pmap.c revision 135452
195142Sjmallett/*-
295142Sjmallett * Copyright (c) 1991 Regents of the University of California.
3 * All rights reserved.
4 * Copyright (c) 1994 John S. Dyson
5 * All rights reserved.
6 * Copyright (c) 1994 David Greenman
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 of UUNET Technologies Inc.
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:	@(#)pmap.c	7.7 (Berkeley)	5/12/91
42 */
43/*-
44 * Copyright (c) 2003 Networks Associates Technology, Inc.
45 * All rights reserved.
46 *
47 * This software was developed for the FreeBSD Project by Jake Burkholder,
48 * Safeport Network Services, and Network Associates Laboratories, the
49 * Security Research Division of Network Associates, Inc. under
50 * DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA
51 * CHATS research program.
52 *
53 * Redistribution and use in source and binary forms, with or without
54 * modification, are permitted provided that the following conditions
55 * are met:
56 * 1. Redistributions of source code must retain the above copyright
57 *    notice, this list of conditions and the following disclaimer.
58 * 2. Redistributions in binary form must reproduce the above copyright
59 *    notice, this list of conditions and the following disclaimer in the
60 *    documentation and/or other materials provided with the distribution.
61 *
62 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
63 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
64 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
65 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
66 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
67 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
68 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
69 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
70 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
71 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
72 * SUCH DAMAGE.
73 */
74
75#include <sys/cdefs.h>
76__FBSDID("$FreeBSD: head/sys/i386/i386/pmap.c 135452 2004-09-19 02:39:31Z alc $");
77
78/*
79 *	Manages physical address maps.
80 *
81 *	In addition to hardware address maps, this
82 *	module is called upon to provide software-use-only
83 *	maps which may or may not be stored in the same
84 *	form as hardware maps.  These pseudo-maps are
85 *	used to store intermediate results from copy
86 *	operations to and from address spaces.
87 *
88 *	Since the information managed by this module is
89 *	also stored by the logical address mapping module,
90 *	this module may throw away valid virtual-to-physical
91 *	mappings at almost any time.  However, invalidations
92 *	of virtual-to-physical mappings must be done as
93 *	requested.
94 *
95 *	In order to cope with hardware architectures which
96 *	make virtual-to-physical map invalidates expensive,
97 *	this module may delay invalidate or reduced protection
98 *	operations until such time as they are actually
99 *	necessary.  This module is given full information as
100 *	to which processors are currently using which maps,
101 *	and to when physical maps must be made correct.
102 */
103
104#include "opt_cpu.h"
105#include "opt_pmap.h"
106#include "opt_msgbuf.h"
107#include "opt_kstack_pages.h"
108
109#include <sys/param.h>
110#include <sys/systm.h>
111#include <sys/kernel.h>
112#include <sys/lock.h>
113#include <sys/mman.h>
114#include <sys/msgbuf.h>
115#include <sys/mutex.h>
116#include <sys/proc.h>
117#include <sys/sx.h>
118#include <sys/user.h>
119#include <sys/vmmeter.h>
120#include <sys/sched.h>
121#include <sys/sysctl.h>
122#ifdef SMP
123#include <sys/smp.h>
124#endif
125
126#include <vm/vm.h>
127#include <vm/vm_param.h>
128#include <vm/vm_kern.h>
129#include <vm/vm_page.h>
130#include <vm/vm_map.h>
131#include <vm/vm_object.h>
132#include <vm/vm_extern.h>
133#include <vm/vm_pageout.h>
134#include <vm/vm_pager.h>
135#include <vm/uma.h>
136
137#include <machine/cpu.h>
138#include <machine/cputypes.h>
139#include <machine/md_var.h>
140#include <machine/specialreg.h>
141#ifdef SMP
142#include <machine/smp.h>
143#endif
144
145#if !defined(CPU_ENABLE_SSE) && defined(I686_CPU)
146#define CPU_ENABLE_SSE
147#endif
148#if defined(CPU_DISABLE_SSE)
149#undef CPU_ENABLE_SSE
150#endif
151
152#ifndef PMAP_SHPGPERPROC
153#define PMAP_SHPGPERPROC 200
154#endif
155
156#if defined(DIAGNOSTIC)
157#define PMAP_DIAGNOSTIC
158#endif
159
160#define MINPV 2048
161
162#if !defined(PMAP_DIAGNOSTIC)
163#define PMAP_INLINE __inline
164#else
165#define PMAP_INLINE
166#endif
167
168/*
169 * Get PDEs and PTEs for user/kernel address space
170 */
171#define	pmap_pde(m, v)	(&((m)->pm_pdir[(vm_offset_t)(v) >> PDRSHIFT]))
172#define pdir_pde(m, v) (m[(vm_offset_t)(v) >> PDRSHIFT])
173
174#define pmap_pde_v(pte)		((*(int *)pte & PG_V) != 0)
175#define pmap_pte_w(pte)		((*(int *)pte & PG_W) != 0)
176#define pmap_pte_m(pte)		((*(int *)pte & PG_M) != 0)
177#define pmap_pte_u(pte)		((*(int *)pte & PG_A) != 0)
178#define pmap_pte_v(pte)		((*(int *)pte & PG_V) != 0)
179
180#define pmap_pte_set_w(pte, v)	((v) ? atomic_set_int((u_int *)(pte), PG_W) : \
181    atomic_clear_int((u_int *)(pte), PG_W))
182#define pmap_pte_set_prot(pte, v) ((*(int *)pte &= ~PG_PROT), (*(int *)pte |= (v)))
183
184struct pmap kernel_pmap_store;
185LIST_HEAD(pmaplist, pmap);
186static struct pmaplist allpmaps;
187static struct mtx allpmaps_lock;
188
189vm_paddr_t avail_end;	/* PA of last available physical page */
190vm_offset_t virtual_avail;	/* VA of first avail page (after kernel bss) */
191vm_offset_t virtual_end;	/* VA of last avail page (end of kernel AS) */
192static boolean_t pmap_initialized = FALSE;	/* Has pmap_init completed? */
193int pgeflag = 0;		/* PG_G or-in */
194int pseflag = 0;		/* PG_PS or-in */
195
196static int nkpt;
197vm_offset_t kernel_vm_end;
198extern u_int32_t KERNend;
199
200#ifdef PAE
201static uma_zone_t pdptzone;
202#endif
203
204/*
205 * Data for the pv entry allocation mechanism
206 */
207static uma_zone_t pvzone;
208static struct vm_object pvzone_obj;
209static int pv_entry_count = 0, pv_entry_max = 0, pv_entry_high_water = 0;
210int pmap_pagedaemon_waken;
211
212/*
213 * All those kernel PT submaps that BSD is so fond of
214 */
215pt_entry_t *CMAP1 = 0;
216static pt_entry_t *CMAP2, *CMAP3;
217caddr_t CADDR1 = 0, ptvmmap = 0;
218static caddr_t CADDR2, CADDR3;
219static struct mtx CMAPCADDR12_lock;
220struct msgbuf *msgbufp = 0;
221
222/*
223 * Crashdump maps.
224 */
225static caddr_t crashdumpmap;
226
227#ifdef SMP
228extern pt_entry_t *SMPpt;
229#endif
230static pt_entry_t *PMAP1 = 0, *PMAP2;
231static pt_entry_t *PADDR1 = 0, *PADDR2;
232#ifdef SMP
233static int PMAP1cpu;
234static int PMAP1changedcpu;
235SYSCTL_INT(_debug, OID_AUTO, PMAP1changedcpu, CTLFLAG_RD,
236	   &PMAP1changedcpu, 0,
237	   "Number of times pmap_pte_quick changed CPU with same PMAP1");
238#endif
239static int PMAP1changed;
240SYSCTL_INT(_debug, OID_AUTO, PMAP1changed, CTLFLAG_RD,
241	   &PMAP1changed, 0,
242	   "Number of times pmap_pte_quick changed PMAP1");
243static int PMAP1unchanged;
244SYSCTL_INT(_debug, OID_AUTO, PMAP1unchanged, CTLFLAG_RD,
245	   &PMAP1unchanged, 0,
246	   "Number of times pmap_pte_quick didn't change PMAP1");
247static struct mtx PMAP2mutex;
248
249static PMAP_INLINE void	free_pv_entry(pv_entry_t pv);
250static pv_entry_t get_pv_entry(void);
251static void	pmap_clear_ptes(vm_page_t m, int bit);
252
253static int pmap_remove_pte(pmap_t pmap, pt_entry_t *ptq, vm_offset_t sva);
254static void pmap_remove_page(struct pmap *pmap, vm_offset_t va);
255static int pmap_remove_entry(struct pmap *pmap, vm_page_t m,
256					vm_offset_t va);
257static void pmap_insert_entry(pmap_t pmap, vm_offset_t va, vm_page_t m);
258
259static vm_page_t pmap_allocpte(pmap_t pmap, vm_offset_t va);
260
261static vm_page_t _pmap_allocpte(pmap_t pmap, unsigned ptepindex);
262static int _pmap_unwire_pte_hold(pmap_t pmap, vm_page_t m);
263static pt_entry_t *pmap_pte_quick(pmap_t pmap, vm_offset_t va);
264static void pmap_pte_release(pt_entry_t *pte);
265static int pmap_unuse_pt(pmap_t, vm_offset_t);
266static vm_offset_t pmap_kmem_choose(vm_offset_t addr);
267#ifdef PAE
268static void *pmap_pdpt_allocf(uma_zone_t zone, int bytes, u_int8_t *flags, int wait);
269#endif
270
271CTASSERT(1 << PDESHIFT == sizeof(pd_entry_t));
272CTASSERT(1 << PTESHIFT == sizeof(pt_entry_t));
273
274/*
275 * Move the kernel virtual free pointer to the next
276 * 4MB.  This is used to help improve performance
277 * by using a large (4MB) page for much of the kernel
278 * (.text, .data, .bss)
279 */
280static vm_offset_t
281pmap_kmem_choose(vm_offset_t addr)
282{
283	vm_offset_t newaddr = addr;
284
285#ifndef DISABLE_PSE
286	if (cpu_feature & CPUID_PSE)
287		newaddr = (addr + PDRMASK) & ~PDRMASK;
288#endif
289	return newaddr;
290}
291
292/*
293 *	Bootstrap the system enough to run with virtual memory.
294 *
295 *	On the i386 this is called after mapping has already been enabled
296 *	and just syncs the pmap module with what has already been done.
297 *	[We can't call it easily with mapping off since the kernel is not
298 *	mapped with PA == VA, hence we would have to relocate every address
299 *	from the linked base (virtual) address "KERNBASE" to the actual
300 *	(physical) address starting relative to 0]
301 */
302void
303pmap_bootstrap(firstaddr, loadaddr)
304	vm_paddr_t firstaddr;
305	vm_paddr_t loadaddr;
306{
307	vm_offset_t va;
308	pt_entry_t *pte, *unused;
309	int i;
310
311	/*
312	 * XXX The calculation of virtual_avail is wrong. It's NKPT*PAGE_SIZE too
313	 * large. It should instead be correctly calculated in locore.s and
314	 * not based on 'first' (which is a physical address, not a virtual
315	 * address, for the start of unused physical memory). The kernel
316	 * page tables are NOT double mapped and thus should not be included
317	 * in this calculation.
318	 */
319	virtual_avail = (vm_offset_t) KERNBASE + firstaddr;
320	virtual_avail = pmap_kmem_choose(virtual_avail);
321
322	virtual_end = VM_MAX_KERNEL_ADDRESS;
323
324	/*
325	 * Initialize the kernel pmap (which is statically allocated).
326	 */
327	PMAP_LOCK_INIT(kernel_pmap);
328	kernel_pmap->pm_pdir = (pd_entry_t *) (KERNBASE + (u_int)IdlePTD);
329#ifdef PAE
330	kernel_pmap->pm_pdpt = (pdpt_entry_t *) (KERNBASE + (u_int)IdlePDPT);
331#endif
332	kernel_pmap->pm_active = -1;	/* don't allow deactivation */
333	TAILQ_INIT(&kernel_pmap->pm_pvlist);
334	LIST_INIT(&allpmaps);
335	mtx_init(&allpmaps_lock, "allpmaps", NULL, MTX_SPIN);
336	mtx_lock_spin(&allpmaps_lock);
337	LIST_INSERT_HEAD(&allpmaps, kernel_pmap, pm_list);
338	mtx_unlock_spin(&allpmaps_lock);
339	nkpt = NKPT;
340
341	/*
342	 * Reserve some special page table entries/VA space for temporary
343	 * mapping of pages.
344	 */
345#define	SYSMAP(c, p, v, n)	\
346	v = (c)va; va += ((n)*PAGE_SIZE); p = pte; pte += (n);
347
348	va = virtual_avail;
349	pte = vtopte(va);
350
351	/*
352	 * CMAP1/CMAP2 are used for zeroing and copying pages.
353	 * CMAP3 is used for the idle process page zeroing.
354	 */
355	SYSMAP(caddr_t, CMAP1, CADDR1, 1)
356	SYSMAP(caddr_t, CMAP2, CADDR2, 1)
357	SYSMAP(caddr_t, CMAP3, CADDR3, 1)
358	*CMAP3 = 0;
359
360	mtx_init(&CMAPCADDR12_lock, "CMAPCADDR12", NULL, MTX_DEF);
361
362	/*
363	 * Crashdump maps.
364	 */
365	SYSMAP(caddr_t, unused, crashdumpmap, MAXDUMPPGS)
366
367	/*
368	 * ptvmmap is used for reading arbitrary physical pages via /dev/mem.
369	 */
370	SYSMAP(caddr_t, unused, ptvmmap, 1)
371
372	/*
373	 * msgbufp is used to map the system message buffer.
374	 */
375	SYSMAP(struct msgbuf *, unused, msgbufp, atop(round_page(MSGBUF_SIZE)))
376
377	/*
378	 * ptemap is used for pmap_pte_quick
379	 */
380	SYSMAP(pt_entry_t *, PMAP1, PADDR1, 1);
381	SYSMAP(pt_entry_t *, PMAP2, PADDR2, 1);
382
383	mtx_init(&PMAP2mutex, "PMAP2", NULL, MTX_DEF);
384
385	virtual_avail = va;
386
387	*CMAP1 = *CMAP2 = 0;
388	for (i = 0; i < NKPT; i++)
389		PTD[i] = 0;
390
391	/* Turn on PG_G on kernel page(s) */
392	pmap_set_pg();
393}
394
395/*
396 * Set PG_G on kernel pages.  Only the BSP calls this when SMP is turned on.
397 */
398void
399pmap_set_pg(void)
400{
401	pd_entry_t pdir;
402	pt_entry_t *pte;
403	vm_offset_t va, endva;
404	int i;
405
406	if (pgeflag == 0)
407		return;
408
409	i = KERNLOAD/NBPDR;
410	endva = KERNBASE + KERNend;
411
412	if (pseflag) {
413		va = KERNBASE + KERNLOAD;
414		while (va  < endva) {
415			pdir = kernel_pmap->pm_pdir[KPTDI+i];
416			pdir |= pgeflag;
417			kernel_pmap->pm_pdir[KPTDI+i] = PTD[KPTDI+i] = pdir;
418			invltlb();	/* Play it safe, invltlb() every time */
419			i++;
420			va += NBPDR;
421		}
422	} else {
423		va = (vm_offset_t)btext;
424		while (va < endva) {
425			pte = vtopte(va);
426			if (*pte)
427				*pte |= pgeflag;
428			invltlb();	/* Play it safe, invltlb() every time */
429			va += PAGE_SIZE;
430		}
431	}
432}
433
434#ifdef PAE
435
436static MALLOC_DEFINE(M_PMAPPDPT, "pmap", "pmap pdpt");
437
438static void *
439pmap_pdpt_allocf(uma_zone_t zone, int bytes, u_int8_t *flags, int wait)
440{
441	*flags = UMA_SLAB_PRIV;
442	return (contigmalloc(PAGE_SIZE, M_PMAPPDPT, 0, 0x0ULL, 0xffffffffULL,
443	    1, 0));
444}
445#endif
446
447/*
448 *	Initialize the pmap module.
449 *	Called by vm_init, to initialize any structures that the pmap
450 *	system needs to map virtual memory.
451 *	pmap_init has been enhanced to support in a fairly consistant
452 *	way, discontiguous physical memory.
453 */
454void
455pmap_init(void)
456{
457	int i;
458
459	/*
460	 * Allocate memory for random pmap data structures.  Includes the
461	 * pv_head_table.
462	 */
463
464	for(i = 0; i < vm_page_array_size; i++) {
465		vm_page_t m;
466
467		m = &vm_page_array[i];
468		TAILQ_INIT(&m->md.pv_list);
469		m->md.pv_list_count = 0;
470	}
471
472	/*
473	 * init the pv free list
474	 */
475	pvzone = uma_zcreate("PV ENTRY", sizeof (struct pv_entry), NULL, NULL,
476	    NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_VM | UMA_ZONE_NOFREE);
477	uma_prealloc(pvzone, MINPV);
478
479#ifdef PAE
480	pdptzone = uma_zcreate("PDPT", NPGPTD * sizeof(pdpt_entry_t), NULL,
481	    NULL, NULL, NULL, (NPGPTD * sizeof(pdpt_entry_t)) - 1,
482	    UMA_ZONE_VM | UMA_ZONE_NOFREE);
483	uma_zone_set_allocf(pdptzone, pmap_pdpt_allocf);
484#endif
485
486	/*
487	 * Now it is safe to enable pv_table recording.
488	 */
489	pmap_initialized = TRUE;
490}
491
492/*
493 * Initialize the address space (zone) for the pv_entries.  Set a
494 * high water mark so that the system can recover from excessive
495 * numbers of pv entries.
496 */
497void
498pmap_init2()
499{
500	int shpgperproc = PMAP_SHPGPERPROC;
501
502	TUNABLE_INT_FETCH("vm.pmap.shpgperproc", &shpgperproc);
503	pv_entry_max = shpgperproc * maxproc + vm_page_array_size;
504	TUNABLE_INT_FETCH("vm.pmap.pv_entries", &pv_entry_max);
505	pv_entry_high_water = 9 * (pv_entry_max / 10);
506	uma_zone_set_obj(pvzone, &pvzone_obj, pv_entry_max);
507}
508
509
510/***************************************************
511 * Low level helper routines.....
512 ***************************************************/
513
514#if defined(PMAP_DIAGNOSTIC)
515
516/*
517 * This code checks for non-writeable/modified pages.
518 * This should be an invalid condition.
519 */
520static int
521pmap_nw_modified(pt_entry_t ptea)
522{
523	int pte;
524
525	pte = (int) ptea;
526
527	if ((pte & (PG_M|PG_RW)) == PG_M)
528		return 1;
529	else
530		return 0;
531}
532#endif
533
534
535/*
536 * this routine defines the region(s) of memory that should
537 * not be tested for the modified bit.
538 */
539static PMAP_INLINE int
540pmap_track_modified(vm_offset_t va)
541{
542	if ((va < kmi.clean_sva) || (va >= kmi.clean_eva))
543		return 1;
544	else
545		return 0;
546}
547
548#ifdef I386_CPU
549/*
550 * i386 only has "invalidate everything" and no SMP to worry about.
551 */
552PMAP_INLINE void
553pmap_invalidate_page(pmap_t pmap, vm_offset_t va)
554{
555
556	if (pmap == kernel_pmap || pmap->pm_active)
557		invltlb();
558}
559
560PMAP_INLINE void
561pmap_invalidate_range(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
562{
563
564	if (pmap == kernel_pmap || pmap->pm_active)
565		invltlb();
566}
567
568PMAP_INLINE void
569pmap_invalidate_all(pmap_t pmap)
570{
571
572	if (pmap == kernel_pmap || pmap->pm_active)
573		invltlb();
574}
575#else /* !I386_CPU */
576#ifdef SMP
577/*
578 * For SMP, these functions have to use the IPI mechanism for coherence.
579 */
580void
581pmap_invalidate_page(pmap_t pmap, vm_offset_t va)
582{
583	u_int cpumask;
584	u_int other_cpus;
585
586	if (smp_started) {
587		if (!(read_eflags() & PSL_I))
588			panic("%s: interrupts disabled", __func__);
589		mtx_lock_spin(&smp_ipi_mtx);
590	} else
591		critical_enter();
592	/*
593	 * We need to disable interrupt preemption but MUST NOT have
594	 * interrupts disabled here.
595	 * XXX we may need to hold schedlock to get a coherent pm_active
596	 * XXX critical sections disable interrupts again
597	 */
598	if (pmap == kernel_pmap || pmap->pm_active == all_cpus) {
599		invlpg(va);
600		smp_invlpg(va);
601	} else {
602		cpumask = PCPU_GET(cpumask);
603		other_cpus = PCPU_GET(other_cpus);
604		if (pmap->pm_active & cpumask)
605			invlpg(va);
606		if (pmap->pm_active & other_cpus)
607			smp_masked_invlpg(pmap->pm_active & other_cpus, va);
608	}
609	if (smp_started)
610		mtx_unlock_spin(&smp_ipi_mtx);
611	else
612		critical_exit();
613}
614
615void
616pmap_invalidate_range(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
617{
618	u_int cpumask;
619	u_int other_cpus;
620	vm_offset_t addr;
621
622	if (smp_started) {
623		if (!(read_eflags() & PSL_I))
624			panic("%s: interrupts disabled", __func__);
625		mtx_lock_spin(&smp_ipi_mtx);
626	} else
627		critical_enter();
628	/*
629	 * We need to disable interrupt preemption but MUST NOT have
630	 * interrupts disabled here.
631	 * XXX we may need to hold schedlock to get a coherent pm_active
632	 * XXX critical sections disable interrupts again
633	 */
634	if (pmap == kernel_pmap || pmap->pm_active == all_cpus) {
635		for (addr = sva; addr < eva; addr += PAGE_SIZE)
636			invlpg(addr);
637		smp_invlpg_range(sva, eva);
638	} else {
639		cpumask = PCPU_GET(cpumask);
640		other_cpus = PCPU_GET(other_cpus);
641		if (pmap->pm_active & cpumask)
642			for (addr = sva; addr < eva; addr += PAGE_SIZE)
643				invlpg(addr);
644		if (pmap->pm_active & other_cpus)
645			smp_masked_invlpg_range(pmap->pm_active & other_cpus,
646			    sva, eva);
647	}
648	if (smp_started)
649		mtx_unlock_spin(&smp_ipi_mtx);
650	else
651		critical_exit();
652}
653
654void
655pmap_invalidate_all(pmap_t pmap)
656{
657	u_int cpumask;
658	u_int other_cpus;
659
660	if (smp_started) {
661		if (!(read_eflags() & PSL_I))
662			panic("%s: interrupts disabled", __func__);
663		mtx_lock_spin(&smp_ipi_mtx);
664	} else
665		critical_enter();
666	/*
667	 * We need to disable interrupt preemption but MUST NOT have
668	 * interrupts disabled here.
669	 * XXX we may need to hold schedlock to get a coherent pm_active
670	 * XXX critical sections disable interrupts again
671	 */
672	if (pmap == kernel_pmap || pmap->pm_active == all_cpus) {
673		invltlb();
674		smp_invltlb();
675	} else {
676		cpumask = PCPU_GET(cpumask);
677		other_cpus = PCPU_GET(other_cpus);
678		if (pmap->pm_active & cpumask)
679			invltlb();
680		if (pmap->pm_active & other_cpus)
681			smp_masked_invltlb(pmap->pm_active & other_cpus);
682	}
683	if (smp_started)
684		mtx_unlock_spin(&smp_ipi_mtx);
685	else
686		critical_exit();
687}
688#else /* !SMP */
689/*
690 * Normal, non-SMP, 486+ invalidation functions.
691 * We inline these within pmap.c for speed.
692 */
693PMAP_INLINE void
694pmap_invalidate_page(pmap_t pmap, vm_offset_t va)
695{
696
697	if (pmap == kernel_pmap || pmap->pm_active)
698		invlpg(va);
699}
700
701PMAP_INLINE void
702pmap_invalidate_range(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
703{
704	vm_offset_t addr;
705
706	if (pmap == kernel_pmap || pmap->pm_active)
707		for (addr = sva; addr < eva; addr += PAGE_SIZE)
708			invlpg(addr);
709}
710
711PMAP_INLINE void
712pmap_invalidate_all(pmap_t pmap)
713{
714
715	if (pmap == kernel_pmap || pmap->pm_active)
716		invltlb();
717}
718#endif /* !SMP */
719#endif /* !I386_CPU */
720
721/*
722 * Are we current address space or kernel?  N.B. We return FALSE when
723 * a pmap's page table is in use because a kernel thread is borrowing
724 * it.  The borrowed page table can change spontaneously, making any
725 * dependence on its continued use subject to a race condition.
726 */
727static __inline int
728pmap_is_current(pmap_t pmap)
729{
730
731	return (pmap == kernel_pmap ||
732		(pmap == vmspace_pmap(curthread->td_proc->p_vmspace) &&
733	    (pmap->pm_pdir[PTDPTDI] & PG_FRAME) == (PTDpde[0] & PG_FRAME)));
734}
735
736/*
737 * If the given pmap is not the current or kernel pmap, the returned pte must
738 * be released by passing it to pmap_pte_release().
739 */
740pt_entry_t *
741pmap_pte(pmap_t pmap, vm_offset_t va)
742{
743	pd_entry_t newpf;
744	pd_entry_t *pde;
745
746	pde = pmap_pde(pmap, va);
747	if (*pde & PG_PS)
748		return (pde);
749	if (*pde != 0) {
750		/* are we current address space or kernel? */
751		if (pmap_is_current(pmap))
752			return (vtopte(va));
753		mtx_lock(&PMAP2mutex);
754		newpf = *pde & PG_FRAME;
755		if ((*PMAP2 & PG_FRAME) != newpf) {
756			*PMAP2 = newpf | PG_RW | PG_V | PG_A | PG_M;
757			pmap_invalidate_page(kernel_pmap, (vm_offset_t)PADDR2);
758		}
759		return (PADDR2 + (i386_btop(va) & (NPTEPG - 1)));
760	}
761	return (0);
762}
763
764/*
765 * Releases a pte that was obtained from pmap_pte().  Be prepared for the pte
766 * being NULL.
767 */
768static __inline void
769pmap_pte_release(pt_entry_t *pte)
770{
771
772	if ((pt_entry_t *)((vm_offset_t)pte & ~PAGE_MASK) == PADDR2)
773		mtx_unlock(&PMAP2mutex);
774}
775
776static __inline void
777invlcaddr(void *caddr)
778{
779#ifdef I386_CPU
780	invltlb();
781#else
782	invlpg((u_int)caddr);
783#endif
784}
785
786/*
787 * Super fast pmap_pte routine best used when scanning
788 * the pv lists.  This eliminates many coarse-grained
789 * invltlb calls.  Note that many of the pv list
790 * scans are across different pmaps.  It is very wasteful
791 * to do an entire invltlb for checking a single mapping.
792 *
793 * If the given pmap is not the current pmap, vm_page_queue_mtx
794 * must be held and curthread pinned to a CPU.
795 */
796static pt_entry_t *
797pmap_pte_quick(pmap_t pmap, vm_offset_t va)
798{
799	pd_entry_t newpf;
800	pd_entry_t *pde;
801
802	pde = pmap_pde(pmap, va);
803	if (*pde & PG_PS)
804		return (pde);
805	if (*pde != 0) {
806		/* are we current address space or kernel? */
807		if (pmap_is_current(pmap))
808			return (vtopte(va));
809		mtx_assert(&vm_page_queue_mtx, MA_OWNED);
810		KASSERT(curthread->td_pinned > 0, ("curthread not pinned"));
811		newpf = *pde & PG_FRAME;
812		if ((*PMAP1 & PG_FRAME) != newpf) {
813			*PMAP1 = newpf | PG_RW | PG_V | PG_A | PG_M;
814#ifdef SMP
815			PMAP1cpu = PCPU_GET(cpuid);
816#endif
817			invlcaddr(PADDR1);
818			PMAP1changed++;
819		} else
820#ifdef SMP
821		if (PMAP1cpu != PCPU_GET(cpuid)) {
822			PMAP1cpu = PCPU_GET(cpuid);
823			invlcaddr(PADDR1);
824			PMAP1changedcpu++;
825		} else
826#endif
827			PMAP1unchanged++;
828		return (PADDR1 + (i386_btop(va) & (NPTEPG - 1)));
829	}
830	return (0);
831}
832
833/*
834 *	Routine:	pmap_extract
835 *	Function:
836 *		Extract the physical page address associated
837 *		with the given map/virtual_address pair.
838 */
839vm_paddr_t
840pmap_extract(pmap_t pmap, vm_offset_t va)
841{
842	vm_paddr_t rtval;
843	pt_entry_t *pte;
844	pd_entry_t pde;
845
846	rtval = 0;
847	PMAP_LOCK(pmap);
848	pde = pmap->pm_pdir[va >> PDRSHIFT];
849	if (pde != 0) {
850		if ((pde & PG_PS) != 0) {
851			rtval = (pde & ~PDRMASK) | (va & PDRMASK);
852			PMAP_UNLOCK(pmap);
853			return rtval;
854		}
855		pte = pmap_pte(pmap, va);
856		rtval = (*pte & PG_FRAME) | (va & PAGE_MASK);
857		pmap_pte_release(pte);
858	}
859	PMAP_UNLOCK(pmap);
860	return (rtval);
861}
862
863/*
864 *	Routine:	pmap_extract_and_hold
865 *	Function:
866 *		Atomically extract and hold the physical page
867 *		with the given pmap and virtual address pair
868 *		if that mapping permits the given protection.
869 */
870vm_page_t
871pmap_extract_and_hold(pmap_t pmap, vm_offset_t va, vm_prot_t prot)
872{
873	pd_entry_t pde;
874	pt_entry_t pte;
875	vm_page_t m;
876
877	m = NULL;
878	vm_page_lock_queues();
879	PMAP_LOCK(pmap);
880	pde = *pmap_pde(pmap, va);
881	if (pde != 0) {
882		if (pde & PG_PS) {
883			if ((pde & PG_RW) || (prot & VM_PROT_WRITE) == 0) {
884				m = PHYS_TO_VM_PAGE((pde & ~PDRMASK) |
885				    (va & PDRMASK));
886				vm_page_hold(m);
887			}
888		} else {
889			sched_pin();
890			pte = *pmap_pte_quick(pmap, va);
891			if (pte != 0 &&
892			    ((pte & PG_RW) || (prot & VM_PROT_WRITE) == 0)) {
893				m = PHYS_TO_VM_PAGE(pte & PG_FRAME);
894				vm_page_hold(m);
895			}
896			sched_unpin();
897		}
898	}
899	vm_page_unlock_queues();
900	PMAP_UNLOCK(pmap);
901	return (m);
902}
903
904/***************************************************
905 * Low level mapping routines.....
906 ***************************************************/
907
908/*
909 * Add a wired page to the kva.
910 * Note: not SMP coherent.
911 */
912PMAP_INLINE void
913pmap_kenter(vm_offset_t va, vm_paddr_t pa)
914{
915	pt_entry_t *pte;
916
917	pte = vtopte(va);
918	pte_store(pte, pa | PG_RW | PG_V | pgeflag);
919}
920
921/*
922 * Remove a page from the kernel pagetables.
923 * Note: not SMP coherent.
924 */
925PMAP_INLINE void
926pmap_kremove(vm_offset_t va)
927{
928	pt_entry_t *pte;
929
930	pte = vtopte(va);
931	pte_clear(pte);
932}
933
934/*
935 *	Used to map a range of physical addresses into kernel
936 *	virtual address space.
937 *
938 *	The value passed in '*virt' is a suggested virtual address for
939 *	the mapping. Architectures which can support a direct-mapped
940 *	physical to virtual region can return the appropriate address
941 *	within that region, leaving '*virt' unchanged. Other
942 *	architectures should map the pages starting at '*virt' and
943 *	update '*virt' with the first usable address after the mapped
944 *	region.
945 */
946vm_offset_t
947pmap_map(vm_offset_t *virt, vm_paddr_t start, vm_paddr_t end, int prot)
948{
949	vm_offset_t va, sva;
950
951	va = sva = *virt;
952	while (start < end) {
953		pmap_kenter(va, start);
954		va += PAGE_SIZE;
955		start += PAGE_SIZE;
956	}
957	pmap_invalidate_range(kernel_pmap, sva, va);
958	*virt = va;
959	return (sva);
960}
961
962
963/*
964 * Add a list of wired pages to the kva
965 * this routine is only used for temporary
966 * kernel mappings that do not need to have
967 * page modification or references recorded.
968 * Note that old mappings are simply written
969 * over.  The page *must* be wired.
970 * Note: SMP coherent.  Uses a ranged shootdown IPI.
971 */
972void
973pmap_qenter(vm_offset_t sva, vm_page_t *m, int count)
974{
975	vm_offset_t va;
976
977	va = sva;
978	while (count-- > 0) {
979		pmap_kenter(va, VM_PAGE_TO_PHYS(*m));
980		va += PAGE_SIZE;
981		m++;
982	}
983	pmap_invalidate_range(kernel_pmap, sva, va);
984}
985
986/*
987 * This routine tears out page mappings from the
988 * kernel -- it is meant only for temporary mappings.
989 * Note: SMP coherent.  Uses a ranged shootdown IPI.
990 */
991void
992pmap_qremove(vm_offset_t sva, int count)
993{
994	vm_offset_t va;
995
996	va = sva;
997	while (count-- > 0) {
998		pmap_kremove(va);
999		va += PAGE_SIZE;
1000	}
1001	pmap_invalidate_range(kernel_pmap, sva, va);
1002}
1003
1004/***************************************************
1005 * Page table page management routines.....
1006 ***************************************************/
1007
1008/*
1009 * This routine unholds page table pages, and if the hold count
1010 * drops to zero, then it decrements the wire count.
1011 */
1012static PMAP_INLINE int
1013pmap_unwire_pte_hold(pmap_t pmap, vm_page_t m)
1014{
1015
1016	vm_page_unhold(m);
1017	if (m->hold_count == 0)
1018		return _pmap_unwire_pte_hold(pmap, m);
1019	else
1020		return 0;
1021}
1022
1023static int
1024_pmap_unwire_pte_hold(pmap_t pmap, vm_page_t m)
1025{
1026	vm_offset_t pteva;
1027
1028	/*
1029	 * unmap the page table page
1030	 */
1031	pmap->pm_pdir[m->pindex] = 0;
1032	--pmap->pm_stats.resident_count;
1033	/*
1034	 * We never unwire a kernel page table page, making a
1035	 * check for the kernel_pmap unnecessary.
1036	 */
1037	if ((pmap->pm_pdir[PTDPTDI] & PG_FRAME) == (PTDpde[0] & PG_FRAME)) {
1038		/*
1039		 * Do an invltlb to make the invalidated mapping
1040		 * take effect immediately.
1041		 */
1042		pteva = VM_MAXUSER_ADDRESS + i386_ptob(m->pindex);
1043		pmap_invalidate_page(pmap, pteva);
1044	}
1045
1046	/*
1047	 * If the page is finally unwired, simply free it.
1048	 */
1049	--m->wire_count;
1050	if (m->wire_count == 0) {
1051		vm_page_free_zero(m);
1052		atomic_subtract_int(&cnt.v_wire_count, 1);
1053	}
1054	return 1;
1055}
1056
1057/*
1058 * After removing a page table entry, this routine is used to
1059 * conditionally free the page, and manage the hold/wire counts.
1060 */
1061static int
1062pmap_unuse_pt(pmap_t pmap, vm_offset_t va)
1063{
1064	pd_entry_t ptepde;
1065	vm_page_t mpte;
1066
1067	if (va >= VM_MAXUSER_ADDRESS)
1068		return 0;
1069	ptepde = *pmap_pde(pmap, va);
1070	mpte = PHYS_TO_VM_PAGE(ptepde & PG_FRAME);
1071	return pmap_unwire_pte_hold(pmap, mpte);
1072}
1073
1074void
1075pmap_pinit0(pmap)
1076	struct pmap *pmap;
1077{
1078
1079	PMAP_LOCK_INIT(pmap);
1080	pmap->pm_pdir = (pd_entry_t *)(KERNBASE + (vm_offset_t)IdlePTD);
1081#ifdef PAE
1082	pmap->pm_pdpt = (pdpt_entry_t *)(KERNBASE + (vm_offset_t)IdlePDPT);
1083#endif
1084	pmap->pm_active = 0;
1085	PCPU_SET(curpmap, pmap);
1086	TAILQ_INIT(&pmap->pm_pvlist);
1087	bzero(&pmap->pm_stats, sizeof pmap->pm_stats);
1088	mtx_lock_spin(&allpmaps_lock);
1089	LIST_INSERT_HEAD(&allpmaps, pmap, pm_list);
1090	mtx_unlock_spin(&allpmaps_lock);
1091}
1092
1093/*
1094 * Initialize a preallocated and zeroed pmap structure,
1095 * such as one in a vmspace structure.
1096 */
1097void
1098pmap_pinit(pmap)
1099	register struct pmap *pmap;
1100{
1101	vm_page_t m, ptdpg[NPGPTD];
1102	vm_paddr_t pa;
1103	static int color;
1104	int i;
1105
1106	PMAP_LOCK_INIT(pmap);
1107
1108	/*
1109	 * No need to allocate page table space yet but we do need a valid
1110	 * page directory table.
1111	 */
1112	if (pmap->pm_pdir == NULL) {
1113		pmap->pm_pdir = (pd_entry_t *)kmem_alloc_nofault(kernel_map,
1114		    NBPTD);
1115#ifdef PAE
1116		pmap->pm_pdpt = uma_zalloc(pdptzone, M_WAITOK | M_ZERO);
1117		KASSERT(((vm_offset_t)pmap->pm_pdpt &
1118		    ((NPGPTD * sizeof(pdpt_entry_t)) - 1)) == 0,
1119		    ("pmap_pinit: pdpt misaligned"));
1120		KASSERT(pmap_kextract((vm_offset_t)pmap->pm_pdpt) < (4ULL<<30),
1121		    ("pmap_pinit: pdpt above 4g"));
1122#endif
1123	}
1124
1125	/*
1126	 * allocate the page directory page(s)
1127	 */
1128	for (i = 0; i < NPGPTD;) {
1129		m = vm_page_alloc(NULL, color++,
1130		    VM_ALLOC_NORMAL | VM_ALLOC_NOOBJ | VM_ALLOC_WIRED |
1131		    VM_ALLOC_ZERO);
1132		if (m == NULL)
1133			VM_WAIT;
1134		else {
1135			ptdpg[i++] = m;
1136		}
1137	}
1138
1139	pmap_qenter((vm_offset_t)pmap->pm_pdir, ptdpg, NPGPTD);
1140
1141	for (i = 0; i < NPGPTD; i++) {
1142		if ((ptdpg[i]->flags & PG_ZERO) == 0)
1143			bzero(pmap->pm_pdir + (i * NPDEPG), PAGE_SIZE);
1144	}
1145
1146	mtx_lock_spin(&allpmaps_lock);
1147	LIST_INSERT_HEAD(&allpmaps, pmap, pm_list);
1148	mtx_unlock_spin(&allpmaps_lock);
1149	/* Wire in kernel global address entries. */
1150	/* XXX copies current process, does not fill in MPPTDI */
1151	bcopy(PTD + KPTDI, pmap->pm_pdir + KPTDI, nkpt * sizeof(pd_entry_t));
1152#ifdef SMP
1153	pmap->pm_pdir[MPPTDI] = PTD[MPPTDI];
1154#endif
1155
1156	/* install self-referential address mapping entry(s) */
1157	for (i = 0; i < NPGPTD; i++) {
1158		pa = VM_PAGE_TO_PHYS(ptdpg[i]);
1159		pmap->pm_pdir[PTDPTDI + i] = pa | PG_V | PG_RW | PG_A | PG_M;
1160#ifdef PAE
1161		pmap->pm_pdpt[i] = pa | PG_V;
1162#endif
1163	}
1164
1165	pmap->pm_active = 0;
1166	TAILQ_INIT(&pmap->pm_pvlist);
1167	bzero(&pmap->pm_stats, sizeof pmap->pm_stats);
1168}
1169
1170/*
1171 * this routine is called if the page table page is not
1172 * mapped correctly.
1173 */
1174static vm_page_t
1175_pmap_allocpte(pmap, ptepindex)
1176	pmap_t	pmap;
1177	unsigned ptepindex;
1178{
1179	vm_paddr_t ptepa;
1180	vm_page_t m;
1181
1182	/*
1183	 * Allocate a page table page.
1184	 */
1185	if ((m = vm_page_alloc(NULL, ptepindex, VM_ALLOC_NOOBJ |
1186	    VM_ALLOC_WIRED | VM_ALLOC_ZERO)) == NULL) {
1187		PMAP_UNLOCK(pmap);
1188		vm_page_unlock_queues();
1189		VM_WAIT;
1190		vm_page_lock_queues();
1191		PMAP_LOCK(pmap);
1192
1193		/*
1194		 * Indicate the need to retry.  While waiting, the page table
1195		 * page may have been allocated.
1196		 */
1197		return (NULL);
1198	}
1199	if ((m->flags & PG_ZERO) == 0)
1200		pmap_zero_page(m);
1201
1202	/*
1203	 * Increment the hold count for the page table page
1204	 * (denoting a new mapping.)
1205	 */
1206	m->hold_count++;
1207
1208	/*
1209	 * Map the pagetable page into the process address space, if
1210	 * it isn't already there.
1211	 */
1212
1213	pmap->pm_stats.resident_count++;
1214
1215	ptepa = VM_PAGE_TO_PHYS(m);
1216	pmap->pm_pdir[ptepindex] =
1217		(pd_entry_t) (ptepa | PG_U | PG_RW | PG_V | PG_A | PG_M);
1218
1219	return m;
1220}
1221
1222static vm_page_t
1223pmap_allocpte(pmap_t pmap, vm_offset_t va)
1224{
1225	unsigned ptepindex;
1226	pd_entry_t ptepa;
1227	vm_page_t m;
1228
1229	/*
1230	 * Calculate pagetable page index
1231	 */
1232	ptepindex = va >> PDRSHIFT;
1233retry:
1234	/*
1235	 * Get the page directory entry
1236	 */
1237	ptepa = pmap->pm_pdir[ptepindex];
1238
1239	/*
1240	 * This supports switching from a 4MB page to a
1241	 * normal 4K page.
1242	 */
1243	if (ptepa & PG_PS) {
1244		pmap->pm_pdir[ptepindex] = 0;
1245		ptepa = 0;
1246		pmap_invalidate_all(kernel_pmap);
1247	}
1248
1249	/*
1250	 * If the page table page is mapped, we just increment the
1251	 * hold count, and activate it.
1252	 */
1253	if (ptepa) {
1254		m = PHYS_TO_VM_PAGE(ptepa);
1255		m->hold_count++;
1256	} else {
1257		/*
1258		 * Here if the pte page isn't mapped, or if it has
1259		 * been deallocated.
1260		 */
1261		m = _pmap_allocpte(pmap, ptepindex);
1262		if (m == NULL)
1263			goto retry;
1264	}
1265	return (m);
1266}
1267
1268
1269/***************************************************
1270* Pmap allocation/deallocation routines.
1271 ***************************************************/
1272
1273#ifdef SMP
1274/*
1275 * Deal with a SMP shootdown of other users of the pmap that we are
1276 * trying to dispose of.  This can be a bit hairy.
1277 */
1278static u_int *lazymask;
1279static u_int lazyptd;
1280static volatile u_int lazywait;
1281
1282void pmap_lazyfix_action(void);
1283
1284void
1285pmap_lazyfix_action(void)
1286{
1287	u_int mymask = PCPU_GET(cpumask);
1288
1289	if (rcr3() == lazyptd)
1290		load_cr3(PCPU_GET(curpcb)->pcb_cr3);
1291	atomic_clear_int(lazymask, mymask);
1292	atomic_store_rel_int(&lazywait, 1);
1293}
1294
1295static void
1296pmap_lazyfix_self(u_int mymask)
1297{
1298
1299	if (rcr3() == lazyptd)
1300		load_cr3(PCPU_GET(curpcb)->pcb_cr3);
1301	atomic_clear_int(lazymask, mymask);
1302}
1303
1304
1305static void
1306pmap_lazyfix(pmap_t pmap)
1307{
1308	u_int mymask = PCPU_GET(cpumask);
1309	u_int mask;
1310	register u_int spins;
1311
1312	while ((mask = pmap->pm_active) != 0) {
1313		spins = 50000000;
1314		mask = mask & -mask;	/* Find least significant set bit */
1315		mtx_lock_spin(&smp_ipi_mtx);
1316#ifdef PAE
1317		lazyptd = vtophys(pmap->pm_pdpt);
1318#else
1319		lazyptd = vtophys(pmap->pm_pdir);
1320#endif
1321		if (mask == mymask) {
1322			lazymask = &pmap->pm_active;
1323			pmap_lazyfix_self(mymask);
1324		} else {
1325			atomic_store_rel_int((u_int *)&lazymask,
1326			    (u_int)&pmap->pm_active);
1327			atomic_store_rel_int(&lazywait, 0);
1328			ipi_selected(mask, IPI_LAZYPMAP);
1329			while (lazywait == 0) {
1330				ia32_pause();
1331				if (--spins == 0)
1332					break;
1333			}
1334		}
1335		mtx_unlock_spin(&smp_ipi_mtx);
1336		if (spins == 0)
1337			printf("pmap_lazyfix: spun for 50000000\n");
1338	}
1339}
1340
1341#else	/* SMP */
1342
1343/*
1344 * Cleaning up on uniprocessor is easy.  For various reasons, we're
1345 * unlikely to have to even execute this code, including the fact
1346 * that the cleanup is deferred until the parent does a wait(2), which
1347 * means that another userland process has run.
1348 */
1349static void
1350pmap_lazyfix(pmap_t pmap)
1351{
1352	u_int cr3;
1353
1354	cr3 = vtophys(pmap->pm_pdir);
1355	if (cr3 == rcr3()) {
1356		load_cr3(PCPU_GET(curpcb)->pcb_cr3);
1357		pmap->pm_active &= ~(PCPU_GET(cpumask));
1358	}
1359}
1360#endif	/* SMP */
1361
1362/*
1363 * Release any resources held by the given physical map.
1364 * Called when a pmap initialized by pmap_pinit is being released.
1365 * Should only be called if the map contains no valid mappings.
1366 */
1367void
1368pmap_release(pmap_t pmap)
1369{
1370	vm_page_t m, ptdpg[NPGPTD];
1371	int i;
1372
1373	KASSERT(pmap->pm_stats.resident_count == 0,
1374	    ("pmap_release: pmap resident count %ld != 0",
1375	    pmap->pm_stats.resident_count));
1376
1377	pmap_lazyfix(pmap);
1378	mtx_lock_spin(&allpmaps_lock);
1379	LIST_REMOVE(pmap, pm_list);
1380	mtx_unlock_spin(&allpmaps_lock);
1381
1382	for (i = 0; i < NPGPTD; i++)
1383		ptdpg[i] = PHYS_TO_VM_PAGE(pmap->pm_pdir[PTDPTDI + i]);
1384
1385	bzero(pmap->pm_pdir + PTDPTDI, (nkpt + NPGPTD) *
1386	    sizeof(*pmap->pm_pdir));
1387#ifdef SMP
1388	pmap->pm_pdir[MPPTDI] = 0;
1389#endif
1390
1391	pmap_qremove((vm_offset_t)pmap->pm_pdir, NPGPTD);
1392
1393	vm_page_lock_queues();
1394	for (i = 0; i < NPGPTD; i++) {
1395		m = ptdpg[i];
1396#ifdef PAE
1397		KASSERT(VM_PAGE_TO_PHYS(m) == (pmap->pm_pdpt[i] & PG_FRAME),
1398		    ("pmap_release: got wrong ptd page"));
1399#endif
1400		m->wire_count--;
1401		atomic_subtract_int(&cnt.v_wire_count, 1);
1402		vm_page_free_zero(m);
1403	}
1404	vm_page_unlock_queues();
1405	PMAP_LOCK_DESTROY(pmap);
1406}
1407
1408static int
1409kvm_size(SYSCTL_HANDLER_ARGS)
1410{
1411	unsigned long ksize = VM_MAX_KERNEL_ADDRESS - KERNBASE;
1412
1413	return sysctl_handle_long(oidp, &ksize, 0, req);
1414}
1415SYSCTL_PROC(_vm, OID_AUTO, kvm_size, CTLTYPE_LONG|CTLFLAG_RD,
1416    0, 0, kvm_size, "IU", "Size of KVM");
1417
1418static int
1419kvm_free(SYSCTL_HANDLER_ARGS)
1420{
1421	unsigned long kfree = VM_MAX_KERNEL_ADDRESS - kernel_vm_end;
1422
1423	return sysctl_handle_long(oidp, &kfree, 0, req);
1424}
1425SYSCTL_PROC(_vm, OID_AUTO, kvm_free, CTLTYPE_LONG|CTLFLAG_RD,
1426    0, 0, kvm_free, "IU", "Amount of KVM free");
1427
1428/*
1429 * grow the number of kernel page table entries, if needed
1430 */
1431void
1432pmap_growkernel(vm_offset_t addr)
1433{
1434	struct pmap *pmap;
1435	vm_paddr_t ptppaddr;
1436	vm_page_t nkpg;
1437	pd_entry_t newpdir;
1438	pt_entry_t *pde;
1439
1440	mtx_assert(&kernel_map->system_mtx, MA_OWNED);
1441	if (kernel_vm_end == 0) {
1442		kernel_vm_end = KERNBASE;
1443		nkpt = 0;
1444		while (pdir_pde(PTD, kernel_vm_end)) {
1445			kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1);
1446			nkpt++;
1447		}
1448	}
1449	addr = roundup2(addr, PAGE_SIZE * NPTEPG);
1450	while (kernel_vm_end < addr) {
1451		if (pdir_pde(PTD, kernel_vm_end)) {
1452			kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1);
1453			continue;
1454		}
1455
1456		/*
1457		 * This index is bogus, but out of the way
1458		 */
1459		nkpg = vm_page_alloc(NULL, nkpt,
1460		    VM_ALLOC_NOOBJ | VM_ALLOC_SYSTEM | VM_ALLOC_WIRED);
1461		if (!nkpg)
1462			panic("pmap_growkernel: no memory to grow kernel");
1463
1464		nkpt++;
1465
1466		pmap_zero_page(nkpg);
1467		ptppaddr = VM_PAGE_TO_PHYS(nkpg);
1468		newpdir = (pd_entry_t) (ptppaddr | PG_V | PG_RW | PG_A | PG_M);
1469		pdir_pde(PTD, kernel_vm_end) = newpdir;
1470
1471		mtx_lock_spin(&allpmaps_lock);
1472		LIST_FOREACH(pmap, &allpmaps, pm_list) {
1473			pde = pmap_pde(pmap, kernel_vm_end);
1474			pde_store(pde, newpdir);
1475		}
1476		mtx_unlock_spin(&allpmaps_lock);
1477		kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1);
1478	}
1479}
1480
1481
1482/***************************************************
1483 * page management routines.
1484 ***************************************************/
1485
1486/*
1487 * free the pv_entry back to the free list
1488 */
1489static PMAP_INLINE void
1490free_pv_entry(pv_entry_t pv)
1491{
1492	pv_entry_count--;
1493	uma_zfree(pvzone, pv);
1494}
1495
1496/*
1497 * get a new pv_entry, allocating a block from the system
1498 * when needed.
1499 * the memory allocation is performed bypassing the malloc code
1500 * because of the possibility of allocations at interrupt time.
1501 */
1502static pv_entry_t
1503get_pv_entry(void)
1504{
1505	pv_entry_count++;
1506	if (pv_entry_high_water &&
1507		(pv_entry_count > pv_entry_high_water) &&
1508		(pmap_pagedaemon_waken == 0)) {
1509		pmap_pagedaemon_waken = 1;
1510		wakeup (&vm_pages_needed);
1511	}
1512	return uma_zalloc(pvzone, M_NOWAIT);
1513}
1514
1515
1516static int
1517pmap_remove_entry(pmap_t pmap, vm_page_t m, vm_offset_t va)
1518{
1519	pv_entry_t pv;
1520	int rtval;
1521
1522	PMAP_LOCK_ASSERT(pmap, MA_OWNED);
1523	mtx_assert(&vm_page_queue_mtx, MA_OWNED);
1524	if (m->md.pv_list_count < pmap->pm_stats.resident_count) {
1525		TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
1526			if (pmap == pv->pv_pmap && va == pv->pv_va)
1527				break;
1528		}
1529	} else {
1530		TAILQ_FOREACH(pv, &pmap->pm_pvlist, pv_plist) {
1531			if (va == pv->pv_va)
1532				break;
1533		}
1534	}
1535
1536	rtval = 0;
1537	if (pv) {
1538		rtval = pmap_unuse_pt(pmap, va);
1539		TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
1540		m->md.pv_list_count--;
1541		if (TAILQ_FIRST(&m->md.pv_list) == NULL)
1542			vm_page_flag_clear(m, PG_WRITEABLE);
1543
1544		TAILQ_REMOVE(&pmap->pm_pvlist, pv, pv_plist);
1545		free_pv_entry(pv);
1546	}
1547
1548	return rtval;
1549}
1550
1551/*
1552 * Create a pv entry for page at pa for
1553 * (pmap, va).
1554 */
1555static void
1556pmap_insert_entry(pmap_t pmap, vm_offset_t va, vm_page_t m)
1557{
1558	pv_entry_t pv;
1559
1560	pv = get_pv_entry();
1561	pv->pv_va = va;
1562	pv->pv_pmap = pmap;
1563
1564	PMAP_LOCK_ASSERT(pmap, MA_OWNED);
1565	mtx_assert(&vm_page_queue_mtx, MA_OWNED);
1566	TAILQ_INSERT_TAIL(&pmap->pm_pvlist, pv, pv_plist);
1567	TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list);
1568	m->md.pv_list_count++;
1569}
1570
1571/*
1572 * pmap_remove_pte: do the things to unmap a page in a process
1573 */
1574static int
1575pmap_remove_pte(pmap_t pmap, pt_entry_t *ptq, vm_offset_t va)
1576{
1577	pt_entry_t oldpte;
1578	vm_page_t m;
1579
1580	mtx_assert(&vm_page_queue_mtx, MA_OWNED);
1581	PMAP_LOCK_ASSERT(pmap, MA_OWNED);
1582	oldpte = pte_load_clear(ptq);
1583	if (oldpte & PG_W)
1584		pmap->pm_stats.wired_count -= 1;
1585	/*
1586	 * Machines that don't support invlpg, also don't support
1587	 * PG_G.
1588	 */
1589	if (oldpte & PG_G)
1590		pmap_invalidate_page(kernel_pmap, va);
1591	pmap->pm_stats.resident_count -= 1;
1592	if (oldpte & PG_MANAGED) {
1593		m = PHYS_TO_VM_PAGE(oldpte);
1594		if (oldpte & PG_M) {
1595#if defined(PMAP_DIAGNOSTIC)
1596			if (pmap_nw_modified((pt_entry_t) oldpte)) {
1597				printf(
1598	"pmap_remove: modified page not writable: va: 0x%x, pte: 0x%x\n",
1599				    va, oldpte);
1600			}
1601#endif
1602			if (pmap_track_modified(va))
1603				vm_page_dirty(m);
1604		}
1605		if (oldpte & PG_A)
1606			vm_page_flag_set(m, PG_REFERENCED);
1607		return pmap_remove_entry(pmap, m, va);
1608	} else {
1609		return pmap_unuse_pt(pmap, va);
1610	}
1611}
1612
1613/*
1614 * Remove a single page from a process address space
1615 */
1616static void
1617pmap_remove_page(pmap_t pmap, vm_offset_t va)
1618{
1619	pt_entry_t *pte;
1620
1621	mtx_assert(&vm_page_queue_mtx, MA_OWNED);
1622	KASSERT(curthread->td_pinned > 0, ("curthread not pinned"));
1623	PMAP_LOCK_ASSERT(pmap, MA_OWNED);
1624	if ((pte = pmap_pte_quick(pmap, va)) == NULL || *pte == 0)
1625		return;
1626	pmap_remove_pte(pmap, pte, va);
1627	pmap_invalidate_page(pmap, va);
1628}
1629
1630/*
1631 *	Remove the given range of addresses from the specified map.
1632 *
1633 *	It is assumed that the start and end are properly
1634 *	rounded to the page size.
1635 */
1636void
1637pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
1638{
1639	vm_offset_t pdnxt;
1640	pd_entry_t ptpaddr;
1641	pt_entry_t *pte;
1642	int anyvalid;
1643
1644	/*
1645	 * Perform an unsynchronized read.  This is, however, safe.
1646	 */
1647	if (pmap->pm_stats.resident_count == 0)
1648		return;
1649
1650	anyvalid = 0;
1651
1652	vm_page_lock_queues();
1653	sched_pin();
1654	PMAP_LOCK(pmap);
1655
1656	/*
1657	 * special handling of removing one page.  a very
1658	 * common operation and easy to short circuit some
1659	 * code.
1660	 */
1661	if ((sva + PAGE_SIZE == eva) &&
1662	    ((pmap->pm_pdir[(sva >> PDRSHIFT)] & PG_PS) == 0)) {
1663		pmap_remove_page(pmap, sva);
1664		goto out;
1665	}
1666
1667	for (; sva < eva; sva = pdnxt) {
1668		unsigned pdirindex;
1669
1670		/*
1671		 * Calculate index for next page table.
1672		 */
1673		pdnxt = (sva + NBPDR) & ~PDRMASK;
1674		if (pmap->pm_stats.resident_count == 0)
1675			break;
1676
1677		pdirindex = sva >> PDRSHIFT;
1678		ptpaddr = pmap->pm_pdir[pdirindex];
1679
1680		/*
1681		 * Weed out invalid mappings. Note: we assume that the page
1682		 * directory table is always allocated, and in kernel virtual.
1683		 */
1684		if (ptpaddr == 0)
1685			continue;
1686
1687		/*
1688		 * Check for large page.
1689		 */
1690		if ((ptpaddr & PG_PS) != 0) {
1691			pmap->pm_pdir[pdirindex] = 0;
1692			pmap->pm_stats.resident_count -= NBPDR / PAGE_SIZE;
1693			anyvalid = 1;
1694			continue;
1695		}
1696
1697		/*
1698		 * Limit our scan to either the end of the va represented
1699		 * by the current page table page, or to the end of the
1700		 * range being removed.
1701		 */
1702		if (pdnxt > eva)
1703			pdnxt = eva;
1704
1705		for (; sva != pdnxt; sva += PAGE_SIZE) {
1706			if ((pte = pmap_pte_quick(pmap, sva)) == NULL ||
1707			    *pte == 0)
1708				continue;
1709			anyvalid = 1;
1710			if (pmap_remove_pte(pmap, pte, sva))
1711				break;
1712		}
1713	}
1714out:
1715	sched_unpin();
1716	vm_page_unlock_queues();
1717	if (anyvalid)
1718		pmap_invalidate_all(pmap);
1719	PMAP_UNLOCK(pmap);
1720}
1721
1722/*
1723 *	Routine:	pmap_remove_all
1724 *	Function:
1725 *		Removes this physical page from
1726 *		all physical maps in which it resides.
1727 *		Reflects back modify bits to the pager.
1728 *
1729 *	Notes:
1730 *		Original versions of this routine were very
1731 *		inefficient because they iteratively called
1732 *		pmap_remove (slow...)
1733 */
1734
1735void
1736pmap_remove_all(vm_page_t m)
1737{
1738	register pv_entry_t pv;
1739	pt_entry_t *pte, tpte;
1740
1741#if defined(PMAP_DIAGNOSTIC)
1742	/*
1743	 * XXX This makes pmap_remove_all() illegal for non-managed pages!
1744	 */
1745	if (!pmap_initialized || (m->flags & PG_FICTITIOUS)) {
1746		panic("pmap_remove_all: illegal for unmanaged page, va: 0x%x",
1747		    VM_PAGE_TO_PHYS(m));
1748	}
1749#endif
1750	mtx_assert(&vm_page_queue_mtx, MA_OWNED);
1751	sched_pin();
1752	while ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) {
1753		PMAP_LOCK(pv->pv_pmap);
1754		pv->pv_pmap->pm_stats.resident_count--;
1755		pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va);
1756		tpte = pte_load_clear(pte);
1757		if (tpte & PG_W)
1758			pv->pv_pmap->pm_stats.wired_count--;
1759		if (tpte & PG_A)
1760			vm_page_flag_set(m, PG_REFERENCED);
1761
1762		/*
1763		 * Update the vm_page_t clean and reference bits.
1764		 */
1765		if (tpte & PG_M) {
1766#if defined(PMAP_DIAGNOSTIC)
1767			if (pmap_nw_modified((pt_entry_t) tpte)) {
1768				printf(
1769	"pmap_remove_all: modified page not writable: va: 0x%x, pte: 0x%x\n",
1770				    pv->pv_va, tpte);
1771			}
1772#endif
1773			if (pmap_track_modified(pv->pv_va))
1774				vm_page_dirty(m);
1775		}
1776		pmap_invalidate_page(pv->pv_pmap, pv->pv_va);
1777		TAILQ_REMOVE(&pv->pv_pmap->pm_pvlist, pv, pv_plist);
1778		TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
1779		m->md.pv_list_count--;
1780		pmap_unuse_pt(pv->pv_pmap, pv->pv_va);
1781		PMAP_UNLOCK(pv->pv_pmap);
1782		free_pv_entry(pv);
1783	}
1784	vm_page_flag_clear(m, PG_WRITEABLE);
1785	sched_unpin();
1786}
1787
1788/*
1789 *	Set the physical protection on the
1790 *	specified range of this map as requested.
1791 */
1792void
1793pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
1794{
1795	vm_offset_t pdnxt;
1796	pd_entry_t ptpaddr;
1797	int anychanged;
1798
1799	if ((prot & VM_PROT_READ) == VM_PROT_NONE) {
1800		pmap_remove(pmap, sva, eva);
1801		return;
1802	}
1803
1804	if (prot & VM_PROT_WRITE)
1805		return;
1806
1807	anychanged = 0;
1808
1809	vm_page_lock_queues();
1810	sched_pin();
1811	PMAP_LOCK(pmap);
1812	for (; sva < eva; sva = pdnxt) {
1813		unsigned obits, pbits, pdirindex;
1814
1815		pdnxt = (sva + NBPDR) & ~PDRMASK;
1816
1817		pdirindex = sva >> PDRSHIFT;
1818		ptpaddr = pmap->pm_pdir[pdirindex];
1819
1820		/*
1821		 * Weed out invalid mappings. Note: we assume that the page
1822		 * directory table is always allocated, and in kernel virtual.
1823		 */
1824		if (ptpaddr == 0)
1825			continue;
1826
1827		/*
1828		 * Check for large page.
1829		 */
1830		if ((ptpaddr & PG_PS) != 0) {
1831			pmap->pm_pdir[pdirindex] &= ~(PG_M|PG_RW);
1832			pmap->pm_stats.resident_count -= NBPDR / PAGE_SIZE;
1833			anychanged = 1;
1834			continue;
1835		}
1836
1837		if (pdnxt > eva)
1838			pdnxt = eva;
1839
1840		for (; sva != pdnxt; sva += PAGE_SIZE) {
1841			pt_entry_t *pte;
1842			vm_page_t m;
1843
1844			if ((pte = pmap_pte_quick(pmap, sva)) == NULL)
1845				continue;
1846retry:
1847			/*
1848			 * Regardless of whether a pte is 32 or 64 bits in
1849			 * size, PG_RW, PG_A, and PG_M are among the least
1850			 * significant 32 bits.
1851			 */
1852			obits = pbits = *(u_int *)pte;
1853			if (pbits & PG_MANAGED) {
1854				m = NULL;
1855				if (pbits & PG_A) {
1856					m = PHYS_TO_VM_PAGE(pbits);
1857					vm_page_flag_set(m, PG_REFERENCED);
1858					pbits &= ~PG_A;
1859				}
1860				if ((pbits & PG_M) != 0 &&
1861				    pmap_track_modified(sva)) {
1862					if (m == NULL)
1863						m = PHYS_TO_VM_PAGE(pbits);
1864					vm_page_dirty(m);
1865				}
1866			}
1867
1868			pbits &= ~(PG_RW | PG_M);
1869
1870			if (pbits != obits) {
1871				if (!atomic_cmpset_int((u_int *)pte, obits,
1872				    pbits))
1873					goto retry;
1874				anychanged = 1;
1875			}
1876		}
1877	}
1878	sched_unpin();
1879	vm_page_unlock_queues();
1880	if (anychanged)
1881		pmap_invalidate_all(pmap);
1882	PMAP_UNLOCK(pmap);
1883}
1884
1885/*
1886 *	Insert the given physical page (p) at
1887 *	the specified virtual address (v) in the
1888 *	target physical map with the protection requested.
1889 *
1890 *	If specified, the page will be wired down, meaning
1891 *	that the related pte can not be reclaimed.
1892 *
1893 *	NB:  This is the only routine which MAY NOT lazy-evaluate
1894 *	or lose information.  That is, this routine must actually
1895 *	insert this page into the given map NOW.
1896 */
1897void
1898pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot,
1899	   boolean_t wired)
1900{
1901	vm_paddr_t pa;
1902	register pt_entry_t *pte;
1903	vm_paddr_t opa;
1904	pt_entry_t origpte, newpte;
1905	vm_page_t mpte;
1906
1907	va &= PG_FRAME;
1908#ifdef PMAP_DIAGNOSTIC
1909	if (va > VM_MAX_KERNEL_ADDRESS)
1910		panic("pmap_enter: toobig");
1911	if ((va >= UPT_MIN_ADDRESS) && (va < UPT_MAX_ADDRESS))
1912		panic("pmap_enter: invalid to pmap_enter page table pages (va: 0x%x)", va);
1913#endif
1914
1915	mpte = NULL;
1916
1917	vm_page_lock_queues();
1918	PMAP_LOCK(pmap);
1919	sched_pin();
1920
1921	/*
1922	 * In the case that a page table page is not
1923	 * resident, we are creating it here.
1924	 */
1925	if (va < VM_MAXUSER_ADDRESS) {
1926		mpte = pmap_allocpte(pmap, va);
1927	}
1928#if 0 && defined(PMAP_DIAGNOSTIC)
1929	else {
1930		pd_entry_t *pdeaddr = pmap_pde(pmap, va);
1931		origpte = *pdeaddr;
1932		if ((origpte & PG_V) == 0) {
1933			panic("pmap_enter: invalid kernel page table page, pdir=%p, pde=%p, va=%p\n",
1934				pmap->pm_pdir[PTDPTDI], origpte, va);
1935		}
1936	}
1937#endif
1938
1939	pte = pmap_pte_quick(pmap, va);
1940
1941	/*
1942	 * Page Directory table entry not valid, we need a new PT page
1943	 */
1944	if (pte == NULL) {
1945		panic("pmap_enter: invalid page directory pdir=%#jx, va=%#x\n",
1946			(uintmax_t)pmap->pm_pdir[PTDPTDI], va);
1947	}
1948
1949	pa = VM_PAGE_TO_PHYS(m) & PG_FRAME;
1950	origpte = *pte;
1951	opa = origpte & PG_FRAME;
1952
1953	if (origpte & PG_PS) {
1954		/*
1955		 * Yes, I know this will truncate upper address bits for PAE,
1956		 * but I'm actually more interested in the lower bits
1957		 */
1958		printf("pmap_enter: va %p, pte %p, origpte %p\n",
1959		    (void *)va, (void *)pte, (void *)(uintptr_t)origpte);
1960		panic("pmap_enter: attempted pmap_enter on 4MB page");
1961	}
1962
1963	/*
1964	 * Mapping has not changed, must be protection or wiring change.
1965	 */
1966	if (origpte && (opa == pa)) {
1967		/*
1968		 * Wiring change, just update stats. We don't worry about
1969		 * wiring PT pages as they remain resident as long as there
1970		 * are valid mappings in them. Hence, if a user page is wired,
1971		 * the PT page will be also.
1972		 */
1973		if (wired && ((origpte & PG_W) == 0))
1974			pmap->pm_stats.wired_count++;
1975		else if (!wired && (origpte & PG_W))
1976			pmap->pm_stats.wired_count--;
1977
1978#if defined(PMAP_DIAGNOSTIC)
1979		if (pmap_nw_modified((pt_entry_t) origpte)) {
1980			printf(
1981	"pmap_enter: modified page not writable: va: 0x%x, pte: 0x%x\n",
1982			    va, origpte);
1983		}
1984#endif
1985
1986		/*
1987		 * Remove extra pte reference
1988		 */
1989		if (mpte)
1990			mpte->hold_count--;
1991
1992		/*
1993		 * We might be turning off write access to the page,
1994		 * so we go ahead and sense modify status.
1995		 */
1996		if (origpte & PG_MANAGED) {
1997			if ((origpte & PG_M) && pmap_track_modified(va)) {
1998				vm_page_t om;
1999				om = PHYS_TO_VM_PAGE(opa);
2000				vm_page_dirty(om);
2001			}
2002			pa |= PG_MANAGED;
2003		}
2004		goto validate;
2005	}
2006	/*
2007	 * Mapping has changed, invalidate old range and fall through to
2008	 * handle validating new mapping.
2009	 */
2010	if (opa) {
2011		int err;
2012		err = pmap_remove_pte(pmap, pte, va);
2013		if (err)
2014			panic("pmap_enter: pte vanished, va: 0x%x", va);
2015	}
2016
2017	/*
2018	 * Enter on the PV list if part of our managed memory. Note that we
2019	 * raise IPL while manipulating pv_table since pmap_enter can be
2020	 * called at interrupt time.
2021	 */
2022	if (pmap_initialized &&
2023	    (m->flags & (PG_FICTITIOUS|PG_UNMANAGED)) == 0) {
2024		pmap_insert_entry(pmap, va, m);
2025		pa |= PG_MANAGED;
2026	}
2027
2028	/*
2029	 * Increment counters
2030	 */
2031	pmap->pm_stats.resident_count++;
2032	if (wired)
2033		pmap->pm_stats.wired_count++;
2034
2035validate:
2036	/*
2037	 * Now validate mapping with desired protection/wiring.
2038	 */
2039	newpte = (pt_entry_t)(pa | PG_V);
2040	if ((prot & VM_PROT_WRITE) != 0)
2041		newpte |= PG_RW;
2042	if (wired)
2043		newpte |= PG_W;
2044	if (va < VM_MAXUSER_ADDRESS)
2045		newpte |= PG_U;
2046	if (pmap == kernel_pmap)
2047		newpte |= pgeflag;
2048
2049	/*
2050	 * if the mapping or permission bits are different, we need
2051	 * to update the pte.
2052	 */
2053	if ((origpte & ~(PG_M|PG_A)) != newpte) {
2054		pte_store(pte, newpte | PG_A);
2055		/*if (origpte)*/ {
2056			pmap_invalidate_page(pmap, va);
2057		}
2058	}
2059	sched_unpin();
2060	vm_page_unlock_queues();
2061	PMAP_UNLOCK(pmap);
2062}
2063
2064/*
2065 * this code makes some *MAJOR* assumptions:
2066 * 1. Current pmap & pmap exists.
2067 * 2. Not wired.
2068 * 3. Read access.
2069 * 4. No page table pages.
2070 * 5. Tlbflush is deferred to calling procedure.
2071 * 6. Page IS managed.
2072 * but is *MUCH* faster than pmap_enter...
2073 */
2074
2075vm_page_t
2076pmap_enter_quick(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_page_t mpte)
2077{
2078	pt_entry_t *pte;
2079	vm_paddr_t pa;
2080
2081	vm_page_lock_queues();
2082	PMAP_LOCK(pmap);
2083
2084	/*
2085	 * In the case that a page table page is not
2086	 * resident, we are creating it here.
2087	 */
2088	if (va < VM_MAXUSER_ADDRESS) {
2089		unsigned ptepindex;
2090		pd_entry_t ptepa;
2091
2092		/*
2093		 * Calculate pagetable page index
2094		 */
2095		ptepindex = va >> PDRSHIFT;
2096		if (mpte && (mpte->pindex == ptepindex)) {
2097			mpte->hold_count++;
2098		} else {
2099retry:
2100			/*
2101			 * Get the page directory entry
2102			 */
2103			ptepa = pmap->pm_pdir[ptepindex];
2104
2105			/*
2106			 * If the page table page is mapped, we just increment
2107			 * the hold count, and activate it.
2108			 */
2109			if (ptepa) {
2110				if (ptepa & PG_PS)
2111					panic("pmap_enter_quick: unexpected mapping into 4MB page");
2112				mpte = PHYS_TO_VM_PAGE(ptepa);
2113				mpte->hold_count++;
2114			} else {
2115				mpte = _pmap_allocpte(pmap, ptepindex);
2116				if (mpte == NULL)
2117					goto retry;
2118			}
2119		}
2120	} else {
2121		mpte = NULL;
2122	}
2123
2124	/*
2125	 * This call to vtopte makes the assumption that we are
2126	 * entering the page into the current pmap.  In order to support
2127	 * quick entry into any pmap, one would likely use pmap_pte_quick.
2128	 * But that isn't as quick as vtopte.
2129	 */
2130	pte = vtopte(va);
2131	if (*pte) {
2132		if (mpte != NULL) {
2133			pmap_unwire_pte_hold(pmap, mpte);
2134			mpte = NULL;
2135		}
2136		goto out;
2137	}
2138
2139	/*
2140	 * Enter on the PV list if part of our managed memory. Note that we
2141	 * raise IPL while manipulating pv_table since pmap_enter can be
2142	 * called at interrupt time.
2143	 */
2144	if ((m->flags & (PG_FICTITIOUS|PG_UNMANAGED)) == 0)
2145		pmap_insert_entry(pmap, va, m);
2146
2147	/*
2148	 * Increment counters
2149	 */
2150	pmap->pm_stats.resident_count++;
2151
2152	pa = VM_PAGE_TO_PHYS(m);
2153
2154	/*
2155	 * Now validate mapping with RO protection
2156	 */
2157	if (m->flags & (PG_FICTITIOUS|PG_UNMANAGED))
2158		pte_store(pte, pa | PG_V | PG_U);
2159	else
2160		pte_store(pte, pa | PG_V | PG_U | PG_MANAGED);
2161out:
2162	vm_page_unlock_queues();
2163	PMAP_UNLOCK(pmap);
2164	return mpte;
2165}
2166
2167/*
2168 * Make a temporary mapping for a physical address.  This is only intended
2169 * to be used for panic dumps.
2170 */
2171void *
2172pmap_kenter_temporary(vm_paddr_t pa, int i)
2173{
2174	vm_offset_t va;
2175
2176	va = (vm_offset_t)crashdumpmap + (i * PAGE_SIZE);
2177	pmap_kenter(va, pa);
2178#ifndef I386_CPU
2179	invlpg(va);
2180#else
2181	invltlb();
2182#endif
2183	return ((void *)crashdumpmap);
2184}
2185
2186/*
2187 * This code maps large physical mmap regions into the
2188 * processor address space.  Note that some shortcuts
2189 * are taken, but the code works.
2190 */
2191void
2192pmap_object_init_pt(pmap_t pmap, vm_offset_t addr,
2193		    vm_object_t object, vm_pindex_t pindex,
2194		    vm_size_t size)
2195{
2196	vm_page_t p;
2197
2198	VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
2199	KASSERT(object->type == OBJT_DEVICE,
2200	    ("pmap_object_init_pt: non-device object"));
2201	if (pseflag &&
2202	    ((addr & (NBPDR - 1)) == 0) && ((size & (NBPDR - 1)) == 0)) {
2203		int i;
2204		vm_page_t m[1];
2205		unsigned int ptepindex;
2206		int npdes;
2207		pd_entry_t ptepa;
2208
2209		PMAP_LOCK(pmap);
2210		if (pmap->pm_pdir[ptepindex = (addr >> PDRSHIFT)])
2211			goto out;
2212		PMAP_UNLOCK(pmap);
2213retry:
2214		p = vm_page_lookup(object, pindex);
2215		if (p != NULL) {
2216			vm_page_lock_queues();
2217			if (vm_page_sleep_if_busy(p, FALSE, "init4p"))
2218				goto retry;
2219		} else {
2220			p = vm_page_alloc(object, pindex, VM_ALLOC_NORMAL);
2221			if (p == NULL)
2222				return;
2223			m[0] = p;
2224
2225			if (vm_pager_get_pages(object, m, 1, 0) != VM_PAGER_OK) {
2226				vm_page_lock_queues();
2227				vm_page_free(p);
2228				vm_page_unlock_queues();
2229				return;
2230			}
2231
2232			p = vm_page_lookup(object, pindex);
2233			vm_page_lock_queues();
2234			vm_page_wakeup(p);
2235		}
2236		vm_page_unlock_queues();
2237
2238		ptepa = VM_PAGE_TO_PHYS(p);
2239		if (ptepa & (NBPDR - 1))
2240			return;
2241
2242		p->valid = VM_PAGE_BITS_ALL;
2243
2244		PMAP_LOCK(pmap);
2245		pmap->pm_stats.resident_count += size >> PAGE_SHIFT;
2246		npdes = size >> PDRSHIFT;
2247		for(i = 0; i < npdes; i++) {
2248			pde_store(&pmap->pm_pdir[ptepindex],
2249			    ptepa | PG_U | PG_RW | PG_V | PG_PS);
2250			ptepa += NBPDR;
2251			ptepindex += 1;
2252		}
2253		pmap_invalidate_all(pmap);
2254out:
2255		PMAP_UNLOCK(pmap);
2256	}
2257}
2258
2259/*
2260 *	Routine:	pmap_change_wiring
2261 *	Function:	Change the wiring attribute for a map/virtual-address
2262 *			pair.
2263 *	In/out conditions:
2264 *			The mapping must already exist in the pmap.
2265 */
2266void
2267pmap_change_wiring(pmap, va, wired)
2268	register pmap_t pmap;
2269	vm_offset_t va;
2270	boolean_t wired;
2271{
2272	register pt_entry_t *pte;
2273
2274	PMAP_LOCK(pmap);
2275	pte = pmap_pte(pmap, va);
2276
2277	if (wired && !pmap_pte_w(pte))
2278		pmap->pm_stats.wired_count++;
2279	else if (!wired && pmap_pte_w(pte))
2280		pmap->pm_stats.wired_count--;
2281
2282	/*
2283	 * Wiring is not a hardware characteristic so there is no need to
2284	 * invalidate TLB.
2285	 */
2286	pmap_pte_set_w(pte, wired);
2287	pmap_pte_release(pte);
2288	PMAP_UNLOCK(pmap);
2289}
2290
2291
2292
2293/*
2294 *	Copy the range specified by src_addr/len
2295 *	from the source map to the range dst_addr/len
2296 *	in the destination map.
2297 *
2298 *	This routine is only advisory and need not do anything.
2299 */
2300
2301void
2302pmap_copy(pmap_t dst_pmap, pmap_t src_pmap, vm_offset_t dst_addr, vm_size_t len,
2303	  vm_offset_t src_addr)
2304{
2305	vm_offset_t addr;
2306	vm_offset_t end_addr = src_addr + len;
2307	vm_offset_t pdnxt;
2308	vm_page_t m;
2309
2310	if (dst_addr != src_addr)
2311		return;
2312
2313	if (!pmap_is_current(src_pmap))
2314		return;
2315
2316	vm_page_lock_queues();
2317	PMAP_LOCK(dst_pmap);
2318	sched_pin();
2319	for (addr = src_addr; addr < end_addr; addr = pdnxt) {
2320		pt_entry_t *src_pte, *dst_pte;
2321		vm_page_t dstmpte, srcmpte;
2322		pd_entry_t srcptepaddr;
2323		unsigned ptepindex;
2324
2325		if (addr >= UPT_MIN_ADDRESS)
2326			panic("pmap_copy: invalid to pmap_copy page tables");
2327
2328		/*
2329		 * Don't let optional prefaulting of pages make us go
2330		 * way below the low water mark of free pages or way
2331		 * above high water mark of used pv entries.
2332		 */
2333		if (cnt.v_free_count < cnt.v_free_reserved ||
2334		    pv_entry_count > pv_entry_high_water)
2335			break;
2336
2337		pdnxt = (addr + NBPDR) & ~PDRMASK;
2338		ptepindex = addr >> PDRSHIFT;
2339
2340		srcptepaddr = src_pmap->pm_pdir[ptepindex];
2341		if (srcptepaddr == 0)
2342			continue;
2343
2344		if (srcptepaddr & PG_PS) {
2345			if (dst_pmap->pm_pdir[ptepindex] == 0) {
2346				dst_pmap->pm_pdir[ptepindex] = srcptepaddr;
2347				dst_pmap->pm_stats.resident_count +=
2348				    NBPDR / PAGE_SIZE;
2349			}
2350			continue;
2351		}
2352
2353		srcmpte = PHYS_TO_VM_PAGE(srcptepaddr);
2354		if (srcmpte->hold_count == 0)
2355			panic("pmap_copy: source page table page is unused");
2356
2357		if (pdnxt > end_addr)
2358			pdnxt = end_addr;
2359
2360		src_pte = vtopte(addr);
2361		while (addr < pdnxt) {
2362			pt_entry_t ptetemp;
2363			ptetemp = *src_pte;
2364			/*
2365			 * we only virtual copy managed pages
2366			 */
2367			if ((ptetemp & PG_MANAGED) != 0) {
2368				/*
2369				 * We have to check after allocpte for the
2370				 * pte still being around...  allocpte can
2371				 * block.
2372				 */
2373				dstmpte = pmap_allocpte(dst_pmap, addr);
2374				dst_pte = pmap_pte_quick(dst_pmap, addr);
2375				if ((*dst_pte == 0) && (ptetemp = *src_pte)) {
2376					/*
2377					 * Clear the modified and
2378					 * accessed (referenced) bits
2379					 * during the copy.
2380					 */
2381					m = PHYS_TO_VM_PAGE(ptetemp);
2382					*dst_pte = ptetemp & ~(PG_M | PG_A);
2383					dst_pmap->pm_stats.resident_count++;
2384					pmap_insert_entry(dst_pmap, addr, m);
2385	 			} else
2386					pmap_unwire_pte_hold(dst_pmap, dstmpte);
2387				if (dstmpte->hold_count >= srcmpte->hold_count)
2388					break;
2389			}
2390			addr += PAGE_SIZE;
2391			src_pte++;
2392		}
2393	}
2394	sched_unpin();
2395	vm_page_unlock_queues();
2396	PMAP_UNLOCK(dst_pmap);
2397}
2398
2399static __inline void
2400pagezero(void *page)
2401{
2402#if defined(I686_CPU)
2403	if (cpu_class == CPUCLASS_686) {
2404#if defined(CPU_ENABLE_SSE)
2405		if (cpu_feature & CPUID_SSE2)
2406			sse2_pagezero(page);
2407		else
2408#endif
2409			i686_pagezero(page);
2410	} else
2411#endif
2412		bzero(page, PAGE_SIZE);
2413}
2414
2415/*
2416 *	pmap_zero_page zeros the specified hardware page by mapping
2417 *	the page into KVM and using bzero to clear its contents.
2418 */
2419void
2420pmap_zero_page(vm_page_t m)
2421{
2422
2423	mtx_lock(&CMAPCADDR12_lock);
2424	if (*CMAP2)
2425		panic("pmap_zero_page: CMAP2 busy");
2426	sched_pin();
2427	*CMAP2 = PG_V | PG_RW | VM_PAGE_TO_PHYS(m) | PG_A | PG_M;
2428	invlcaddr(CADDR2);
2429	pagezero(CADDR2);
2430	*CMAP2 = 0;
2431	sched_unpin();
2432	mtx_unlock(&CMAPCADDR12_lock);
2433}
2434
2435/*
2436 *	pmap_zero_page_area zeros the specified hardware page by mapping
2437 *	the page into KVM and using bzero to clear its contents.
2438 *
2439 *	off and size may not cover an area beyond a single hardware page.
2440 */
2441void
2442pmap_zero_page_area(vm_page_t m, int off, int size)
2443{
2444
2445	mtx_lock(&CMAPCADDR12_lock);
2446	if (*CMAP2)
2447		panic("pmap_zero_page: CMAP2 busy");
2448	sched_pin();
2449	*CMAP2 = PG_V | PG_RW | VM_PAGE_TO_PHYS(m) | PG_A | PG_M;
2450	invlcaddr(CADDR2);
2451	if (off == 0 && size == PAGE_SIZE)
2452		pagezero(CADDR2);
2453	else
2454		bzero((char *)CADDR2 + off, size);
2455	*CMAP2 = 0;
2456	sched_unpin();
2457	mtx_unlock(&CMAPCADDR12_lock);
2458}
2459
2460/*
2461 *	pmap_zero_page_idle zeros the specified hardware page by mapping
2462 *	the page into KVM and using bzero to clear its contents.  This
2463 *	is intended to be called from the vm_pagezero process only and
2464 *	outside of Giant.
2465 */
2466void
2467pmap_zero_page_idle(vm_page_t m)
2468{
2469
2470	if (*CMAP3)
2471		panic("pmap_zero_page: CMAP3 busy");
2472	sched_pin();
2473	*CMAP3 = PG_V | PG_RW | VM_PAGE_TO_PHYS(m) | PG_A | PG_M;
2474	invlcaddr(CADDR3);
2475	pagezero(CADDR3);
2476	*CMAP3 = 0;
2477	sched_unpin();
2478}
2479
2480/*
2481 *	pmap_copy_page copies the specified (machine independent)
2482 *	page by mapping the page into virtual memory and using
2483 *	bcopy to copy the page, one machine dependent page at a
2484 *	time.
2485 */
2486void
2487pmap_copy_page(vm_page_t src, vm_page_t dst)
2488{
2489
2490	mtx_lock(&CMAPCADDR12_lock);
2491	if (*CMAP1)
2492		panic("pmap_copy_page: CMAP1 busy");
2493	if (*CMAP2)
2494		panic("pmap_copy_page: CMAP2 busy");
2495	sched_pin();
2496#ifdef I386_CPU
2497	invltlb();
2498#else
2499	invlpg((u_int)CADDR1);
2500	invlpg((u_int)CADDR2);
2501#endif
2502	*CMAP1 = PG_V | VM_PAGE_TO_PHYS(src) | PG_A;
2503	*CMAP2 = PG_V | PG_RW | VM_PAGE_TO_PHYS(dst) | PG_A | PG_M;
2504	bcopy(CADDR1, CADDR2, PAGE_SIZE);
2505	*CMAP1 = 0;
2506	*CMAP2 = 0;
2507	sched_unpin();
2508	mtx_unlock(&CMAPCADDR12_lock);
2509}
2510
2511/*
2512 * Returns true if the pmap's pv is one of the first
2513 * 16 pvs linked to from this page.  This count may
2514 * be changed upwards or downwards in the future; it
2515 * is only necessary that true be returned for a small
2516 * subset of pmaps for proper page aging.
2517 */
2518boolean_t
2519pmap_page_exists_quick(pmap, m)
2520	pmap_t pmap;
2521	vm_page_t m;
2522{
2523	pv_entry_t pv;
2524	int loops = 0;
2525
2526	if (!pmap_initialized || (m->flags & PG_FICTITIOUS))
2527		return FALSE;
2528
2529	mtx_assert(&vm_page_queue_mtx, MA_OWNED);
2530	TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
2531		if (pv->pv_pmap == pmap) {
2532			return TRUE;
2533		}
2534		loops++;
2535		if (loops >= 16)
2536			break;
2537	}
2538	return (FALSE);
2539}
2540
2541#define PMAP_REMOVE_PAGES_CURPROC_ONLY
2542/*
2543 * Remove all pages from specified address space
2544 * this aids process exit speeds.  Also, this code
2545 * is special cased for current process only, but
2546 * can have the more generic (and slightly slower)
2547 * mode enabled.  This is much faster than pmap_remove
2548 * in the case of running down an entire address space.
2549 */
2550void
2551pmap_remove_pages(pmap, sva, eva)
2552	pmap_t pmap;
2553	vm_offset_t sva, eva;
2554{
2555	pt_entry_t *pte, tpte;
2556	vm_page_t m;
2557	pv_entry_t pv, npv;
2558
2559#ifdef PMAP_REMOVE_PAGES_CURPROC_ONLY
2560	if (pmap != vmspace_pmap(curthread->td_proc->p_vmspace)) {
2561		printf("warning: pmap_remove_pages called with non-current pmap\n");
2562		return;
2563	}
2564#endif
2565	vm_page_lock_queues();
2566	PMAP_LOCK(pmap);
2567	sched_pin();
2568	for (pv = TAILQ_FIRST(&pmap->pm_pvlist); pv; pv = npv) {
2569
2570		if (pv->pv_va >= eva || pv->pv_va < sva) {
2571			npv = TAILQ_NEXT(pv, pv_plist);
2572			continue;
2573		}
2574
2575#ifdef PMAP_REMOVE_PAGES_CURPROC_ONLY
2576		pte = vtopte(pv->pv_va);
2577#else
2578		pte = pmap_pte_quick(pmap, pv->pv_va);
2579#endif
2580		tpte = *pte;
2581
2582		if (tpte == 0) {
2583			printf("TPTE at %p  IS ZERO @ VA %08x\n",
2584							pte, pv->pv_va);
2585			panic("bad pte");
2586		}
2587
2588/*
2589 * We cannot remove wired pages from a process' mapping at this time
2590 */
2591		if (tpte & PG_W) {
2592			npv = TAILQ_NEXT(pv, pv_plist);
2593			continue;
2594		}
2595
2596		m = PHYS_TO_VM_PAGE(tpte);
2597		KASSERT(m->phys_addr == (tpte & PG_FRAME),
2598		    ("vm_page_t %p phys_addr mismatch %016jx %016jx",
2599		    m, (uintmax_t)m->phys_addr, (uintmax_t)tpte));
2600
2601		KASSERT(m < &vm_page_array[vm_page_array_size],
2602			("pmap_remove_pages: bad tpte %#jx", (uintmax_t)tpte));
2603
2604		pmap->pm_stats.resident_count--;
2605
2606		pte_clear(pte);
2607
2608		/*
2609		 * Update the vm_page_t clean and reference bits.
2610		 */
2611		if (tpte & PG_M) {
2612			vm_page_dirty(m);
2613		}
2614
2615		npv = TAILQ_NEXT(pv, pv_plist);
2616		TAILQ_REMOVE(&pmap->pm_pvlist, pv, pv_plist);
2617
2618		m->md.pv_list_count--;
2619		TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
2620		if (TAILQ_EMPTY(&m->md.pv_list))
2621			vm_page_flag_clear(m, PG_WRITEABLE);
2622
2623		pmap_unuse_pt(pmap, pv->pv_va);
2624		free_pv_entry(pv);
2625	}
2626	sched_unpin();
2627	pmap_invalidate_all(pmap);
2628	PMAP_UNLOCK(pmap);
2629	vm_page_unlock_queues();
2630}
2631
2632/*
2633 *	pmap_is_modified:
2634 *
2635 *	Return whether or not the specified physical page was modified
2636 *	in any physical maps.
2637 */
2638boolean_t
2639pmap_is_modified(vm_page_t m)
2640{
2641	pv_entry_t pv;
2642	pt_entry_t *pte;
2643	boolean_t rv;
2644
2645	rv = FALSE;
2646	if (!pmap_initialized || (m->flags & PG_FICTITIOUS))
2647		return (rv);
2648
2649	sched_pin();
2650	mtx_assert(&vm_page_queue_mtx, MA_OWNED);
2651	TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
2652		/*
2653		 * if the bit being tested is the modified bit, then
2654		 * mark clean_map and ptes as never
2655		 * modified.
2656		 */
2657		if (!pmap_track_modified(pv->pv_va))
2658			continue;
2659#if defined(PMAP_DIAGNOSTIC)
2660		if (!pv->pv_pmap) {
2661			printf("Null pmap (tb) at va: 0x%x\n", pv->pv_va);
2662			continue;
2663		}
2664#endif
2665		PMAP_LOCK(pv->pv_pmap);
2666		pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va);
2667		rv = (*pte & PG_M) != 0;
2668		PMAP_UNLOCK(pv->pv_pmap);
2669		if (rv)
2670			break;
2671	}
2672	sched_unpin();
2673	return (rv);
2674}
2675
2676/*
2677 *	pmap_is_prefaultable:
2678 *
2679 *	Return whether or not the specified virtual address is elgible
2680 *	for prefault.
2681 */
2682boolean_t
2683pmap_is_prefaultable(pmap_t pmap, vm_offset_t addr)
2684{
2685	pt_entry_t *pte;
2686	boolean_t rv;
2687
2688	rv = FALSE;
2689	PMAP_LOCK(pmap);
2690	if (*pmap_pde(pmap, addr)) {
2691		pte = vtopte(addr);
2692		rv = *pte == 0;
2693	}
2694	PMAP_UNLOCK(pmap);
2695	return (rv);
2696}
2697
2698/*
2699 *	Clear the given bit in each of the given page's ptes.  The bit is
2700 *	expressed as a 32-bit mask.  Consequently, if the pte is 64 bits in
2701 *	size, only a bit within the least significant 32 can be cleared.
2702 */
2703static __inline void
2704pmap_clear_ptes(vm_page_t m, int bit)
2705{
2706	register pv_entry_t pv;
2707	pt_entry_t pbits, *pte;
2708
2709	if (!pmap_initialized || (m->flags & PG_FICTITIOUS) ||
2710	    (bit == PG_RW && (m->flags & PG_WRITEABLE) == 0))
2711		return;
2712
2713	sched_pin();
2714	mtx_assert(&vm_page_queue_mtx, MA_OWNED);
2715	/*
2716	 * Loop over all current mappings setting/clearing as appropos If
2717	 * setting RO do we need to clear the VAC?
2718	 */
2719	TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
2720		/*
2721		 * don't write protect pager mappings
2722		 */
2723		if (bit == PG_RW) {
2724			if (!pmap_track_modified(pv->pv_va))
2725				continue;
2726		}
2727
2728#if defined(PMAP_DIAGNOSTIC)
2729		if (!pv->pv_pmap) {
2730			printf("Null pmap (cb) at va: 0x%x\n", pv->pv_va);
2731			continue;
2732		}
2733#endif
2734
2735		PMAP_LOCK(pv->pv_pmap);
2736		pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va);
2737retry:
2738		pbits = *pte;
2739		if (pbits & bit) {
2740			if (bit == PG_RW) {
2741				/*
2742				 * Regardless of whether a pte is 32 or 64 bits
2743				 * in size, PG_RW and PG_M are among the least
2744				 * significant 32 bits.
2745				 */
2746				if (!atomic_cmpset_int((u_int *)pte, pbits,
2747				    pbits & ~(PG_RW | PG_M)))
2748					goto retry;
2749				if (pbits & PG_M) {
2750					vm_page_dirty(m);
2751				}
2752			} else {
2753				atomic_clear_int((u_int *)pte, bit);
2754			}
2755			pmap_invalidate_page(pv->pv_pmap, pv->pv_va);
2756		}
2757		PMAP_UNLOCK(pv->pv_pmap);
2758	}
2759	if (bit == PG_RW)
2760		vm_page_flag_clear(m, PG_WRITEABLE);
2761	sched_unpin();
2762}
2763
2764/*
2765 *      pmap_page_protect:
2766 *
2767 *      Lower the permission for all mappings to a given page.
2768 */
2769void
2770pmap_page_protect(vm_page_t m, vm_prot_t prot)
2771{
2772	if ((prot & VM_PROT_WRITE) == 0) {
2773		if (prot & (VM_PROT_READ | VM_PROT_EXECUTE)) {
2774			pmap_clear_ptes(m, PG_RW);
2775		} else {
2776			pmap_remove_all(m);
2777		}
2778	}
2779}
2780
2781/*
2782 *	pmap_ts_referenced:
2783 *
2784 *	Return a count of reference bits for a page, clearing those bits.
2785 *	It is not necessary for every reference bit to be cleared, but it
2786 *	is necessary that 0 only be returned when there are truly no
2787 *	reference bits set.
2788 *
2789 *	XXX: The exact number of bits to check and clear is a matter that
2790 *	should be tested and standardized at some point in the future for
2791 *	optimal aging of shared pages.
2792 */
2793int
2794pmap_ts_referenced(vm_page_t m)
2795{
2796	register pv_entry_t pv, pvf, pvn;
2797	pt_entry_t *pte;
2798	pt_entry_t v;
2799	int rtval = 0;
2800
2801	if (!pmap_initialized || (m->flags & PG_FICTITIOUS))
2802		return (rtval);
2803
2804	sched_pin();
2805	mtx_assert(&vm_page_queue_mtx, MA_OWNED);
2806	if ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) {
2807
2808		pvf = pv;
2809
2810		do {
2811			pvn = TAILQ_NEXT(pv, pv_list);
2812
2813			TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
2814
2815			TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list);
2816
2817			if (!pmap_track_modified(pv->pv_va))
2818				continue;
2819
2820			PMAP_LOCK(pv->pv_pmap);
2821			pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va);
2822
2823			if (pte && ((v = pte_load(pte)) & PG_A) != 0) {
2824				atomic_clear_int((u_int *)pte, PG_A);
2825				pmap_invalidate_page(pv->pv_pmap, pv->pv_va);
2826
2827				rtval++;
2828				if (rtval > 4) {
2829					PMAP_UNLOCK(pv->pv_pmap);
2830					break;
2831				}
2832			}
2833			PMAP_UNLOCK(pv->pv_pmap);
2834		} while ((pv = pvn) != NULL && pv != pvf);
2835	}
2836	sched_unpin();
2837
2838	return (rtval);
2839}
2840
2841/*
2842 *	Clear the modify bits on the specified physical page.
2843 */
2844void
2845pmap_clear_modify(vm_page_t m)
2846{
2847	pmap_clear_ptes(m, PG_M);
2848}
2849
2850/*
2851 *	pmap_clear_reference:
2852 *
2853 *	Clear the reference bit on the specified physical page.
2854 */
2855void
2856pmap_clear_reference(vm_page_t m)
2857{
2858	pmap_clear_ptes(m, PG_A);
2859}
2860
2861/*
2862 * Miscellaneous support routines follow
2863 */
2864
2865/*
2866 * Map a set of physical memory pages into the kernel virtual
2867 * address space. Return a pointer to where it is mapped. This
2868 * routine is intended to be used for mapping device memory,
2869 * NOT real memory.
2870 */
2871void *
2872pmap_mapdev(pa, size)
2873	vm_paddr_t pa;
2874	vm_size_t size;
2875{
2876	vm_offset_t va, tmpva, offset;
2877
2878	offset = pa & PAGE_MASK;
2879	size = roundup(offset + size, PAGE_SIZE);
2880	pa = pa & PG_FRAME;
2881
2882	if (pa < KERNLOAD && pa + size <= KERNLOAD)
2883		va = KERNBASE + pa;
2884	else
2885		va = kmem_alloc_nofault(kernel_map, size);
2886	if (!va)
2887		panic("pmap_mapdev: Couldn't alloc kernel virtual memory");
2888
2889	for (tmpva = va; size > 0; ) {
2890		pmap_kenter(tmpva, pa);
2891		size -= PAGE_SIZE;
2892		tmpva += PAGE_SIZE;
2893		pa += PAGE_SIZE;
2894	}
2895	pmap_invalidate_range(kernel_pmap, va, tmpva);
2896	return ((void *)(va + offset));
2897}
2898
2899void
2900pmap_unmapdev(va, size)
2901	vm_offset_t va;
2902	vm_size_t size;
2903{
2904	vm_offset_t base, offset, tmpva;
2905
2906	if (va >= KERNBASE && va + size <= KERNBASE + KERNLOAD)
2907		return;
2908	base = va & PG_FRAME;
2909	offset = va & PAGE_MASK;
2910	size = roundup(offset + size, PAGE_SIZE);
2911	for (tmpva = base; tmpva < (base + size); tmpva += PAGE_SIZE)
2912		pmap_kremove(tmpva);
2913	pmap_invalidate_range(kernel_pmap, va, tmpva);
2914	kmem_free(kernel_map, base, size);
2915}
2916
2917/*
2918 * perform the pmap work for mincore
2919 */
2920int
2921pmap_mincore(pmap, addr)
2922	pmap_t pmap;
2923	vm_offset_t addr;
2924{
2925	pt_entry_t *ptep, pte;
2926	vm_page_t m;
2927	int val = 0;
2928
2929	PMAP_LOCK(pmap);
2930	ptep = pmap_pte(pmap, addr);
2931	pte = (ptep != NULL) ? *ptep : 0;
2932	pmap_pte_release(ptep);
2933	PMAP_UNLOCK(pmap);
2934
2935	if (pte != 0) {
2936		vm_paddr_t pa;
2937
2938		val = MINCORE_INCORE;
2939		if ((pte & PG_MANAGED) == 0)
2940			return val;
2941
2942		pa = pte & PG_FRAME;
2943
2944		m = PHYS_TO_VM_PAGE(pa);
2945
2946		/*
2947		 * Modified by us
2948		 */
2949		if (pte & PG_M)
2950			val |= MINCORE_MODIFIED|MINCORE_MODIFIED_OTHER;
2951		else {
2952			/*
2953			 * Modified by someone else
2954			 */
2955			vm_page_lock_queues();
2956			if (m->dirty || pmap_is_modified(m))
2957				val |= MINCORE_MODIFIED_OTHER;
2958			vm_page_unlock_queues();
2959		}
2960		/*
2961		 * Referenced by us
2962		 */
2963		if (pte & PG_A)
2964			val |= MINCORE_REFERENCED|MINCORE_REFERENCED_OTHER;
2965		else {
2966			/*
2967			 * Referenced by someone else
2968			 */
2969			vm_page_lock_queues();
2970			if ((m->flags & PG_REFERENCED) ||
2971			    pmap_ts_referenced(m)) {
2972				val |= MINCORE_REFERENCED_OTHER;
2973				vm_page_flag_set(m, PG_REFERENCED);
2974			}
2975			vm_page_unlock_queues();
2976		}
2977	}
2978	return val;
2979}
2980
2981void
2982pmap_activate(struct thread *td)
2983{
2984	struct proc *p = td->td_proc;
2985	pmap_t	pmap, oldpmap;
2986	u_int32_t  cr3;
2987
2988	critical_enter();
2989	pmap = vmspace_pmap(td->td_proc->p_vmspace);
2990	oldpmap = PCPU_GET(curpmap);
2991#if defined(SMP)
2992	atomic_clear_int(&oldpmap->pm_active, PCPU_GET(cpumask));
2993	atomic_set_int(&pmap->pm_active, PCPU_GET(cpumask));
2994#else
2995	oldpmap->pm_active &= ~1;
2996	pmap->pm_active |= 1;
2997#endif
2998#ifdef PAE
2999	cr3 = vtophys(pmap->pm_pdpt);
3000#else
3001	cr3 = vtophys(pmap->pm_pdir);
3002#endif
3003	/* XXXKSE this is wrong.
3004	 * pmap_activate is for the current thread on the current cpu
3005	 */
3006	if (p->p_flag & P_SA) {
3007		/* Make sure all other cr3 entries are updated. */
3008		/* what if they are running?  XXXKSE (maybe abort them) */
3009		FOREACH_THREAD_IN_PROC(p, td) {
3010			td->td_pcb->pcb_cr3 = cr3;
3011		}
3012	} else {
3013		td->td_pcb->pcb_cr3 = cr3;
3014	}
3015	load_cr3(cr3);
3016	PCPU_SET(curpmap, pmap);
3017	critical_exit();
3018}
3019
3020vm_offset_t
3021pmap_addr_hint(vm_object_t obj, vm_offset_t addr, vm_size_t size)
3022{
3023
3024	if ((obj == NULL) || (size < NBPDR) || (obj->type != OBJT_DEVICE)) {
3025		return addr;
3026	}
3027
3028	addr = (addr + PDRMASK) & ~PDRMASK;
3029	return addr;
3030}
3031
3032
3033#if defined(PMAP_DEBUG)
3034pmap_pid_dump(int pid)
3035{
3036	pmap_t pmap;
3037	struct proc *p;
3038	int npte = 0;
3039	int index;
3040
3041	sx_slock(&allproc_lock);
3042	LIST_FOREACH(p, &allproc, p_list) {
3043		if (p->p_pid != pid)
3044			continue;
3045
3046		if (p->p_vmspace) {
3047			int i,j;
3048			index = 0;
3049			pmap = vmspace_pmap(p->p_vmspace);
3050			for (i = 0; i < NPDEPTD; i++) {
3051				pd_entry_t *pde;
3052				pt_entry_t *pte;
3053				vm_offset_t base = i << PDRSHIFT;
3054
3055				pde = &pmap->pm_pdir[i];
3056				if (pde && pmap_pde_v(pde)) {
3057					for (j = 0; j < NPTEPG; j++) {
3058						vm_offset_t va = base + (j << PAGE_SHIFT);
3059						if (va >= (vm_offset_t) VM_MIN_KERNEL_ADDRESS) {
3060							if (index) {
3061								index = 0;
3062								printf("\n");
3063							}
3064							sx_sunlock(&allproc_lock);
3065							return npte;
3066						}
3067						pte = pmap_pte(pmap, va);
3068						if (pte && pmap_pte_v(pte)) {
3069							pt_entry_t pa;
3070							vm_page_t m;
3071							pa = *pte;
3072							m = PHYS_TO_VM_PAGE(pa);
3073							printf("va: 0x%x, pt: 0x%x, h: %d, w: %d, f: 0x%x",
3074								va, pa, m->hold_count, m->wire_count, m->flags);
3075							npte++;
3076							index++;
3077							if (index >= 2) {
3078								index = 0;
3079								printf("\n");
3080							} else {
3081								printf(" ");
3082							}
3083						}
3084					}
3085				}
3086			}
3087		}
3088	}
3089	sx_sunlock(&allproc_lock);
3090	return npte;
3091}
3092#endif
3093
3094#if defined(DEBUG)
3095
3096static void	pads(pmap_t pm);
3097void		pmap_pvdump(vm_offset_t pa);
3098
3099/* print address space of pmap*/
3100static void
3101pads(pm)
3102	pmap_t pm;
3103{
3104	int i, j;
3105	vm_paddr_t va;
3106	pt_entry_t *ptep;
3107
3108	if (pm == kernel_pmap)
3109		return;
3110	for (i = 0; i < NPDEPTD; i++)
3111		if (pm->pm_pdir[i])
3112			for (j = 0; j < NPTEPG; j++) {
3113				va = (i << PDRSHIFT) + (j << PAGE_SHIFT);
3114				if (pm == kernel_pmap && va < KERNBASE)
3115					continue;
3116				if (pm != kernel_pmap && va > UPT_MAX_ADDRESS)
3117					continue;
3118				ptep = pmap_pte(pm, va);
3119				if (pmap_pte_v(ptep))
3120					printf("%x:%x ", va, *ptep);
3121			};
3122
3123}
3124
3125void
3126pmap_pvdump(pa)
3127	vm_paddr_t pa;
3128{
3129	pv_entry_t pv;
3130	vm_page_t m;
3131
3132	printf("pa %x", pa);
3133	m = PHYS_TO_VM_PAGE(pa);
3134	TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
3135		printf(" -> pmap %p, va %x", (void *)pv->pv_pmap, pv->pv_va);
3136		pads(pv->pv_pmap);
3137	}
3138	printf(" ");
3139}
3140#endif
3141