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 $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
41 * $FreeBSD: src/sys/i386/i386/vm_machdep.c,v 1.132.2.9 2003/01/25 19:02:23 dillon Exp $
42 * $DragonFly: src/sys/platform/pc32/i386/vm_machdep.c,v 1.13 2003/06/28 04:16:02 dillon Exp $
46 #include "opt_user_ldt.h"
50 #include "opt_reset.h"
52 #include <sys/param.h>
53 #include <sys/systm.h>
54 #include <sys/malloc.h>
57 #include <sys/vnode.h>
58 #include <sys/vmmeter.h>
59 #include <sys/kernel.h>
60 #include <sys/sysctl.h>
61 #include <sys/unistd.h>
63 #include <machine/clock.h>
64 #include <machine/cpu.h>
65 #include <machine/md_var.h>
67 #include <machine/smp.h>
69 #include <machine/pcb.h>
70 #include <machine/pcb_ext.h>
71 #include <machine/vm86.h>
72 #include <machine/globaldata.h> /* npxthread */
75 #include <vm/vm_param.h>
77 #include <vm/vm_kern.h>
78 #include <vm/vm_page.h>
79 #include <vm/vm_map.h>
80 #include <vm/vm_extern.h>
83 #include <sys/thread2.h>
86 #include <pc98/pc98/pc98.h>
88 #include <i386/isa/isa.h>
91 static void cpu_reset_real __P((void));
93 static void cpu_reset_proxy __P((void));
94 static u_int cpu_reset_proxyid;
95 static volatile u_int cpu_reset_proxy_active;
97 extern int _ucodesel, _udatasel;
100 * quick version of vm_fault
103 vm_fault_quick(v, prot)
109 if (prot & VM_PROT_WRITE)
110 r = subyte(v, fubyte(v));
117 * Finish a fork operation, with process p2 nearly set up.
118 * Copy and update the pcb, set up the stack so that the child
119 * ready to run and return to user mode.
122 cpu_fork(p1, p2, flags)
123 register struct proc *p1, *p2;
128 if ((flags & RFPROC) == 0) {
130 if ((flags & RFMEM) == 0) {
131 /* unshare user LDT */
132 struct pcb *pcb1 = p1->p_thread->td_pcb;
133 struct pcb_ldt *pcb_ldt = pcb1->pcb_ldt;
134 if (pcb_ldt && pcb_ldt->ldt_refcnt > 1) {
135 pcb_ldt = user_ldt_alloc(pcb1,pcb_ldt->ldt_len);
137 pcb1->pcb_ldt = pcb_ldt;
146 /* Ensure that p1's pcb is up to date. */
147 if (npxthread == p1->p_thread)
148 npxsave(&p1->p_thread->td_pcb->pcb_save);
152 pcb2 = p2->p_thread->td_pcb;
153 *pcb2 = *p1->p_thread->td_pcb;
156 * Create a new fresh stack for the new process.
157 * Copy the trap frame for the return to user mode as if from a
158 * syscall. This copies the user mode register values. The
159 * 16 byte offset saves space for vm86, and must match
160 * common_tss.esp0 (kernel stack pointer on entry from user mode)
162 * pcb_esp must allocate an additional call-return pointer below
163 * the trap frame which will be restored by cpu_restore, and the
164 * thread's td_sp pointer must allocate an additonal call-return
165 * pointer below the pcb_esp call-return pointer to hold the LWKT
166 * restore function pointer.
168 * The LWKT restore function pointer must be set to cpu_restore,
169 * which is our standard heavy weight process switch-in function.
170 * YYY eventually we should shortcut fork_return and fork_trampoline
171 * to use the LWKT restore function directly so we can get rid of
172 * all the extra crap we are setting up.
174 p2->p_md.md_regs = (struct trapframe *)((char *)pcb2 - 16) - 1;
175 bcopy(p1->p_md.md_regs, p2->p_md.md_regs, sizeof(*p2->p_md.md_regs));
178 * Set registers for trampoline to user mode. Leave space for the
179 * return address on stack. These are the kernel mode register values.
181 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdir);
183 pcb2->pcb_esi = (int)fork_return; /* fork_trampoline argument */
185 pcb2->pcb_esp = (int)p2->p_md.md_regs - sizeof(void *);
186 pcb2->pcb_ebx = (int)p2; /* fork_trampoline argument */
187 pcb2->pcb_eip = (int)fork_trampoline;
188 p2->p_thread->td_sp = (char *)(pcb2->pcb_esp - sizeof(void *));
189 *(void **)p2->p_thread->td_sp = (void *)cpu_heavy_restore;
191 * pcb2->pcb_ldt: duplicated below, if necessary.
192 * pcb2->pcb_savefpu: cloned above.
193 * pcb2->pcb_flags: cloned above (always 0 here?).
194 * pcb2->pcb_onfault: cloned above (always NULL here?).
198 pcb2->pcb_mpnest = 1;
201 * XXX don't copy the i/o pages. this should probably be fixed.
206 /* Copy the LDT, if necessary. */
207 if (pcb2->pcb_ldt != 0) {
209 pcb2->pcb_ldt->ldt_refcnt++;
211 pcb2->pcb_ldt = user_ldt_alloc(pcb2,
212 pcb2->pcb_ldt->ldt_len);
218 * Now, cpu_switch() can schedule the new process.
219 * pcb_esp is loaded pointing to the cpu_switch() stack frame
220 * containing the return address when exiting cpu_switch.
221 * This will normally be to fork_trampoline(), which will have
222 * %ebx loaded with the new proc's pointer. fork_trampoline()
223 * will set up a stack to call fork_return(p, frame); to complete
224 * the return to user-mode.
229 * Intercept the return address from a freshly forked process that has NOT
230 * been scheduled yet.
232 * This is needed to make kernel threads stay in kernel mode.
235 cpu_set_fork_handler(p, func, arg)
237 void (*func) __P((void *));
241 * Note that the trap frame follows the args, so the function
242 * is really called like this: func(arg, frame);
244 p->p_thread->td_pcb->pcb_esi = (int) func; /* function */
245 p->p_thread->td_pcb->pcb_ebx = (int) arg; /* first arg */
249 cpu_set_thread_handler(thread_t td, void (*rfunc)(void), void *func, void *arg)
251 td->td_pcb->pcb_esi = (int)func;
252 td->td_pcb->pcb_ebx = (int) arg;
253 td->td_switch = cpu_lwkt_switch;
254 td->td_sp -= sizeof(void *);
255 *(void **)td->td_sp = rfunc; /* exit function on return */
256 td->td_sp -= sizeof(void *);
257 *(void **)td->td_sp = cpu_kthread_restore;
263 struct thread *td = curthread;
268 KKASSERT(td->td_proc);
269 npxexit(td->td_proc);
276 if (pcb->pcb_ext != 0) {
278 * XXX do we need to move the TSS off the allocated pages
279 * before freeing them? (not done here)
281 kmem_free(kernel_map, (vm_offset_t)pcb->pcb_ext,
288 if (pcb->pcb_flags & PCB_DBREGS) {
290 * disable all hardware breakpoints
293 pcb->pcb_flags &= ~PCB_DBREGS;
298 lwkt_deschedule_self();
303 * Terminate the current thread. The caller must have already acquired
304 * the thread's rwlock and placed it on a reap list or otherwise notified
305 * a reaper of its existance. We set a special assembly switch function which
306 * releases td_rwlock after it has cleaned up the MMU state and switched
309 * Must be caller from a critical section and with the thread descheduled.
312 cpu_thread_exit(void)
314 curthread->td_switch = cpu_exit_switch;
320 * Process Reaper. Called after the caller has acquired the thread's
321 * rwlock and removed it from the reap list.
324 cpu_proc_wait(struct proc *p)
328 /* drop per-process resources */
329 td = pmap_dispose_proc(p);
331 lwkt_free_thread(td);
335 * Dump the machine specific header information at the start of a core dump.
338 cpu_coredump(struct thread *td, struct vnode *vp, struct ucred *cred)
340 struct proc *p = td->td_proc;
345 tempuser = malloc(ctob(UPAGES), M_TEMP, M_WAITOK);
349 bzero(tempuser, ctob(UPAGES));
350 bcopy(p->p_addr, tempuser, sizeof(struct user));
351 bcopy(p->p_md.md_regs,
352 tempuser + ((caddr_t) p->p_md.md_regs - (caddr_t) p->p_addr),
353 sizeof(struct trapframe));
354 bcopy(p->p_thread->td_pcb, tempuser + ((char *)p->p_thread->td_pcb - (char *)p->p_addr), sizeof(struct pcb));
356 error = vn_rdwr(UIO_WRITE, vp, (caddr_t) tempuser, ctob(UPAGES),
357 (off_t)0, UIO_SYSSPACE, IO_UNIT, cred, (int *)NULL, td);
359 free(tempuser, M_TEMP);
366 setredzone(pte, vaddr)
370 /* eventually do this by setting up an expand-down stack segment
371 for ss0: selector, allowing stack access down to top of u.
372 this means though that protection violations need to be handled
373 thru a double fault exception that must do an integral task
374 switch to a known good context, within which a dump can be
375 taken. a sensible scheme might be to save the initial context
376 used by sched (that has physical memory mapped 1:1 at bottom)
377 and take the dump while still in mapped mode */
382 * Convert kernel VA to physical address
389 va = pmap_kextract((vm_offset_t)addr);
391 panic("kvtop: zero page frame");
396 * Force reset the processor by invalidating the entire address space!
405 cpu_reset_proxy_active = 1;
406 while (cpu_reset_proxy_active == 1)
407 ; /* Wait for other cpu to disable interupts */
408 saved_mp_lock = mp_lock;
410 printf("cpu_reset_proxy: Grabbed mp lock for BSP\n");
411 cpu_reset_proxy_active = 3;
412 while (cpu_reset_proxy_active == 3)
413 ; /* Wait for other cpu to enable interrupts */
414 stop_cpus((1<<cpu_reset_proxyid));
415 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid);
425 if (smp_active == 0) {
432 printf("cpu_reset called on cpu#%d\n",cpuid);
434 map = other_cpus & ~ stopped_cpus;
437 printf("cpu_reset: Stopping other CPUs\n");
438 stop_cpus(map); /* Stop all other CPUs */
446 /* We are not BSP (CPU #0) */
448 cpu_reset_proxyid = cpuid;
449 cpustop_restartfunc = cpu_reset_proxy;
450 printf("cpu_reset: Restarting BSP\n");
451 started_cpus = (1<<0); /* Restart CPU #0 */
454 while (cpu_reset_proxy_active == 0 && cnt < 10000000)
455 cnt++; /* Wait for BSP to announce restart */
456 if (cpu_reset_proxy_active == 0)
457 printf("cpu_reset: Failed to restart BSP\n");
458 __asm __volatile("cli" : : : "memory");
459 cpu_reset_proxy_active = 2;
461 while (cpu_reset_proxy_active == 2 && cnt < 10000000)
462 cnt++; /* Do nothing */
463 if (cpu_reset_proxy_active == 2) {
464 printf("cpu_reset: BSP did not grab mp lock\n");
465 cpu_reset_real(); /* XXX: Bogus ? */
467 cpu_reset_proxy_active = 4;
468 __asm __volatile("sti" : : : "memory");
484 * Attempt to do a CPU reset via CPU reset port.
487 if ((inb(0x35) & 0xa0) != 0xa0) {
488 outb(0x37, 0x0f); /* SHUT0 = 0. */
489 outb(0x37, 0x0b); /* SHUT1 = 0. */
491 outb(0xf0, 0x00); /* Reset. */
494 * Attempt to do a CPU reset via the keyboard controller,
495 * do not turn of the GateA20, as any machine that fails
496 * to do the reset here would then end up in no man's land.
499 #if !defined(BROKEN_KEYBOARD_RESET)
500 outb(IO_KBD + 4, 0xFE);
501 DELAY(500000); /* wait 0.5 sec to see if that did it */
502 printf("Keyboard reset did not work, attempting CPU shutdown\n");
503 DELAY(1000000); /* wait 1 sec for printf to complete */
506 /* force a shutdown by unmapping entire address space ! */
507 bzero((caddr_t) PTD, PAGE_SIZE);
509 /* "good night, sweet prince .... <THUNK!>" */
522 rv = vm_map_growstack (p, sp);
523 if (rv != KERN_SUCCESS)
529 SYSCTL_DECL(_vm_stats_misc);
531 static int cnt_prezero;
533 SYSCTL_INT(_vm_stats_misc, OID_AUTO,
534 cnt_prezero, CTLFLAG_RD, &cnt_prezero, 0, "");
537 * Implement the pre-zeroed page mechanism.
538 * This routine is called from the idle loop.
541 #define ZIDLE_LO(v) ((v) * 2 / 3)
542 #define ZIDLE_HI(v) ((v) * 4 / 5)
547 static int free_rover;
548 static int zero_state;
553 * Attempt to maintain approximately 1/2 of our free pages in a
554 * PG_ZERO'd state. Add some hysteresis to (attempt to) avoid
555 * generally zeroing a page when the system is near steady-state.
556 * Otherwise we might get 'flutter' during disk I/O / IPC or
557 * fast sleeps. We also do not want to be continuously zeroing
558 * pages because doing so may flush our L1 and L2 caches too much.
561 if (zero_state && vm_page_zero_count >= ZIDLE_LO(cnt.v_free_count))
563 if (vm_page_zero_count >= ZIDLE_HI(cnt.v_free_count))
570 __asm __volatile("sti" : : : "memory");
572 m = vm_page_list_find(PQ_FREE, free_rover, FALSE);
573 if (m != NULL && (m->flags & PG_ZERO) == 0) {
574 vm_page_queues[m->queue].lcnt--;
575 TAILQ_REMOVE(&vm_page_queues[m->queue].pl, m, pageq);
578 pmap_zero_page(VM_PAGE_TO_PHYS(m));
580 vm_page_flag_set(m, PG_ZERO);
581 m->queue = PQ_FREE + m->pc;
582 vm_page_queues[m->queue].lcnt++;
583 TAILQ_INSERT_TAIL(&vm_page_queues[m->queue].pl, m,
585 ++vm_page_zero_count;
587 if (vm_page_zero_count >= ZIDLE_HI(cnt.v_free_count))
590 free_rover = (free_rover + PQ_PRIME2) & PQ_L2_MASK;
592 __asm __volatile("cli" : : : "memory");
601 * We have to enable interrupts for a moment if the try_mplock fails
602 * in order to potentially take an IPI. XXX this should be in
605 __asm __volatile("sti; nop; cli" : : : "memory");
610 * Software interrupt handler for queued VM system processing.
615 if (busdma_swi_pending != 0)
620 * Tell whether this address is in some physical memory region.
621 * Currently used by the kernel coredump code in order to avoid
622 * dumping the ``ISA memory hole'' which could cause indefinite hangs,
623 * or other unpredictable behaviour.
629 is_physical_memory(addr)
634 /* The ISA ``memory hole''. */
635 if (addr >= 0xa0000 && addr < 0x100000)
640 * stuff other tests for known memory-mapped devices (PCI?)