vm_machdep.c revision 109877
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 * $FreeBSD: head/sys/amd64/amd64/vm_machdep.c 109877 2003-01-26 11:41:35Z davidxu $
42 */
43
44#include "opt_npx.h"
45#ifdef PC98
46#include "opt_pc98.h"
47#endif
48#include "opt_reset.h"
49#include "opt_isa.h"
50#include "opt_kstack_pages.h"
51
52#include <sys/param.h>
53#include <sys/systm.h>
54#include <sys/malloc.h>
55#include <sys/proc.h>
56#include <sys/kse.h>
57#include <sys/bio.h>
58#include <sys/buf.h>
59#include <sys/vnode.h>
60#include <sys/vmmeter.h>
61#include <sys/kernel.h>
62#include <sys/ktr.h>
63#include <sys/mutex.h>
64#include <sys/smp.h>
65#include <sys/sysctl.h>
66#include <sys/unistd.h>
67
68#include <machine/cpu.h>
69#include <machine/md_var.h>
70#include <machine/pcb.h>
71#include <machine/pcb_ext.h>
72#include <machine/vm86.h>
73
74#include <vm/vm.h>
75#include <vm/vm_param.h>
76#include <sys/lock.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>
81
82#include <sys/user.h>
83
84#ifdef PC98
85#include <pc98/pc98/pc98.h>
86#else
87#include <i386/isa/isa.h>
88#endif
89
90static void	cpu_reset_real(void);
91#ifdef SMP
92static void	cpu_reset_proxy(void);
93static u_int	cpu_reset_proxyid;
94static volatile u_int	cpu_reset_proxy_active;
95#endif
96extern int	_ucodesel, _udatasel;
97
98/*
99 * Finish a fork operation, with process p2 nearly set up.
100 * Copy and update the pcb, set up the stack so that the child
101 * ready to run and return to user mode.
102 */
103void
104cpu_fork(td1, p2, td2, flags)
105	register struct thread *td1;
106	register struct proc *p2;
107	struct thread *td2;
108	int flags;
109{
110	register struct proc *p1;
111	struct pcb *pcb2;
112	struct mdproc *mdp2;
113#ifdef DEV_NPX
114	register_t savecrit;
115#endif
116
117	p1 = td1->td_proc;
118	if ((flags & RFPROC) == 0) {
119		if ((flags & RFMEM) == 0) {
120			/* unshare user LDT */
121			struct mdproc *mdp1 = &p1->p_md;
122			struct proc_ldt *pldt = mdp1->md_ldt;
123			if (pldt && pldt->ldt_refcnt > 1) {
124				pldt = user_ldt_alloc(mdp1, pldt->ldt_len);
125				if (pldt == NULL)
126					panic("could not copy LDT");
127				mdp1->md_ldt = pldt;
128				set_user_ldt(mdp1);
129				user_ldt_free(td1);
130			}
131		}
132		return;
133	}
134
135	/* Ensure that p1's pcb is up to date. */
136#ifdef DEV_NPX
137	if (td1 == curthread)
138		td1->td_pcb->pcb_gs = rgs();
139	savecrit = intr_disable();
140	if (PCPU_GET(fpcurthread) == td1)
141		npxsave(&td1->td_pcb->pcb_save);
142	intr_restore(savecrit);
143#endif
144
145	/* Point the pcb to the top of the stack */
146	pcb2 = (struct pcb *)(td2->td_kstack + KSTACK_PAGES * PAGE_SIZE) - 1;
147	td2->td_pcb = pcb2;
148
149	/* Copy p1's pcb */
150	bcopy(td1->td_pcb, pcb2, sizeof(*pcb2));
151
152	/* Point mdproc and then copy over td1's contents */
153	mdp2 = &p2->p_md;
154	bcopy(&p1->p_md, mdp2, sizeof(*mdp2));
155
156	/*
157	 * Create a new fresh stack for the new process.
158	 * Copy the trap frame for the return to user mode as if from a
159	 * syscall.  This copies most of the user mode register values.
160	 * The -16 is so we can expand the trapframe if we go to vm86.
161	 */
162	td2->td_frame = (struct trapframe *)((caddr_t)td2->td_pcb - 16) - 1;
163	bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe));
164
165	td2->td_frame->tf_eax = 0;		/* Child returns zero */
166	td2->td_frame->tf_eflags &= ~PSL_C;	/* success */
167	td2->td_frame->tf_edx = 1;
168
169	/*
170	 * Set registers for trampoline to user mode.  Leave space for the
171	 * return address on stack.  These are the kernel mode register values.
172	 */
173	pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdir);
174	pcb2->pcb_edi = 0;
175	pcb2->pcb_esi = (int)fork_return;	/* fork_trampoline argument */
176	pcb2->pcb_ebp = 0;
177	pcb2->pcb_esp = (int)td2->td_frame - sizeof(void *);
178	pcb2->pcb_ebx = (int)td2;		/* fork_trampoline argument */
179	pcb2->pcb_eip = (int)fork_trampoline;
180	pcb2->pcb_psl = td2->td_frame->tf_eflags & ~PSL_I; /* ints disabled */
181	/*-
182	 * pcb2->pcb_dr*:	cloned above.
183	 * pcb2->pcb_savefpu:	cloned above.
184	 * pcb2->pcb_flags:	cloned above.
185	 * pcb2->pcb_onfault:	cloned above (always NULL here?).
186	 * pcb2->pcb_gs:	cloned above.
187	 * pcb2->pcb_ext:	cleared below.
188	 */
189
190	/*
191	 * XXX don't copy the i/o pages.  this should probably be fixed.
192	 */
193	pcb2->pcb_ext = 0;
194
195        /* Copy the LDT, if necessary. */
196	mtx_lock_spin(&sched_lock);
197        if (mdp2->md_ldt != 0) {
198		if (flags & RFMEM) {
199			mdp2->md_ldt->ldt_refcnt++;
200		} else {
201			mdp2->md_ldt = user_ldt_alloc(mdp2,
202			    mdp2->md_ldt->ldt_len);
203			if (mdp2->md_ldt == NULL)
204				panic("could not copy LDT");
205		}
206        }
207	mtx_unlock_spin(&sched_lock);
208
209	/*
210	 * Now, cpu_switch() can schedule the new process.
211	 * pcb_esp is loaded pointing to the cpu_switch() stack frame
212	 * containing the return address when exiting cpu_switch.
213	 * This will normally be to fork_trampoline(), which will have
214	 * %ebx loaded with the new proc's pointer.  fork_trampoline()
215	 * will set up a stack to call fork_return(p, frame); to complete
216	 * the return to user-mode.
217	 */
218}
219
220/*
221 * Intercept the return address from a freshly forked process that has NOT
222 * been scheduled yet.
223 *
224 * This is needed to make kernel threads stay in kernel mode.
225 */
226void
227cpu_set_fork_handler(td, func, arg)
228	struct thread *td;
229	void (*func)(void *);
230	void *arg;
231{
232	/*
233	 * Note that the trap frame follows the args, so the function
234	 * is really called like this:  func(arg, frame);
235	 */
236	td->td_pcb->pcb_esi = (int) func;	/* function */
237	td->td_pcb->pcb_ebx = (int) arg;	/* first arg */
238}
239
240void
241cpu_exit(struct thread *td)
242{
243	struct mdproc *mdp;
244
245	mdp = &td->td_proc->p_md;
246	if (mdp->md_ldt)
247		user_ldt_free(td);
248	reset_dbregs();
249}
250
251void
252cpu_thread_exit(struct thread *td)
253{
254	struct pcb *pcb = td->td_pcb;
255#ifdef DEV_NPX
256	npxexit(td);
257#endif
258        if (pcb->pcb_flags & PCB_DBREGS) {
259                /*
260                 * disable all hardware breakpoints
261                 */
262                reset_dbregs();
263                pcb->pcb_flags &= ~PCB_DBREGS;
264        }
265}
266
267void
268cpu_thread_clean(struct thread *td)
269{
270	struct pcb *pcb;
271
272	pcb = td->td_pcb;
273	if (pcb->pcb_ext != 0) {
274		/* XXXKSE  XXXSMP  not SMP SAFE.. what locks do we have? */
275		/* if (pcb->pcb_ext->ext_refcount-- == 1) ?? */
276		/*
277		 * XXX do we need to move the TSS off the allocated pages
278		 * before freeing them?  (not done here)
279		 */
280		mtx_lock(&Giant);
281		kmem_free(kernel_map, (vm_offset_t)pcb->pcb_ext,
282		    ctob(IOPAGES + 1));
283		mtx_unlock(&Giant);
284		pcb->pcb_ext = 0;
285	}
286}
287
288void
289cpu_sched_exit(td)
290	register struct thread *td;
291{
292}
293
294void
295cpu_thread_setup(struct thread *td)
296{
297
298	td->td_pcb =
299	     (struct pcb *)(td->td_kstack + KSTACK_PAGES * PAGE_SIZE) - 1;
300	td->td_frame = (struct trapframe *)((caddr_t)td->td_pcb - 16) - 1;
301}
302
303/*
304 * Initialize machine state (pcb and trap frame) for a new thread about to
305 * upcall. Pu t enough state in the new thread's PCB to get it to go back
306 * userret(), where we can intercept it again to set the return (upcall)
307 * Address and stack, along with those from upcals that are from other sources
308 * such as those generated in thread_userret() itself.
309 */
310void
311cpu_set_upcall(struct thread *td, void *pcb)
312{
313	struct pcb *pcb2;
314
315	/* Point the pcb to the top of the stack. */
316	pcb2 = td->td_pcb;
317
318	/*
319	 * Copy the upcall pcb.  This loads kernel regs.
320	 * Those not loaded individually below get their default
321	 * values here.
322	 *
323	 * XXXKSE It might be a good idea to simply skip this as
324	 * the values of the other registers may be unimportant.
325	 * This would remove any requirement for knowing the KSE
326	 * at this time (see the matching comment below for
327	 * more analysis) (need a good safe default).
328	 */
329	bcopy(pcb, pcb2, sizeof(*pcb2));
330
331	/*
332	 * Create a new fresh stack for the new thread.
333	 * The -16 is so we can expand the trapframe if we go to vm86.
334	 * Don't forget to set this stack value into whatever supplies
335	 * the address for the fault handlers.
336	 * The contexts are filled in at the time we actually DO the
337	 * upcall as only then do we know which KSE we got.
338	 */
339	td->td_frame = (struct trapframe *)((caddr_t)pcb2 - 16) - 1;
340
341	/*
342	 * Set registers for trampoline to user mode.  Leave space for the
343	 * return address on stack.  These are the kernel mode register values.
344	 */
345	pcb2->pcb_cr3 = vtophys(vmspace_pmap(td->td_proc->p_vmspace)->pm_pdir);
346	pcb2->pcb_edi = 0;
347	pcb2->pcb_esi = (int)fork_return;		    /* trampoline arg */
348	pcb2->pcb_ebp = 0;
349	pcb2->pcb_esp = (int)td->td_frame - sizeof(void *); /* trampoline arg */
350	pcb2->pcb_ebx = (int)td;			    /* trampoline arg */
351	pcb2->pcb_eip = (int)fork_trampoline;
352	pcb2->pcb_psl &= ~(PSL_I);	/* interrupts must be disabled */
353	/*
354	 * If we didn't copy the pcb, we'd need to do the following registers:
355	 * pcb2->pcb_dr*:	cloned above.
356	 * pcb2->pcb_savefpu:	cloned above.
357	 * pcb2->pcb_flags:	cloned above.
358	 * pcb2->pcb_onfault:	cloned above (always NULL here?).
359	 * pcb2->pcb_gs:	cloned above.  XXXKSE ???
360	 * pcb2->pcb_ext:	cleared below.
361	 */
362	 pcb2->pcb_ext = NULL;
363}
364
365/*
366 * Set that machine state for performing an upcall that has to
367 * be done in thread_userret() so that those upcalls generated
368 * in thread_userret() itself can be done as well.
369 */
370void
371cpu_set_upcall_kse(struct thread *td, struct kse_upcall *ku)
372{
373
374	/*
375	 * Do any extra cleaning that needs to be done.
376	 * The thread may have optional components
377	 * that are not present in a fresh thread.
378	 * This may be a recycled thread so make it look
379	 * as though it's newly allocated.
380	 */
381	cpu_thread_clean(td);
382
383	/*
384	 * Set the trap frame to point at the beginning of the uts
385	 * function.
386	 */
387	td->td_frame->tf_esp =
388	    (int)ku->ku_stack.ss_sp + ku->ku_stack.ss_size - 16;
389	td->td_frame->tf_eip = (int)ku->ku_func;
390
391	/*
392	 * Pass the address of the mailbox for this kse to the uts
393	 * function as a parameter on the stack.
394	 */
395	suword((void *)(td->td_frame->tf_esp + sizeof(void *)),
396	    (int)ku->ku_mailbox);
397}
398
399void
400cpu_wait(p)
401	struct proc *p;
402{
403}
404
405/*
406 * Convert kernel VA to physical address
407 */
408u_long
409kvtop(void *addr)
410{
411	vm_offset_t va;
412
413	va = pmap_kextract((vm_offset_t)addr);
414	if (va == 0)
415		panic("kvtop: zero page frame");
416	return((int)va);
417}
418
419/*
420 * Force reset the processor by invalidating the entire address space!
421 */
422
423#ifdef SMP
424static void
425cpu_reset_proxy()
426{
427
428	cpu_reset_proxy_active = 1;
429	while (cpu_reset_proxy_active == 1)
430		;	 /* Wait for other cpu to see that we've started */
431	stop_cpus((1<<cpu_reset_proxyid));
432	printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid);
433	DELAY(1000000);
434	cpu_reset_real();
435}
436#endif
437
438void
439cpu_reset()
440{
441#ifdef SMP
442	if (smp_active == 0) {
443		cpu_reset_real();
444		/* NOTREACHED */
445	} else {
446
447		u_int map;
448		int cnt;
449		printf("cpu_reset called on cpu#%d\n", PCPU_GET(cpuid));
450
451		map = PCPU_GET(other_cpus) & ~ stopped_cpus;
452
453		if (map != 0) {
454			printf("cpu_reset: Stopping other CPUs\n");
455			stop_cpus(map);		/* Stop all other CPUs */
456		}
457
458		if (PCPU_GET(cpuid) == 0) {
459			DELAY(1000000);
460			cpu_reset_real();
461			/* NOTREACHED */
462		} else {
463			/* We are not BSP (CPU #0) */
464
465			cpu_reset_proxyid = PCPU_GET(cpuid);
466			cpustop_restartfunc = cpu_reset_proxy;
467			cpu_reset_proxy_active = 0;
468			printf("cpu_reset: Restarting BSP\n");
469			started_cpus = (1<<0);		/* Restart CPU #0 */
470
471			cnt = 0;
472			while (cpu_reset_proxy_active == 0 && cnt < 10000000)
473				cnt++;	/* Wait for BSP to announce restart */
474			if (cpu_reset_proxy_active == 0)
475				printf("cpu_reset: Failed to restart BSP\n");
476			enable_intr();
477			cpu_reset_proxy_active = 2;
478
479			while (1);
480			/* NOTREACHED */
481		}
482	}
483#else
484	cpu_reset_real();
485#endif
486}
487
488static void
489cpu_reset_real()
490{
491
492#ifdef PC98
493	/*
494	 * Attempt to do a CPU reset via CPU reset port.
495	 */
496	disable_intr();
497	if ((inb(0x35) & 0xa0) != 0xa0) {
498		outb(0x37, 0x0f);		/* SHUT0 = 0. */
499		outb(0x37, 0x0b);		/* SHUT1 = 0. */
500	}
501	outb(0xf0, 0x00);		/* Reset. */
502#else
503	/*
504	 * Attempt to do a CPU reset via the keyboard controller,
505	 * do not turn of the GateA20, as any machine that fails
506	 * to do the reset here would then end up in no man's land.
507	 */
508
509#if !defined(BROKEN_KEYBOARD_RESET)
510	outb(IO_KBD + 4, 0xFE);
511	DELAY(500000);	/* wait 0.5 sec to see if that did it */
512	printf("Keyboard reset did not work, attempting CPU shutdown\n");
513	DELAY(1000000);	/* wait 1 sec for printf to complete */
514#endif
515#endif /* PC98 */
516	/* force a shutdown by unmapping entire address space ! */
517	bzero((caddr_t) PTD, PAGE_SIZE);
518
519	/* "good night, sweet prince .... <THUNK!>" */
520	invltlb();
521	/* NOTREACHED */
522	while(1);
523}
524
525/*
526 * Software interrupt handler for queued VM system processing.
527 */
528void
529swi_vm(void *dummy)
530{
531	if (busdma_swi_pending != 0)
532		busdma_swi();
533}
534
535/*
536 * Tell whether this address is in some physical memory region.
537 * Currently used by the kernel coredump code in order to avoid
538 * dumping the ``ISA memory hole'' which could cause indefinite hangs,
539 * or other unpredictable behaviour.
540 */
541
542int
543is_physical_memory(addr)
544	vm_offset_t addr;
545{
546
547#ifdef DEV_ISA
548	/* The ISA ``memory hole''. */
549	if (addr >= 0xa0000 && addr < 0x100000)
550		return 0;
551#endif
552
553	/*
554	 * stuff other tests for known memory-mapped devices (PCI?)
555	 * here
556	 */
557
558	return 1;
559}
560