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
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.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
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.
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
39 * from: @(#)vm_machdep.c 7.3 (Berkeley) 5/13/91
40 * Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD$");
48 #include "opt_reset.h"
52 #include <sys/param.h>
53 #include <sys/systm.h>
56 #include <sys/kernel.h>
59 #include <sys/malloc.h>
61 #include <sys/mutex.h>
62 #include <sys/pioctl.h>
64 #include <sys/sysent.h>
65 #include <sys/sf_buf.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>
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>
82 #include <machine/elan_mmcr.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>
93 #include <xen/hypervisor.h>
96 #include <pc98/cbus/cbus.h>
98 #include <x86/isa/isa.h>
102 #include <machine/xbox.h>
106 #define NSFBUFS (512 + maxusers * 16)
109 #if !defined(CPU_DISABLE_SSE) && defined(I686_CPU)
110 #define CPU_ENABLE_SSE
113 _Static_assert(OFFSETOF_CURTHREAD == offsetof(struct pcpu, pc_curthread),
114 "OFFSETOF_CURTHREAD does not correspond with offset of pc_curthread.");
115 _Static_assert(OFFSETOF_CURPCB == offsetof(struct pcpu, pc_curpcb),
116 "OFFSETOF_CURPCB does not correspond with offset of pc_curpcb.");
118 static void cpu_reset_real(void);
120 static void cpu_reset_proxy(void);
121 static u_int cpu_reset_proxyid;
122 static volatile u_int cpu_reset_proxy_active;
126 static int nsfbufspeak;
127 static int nsfbufsused;
129 SYSCTL_INT(_kern_ipc, OID_AUTO, nsfbufs, CTLFLAG_RDTUN, &nsfbufs, 0,
130 "Maximum number of sendfile(2) sf_bufs available");
131 SYSCTL_INT(_kern_ipc, OID_AUTO, nsfbufspeak, CTLFLAG_RD, &nsfbufspeak, 0,
132 "Number of sendfile(2) sf_bufs at peak usage");
133 SYSCTL_INT(_kern_ipc, OID_AUTO, nsfbufsused, CTLFLAG_RD, &nsfbufsused, 0,
134 "Number of sendfile(2) sf_bufs in use");
136 static void sf_buf_init(void *arg);
137 SYSINIT(sock_sf, SI_SUB_MBUF, SI_ORDER_ANY, sf_buf_init, NULL);
139 LIST_HEAD(sf_head, sf_buf);
142 * A hash table of active sendfile(2) buffers
144 static struct sf_head *sf_buf_active;
145 static u_long sf_buf_hashmask;
147 #define SF_BUF_HASH(m) (((m) - vm_page_array) & sf_buf_hashmask)
149 static TAILQ_HEAD(, sf_buf) sf_buf_freelist;
150 static u_int sf_buf_alloc_want;
153 * A lock used to synchronize access to the hash table and free list
155 static struct mtx sf_buf_lock;
158 get_pcb_user_save_td(struct thread *td)
161 p = td->td_kstack + td->td_kstack_pages * PAGE_SIZE -
162 cpu_max_ext_state_size;
163 KASSERT((p % 64) == 0, ("Unaligned pcb_user_save area"));
164 return ((union savefpu *)p);
168 get_pcb_user_save_pcb(struct pcb *pcb)
172 p = (vm_offset_t)(pcb + 1);
173 return ((union savefpu *)p);
177 get_pcb_td(struct thread *td)
181 p = td->td_kstack + td->td_kstack_pages * PAGE_SIZE -
182 cpu_max_ext_state_size - sizeof(struct pcb);
183 return ((struct pcb *)p);
187 alloc_fpusave(int flags)
190 #ifdef CPU_ENABLE_SSE
191 struct savefpu_ymm *sf;
194 res = malloc(cpu_max_ext_state_size, M_DEVBUF, flags);
195 #ifdef CPU_ENABLE_SSE
197 sf = (struct savefpu_ymm *)res;
198 bzero(&sf->sv_xstate.sx_hd, sizeof(sf->sv_xstate.sx_hd));
199 sf->sv_xstate.sx_hd.xstate_bv = xsave_mask;
206 * Finish a fork operation, with process p2 nearly set up.
207 * Copy and update the pcb, set up the stack so that the child
208 * ready to run and return to user mode.
211 cpu_fork(td1, p2, td2, flags)
212 register struct thread *td1;
213 register struct proc *p2;
217 register struct proc *p1;
222 if ((flags & RFPROC) == 0) {
223 if ((flags & RFMEM) == 0) {
224 /* unshare user LDT */
225 struct mdproc *mdp1 = &p1->p_md;
226 struct proc_ldt *pldt, *pldt1;
228 mtx_lock_spin(&dt_lock);
229 if ((pldt1 = mdp1->md_ldt) != NULL &&
230 pldt1->ldt_refcnt > 1) {
231 pldt = user_ldt_alloc(mdp1, pldt1->ldt_len);
233 panic("could not copy LDT");
236 user_ldt_deref(pldt1);
238 mtx_unlock_spin(&dt_lock);
243 /* Ensure that td1's pcb is up to date. */
244 if (td1 == curthread)
245 td1->td_pcb->pcb_gs = rgs();
248 if (PCPU_GET(fpcurthread) == td1)
249 npxsave(td1->td_pcb->pcb_save);
253 /* Point the pcb to the top of the stack */
254 pcb2 = get_pcb_td(td2);
258 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2));
260 /* Properly initialize pcb_save */
261 pcb2->pcb_save = get_pcb_user_save_pcb(pcb2);
262 bcopy(get_pcb_user_save_td(td1), get_pcb_user_save_pcb(pcb2),
263 cpu_max_ext_state_size);
265 /* Point mdproc and then copy over td1's contents */
267 bcopy(&p1->p_md, mdp2, sizeof(*mdp2));
270 * Create a new fresh stack for the new process.
271 * Copy the trap frame for the return to user mode as if from a
272 * syscall. This copies most of the user mode register values.
273 * The -16 is so we can expand the trapframe if we go to vm86.
275 td2->td_frame = (struct trapframe *)((caddr_t)td2->td_pcb - 16) - 1;
276 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe));
278 td2->td_frame->tf_eax = 0; /* Child returns zero */
279 td2->td_frame->tf_eflags &= ~PSL_C; /* success */
280 td2->td_frame->tf_edx = 1;
283 * If the parent process has the trap bit set (i.e. a debugger had
284 * single stepped the process to the system call), we need to clear
285 * the trap flag from the new frame unless the debugger had set PF_FORK
286 * on the parent. Otherwise, the child will receive a (likely
287 * unexpected) SIGTRAP when it executes the first instruction after
288 * returning to userland.
290 if ((p1->p_pfsflags & PF_FORK) == 0)
291 td2->td_frame->tf_eflags &= ~PSL_T;
294 * Set registers for trampoline to user mode. Leave space for the
295 * return address on stack. These are the kernel mode register values.
297 #if defined(PAE) || defined(PAE_TABLES)
298 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdpt);
300 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdir);
303 pcb2->pcb_esi = (int)fork_return; /* fork_trampoline argument */
305 pcb2->pcb_esp = (int)td2->td_frame - sizeof(void *);
306 pcb2->pcb_ebx = (int)td2; /* fork_trampoline argument */
307 pcb2->pcb_eip = (int)fork_trampoline;
308 pcb2->pcb_psl = PSL_KERNEL; /* ints disabled */
310 * pcb2->pcb_dr*: cloned above.
311 * pcb2->pcb_savefpu: cloned above.
312 * pcb2->pcb_flags: cloned above.
313 * pcb2->pcb_onfault: cloned above (always NULL here?).
314 * pcb2->pcb_gs: cloned above.
315 * pcb2->pcb_ext: cleared below.
319 * XXX don't copy the i/o pages. this should probably be fixed.
323 /* Copy the LDT, if necessary. */
324 mtx_lock_spin(&dt_lock);
325 if (mdp2->md_ldt != NULL) {
327 mdp2->md_ldt->ldt_refcnt++;
329 mdp2->md_ldt = user_ldt_alloc(mdp2,
330 mdp2->md_ldt->ldt_len);
331 if (mdp2->md_ldt == NULL)
332 panic("could not copy LDT");
335 mtx_unlock_spin(&dt_lock);
337 /* Setup to release spin count in fork_exit(). */
338 td2->td_md.md_spinlock_count = 1;
340 * XXX XEN need to check on PSL_USER is handled
342 td2->td_md.md_saved_flags = PSL_KERNEL | PSL_I;
344 * Now, cpu_switch() can schedule the new process.
345 * pcb_esp is loaded pointing to the cpu_switch() stack frame
346 * containing the return address when exiting cpu_switch.
347 * This will normally be to fork_trampoline(), which will have
348 * %ebx loaded with the new proc's pointer. fork_trampoline()
349 * will set up a stack to call fork_return(p, frame); to complete
350 * the return to user-mode.
355 * Intercept the return address from a freshly forked process that has NOT
356 * been scheduled yet.
358 * This is needed to make kernel threads stay in kernel mode.
361 cpu_set_fork_handler(td, func, arg)
363 void (*func)(void *);
367 * Note that the trap frame follows the args, so the function
368 * is really called like this: func(arg, frame);
370 td->td_pcb->pcb_esi = (int) func; /* function */
371 td->td_pcb->pcb_ebx = (int) arg; /* first arg */
375 cpu_exit(struct thread *td)
379 * If this process has a custom LDT, release it. Reset pc->pcb_gs
380 * and %gs before we free it in case they refer to an LDT entry.
382 mtx_lock_spin(&dt_lock);
383 if (td->td_proc->p_md.md_ldt) {
384 td->td_pcb->pcb_gs = _udatasel;
388 mtx_unlock_spin(&dt_lock);
392 cpu_thread_exit(struct thread *td)
397 if (td == PCPU_GET(fpcurthread))
402 /* Disable any hardware breakpoints. */
403 if (td->td_pcb->pcb_flags & PCB_DBREGS) {
405 td->td_pcb->pcb_flags &= ~PCB_DBREGS;
410 cpu_thread_clean(struct thread *td)
415 if (pcb->pcb_ext != NULL) {
416 /* if (pcb->pcb_ext->ext_refcount-- == 1) ?? */
418 * XXX do we need to move the TSS off the allocated pages
419 * before freeing them? (not done here)
421 kmem_free(kernel_arena, (vm_offset_t)pcb->pcb_ext,
428 cpu_thread_swapin(struct thread *td)
433 cpu_thread_swapout(struct thread *td)
438 cpu_thread_alloc(struct thread *td)
441 #ifdef CPU_ENABLE_SSE
442 struct xstate_hdr *xhdr;
445 td->td_pcb = pcb = get_pcb_td(td);
446 td->td_frame = (struct trapframe *)((caddr_t)pcb - 16) - 1;
448 pcb->pcb_save = get_pcb_user_save_pcb(pcb);
449 #ifdef CPU_ENABLE_SSE
451 xhdr = (struct xstate_hdr *)(pcb->pcb_save + 1);
452 bzero(xhdr, sizeof(*xhdr));
453 xhdr->xstate_bv = xsave_mask;
459 cpu_thread_free(struct thread *td)
462 cpu_thread_clean(td);
466 cpu_set_syscall_retval(struct thread *td, int error)
471 td->td_frame->tf_eax = td->td_retval[0];
472 td->td_frame->tf_edx = td->td_retval[1];
473 td->td_frame->tf_eflags &= ~PSL_C;
478 * Reconstruct pc, assuming lcall $X,y is 7 bytes, int
479 * 0x80 is 2 bytes. We saved this in tf_err.
481 td->td_frame->tf_eip -= td->td_frame->tf_err;
488 if (td->td_proc->p_sysent->sv_errsize) {
489 if (error >= td->td_proc->p_sysent->sv_errsize)
490 error = -1; /* XXX */
492 error = td->td_proc->p_sysent->sv_errtbl[error];
494 td->td_frame->tf_eax = error;
495 td->td_frame->tf_eflags |= PSL_C;
501 * Initialize machine state (pcb and trap frame) for a new thread about to
502 * upcall. Put enough state in the new thread's PCB to get it to go back
503 * userret(), where we can intercept it again to set the return (upcall)
504 * Address and stack, along with those from upcals that are from other sources
505 * such as those generated in thread_userret() itself.
508 cpu_set_upcall(struct thread *td, struct thread *td0)
512 /* Point the pcb to the top of the stack. */
516 * Copy the upcall pcb. This loads kernel regs.
517 * Those not loaded individually below get their default
520 bcopy(td0->td_pcb, pcb2, sizeof(*pcb2));
521 pcb2->pcb_flags &= ~(PCB_NPXINITDONE | PCB_NPXUSERINITDONE |
523 pcb2->pcb_save = get_pcb_user_save_pcb(pcb2);
524 bcopy(get_pcb_user_save_td(td0), pcb2->pcb_save,
525 cpu_max_ext_state_size);
528 * Create a new fresh stack for the new thread.
530 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe));
532 /* If the current thread has the trap bit set (i.e. a debugger had
533 * single stepped the process to the system call), we need to clear
534 * the trap flag from the new frame. Otherwise, the new thread will
535 * receive a (likely unexpected) SIGTRAP when it executes the first
536 * instruction after returning to userland.
538 td->td_frame->tf_eflags &= ~PSL_T;
541 * Set registers for trampoline to user mode. Leave space for the
542 * return address on stack. These are the kernel mode register values.
545 pcb2->pcb_esi = (int)fork_return; /* trampoline arg */
547 pcb2->pcb_esp = (int)td->td_frame - sizeof(void *); /* trampoline arg */
548 pcb2->pcb_ebx = (int)td; /* trampoline arg */
549 pcb2->pcb_eip = (int)fork_trampoline;
550 pcb2->pcb_psl &= ~(PSL_I); /* interrupts must be disabled */
551 pcb2->pcb_gs = rgs();
553 * If we didn't copy the pcb, we'd need to do the following registers:
554 * pcb2->pcb_cr3: cloned above.
555 * pcb2->pcb_dr*: cloned above.
556 * pcb2->pcb_savefpu: cloned above.
557 * pcb2->pcb_flags: cloned above.
558 * pcb2->pcb_onfault: cloned above (always NULL here?).
559 * pcb2->pcb_gs: cloned above.
560 * pcb2->pcb_ext: cleared below.
562 pcb2->pcb_ext = NULL;
564 /* Setup to release spin count in fork_exit(). */
565 td->td_md.md_spinlock_count = 1;
566 td->td_md.md_saved_flags = PSL_KERNEL | PSL_I;
570 * Set that machine state for performing an upcall that has to
571 * be done in thread_userret() so that those upcalls generated
572 * in thread_userret() itself can be done as well.
575 cpu_set_upcall_kse(struct thread *td, void (*entry)(void *), void *arg,
580 * Do any extra cleaning that needs to be done.
581 * The thread may have optional components
582 * that are not present in a fresh thread.
583 * This may be a recycled thread so make it look
584 * as though it's newly allocated.
586 cpu_thread_clean(td);
589 * Set the trap frame to point at the beginning of the uts
592 td->td_frame->tf_ebp = 0;
593 td->td_frame->tf_esp =
594 (((int)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4;
595 td->td_frame->tf_eip = (int)entry;
598 * Pass the address of the mailbox for this kse to the uts
599 * function as a parameter on the stack.
601 suword((void *)(td->td_frame->tf_esp + sizeof(void *)),
606 cpu_set_user_tls(struct thread *td, void *tls_base)
608 struct segment_descriptor sd;
612 * Construct a descriptor and store it in the pcb for
613 * the next context switch. Also store it in the gdt
614 * so that the load of tf_fs into %fs will activate it
615 * at return to userland.
617 base = (uint32_t)tls_base;
618 sd.sd_lobase = base & 0xffffff;
619 sd.sd_hibase = (base >> 24) & 0xff;
620 sd.sd_lolimit = 0xffff; /* 4GB limit, wraps around */
622 sd.sd_type = SDT_MEMRWA;
630 td->td_pcb->pcb_gsd = sd;
631 if (td == curthread) {
632 PCPU_GET(fsgs_gdt)[1] = sd;
633 load_gs(GSEL(GUGS_SEL, SEL_UPL));
640 * Convert kernel VA to physical address
647 pa = pmap_kextract((vm_offset_t)addr);
649 panic("kvtop: zero page frame");
659 cpu_reset_proxy_active = 1;
660 while (cpu_reset_proxy_active == 1)
661 ; /* Wait for other cpu to see that we've started */
662 CPU_SETOF(cpu_reset_proxyid, &tcrp);
664 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid);
674 if (arch_i386_is_xbox) {
675 /* Kick the PIC16L, it can reboot the box */
687 CPU_CLR(PCPU_GET(cpuid), &map);
688 CPU_NAND(&map, &stopped_cpus);
689 if (!CPU_EMPTY(&map)) {
690 printf("cpu_reset: Stopping other CPUs\n");
694 if (PCPU_GET(cpuid) != 0) {
695 cpu_reset_proxyid = PCPU_GET(cpuid);
696 cpustop_restartfunc = cpu_reset_proxy;
697 cpu_reset_proxy_active = 0;
698 printf("cpu_reset: Restarting BSP\n");
700 /* Restart CPU #0. */
701 /* XXX: restart_cpus(1 << 0); */
702 CPU_SETOF(0, &started_cpus);
706 while (cpu_reset_proxy_active == 0 && cnt < 10000000)
707 cnt++; /* Wait for BSP to announce restart */
708 if (cpu_reset_proxy_active == 0)
709 printf("cpu_reset: Failed to restart BSP\n");
711 cpu_reset_proxy_active = 2;
727 struct region_descriptor null_idt;
734 if (smp_processor_id() == 0)
735 HYPERVISOR_shutdown(SHUTDOWN_reboot);
737 HYPERVISOR_shutdown(SHUTDOWN_poweroff);
740 if (elan_mmcr != NULL)
741 elan_mmcr->RESCFG = 1;
744 if (cpu == CPU_GEODE1100) {
745 /* Attempt Geode's own reset */
746 outl(0xcf8, 0x80009044ul);
752 * Attempt to do a CPU reset via CPU reset port.
754 if ((inb(0x35) & 0xa0) != 0xa0) {
755 outb(0x37, 0x0f); /* SHUT0 = 0. */
756 outb(0x37, 0x0b); /* SHUT1 = 0. */
758 outb(0xf0, 0x00); /* Reset. */
760 #if !defined(BROKEN_KEYBOARD_RESET)
762 * Attempt to do a CPU reset via the keyboard controller,
763 * do not turn off GateA20, as any machine that fails
764 * to do the reset here would then end up in no man's land.
766 outb(IO_KBD + 4, 0xFE);
767 DELAY(500000); /* wait 0.5 sec to see if that did it */
771 * Attempt to force a reset via the Reset Control register at
772 * I/O port 0xcf9. Bit 2 forces a system reset when it
773 * transitions from 0 to 1. Bit 1 selects the type of reset
774 * to attempt: 0 selects a "soft" reset, and 1 selects a
775 * "hard" reset. We try a "hard" reset. The first write sets
776 * bit 1 to select a "hard" reset and clears bit 2. The
777 * second write forces a 0 -> 1 transition in bit 2 to trigger
782 DELAY(500000); /* wait 0.5 sec to see if that did it */
785 * Attempt to force a reset via the Fast A20 and Init register
786 * at I/O port 0x92. Bit 1 serves as an alternate A20 gate.
787 * Bit 0 asserts INIT# when set to 1. We are careful to only
788 * preserve bit 1 while setting bit 0. We also must clear bit
789 * 0 before setting it if it isn't already clear.
794 outb(0x92, b & 0xfe);
796 DELAY(500000); /* wait 0.5 sec to see if that did it */
800 printf("No known reset method worked, attempting CPU shutdown\n");
801 DELAY(1000000); /* wait 1 sec for printf to complete */
804 null_idt.rd_limit = 0;
805 null_idt.rd_base = 0;
808 /* "good night, sweet prince .... <THUNK!>" */
816 * Allocate a pool of sf_bufs (sendfile(2) or "super-fast" if you prefer. :-))
819 sf_buf_init(void *arg)
821 struct sf_buf *sf_bufs;
826 TUNABLE_INT_FETCH("kern.ipc.nsfbufs", &nsfbufs);
828 sf_buf_active = hashinit(nsfbufs, M_TEMP, &sf_buf_hashmask);
829 TAILQ_INIT(&sf_buf_freelist);
830 sf_base = kva_alloc(nsfbufs * PAGE_SIZE);
831 sf_bufs = malloc(nsfbufs * sizeof(struct sf_buf), M_TEMP,
833 for (i = 0; i < nsfbufs; i++) {
834 sf_bufs[i].kva = sf_base + i * PAGE_SIZE;
835 TAILQ_INSERT_TAIL(&sf_buf_freelist, &sf_bufs[i], free_entry);
837 sf_buf_alloc_want = 0;
838 mtx_init(&sf_buf_lock, "sf_buf", NULL, MTX_DEF);
842 * Invalidate the cache lines that may belong to the page, if
843 * (possibly old) mapping of the page by sf buffer exists. Returns
844 * TRUE when mapping was found and cache invalidated.
847 sf_buf_invalidate_cache(vm_page_t m)
849 struct sf_head *hash_list;
853 hash_list = &sf_buf_active[SF_BUF_HASH(m)];
855 mtx_lock(&sf_buf_lock);
856 LIST_FOREACH(sf, hash_list, list_entry) {
859 * Use pmap_qenter to update the pte for
860 * existing mapping, in particular, the PAT
861 * settings are recalculated.
863 pmap_qenter(sf->kva, &m, 1);
864 pmap_invalidate_cache_range(sf->kva, sf->kva +
870 mtx_unlock(&sf_buf_lock);
875 * Get an sf_buf from the freelist. May block if none are available.
878 sf_buf_alloc(struct vm_page *m, int flags)
880 pt_entry_t opte, *ptep;
881 struct sf_head *hash_list;
889 KASSERT(curthread->td_pinned > 0 || (flags & SFB_CPUPRIVATE) == 0,
890 ("sf_buf_alloc(SFB_CPUPRIVATE): curthread not pinned"));
891 hash_list = &sf_buf_active[SF_BUF_HASH(m)];
892 mtx_lock(&sf_buf_lock);
893 LIST_FOREACH(sf, hash_list, list_entry) {
896 if (sf->ref_count == 1) {
897 TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry);
899 nsfbufspeak = imax(nsfbufspeak, nsfbufsused);
908 while ((sf = TAILQ_FIRST(&sf_buf_freelist)) == NULL) {
909 if (flags & SFB_NOWAIT)
912 SFSTAT_INC(sf_allocwait);
913 error = msleep(&sf_buf_freelist, &sf_buf_lock,
914 (flags & SFB_CATCH) ? PCATCH | PVM : PVM, "sfbufa", 0);
918 * If we got a signal, don't risk going back to sleep.
923 TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry);
925 LIST_REMOVE(sf, list_entry);
926 LIST_INSERT_HEAD(hash_list, sf, list_entry);
930 nsfbufspeak = imax(nsfbufspeak, nsfbufsused);
933 * Update the sf_buf's virtual-to-physical mapping, flushing the
934 * virtual address from the TLB. Since the reference count for
935 * the sf_buf's old mapping was zero, that mapping is not
936 * currently in use. Consequently, there is no need to exchange
937 * the old and new PTEs atomically, even under PAE.
939 ptep = vtopte(sf->kva);
942 PT_SET_MA(sf->kva, xpmap_ptom(VM_PAGE_TO_PHYS(m)) | pgeflag
943 | PG_RW | PG_V | pmap_cache_bits(m->md.pat_mode, 0));
945 *ptep = VM_PAGE_TO_PHYS(m) | pgeflag | PG_RW | PG_V |
946 pmap_cache_bits(m->md.pat_mode, 0);
950 * Avoid unnecessary TLB invalidations: If the sf_buf's old
951 * virtual-to-physical mapping was not used, then any processor
952 * that has invalidated the sf_buf's virtual address from its TLB
953 * since the last used mapping need not invalidate again.
956 if ((opte & (PG_V | PG_A)) == (PG_V | PG_A))
957 CPU_ZERO(&sf->cpumask);
960 cpuid = PCPU_GET(cpuid);
961 if (!CPU_ISSET(cpuid, &sf->cpumask)) {
962 CPU_SET(cpuid, &sf->cpumask);
965 if ((flags & SFB_CPUPRIVATE) == 0) {
966 other_cpus = all_cpus;
967 CPU_CLR(cpuid, &other_cpus);
968 CPU_NAND(&other_cpus, &sf->cpumask);
969 if (!CPU_EMPTY(&other_cpus)) {
970 CPU_OR(&sf->cpumask, &other_cpus);
971 smp_masked_invlpg(other_cpus, sf->kva);
976 if ((opte & (PG_V | PG_A)) == (PG_V | PG_A))
977 pmap_invalidate_page(kernel_pmap, sf->kva);
980 mtx_unlock(&sf_buf_lock);
985 * Remove a reference from the given sf_buf, adding it to the free
986 * list when its reference count reaches zero. A freed sf_buf still,
987 * however, retains its virtual-to-physical mapping until it is
988 * recycled or reactivated by sf_buf_alloc(9).
991 sf_buf_free(struct sf_buf *sf)
994 mtx_lock(&sf_buf_lock);
996 if (sf->ref_count == 0) {
997 TAILQ_INSERT_TAIL(&sf_buf_freelist, sf, free_entry);
1001 * Xen doesn't like having dangling R/W mappings
1003 pmap_qremove(sf->kva, 1);
1005 LIST_REMOVE(sf, list_entry);
1007 if (sf_buf_alloc_want > 0)
1008 wakeup(&sf_buf_freelist);
1010 mtx_unlock(&sf_buf_lock);
1014 * Software interrupt handler for queued VM system processing.
1019 if (busdma_swi_pending != 0)
1024 * Tell whether this address is in some physical memory region.
1025 * Currently used by the kernel coredump code in order to avoid
1026 * dumping the ``ISA memory hole'' which could cause indefinite hangs,
1027 * or other unpredictable behaviour.
1031 is_physical_memory(vm_paddr_t addr)
1035 /* The ISA ``memory hole''. */
1036 if (addr >= 0xa0000 && addr < 0x100000)
1041 * stuff other tests for known memory-mapped devices (PCI?)