1 /*-
2 * SPDX-License-Identifier: BSD-4-Clause
3 *
4 * Copyright (c) 1982, 1986 The Regents of the University of California.
5 * Copyright (c) 1989, 1990 William Jolitz
6 * Copyright (c) 1994 John Dyson
7 * All rights reserved.
8 *
9 * This code is derived from software contributed to Berkeley by
10 * the Systems Programming Group of the University of Utah Computer
11 * Science Department, and William Jolitz.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. All advertising materials mentioning features or use of this software
22 * must display the following acknowledgement:
23 * This product includes software developed by the University of
24 * California, Berkeley and its contributors.
25 * 4. Neither the name of the University nor the names of its contributors
26 * may be used to endorse or promote products derived from this software
27 * without specific prior written permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 * SUCH DAMAGE.
40 *
41 * from: @(#)vm_machdep.c 7.3 (Berkeley) 5/13/91
42 * Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
43 */
44
45 #include <sys/cdefs.h>
46 #include "opt_isa.h"
47 #include "opt_npx.h"
48 #include "opt_reset.h"
49 #include "opt_cpu.h"
50
51 #include <sys/param.h>
52 #include <sys/systm.h>
53 #include <sys/bio.h>
54 #include <sys/buf.h>
55 #include <sys/kernel.h>
56 #include <sys/ktr.h>
57 #include <sys/lock.h>
58 #include <sys/malloc.h>
59 #include <sys/mbuf.h>
60 #include <sys/mutex.h>
61 #include <sys/proc.h>
62 #include <sys/sysent.h>
63 #include <sys/sf_buf.h>
64 #include <sys/smp.h>
65 #include <sys/sched.h>
66 #include <sys/sysctl.h>
67 #include <sys/unistd.h>
68 #include <sys/vnode.h>
69 #include <sys/vmmeter.h>
70
71 #include <machine/cpu.h>
72 #include <machine/cputypes.h>
73 #include <machine/md_var.h>
74 #include <machine/pcb.h>
75 #include <machine/pcb_ext.h>
76 #include <machine/smp.h>
77 #include <machine/vm86.h>
78
79 #include <vm/vm.h>
80 #include <vm/vm_extern.h>
81 #include <vm/vm_kern.h>
82 #include <vm/vm_page.h>
83 #include <vm/vm_map.h>
84 #include <vm/vm_param.h>
85
86 _Static_assert(__OFFSETOF_MONITORBUF == offsetof(struct pcpu, pc_monitorbuf),
87 "__OFFSETOF_MONITORBUF does not correspond with offset of pc_monitorbuf.");
88
89 union savefpu *
get_pcb_user_save_td(struct thread * td)90 get_pcb_user_save_td(struct thread *td)
91 {
92 vm_offset_t p;
93
94 p = td->td_kstack + td->td_kstack_pages * PAGE_SIZE -
95 roundup2(cpu_max_ext_state_size, XSAVE_AREA_ALIGN);
96 KASSERT((p % XSAVE_AREA_ALIGN) == 0, ("Unaligned pcb_user_save area"));
97 return ((union savefpu *)p);
98 }
99
100 union savefpu *
get_pcb_user_save_pcb(struct pcb * pcb)101 get_pcb_user_save_pcb(struct pcb *pcb)
102 {
103 vm_offset_t p;
104
105 p = (vm_offset_t)(pcb + 1);
106 return ((union savefpu *)p);
107 }
108
109 struct pcb *
get_pcb_td(struct thread * td)110 get_pcb_td(struct thread *td)
111 {
112 vm_offset_t p;
113
114 p = td->td_kstack + td->td_kstack_pages * PAGE_SIZE -
115 roundup2(cpu_max_ext_state_size, XSAVE_AREA_ALIGN) -
116 sizeof(struct pcb);
117 return ((struct pcb *)p);
118 }
119
120 void *
alloc_fpusave(int flags)121 alloc_fpusave(int flags)
122 {
123 void *res;
124 struct savefpu_ymm *sf;
125
126 res = malloc(cpu_max_ext_state_size, M_DEVBUF, flags);
127 if (use_xsave) {
128 sf = (struct savefpu_ymm *)res;
129 bzero(&sf->sv_xstate.sx_hd, sizeof(sf->sv_xstate.sx_hd));
130 sf->sv_xstate.sx_hd.xstate_bv = xsave_mask;
131 }
132 return (res);
133 }
134
135 /*
136 * Common code shared between cpu_fork() and cpu_copy_thread() for
137 * initializing a thread.
138 */
139 static void
copy_thread(struct thread * td1,struct thread * td2)140 copy_thread(struct thread *td1, struct thread *td2)
141 {
142 struct pcb *pcb2;
143
144 pcb2 = td2->td_pcb;
145
146 /* Ensure that td1's pcb is up to date for user threads. */
147 if ((td2->td_pflags & TDP_KTHREAD) == 0) {
148 MPASS(td1 == curthread);
149 td1->td_pcb->pcb_gs = rgs();
150 critical_enter();
151 if (PCPU_GET(fpcurthread) == td1)
152 npxsave(td1->td_pcb->pcb_save);
153 critical_exit();
154 }
155
156 /* Copy td1's pcb */
157 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2));
158
159 /* Properly initialize pcb_save */
160 pcb2->pcb_save = get_pcb_user_save_pcb(pcb2);
161
162 /* Kernel threads start with clean NPX and segment bases. */
163 if ((td2->td_pflags & TDP_KTHREAD) != 0) {
164 pcb2->pcb_gs = _udatasel;
165 set_fsbase(td2, 0);
166 set_gsbase(td2, 0);
167 pcb2->pcb_flags &= ~(PCB_NPXINITDONE | PCB_NPXUSERINITDONE |
168 PCB_KERNNPX | PCB_KERNNPX_THR);
169 } else {
170 MPASS((pcb2->pcb_flags & (PCB_KERNNPX | PCB_KERNNPX_THR)) == 0);
171 bcopy(get_pcb_user_save_td(td1), get_pcb_user_save_pcb(pcb2),
172 cpu_max_ext_state_size);
173 }
174
175 /*
176 * Set registers for trampoline to user mode. Leave space for the
177 * return address on stack. These are the kernel mode register values.
178 */
179 pcb2->pcb_edi = 0;
180 pcb2->pcb_esi = (int)fork_return; /* trampoline arg */
181 pcb2->pcb_ebp = 0;
182 pcb2->pcb_esp = (int)td2->td_frame - sizeof(void *); /* trampoline arg */
183 pcb2->pcb_ebx = (int)td2; /* trampoline arg */
184 pcb2->pcb_eip = (int)fork_trampoline + setidt_disp;
185 /*
186 * If we didn't copy the pcb, we'd need to do the following registers:
187 * pcb2->pcb_cr3: cloned above.
188 * pcb2->pcb_dr*: cloned above.
189 * pcb2->pcb_savefpu: cloned above.
190 * pcb2->pcb_flags: cloned above.
191 * pcb2->pcb_onfault: cloned above (always NULL here?).
192 * pcb2->pcb_gs: cloned above.
193 * pcb2->pcb_ext: cleared below.
194 */
195 pcb2->pcb_ext = NULL;
196
197 /* Setup to release spin count in fork_exit(). */
198 td2->td_md.md_spinlock_count = 1;
199 td2->td_md.md_saved_flags = PSL_KERNEL | PSL_I;
200 }
201
202 /*
203 * Finish a fork operation, with process p2 nearly set up.
204 * Copy and update the pcb, set up the stack so that the child
205 * ready to run and return to user mode.
206 */
207 void
cpu_fork(struct thread * td1,struct proc * p2,struct thread * td2,int flags)208 cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
209 {
210 struct proc *p1;
211 struct pcb *pcb2;
212 struct mdproc *mdp2;
213
214 p1 = td1->td_proc;
215 if ((flags & RFPROC) == 0) {
216 if ((flags & RFMEM) == 0) {
217 /* unshare user LDT */
218 struct mdproc *mdp1 = &p1->p_md;
219 struct proc_ldt *pldt, *pldt1;
220
221 mtx_lock_spin(&dt_lock);
222 if ((pldt1 = mdp1->md_ldt) != NULL &&
223 pldt1->ldt_refcnt > 1) {
224 pldt = user_ldt_alloc(mdp1, pldt1->ldt_len);
225 if (pldt == NULL)
226 panic("could not copy LDT");
227 mdp1->md_ldt = pldt;
228 set_user_ldt(mdp1);
229 user_ldt_deref(pldt1);
230 } else
231 mtx_unlock_spin(&dt_lock);
232 }
233 return;
234 }
235
236 /* Point the pcb to the top of the stack */
237 pcb2 = get_pcb_td(td2);
238 td2->td_pcb = pcb2;
239
240 copy_thread(td1, td2);
241
242 /* Reset debug registers in the new process */
243 x86_clear_dbregs(pcb2);
244
245 /* Point mdproc and then copy over td1's contents */
246 mdp2 = &p2->p_md;
247 bcopy(&p1->p_md, mdp2, sizeof(*mdp2));
248
249 /*
250 * Copy the trap frame for the return to user mode as if from a
251 * syscall. This copies most of the user mode register values.
252 * The -VM86_STACK_SPACE (-16) is so we can expand the trapframe
253 * if we go to vm86.
254 */
255 td2->td_frame = (struct trapframe *)((caddr_t)td2->td_pcb -
256 VM86_STACK_SPACE) - 1;
257 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe));
258
259 /* Set child return values. */
260 p2->p_sysent->sv_set_fork_retval(td2);
261
262 /*
263 * If the parent process has the trap bit set (i.e. a debugger
264 * had single stepped the process to the system call), we need
265 * to clear the trap flag from the new frame.
266 */
267 td2->td_frame->tf_eflags &= ~PSL_T;
268
269 /* Set cr3 for the new process. */
270 pcb2->pcb_cr3 = pmap_get_cr3(vmspace_pmap(p2->p_vmspace));
271
272 /*
273 * XXX don't copy the i/o pages. this should probably be fixed.
274 */
275 pcb2->pcb_ext = NULL;
276
277 /* Copy the LDT, if necessary. */
278 mtx_lock_spin(&dt_lock);
279 if (mdp2->md_ldt != NULL) {
280 if (flags & RFMEM) {
281 mdp2->md_ldt->ldt_refcnt++;
282 } else {
283 mdp2->md_ldt = user_ldt_alloc(mdp2,
284 mdp2->md_ldt->ldt_len);
285 if (mdp2->md_ldt == NULL)
286 panic("could not copy LDT");
287 }
288 }
289 mtx_unlock_spin(&dt_lock);
290
291 /*
292 * Now, cpu_switch() can schedule the new process.
293 * pcb_esp is loaded pointing to the cpu_switch() stack frame
294 * containing the return address when exiting cpu_switch.
295 * This will normally be to fork_trampoline(), which will have
296 * %ebx loaded with the new proc's pointer. fork_trampoline()
297 * will set up a stack to call fork_return(p, frame); to complete
298 * the return to user-mode.
299 */
300 }
301
302 void
x86_set_fork_retval(struct thread * td)303 x86_set_fork_retval(struct thread *td)
304 {
305 struct trapframe * frame = td->td_frame;
306
307 frame->tf_eax = 0; /* Child returns zero */
308 frame->tf_eflags &= ~PSL_C; /* success */
309 frame->tf_edx = 1; /* System V emulation */
310 }
311
312 /*
313 * Intercept the return address from a freshly forked process that has NOT
314 * been scheduled yet.
315 *
316 * This is needed to make kernel threads stay in kernel mode.
317 */
318 void
cpu_fork_kthread_handler(struct thread * td,void (* func)(void *),void * arg)319 cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg)
320 {
321 /*
322 * Note that the trap frame follows the args, so the function
323 * is really called like this: func(arg, frame);
324 */
325 td->td_pcb->pcb_esi = (int) func; /* function */
326 td->td_pcb->pcb_ebx = (int) arg; /* first arg */
327 }
328
329 void
cpu_exit(struct thread * td)330 cpu_exit(struct thread *td)
331 {
332
333 /*
334 * If this process has a custom LDT, release it. Reset pc->pcb_gs
335 * and %gs before we free it in case they refer to an LDT entry.
336 */
337 mtx_lock_spin(&dt_lock);
338 if (td->td_proc->p_md.md_ldt) {
339 td->td_pcb->pcb_gs = _udatasel;
340 load_gs(_udatasel);
341 user_ldt_free(td);
342 } else
343 mtx_unlock_spin(&dt_lock);
344 }
345
346 void
cpu_thread_exit(struct thread * td)347 cpu_thread_exit(struct thread *td)
348 {
349
350 critical_enter();
351 if (td == PCPU_GET(fpcurthread))
352 npxdrop();
353 critical_exit();
354
355 /* Disable any hardware breakpoints. */
356 if (td->td_pcb->pcb_flags & PCB_DBREGS) {
357 reset_dbregs();
358 td->td_pcb->pcb_flags &= ~PCB_DBREGS;
359 }
360 }
361
362 void
cpu_thread_clean(struct thread * td)363 cpu_thread_clean(struct thread *td)
364 {
365 struct pcb *pcb;
366
367 pcb = td->td_pcb;
368 if (pcb->pcb_ext != NULL) {
369 /* if (pcb->pcb_ext->ext_refcount-- == 1) ?? */
370 /*
371 * XXX do we need to move the TSS off the allocated pages
372 * before freeing them? (not done here)
373 */
374 pmap_trm_free(pcb->pcb_ext, ctob(IOPAGES + 1));
375 pcb->pcb_ext = NULL;
376 }
377 }
378
379 void
cpu_thread_swapin(struct thread * td)380 cpu_thread_swapin(struct thread *td)
381 {
382 }
383
384 void
cpu_thread_swapout(struct thread * td)385 cpu_thread_swapout(struct thread *td)
386 {
387 }
388
389 void
cpu_thread_alloc(struct thread * td)390 cpu_thread_alloc(struct thread *td)
391 {
392 struct pcb *pcb;
393 struct xstate_hdr *xhdr;
394
395 td->td_pcb = pcb = get_pcb_td(td);
396 td->td_frame = (struct trapframe *)((caddr_t)pcb -
397 VM86_STACK_SPACE) - 1;
398 pcb->pcb_ext = NULL;
399 pcb->pcb_save = get_pcb_user_save_pcb(pcb);
400 if (use_xsave) {
401 xhdr = (struct xstate_hdr *)(pcb->pcb_save + 1);
402 bzero(xhdr, sizeof(*xhdr));
403 xhdr->xstate_bv = xsave_mask;
404 }
405 }
406
407 void
cpu_thread_free(struct thread * td)408 cpu_thread_free(struct thread *td)
409 {
410
411 cpu_thread_clean(td);
412 }
413
414 bool
cpu_exec_vmspace_reuse(struct proc * p __unused,vm_map_t map __unused)415 cpu_exec_vmspace_reuse(struct proc *p __unused, vm_map_t map __unused)
416 {
417
418 return (true);
419 }
420
421 int
cpu_procctl(struct thread * td __unused,int idtype __unused,id_t id __unused,int com __unused,void * data __unused)422 cpu_procctl(struct thread *td __unused, int idtype __unused, id_t id __unused,
423 int com __unused, void *data __unused)
424 {
425
426 return (EINVAL);
427 }
428
429 void
cpu_set_syscall_retval(struct thread * td,int error)430 cpu_set_syscall_retval(struct thread *td, int error)
431 {
432
433 switch (error) {
434 case 0:
435 td->td_frame->tf_eax = td->td_retval[0];
436 td->td_frame->tf_edx = td->td_retval[1];
437 td->td_frame->tf_eflags &= ~PSL_C;
438 break;
439
440 case ERESTART:
441 /*
442 * Reconstruct pc, assuming lcall $X,y is 7 bytes, int
443 * 0x80 is 2 bytes. We saved this in tf_err.
444 */
445 td->td_frame->tf_eip -= td->td_frame->tf_err;
446 break;
447
448 case EJUSTRETURN:
449 break;
450
451 default:
452 td->td_frame->tf_eax = error;
453 td->td_frame->tf_eflags |= PSL_C;
454 break;
455 }
456 }
457
458 /*
459 * Initialize machine state, mostly pcb and trap frame for a new
460 * thread, about to return to userspace. Put enough state in the new
461 * thread's PCB to get it to go back to the fork_return(), which
462 * finalizes the thread state and handles peculiarities of the first
463 * return to userspace for the new thread.
464 */
465 void
cpu_copy_thread(struct thread * td,struct thread * td0)466 cpu_copy_thread(struct thread *td, struct thread *td0)
467 {
468 copy_thread(td0, td);
469
470 /*
471 * Copy user general-purpose registers.
472 *
473 * Some of these registers are rewritten by cpu_set_upcall()
474 * and linux_set_upcall().
475 */
476 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe));
477
478 /* If the current thread has the trap bit set (i.e. a debugger had
479 * single stepped the process to the system call), we need to clear
480 * the trap flag from the new frame. Otherwise, the new thread will
481 * receive a (likely unexpected) SIGTRAP when it executes the first
482 * instruction after returning to userland.
483 */
484 td->td_frame->tf_eflags &= ~PSL_T;
485 }
486
487 /*
488 * Set that machine state for performing an upcall that starts
489 * the entry function with the given argument.
490 */
491 int
cpu_set_upcall(struct thread * td,void (* entry)(void *),void * arg,stack_t * stack)492 cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg,
493 stack_t *stack)
494 {
495
496 /*
497 * Do any extra cleaning that needs to be done.
498 * The thread may have optional components
499 * that are not present in a fresh thread.
500 * This may be a recycled thread so make it look
501 * as though it's newly allocated.
502 */
503 cpu_thread_clean(td);
504
505 /*
506 * Set the trap frame to point at the beginning of the entry
507 * function.
508 */
509 td->td_frame->tf_ebp = 0;
510 td->td_frame->tf_esp =
511 (((int)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4;
512 td->td_frame->tf_eip = (int)entry;
513
514 /* Return address sentinel value to stop stack unwinding. */
515 if (suword((void *)td->td_frame->tf_esp, 0) != 0)
516 return (EFAULT);
517
518 /* Pass the argument to the entry point. */
519 if (suword((void *)(td->td_frame->tf_esp + sizeof(void *)),
520 (int)arg) != 0)
521 return (EFAULT);
522 return (0);
523 }
524
525 int
cpu_set_user_tls(struct thread * td,void * tls_base)526 cpu_set_user_tls(struct thread *td, void *tls_base)
527 {
528 struct segment_descriptor sd;
529 uint32_t base;
530
531 /*
532 * Construct a descriptor and store it in the pcb for
533 * the next context switch. Also store it in the gdt
534 * so that the load of tf_fs into %fs will activate it
535 * at return to userland.
536 */
537 base = (uint32_t)tls_base;
538 sd.sd_lobase = base & 0xffffff;
539 sd.sd_hibase = (base >> 24) & 0xff;
540 sd.sd_lolimit = 0xffff; /* 4GB limit, wraps around */
541 sd.sd_hilimit = 0xf;
542 sd.sd_type = SDT_MEMRWA;
543 sd.sd_dpl = SEL_UPL;
544 sd.sd_p = 1;
545 sd.sd_xx = 0;
546 sd.sd_def32 = 1;
547 sd.sd_gran = 1;
548 critical_enter();
549 /* set %gs */
550 td->td_pcb->pcb_gsd = sd;
551 if (td == curthread) {
552 PCPU_GET(fsgs_gdt)[1] = sd;
553 load_gs(GSEL(GUGS_SEL, SEL_UPL));
554 }
555 critical_exit();
556 return (0);
557 }
558
559 /*
560 * Convert kernel VA to physical address
561 */
562 vm_paddr_t
kvtop(void * addr)563 kvtop(void *addr)
564 {
565 vm_paddr_t pa;
566
567 pa = pmap_kextract((vm_offset_t)addr);
568 if (pa == 0)
569 panic("kvtop: zero page frame");
570 return (pa);
571 }
572
573 /*
574 * Get an sf_buf from the freelist. May block if none are available.
575 */
576 void
sf_buf_map(struct sf_buf * sf,int flags)577 sf_buf_map(struct sf_buf *sf, int flags)
578 {
579
580 pmap_sf_buf_map(sf);
581 #ifdef SMP
582 sf_buf_shootdown(sf, flags);
583 #endif
584 }
585
586 #ifdef SMP
587 static void
sf_buf_shootdown_curcpu_cb(pmap_t pmap __unused,vm_offset_t addr1 __unused,vm_offset_t addr2 __unused)588 sf_buf_shootdown_curcpu_cb(pmap_t pmap __unused,
589 vm_offset_t addr1 __unused, vm_offset_t addr2 __unused)
590 {
591 }
592
593 void
sf_buf_shootdown(struct sf_buf * sf,int flags)594 sf_buf_shootdown(struct sf_buf *sf, int flags)
595 {
596 cpuset_t other_cpus;
597 u_int cpuid;
598
599 sched_pin();
600 cpuid = PCPU_GET(cpuid);
601 if (!CPU_ISSET(cpuid, &sf->cpumask)) {
602 CPU_SET(cpuid, &sf->cpumask);
603 invlpg(sf->kva);
604 }
605 if ((flags & SFB_CPUPRIVATE) == 0) {
606 other_cpus = all_cpus;
607 CPU_CLR(cpuid, &other_cpus);
608 CPU_ANDNOT(&other_cpus, &other_cpus, &sf->cpumask);
609 if (!CPU_EMPTY(&other_cpus)) {
610 CPU_OR(&sf->cpumask, &sf->cpumask, &other_cpus);
611 smp_masked_invlpg(other_cpus, sf->kva, kernel_pmap,
612 sf_buf_shootdown_curcpu_cb);
613 }
614 }
615 sched_unpin();
616 }
617 #endif
618
619 /*
620 * MD part of sf_buf_free().
621 */
622 int
sf_buf_unmap(struct sf_buf * sf)623 sf_buf_unmap(struct sf_buf *sf)
624 {
625
626 return (0);
627 }
628
629 static void
sf_buf_invalidate(struct sf_buf * sf)630 sf_buf_invalidate(struct sf_buf *sf)
631 {
632 vm_page_t m = sf->m;
633
634 /*
635 * Use pmap_qenter to update the pte for
636 * existing mapping, in particular, the PAT
637 * settings are recalculated.
638 */
639 pmap_qenter(sf->kva, &m, 1);
640 pmap_invalidate_cache_range(sf->kva, sf->kva + PAGE_SIZE);
641 }
642
643 /*
644 * Invalidate the cache lines that may belong to the page, if
645 * (possibly old) mapping of the page by sf buffer exists. Returns
646 * TRUE when mapping was found and cache invalidated.
647 */
648 boolean_t
sf_buf_invalidate_cache(vm_page_t m)649 sf_buf_invalidate_cache(vm_page_t m)
650 {
651
652 return (sf_buf_process_page(m, sf_buf_invalidate));
653 }
654