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 1.59 2007/04/30 07:18:55 dillon Exp $
47 #include "opt_reset.h"
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/malloc.h>
54 #include <sys/interrupt.h>
55 #include <sys/vnode.h>
56 #include <sys/vmmeter.h>
57 #include <sys/kernel.h>
58 #include <sys/sysctl.h>
59 #include <sys/unistd.h>
61 #include <machine/clock.h>
62 #include <machine/cpu.h>
63 #include <machine/md_var.h>
64 #include <machine/smp.h>
65 #include <machine/pcb.h>
66 #include <machine/pcb_ext.h>
67 #include <machine/vm86.h>
68 #include <machine/segments.h>
69 #include <machine/globaldata.h> /* npxthread */
72 #include <vm/vm_param.h>
74 #include <vm/vm_kern.h>
75 #include <vm/vm_page.h>
76 #include <vm/vm_map.h>
77 #include <vm/vm_extern.h>
80 #include <sys/thread2.h>
82 #include <bus/isa/i386/isa.h>
84 static void cpu_reset_real (void);
86 static void cpu_reset_proxy (void);
87 static u_int cpu_reset_proxyid;
88 static volatile u_int cpu_reset_proxy_active;
90 extern int _ucodesel, _udatasel;
94 * Finish a fork operation, with lwp lp2 nearly set up.
95 * Copy and update the pcb, set up the stack so that the child
96 * ready to run and return to user mode.
99 cpu_fork(struct lwp *lp1, struct lwp *lp2, int flags)
103 if ((flags & RFPROC) == 0) {
104 if ((flags & RFMEM) == 0) {
105 /* unshare user LDT */
106 struct pcb *pcb1 = lp1->lwp_thread->td_pcb;
107 struct pcb_ldt *pcb_ldt = pcb1->pcb_ldt;
108 if (pcb_ldt && pcb_ldt->ldt_refcnt > 1) {
109 pcb_ldt = user_ldt_alloc(pcb1,pcb_ldt->ldt_len);
111 pcb1->pcb_ldt = pcb_ldt;
119 /* Ensure that lp1's pcb is up to date. */
120 if (mdcpu->gd_npxthread == lp1->lwp_thread)
121 npxsave(lp1->lwp_thread->td_savefpu);
125 * Copy lp1's PCB. This really only applies to the
126 * debug registers and FP state, but its faster to just copy the
127 * whole thing. Because we only save the PCB at switchout time,
128 * the register state may not be current.
130 pcb2 = lp2->lwp_thread->td_pcb;
131 *pcb2 = *lp1->lwp_thread->td_pcb;
134 * Create a new fresh stack for the new process.
135 * Copy the trap frame for the return to user mode as if from a
136 * syscall. This copies the user mode register values. The
137 * 16 byte offset saves space for vm86, and must match
138 * common_tss.esp0 (kernel stack pointer on entry from user mode)
140 * pcb_esp must allocate an additional call-return pointer below
141 * the trap frame which will be restored by cpu_restore from
142 * PCB_EIP, and the thread's td_sp pointer must allocate an
143 * additonal two worsd below the pcb_esp call-return pointer to
144 * hold the LWKT restore function pointer and eflags.
146 * The LWKT restore function pointer must be set to cpu_restore,
147 * which is our standard heavy weight process switch-in function.
148 * YYY eventually we should shortcut fork_return and fork_trampoline
149 * to use the LWKT restore function directly so we can get rid of
150 * all the extra crap we are setting up.
152 lp2->lwp_md.md_regs = (struct trapframe *)((char *)pcb2 - 16) - 1;
153 bcopy(lp1->lwp_md.md_regs, lp2->lwp_md.md_regs, sizeof(*lp2->lwp_md.md_regs));
156 * Set registers for trampoline to user mode. Leave space for the
157 * return address on stack. These are the kernel mode register values.
159 pcb2->pcb_cr3 = vtophys(vmspace_pmap(lp2->lwp_proc->p_vmspace)->pm_pdir);
161 pcb2->pcb_esi = (int)fork_return; /* fork_trampoline argument */
163 pcb2->pcb_esp = (int)lp2->lwp_md.md_regs - sizeof(void *);
164 pcb2->pcb_ebx = (int)lp2; /* fork_trampoline argument */
165 pcb2->pcb_eip = (int)fork_trampoline;
166 lp2->lwp_thread->td_sp = (char *)(pcb2->pcb_esp - sizeof(void *));
167 *(u_int32_t *)lp2->lwp_thread->td_sp = PSL_USER;
168 lp2->lwp_thread->td_sp -= sizeof(void *);
169 *(void **)lp2->lwp_thread->td_sp = (void *)cpu_heavy_restore;
172 * pcb2->pcb_ldt: duplicated below, if necessary.
173 * pcb2->pcb_savefpu: cloned above.
174 * pcb2->pcb_flags: cloned above (always 0 here?).
175 * pcb2->pcb_onfault: cloned above (always NULL here?).
179 * XXX don't copy the i/o pages. this should probably be fixed.
183 /* Copy the LDT, if necessary. */
184 if (pcb2->pcb_ldt != 0) {
186 pcb2->pcb_ldt->ldt_refcnt++;
188 pcb2->pcb_ldt = user_ldt_alloc(pcb2,
189 pcb2->pcb_ldt->ldt_len);
192 bcopy(&lp1->lwp_thread->td_tls, &lp2->lwp_thread->td_tls,
193 sizeof(lp2->lwp_thread->td_tls));
195 * Now, cpu_switch() can schedule the new lwp.
196 * pcb_esp is loaded pointing to the cpu_switch() stack frame
197 * containing the return address when exiting cpu_switch.
198 * This will normally be to fork_trampoline(), which will have
199 * %ebx loaded with the new lwp's pointer. fork_trampoline()
200 * will set up a stack to call fork_return(lp, frame); to complete
201 * the return to user-mode.
206 * Prepare new lwp to return to the address specified in params.
209 cpu_prepare_lwp(struct lwp *lp, struct lwp_params *params)
211 struct trapframe *regs = lp->lwp_md.md_regs;
212 void *bad_return = NULL;
215 regs->tf_eip = params->func;
216 regs->tf_esp = params->stack;
217 /* Set up argument for function call */
218 regs->tf_esp -= sizeof(params->arg);
219 error = copyout(¶ms->arg, regs->tf_esp, sizeof(params->arg));
223 * Set up fake return address. As the lwp function may never return,
224 * we simply copy out a NULL pointer and force the lwp to receive
225 * a SIGSEGV if it returns anyways.
227 regs->tf_esp -= sizeof(void *);
228 error = copyout(&bad_return, regs->tf_esp, sizeof(bad_return));
232 cpu_set_fork_handler(lp,
233 (void (*)(void *, struct trapframe *))generic_lwp_return, lp);
238 * Intercept the return address from a freshly forked process that has NOT
239 * been scheduled yet.
241 * This is needed to make kernel threads stay in kernel mode.
244 cpu_set_fork_handler(struct lwp *lp, void (*func)(void *, struct trapframe *),
248 * Note that the trap frame follows the args, so the function
249 * is really called like this: func(arg, frame);
251 lp->lwp_thread->td_pcb->pcb_esi = (int) func; /* function */
252 lp->lwp_thread->td_pcb->pcb_ebx = (int) arg; /* first arg */
256 cpu_set_thread_handler(thread_t td, void (*rfunc)(void), void *func, void *arg)
258 td->td_pcb->pcb_esi = (int)func;
259 td->td_pcb->pcb_ebx = (int) arg;
260 td->td_switch = cpu_lwkt_switch;
261 td->td_sp -= sizeof(void *);
262 *(void **)td->td_sp = rfunc; /* exit function on return */
263 td->td_sp -= sizeof(void *);
264 *(void **)td->td_sp = cpu_kthread_restore;
270 struct thread *td = curthread;
279 * If we were using a private TSS do a forced-switch to ourselves
280 * to switch back to the common TSS before freeing it.
283 if ((ext = pcb->pcb_ext) != NULL) {
288 kmem_free(&kernel_map, (vm_offset_t)ext, ctob(IOPAGES + 1));
291 if (pcb->pcb_flags & PCB_DBREGS) {
293 * disable all hardware breakpoints
296 pcb->pcb_flags &= ~PCB_DBREGS;
298 td->td_gd->gd_cnt.v_swtch++;
300 crit_enter_quick(td);
301 lwkt_deschedule_self(td);
302 lwkt_remove_tdallq(td);
307 * Terminate the current thread. The caller must have already acquired
308 * the thread's rwlock and placed it on a reap list or otherwise notified
309 * a reaper of its existance. We set a special assembly switch function which
310 * releases td_rwlock after it has cleaned up the MMU state and switched
313 * Must be caller from a critical section and with the thread descheduled.
316 cpu_thread_exit(void)
318 curthread->td_switch = cpu_exit_switch;
319 curthread->td_flags |= TDF_EXITING;
325 * Process Reaper. Called after the caller has acquired the thread's
326 * rwlock and removed it from the reap list.
329 cpu_proc_wait(struct proc *p)
331 /* drop per-process resources */
332 pmap_dispose_proc(p);
337 setredzone(u_short *pte, caddr_t vaddr)
339 /* eventually do this by setting up an expand-down stack segment
340 for ss0: selector, allowing stack access down to top of u.
341 this means though that protection violations need to be handled
342 thru a double fault exception that must do an integral task
343 switch to a known good context, within which a dump can be
344 taken. a sensible scheme might be to save the initial context
345 used by sched (that has physical memory mapped 1:1 at bottom)
346 and take the dump while still in mapped mode */
351 * Convert kernel VA to physical address
358 pa = pmap_kextract((vm_offset_t)addr);
360 panic("kvtop: zero page frame");
365 * Force reset the processor by invalidating the entire address space!
370 cpu_reset_proxy(void)
374 cpu_reset_proxy_active = 1;
375 while (cpu_reset_proxy_active == 1)
376 ; /* Wait for other cpu to disable interupts */
377 saved_mp_lock = mp_lock;
378 mp_lock = 0; /* BSP */
379 kprintf("cpu_reset_proxy: Grabbed mp lock for BSP\n");
380 cpu_reset_proxy_active = 3;
381 while (cpu_reset_proxy_active == 3)
382 ; /* Wait for other cpu to enable interrupts */
383 stop_cpus((1<<cpu_reset_proxyid));
384 kprintf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid);
394 if (smp_active_mask == 1) {
400 kprintf("cpu_reset called on cpu#%d\n",mycpu->gd_cpuid);
402 map = mycpu->gd_other_cpus & ~stopped_cpus & smp_active_mask;
405 kprintf("cpu_reset: Stopping other CPUs\n");
406 stop_cpus(map); /* Stop all other CPUs */
409 if (mycpu->gd_cpuid == 0) {
414 /* We are not BSP (CPU #0) */
416 cpu_reset_proxyid = mycpu->gd_cpuid;
417 cpustop_restartfunc = cpu_reset_proxy;
418 kprintf("cpu_reset: Restarting BSP\n");
419 started_cpus = (1<<0); /* Restart CPU #0 */
422 while (cpu_reset_proxy_active == 0 && cnt < 10000000)
423 cnt++; /* Wait for BSP to announce restart */
424 if (cpu_reset_proxy_active == 0)
425 kprintf("cpu_reset: Failed to restart BSP\n");
426 __asm __volatile("cli" : : : "memory");
427 cpu_reset_proxy_active = 2;
429 while (cpu_reset_proxy_active == 2 && cnt < 10000000)
430 cnt++; /* Do nothing */
431 if (cpu_reset_proxy_active == 2) {
432 kprintf("cpu_reset: BSP did not grab mp lock\n");
433 cpu_reset_real(); /* XXX: Bogus ? */
435 cpu_reset_proxy_active = 4;
436 __asm __volatile("sti" : : : "memory");
450 * Attempt to do a CPU reset via the keyboard controller,
451 * do not turn of the GateA20, as any machine that fails
452 * to do the reset here would then end up in no man's land.
455 #if !defined(BROKEN_KEYBOARD_RESET)
456 outb(IO_KBD + 4, 0xFE);
457 DELAY(500000); /* wait 0.5 sec to see if that did it */
458 kprintf("Keyboard reset did not work, attempting CPU shutdown\n");
459 DELAY(1000000); /* wait 1 sec for kprintf to complete */
461 /* force a shutdown by unmapping entire address space ! */
462 bzero((caddr_t) PTD, PAGE_SIZE);
464 /* "good night, sweet prince .... <THUNK!>" */
471 grow_stack(struct proc *p, u_int sp)
475 rv = vm_map_growstack (p, sp);
476 if (rv != KERN_SUCCESS)
482 SYSCTL_DECL(_vm_stats_misc);
484 static int cnt_prezero;
486 SYSCTL_INT(_vm_stats_misc, OID_AUTO,
487 cnt_prezero, CTLFLAG_RD, &cnt_prezero, 0, "");
490 swi_vm(void *arg, void *frame)
492 if (busdma_swi_pending != 0)
497 swi_vm_setup(void *arg)
499 register_swi(SWI_VM, swi_vm, NULL, "swi_vm", NULL);
502 SYSINIT(vm_setup, SI_BOOT2_MACHDEP, SI_ORDER_ANY, swi_vm_setup, NULL);
506 * Tell whether this address is in some physical memory region.
507 * Currently used by the kernel coredump code in order to avoid
508 * dumping the ``ISA memory hole'' which could cause indefinite hangs,
509 * or other unpredictable behaviour.
513 is_physical_memory(vm_offset_t addr)
517 /* The ISA ``memory hole''. */
518 if (addr >= 0xa0000 && addr < 0x100000)
523 * stuff other tests for known memory-mapped devices (PCI?)
531 * platform-specific vmspace initialization (nothing for i386)
534 cpu_vmspace_alloc(struct vmspace *vm __unused)
539 cpu_vmspace_free(struct vmspace *vm __unused)
544 * Used by /dev/kmem to determine if we can safely read or write
545 * the requested KVA range.
548 kvm_access_check(vm_offset_t saddr, vm_offset_t eaddr, int prot)
552 if (saddr < KvaStart)
556 for (addr = saddr; addr < eaddr; addr += PAGE_SIZE) {
557 if (pmap_extract(&kernel_pmap, addr) == 0)
560 if (!kernacc((caddr_t)saddr, eaddr - saddr, prot))