRIVATE) == 0,
809 ("sf_buf_alloc(SFB_CPUPRIVATE): curthread not pinned"));
810 hash_list = &sf_buf_active[SF_BUF_HASH(m)];
811 mtx_lock(&sf_buf_lock);
812 LIST_FOREACH(sf, hash_list, list_entry) {
813 if (sf->m == m) {
814 sf->ref_count++;
815 if (sf->ref_count == 1) {
816 TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry);
817 nsfbufsused++;
818 nsfbufspeak = imax(nsfbufspeak, nsfbufsused);
819 }
820 #ifdef SMP
821 goto shootdown;
822 #else
823 goto done;
824 #endif
825 }
826 }
827 while ((sf = TAILQ_FIRST(&sf_buf_freelist)) == NULL) {
828 if (flags & SFB_NOWAIT)
829 goto done;
830 sf_buf_alloc_want++;
831 mbstat.sf_allocwait++;
832 error = msleep(&sf_buf_freelist, &sf_buf_lock,
833 (flags & SFB_CATCH) ? PCATCH | PVM : PVM, "sfbufa", 0);
834 sf_buf_alloc_want--;
835
836 /*
837 * If we got a signal, don't risk going back to sleep.
838 */
839 if (error)
840 goto done;
841 }
842 TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry);
843 if (sf->m != NULL)
844 LIST_REMOVE(sf, list_entry);
845 LIST_INSERT_HEAD(hash_list, sf, list_entry);
846 sf->ref_count = 1;
847 sf->m = m;
848 nsfbufsused++;
849 nsfbufspeak = imax(nsfbufspeak, nsfbufsused);
850
851 /*
852 * Update the sf_buf's virtual-to-physical mapping, flushing the
853 * virtual address from the TLB. Since the reference count for
854 * the sf_buf's old mapping was zero, that mapping is not
855 * currently in use. Consequently, there is no need to exchange
856 * the old and new PTEs atomically, even under PAE.
857 */
858 ptep = vtopte(sf->kva);
859 opte = *ptep;
860 #ifdef XEN
861 PT_SET_MA(sf->kva, xpmap_ptom(VM_PAGE_TO_PHYS(m)) | pgeflag
862 | PG_RW | PG_V | pmap_cache_bits(m->md.pat_mode, 0));
863 #else
864 *ptep = VM_PAGE_TO_PHYS(m) | pgeflag | PG_RW | PG_V |
865 pmap_cache_bits(m->md.pat_mode, 0);
866 #endif
867
868 /*
869 * Avoid unnecessary TLB invalidations: If the sf_buf's old
870 * virtual-to-physical mapping was not used, then any processor
871 * that has invalidated the sf_buf's virtual address from its TLB
872 * since the last used mapping need not invalidate again.
873 */
874 #ifdef SMP
875 if ((opte & (PG_V | PG_A)) == (PG_V | PG_A))
876 CPU_ZERO(&sf->cpumask);
877 shootdown:
878 sched_pin();
879 cpuid = PCPU_GET(cpuid);
880 if (!CPU_ISSET(cpuid, &sf->cpumask)) {
881 CPU_SET(cpuid, &sf->cpumask);
882 invlpg(sf->kva);
883 }
884 if ((flags & SFB_CPUPRIVATE) == 0) {
885 other_cpus = all_cpus;
886 CPU_CLR(cpuid, &other_cpus);
887 CPU_NAND(&other_cpus, &sf->cpumask);
888 if (!CPU_EMPTY(&other_cpus)) {
889 CPU_OR(&sf->cpumask, &other_cpus);
890 smp_masked_invlpg(other_cpus, sf->kva);
891 }
892 }
893 sched_unpin();
894 #else
895 if ((opte & (PG_V | PG_A)) == (PG_V | PG_A))
896 pmap_invalidate_page(kernel_pmap, sf->kva);
897 #endif
898 done:
899 mtx_unlock(&sf_buf_lock);
900 return (sf);
901 }
902
903 /*
904 * Remove a reference from the given sf_buf, adding it to the free
905 * list when its reference count reaches zero. A freed sf_buf still,
906 * however, retains its virtual-to-physical mapping until it is
907 * recycled or reactivated by sf_buf_alloc(9).
908 */
909 void
910 sf_buf_free(struct sf_buf *sf)
911 {
912
913 mtx_lock(&sf_buf_lock);
914 sf->ref_count--;
915 if (sf->ref_count == 0) {
916 TAILQ_INSERT_TAIL(&sf_buf_freelist, sf, free_entry);
917 nsfbufsused--;
918 #ifdef XEN
919 /*
920 * Xen doesn't like having dangling R/W mappings
921 */
922 pmap_qremove(sf->kva, 1);
923 sf->m = NULL;
924 LIST_REMOVE(sf, list_entry);
925 #endif
926 if (sf_buf_alloc_want > 0)
927 wakeup(&sf_buf_freelist);
928 }
929 mtx_unlock(&sf_buf_lock);
930 }
931
932 /*
933 * Software interrupt handler for queued VM system processing.
934 */
935 void
936 swi_vm(void *dummy)
937 {
938 if (busdma_swi_pending != 0)
939 busdma_swi();
940 }
941
942 /*
943 * Tell whether this address is in some physical memory region.
944 * Currently used by the kernel coredump code in order to avoid
945 * dumping the ``ISA memory hole'' which could cause indefinite hangs,
946 * or other unpredictable behaviour.
947 */
948
949 int
950 is_physical_memory(vm_paddr_t addr)
951 {
952
953 #ifdef DEV_ISA
954 /* The ISA ``memory hole''. */
955 if (addr >= 0xa0000 && addr < 0x100000)
956 return 0;
957 #endif
958
959 /*
960 * stuff other tests for known memory-mapped devices (PCI?)
961 * here
962 */
963
964 return 1;
965 }
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