pmap.c revision 76827
1/*
2 * 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 * $FreeBSD: head/sys/i386/i386/pmap.c 76827 2001-05-19 01:28:09Z alfred $
43 */
44
45/*
46 *	Manages physical address maps.
47 *
48 *	In addition to hardware address maps, this
49 *	module is called upon to provide software-use-only
50 *	maps which may or may not be stored in the same
51 *	form as hardware maps.  These pseudo-maps are
52 *	used to store intermediate results from copy
53 *	operations to and from address spaces.
54 *
55 *	Since the information managed by this module is
56 *	also stored by the logical address mapping module,
57 *	this module may throw away valid virtual-to-physical
58 *	mappings at almost any time.  However, invalidations
59 *	of virtual-to-physical mappings must be done as
60 *	requested.
61 *
62 *	In order to cope with hardware architectures which
63 *	make virtual-to-physical map invalidates expensive,
64 *	this module may delay invalidate or reduced protection
65 *	operations until such time as they are actually
66 *	necessary.  This module is given full information as
67 *	to which processors are currently using which maps,
68 *	and to when physical maps must be made correct.
69 */
70
71#include "opt_disable_pse.h"
72#include "opt_pmap.h"
73#include "opt_msgbuf.h"
74
75#include <sys/param.h>
76#include <sys/systm.h>
77#include <sys/lock.h>
78#include <sys/mutex.h>
79#include <sys/mman.h>
80#include <sys/msgbuf.h>
81#include <sys/proc.h>
82#include <sys/sx.h>
83#include <sys/user.h>
84#include <sys/vmmeter.h>
85
86#include <vm/vm.h>
87#include <vm/vm_param.h>
88#include <vm/vm_kern.h>
89#include <vm/vm_page.h>
90#include <vm/vm_map.h>
91#include <vm/vm_object.h>
92#include <vm/vm_extern.h>
93#include <vm/vm_pageout.h>
94#include <vm/vm_pager.h>
95#include <vm/vm_zone.h>
96
97#include <machine/cputypes.h>
98#include <machine/md_var.h>
99#include <machine/specialreg.h>
100#if defined(SMP) || defined(APIC_IO)
101#include <machine/smp.h>
102#include <machine/apic.h>
103#include <machine/segments.h>
104#include <machine/tss.h>
105#include <machine/globaldata.h>
106#endif /* SMP || APIC_IO */
107
108#define PMAP_KEEP_PDIRS
109#ifndef PMAP_SHPGPERPROC
110#define PMAP_SHPGPERPROC 200
111#endif
112
113#if defined(DIAGNOSTIC)
114#define PMAP_DIAGNOSTIC
115#endif
116
117#define MINPV 2048
118
119#if !defined(PMAP_DIAGNOSTIC)
120#define PMAP_INLINE __inline
121#else
122#define PMAP_INLINE
123#endif
124
125/*
126 * Get PDEs and PTEs for user/kernel address space
127 */
128#define	pmap_pde(m, v)	(&((m)->pm_pdir[(vm_offset_t)(v) >> PDRSHIFT]))
129#define pdir_pde(m, v) (m[(vm_offset_t)(v) >> PDRSHIFT])
130
131#define pmap_pde_v(pte)		((*(int *)pte & PG_V) != 0)
132#define pmap_pte_w(pte)		((*(int *)pte & PG_W) != 0)
133#define pmap_pte_m(pte)		((*(int *)pte & PG_M) != 0)
134#define pmap_pte_u(pte)		((*(int *)pte & PG_A) != 0)
135#define pmap_pte_v(pte)		((*(int *)pte & PG_V) != 0)
136
137#define pmap_pte_set_w(pte, v) ((v)?(*(int *)pte |= PG_W):(*(int *)pte &= ~PG_W))
138#define pmap_pte_set_prot(pte, v) ((*(int *)pte &= ~PG_PROT), (*(int *)pte |= (v)))
139
140/*
141 * Given a map and a machine independent protection code,
142 * convert to a vax protection code.
143 */
144#define pte_prot(m, p)	(protection_codes[p])
145static int protection_codes[8];
146
147static struct pmap kernel_pmap_store;
148pmap_t kernel_pmap;
149LIST_HEAD(pmaplist, pmap);
150struct pmaplist allpmaps;
151
152vm_offset_t avail_start;	/* PA of first available physical page */
153vm_offset_t avail_end;		/* PA of last available physical page */
154vm_offset_t virtual_avail;	/* VA of first avail page (after kernel bss) */
155vm_offset_t virtual_end;	/* VA of last avail page (end of kernel AS) */
156static boolean_t pmap_initialized = FALSE;	/* Has pmap_init completed? */
157static int pgeflag;		/* PG_G or-in */
158static int pseflag;		/* PG_PS or-in */
159
160static vm_object_t kptobj;
161
162static int nkpt;
163vm_offset_t kernel_vm_end;
164
165/*
166 * Data for the pv entry allocation mechanism
167 */
168static vm_zone_t pvzone;
169static struct vm_zone pvzone_store;
170static struct vm_object pvzone_obj;
171static int pv_entry_count=0, pv_entry_max=0, pv_entry_high_water=0;
172static int pmap_pagedaemon_waken = 0;
173static struct pv_entry *pvinit;
174
175/*
176 * All those kernel PT submaps that BSD is so fond of
177 */
178pt_entry_t *CMAP1 = 0;
179static pt_entry_t *CMAP2, *ptmmap;
180caddr_t CADDR1 = 0, ptvmmap = 0;
181static caddr_t CADDR2;
182static pt_entry_t *msgbufmap;
183struct msgbuf *msgbufp=0;
184
185/*
186 * Crashdump maps.
187 */
188static pt_entry_t *pt_crashdumpmap;
189static caddr_t crashdumpmap;
190
191#ifdef SMP
192extern pt_entry_t *SMPpt;
193#endif
194static pt_entry_t *PMAP1 = 0;
195static unsigned *PADDR1 = 0;
196
197static PMAP_INLINE void	free_pv_entry __P((pv_entry_t pv));
198static unsigned * get_ptbase __P((pmap_t pmap));
199static pv_entry_t get_pv_entry __P((void));
200static void	i386_protection_init __P((void));
201static __inline void	pmap_changebit __P((vm_page_t m, int bit, boolean_t setem));
202
203static void	pmap_remove_all __P((vm_page_t m));
204static vm_page_t pmap_enter_quick __P((pmap_t pmap, vm_offset_t va,
205				      vm_page_t m, vm_page_t mpte));
206static int pmap_remove_pte __P((struct pmap *pmap, unsigned *ptq,
207					vm_offset_t sva));
208static void pmap_remove_page __P((struct pmap *pmap, vm_offset_t va));
209static int pmap_remove_entry __P((struct pmap *pmap, vm_page_t m,
210					vm_offset_t va));
211static boolean_t pmap_testbit __P((vm_page_t m, int bit));
212static void pmap_insert_entry __P((pmap_t pmap, vm_offset_t va,
213		vm_page_t mpte, vm_page_t m));
214
215static vm_page_t pmap_allocpte __P((pmap_t pmap, vm_offset_t va));
216
217static int pmap_release_free_page __P((pmap_t pmap, vm_page_t p));
218static vm_page_t _pmap_allocpte __P((pmap_t pmap, unsigned ptepindex));
219static unsigned * pmap_pte_quick __P((pmap_t pmap, vm_offset_t va));
220static vm_page_t pmap_page_lookup __P((vm_object_t object, vm_pindex_t pindex));
221static int pmap_unuse_pt __P((pmap_t, vm_offset_t, vm_page_t));
222static vm_offset_t pmap_kmem_choose(vm_offset_t addr);
223
224static unsigned pdir4mb;
225
226/*
227 *	Routine:	pmap_pte
228 *	Function:
229 *		Extract the page table entry associated
230 *		with the given map/virtual_address pair.
231 */
232
233PMAP_INLINE unsigned *
234pmap_pte(pmap, va)
235	register pmap_t pmap;
236	vm_offset_t va;
237{
238	unsigned *pdeaddr;
239
240	if (pmap) {
241		pdeaddr = (unsigned *) pmap_pde(pmap, va);
242		if (*pdeaddr & PG_PS)
243			return pdeaddr;
244		if (*pdeaddr) {
245			return get_ptbase(pmap) + i386_btop(va);
246		}
247	}
248	return (0);
249}
250
251/*
252 * Move the kernel virtual free pointer to the next
253 * 4MB.  This is used to help improve performance
254 * by using a large (4MB) page for much of the kernel
255 * (.text, .data, .bss)
256 */
257static vm_offset_t
258pmap_kmem_choose(vm_offset_t addr)
259{
260	vm_offset_t newaddr = addr;
261#ifndef DISABLE_PSE
262	if (cpu_feature & CPUID_PSE) {
263		newaddr = (addr + (NBPDR - 1)) & ~(NBPDR - 1);
264	}
265#endif
266	return newaddr;
267}
268
269/*
270 *	Bootstrap the system enough to run with virtual memory.
271 *
272 *	On the i386 this is called after mapping has already been enabled
273 *	and just syncs the pmap module with what has already been done.
274 *	[We can't call it easily with mapping off since the kernel is not
275 *	mapped with PA == VA, hence we would have to relocate every address
276 *	from the linked base (virtual) address "KERNBASE" to the actual
277 *	(physical) address starting relative to 0]
278 */
279void
280pmap_bootstrap(firstaddr, loadaddr)
281	vm_offset_t firstaddr;
282	vm_offset_t loadaddr;
283{
284	vm_offset_t va;
285	pt_entry_t *pte;
286	int i;
287
288	avail_start = firstaddr;
289
290	/*
291	 * XXX The calculation of virtual_avail is wrong. It's NKPT*PAGE_SIZE too
292	 * large. It should instead be correctly calculated in locore.s and
293	 * not based on 'first' (which is a physical address, not a virtual
294	 * address, for the start of unused physical memory). The kernel
295	 * page tables are NOT double mapped and thus should not be included
296	 * in this calculation.
297	 */
298	virtual_avail = (vm_offset_t) KERNBASE + firstaddr;
299	virtual_avail = pmap_kmem_choose(virtual_avail);
300
301	virtual_end = VM_MAX_KERNEL_ADDRESS;
302
303	/*
304	 * Initialize protection array.
305	 */
306	i386_protection_init();
307
308	/*
309	 * The kernel's pmap is statically allocated so we don't have to use
310	 * pmap_create, which is unlikely to work correctly at this part of
311	 * the boot sequence (XXX and which no longer exists).
312	 */
313	kernel_pmap = &kernel_pmap_store;
314
315	kernel_pmap->pm_pdir = (pd_entry_t *) (KERNBASE + (u_int)IdlePTD);
316	kernel_pmap->pm_count = 1;
317	kernel_pmap->pm_active = -1;	/* don't allow deactivation */
318	TAILQ_INIT(&kernel_pmap->pm_pvlist);
319	LIST_INIT(&allpmaps);
320	LIST_INSERT_HEAD(&allpmaps, kernel_pmap, pm_list);
321	nkpt = NKPT;
322
323	/*
324	 * Reserve some special page table entries/VA space for temporary
325	 * mapping of pages.
326	 */
327#define	SYSMAP(c, p, v, n)	\
328	v = (c)va; va += ((n)*PAGE_SIZE); p = pte; pte += (n);
329
330	va = virtual_avail;
331	pte = (pt_entry_t *) pmap_pte(kernel_pmap, va);
332
333	/*
334	 * CMAP1/CMAP2 are used for zeroing and copying pages.
335	 */
336	SYSMAP(caddr_t, CMAP1, CADDR1, 1)
337	SYSMAP(caddr_t, CMAP2, CADDR2, 1)
338
339	/*
340	 * Crashdump maps.
341	 */
342	SYSMAP(caddr_t, pt_crashdumpmap, crashdumpmap, MAXDUMPPGS);
343
344	/*
345	 * ptvmmap is used for reading arbitrary physical pages via /dev/mem.
346	 * XXX ptmmap is not used.
347	 */
348	SYSMAP(caddr_t, ptmmap, ptvmmap, 1)
349
350	/*
351	 * msgbufp is used to map the system message buffer.
352	 * XXX msgbufmap is not used.
353	 */
354	SYSMAP(struct msgbuf *, msgbufmap, msgbufp,
355	       atop(round_page(MSGBUF_SIZE)))
356
357	/*
358	 * ptemap is used for pmap_pte_quick
359	 */
360	SYSMAP(unsigned *, PMAP1, PADDR1, 1);
361
362	virtual_avail = va;
363
364	*(int *) CMAP1 = *(int *) CMAP2 = 0;
365	for (i = 0; i < NKPT; i++)
366		PTD[i] = 0;
367
368	pgeflag = 0;
369#if !defined(SMP)			/* XXX - see also mp_machdep.c */
370	if (cpu_feature & CPUID_PGE) {
371		pgeflag = PG_G;
372	}
373#endif
374
375/*
376 * Initialize the 4MB page size flag
377 */
378	pseflag = 0;
379/*
380 * The 4MB page version of the initial
381 * kernel page mapping.
382 */
383	pdir4mb = 0;
384
385#if !defined(DISABLE_PSE)
386	if (cpu_feature & CPUID_PSE) {
387		unsigned ptditmp;
388		/*
389		 * Note that we have enabled PSE mode
390		 */
391		pseflag = PG_PS;
392		ptditmp = *((unsigned *)PTmap + i386_btop(KERNBASE));
393		ptditmp &= ~(NBPDR - 1);
394		ptditmp |= PG_V | PG_RW | PG_PS | PG_U | pgeflag;
395		pdir4mb = ptditmp;
396
397#if !defined(SMP)
398		/*
399		 * Enable the PSE mode.
400		 */
401		load_cr4(rcr4() | CR4_PSE);
402
403		/*
404		 * We can do the mapping here for the single processor
405		 * case.  We simply ignore the old page table page from
406		 * now on.
407		 */
408		/*
409		 * For SMP, we still need 4K pages to bootstrap APs,
410		 * PSE will be enabled as soon as all APs are up.
411		 */
412		PTD[KPTDI] = (pd_entry_t) ptditmp;
413		kernel_pmap->pm_pdir[KPTDI] = (pd_entry_t) ptditmp;
414		invltlb();
415#endif
416	}
417#endif
418
419#ifdef SMP
420	if (cpu_apic_address == 0)
421		panic("pmap_bootstrap: no local apic! (non-SMP hardware?)");
422
423	/* local apic is mapped on last page */
424	SMPpt[NPTEPG - 1] = (pt_entry_t)(PG_V | PG_RW | PG_N | pgeflag |
425	    (cpu_apic_address & PG_FRAME));
426#endif
427
428	invltlb();
429}
430
431#ifdef SMP
432/*
433 * Set 4mb pdir for mp startup
434 */
435void
436pmap_set_opt(void)
437{
438	if (pseflag && (cpu_feature & CPUID_PSE)) {
439		load_cr4(rcr4() | CR4_PSE);
440		if (pdir4mb && PCPU_GET(cpuid) == 0) {	/* only on BSP */
441			kernel_pmap->pm_pdir[KPTDI] =
442			    PTD[KPTDI] = (pd_entry_t)pdir4mb;
443			cpu_invltlb();
444		}
445	}
446}
447#endif
448
449/*
450 *	Initialize the pmap module.
451 *	Called by vm_init, to initialize any structures that the pmap
452 *	system needs to map virtual memory.
453 *	pmap_init has been enhanced to support in a fairly consistant
454 *	way, discontiguous physical memory.
455 */
456void
457pmap_init(phys_start, phys_end)
458	vm_offset_t phys_start, phys_end;
459{
460	int i;
461	int initial_pvs;
462
463	/*
464	 * object for kernel page table pages
465	 */
466	kptobj = vm_object_allocate(OBJT_DEFAULT, NKPDE);
467
468	/*
469	 * Allocate memory for random pmap data structures.  Includes the
470	 * pv_head_table.
471	 */
472
473	for(i = 0; i < vm_page_array_size; i++) {
474		vm_page_t m;
475
476		m = &vm_page_array[i];
477		TAILQ_INIT(&m->md.pv_list);
478		m->md.pv_list_count = 0;
479	}
480
481	/*
482	 * init the pv free list
483	 */
484	initial_pvs = vm_page_array_size;
485	if (initial_pvs < MINPV)
486		initial_pvs = MINPV;
487	pvzone = &pvzone_store;
488	pvinit = (struct pv_entry *) kmem_alloc(kernel_map,
489		initial_pvs * sizeof (struct pv_entry));
490	zbootinit(pvzone, "PV ENTRY", sizeof (struct pv_entry), pvinit,
491	    vm_page_array_size);
492
493	/*
494	 * Now it is safe to enable pv_table recording.
495	 */
496	pmap_initialized = TRUE;
497}
498
499/*
500 * Initialize the address space (zone) for the pv_entries.  Set a
501 * high water mark so that the system can recover from excessive
502 * numbers of pv entries.
503 */
504void
505pmap_init2()
506{
507	pv_entry_max = PMAP_SHPGPERPROC * maxproc + vm_page_array_size;
508	pv_entry_high_water = 9 * (pv_entry_max / 10);
509	zinitna(pvzone, &pvzone_obj, NULL, 0, pv_entry_max, ZONE_INTERRUPT, 1);
510}
511
512
513/***************************************************
514 * Low level helper routines.....
515 ***************************************************/
516
517#if defined(PMAP_DIAGNOSTIC)
518
519/*
520 * This code checks for non-writeable/modified pages.
521 * This should be an invalid condition.
522 */
523static int
524pmap_nw_modified(pt_entry_t ptea)
525{
526	int pte;
527
528	pte = (int) ptea;
529
530	if ((pte & (PG_M|PG_RW)) == PG_M)
531		return 1;
532	else
533		return 0;
534}
535#endif
536
537
538/*
539 * this routine defines the region(s) of memory that should
540 * not be tested for the modified bit.
541 */
542static PMAP_INLINE int
543pmap_track_modified(vm_offset_t va)
544{
545	if ((va < clean_sva) || (va >= clean_eva))
546		return 1;
547	else
548		return 0;
549}
550
551static PMAP_INLINE void
552invltlb_1pg(vm_offset_t va)
553{
554#ifdef I386_CPU
555	invltlb();
556#else
557	invlpg(va);
558#endif
559}
560
561static __inline void
562pmap_TLB_invalidate(pmap_t pmap, vm_offset_t va)
563{
564#if defined(SMP)
565	if (pmap->pm_active & (1 << PCPU_GET(cpuid)))
566		cpu_invlpg((void *)va);
567	if (pmap->pm_active & PCPU_GET(other_cpus))
568		smp_invltlb();
569#else
570	if (pmap->pm_active)
571		invltlb_1pg(va);
572#endif
573}
574
575static __inline void
576pmap_TLB_invalidate_all(pmap_t pmap)
577{
578#if defined(SMP)
579	if (pmap->pm_active & (1 << PCPU_GET(cpuid)))
580		cpu_invltlb();
581	if (pmap->pm_active & PCPU_GET(other_cpus))
582		smp_invltlb();
583#else
584	if (pmap->pm_active)
585		invltlb();
586#endif
587}
588
589static unsigned *
590get_ptbase(pmap)
591	pmap_t pmap;
592{
593	unsigned frame = (unsigned) pmap->pm_pdir[PTDPTDI] & PG_FRAME;
594
595	/* are we current address space or kernel? */
596	if (pmap == kernel_pmap || frame == (((unsigned) PTDpde) & PG_FRAME)) {
597		return (unsigned *) PTmap;
598	}
599	/* otherwise, we are alternate address space */
600	if (frame != (((unsigned) APTDpde) & PG_FRAME)) {
601		APTDpde = (pd_entry_t) (frame | PG_RW | PG_V);
602#if defined(SMP)
603		/* The page directory is not shared between CPUs */
604		cpu_invltlb();
605#else
606		invltlb();
607#endif
608	}
609	return (unsigned *) APTmap;
610}
611
612/*
613 * Super fast pmap_pte routine best used when scanning
614 * the pv lists.  This eliminates many coarse-grained
615 * invltlb calls.  Note that many of the pv list
616 * scans are across different pmaps.  It is very wasteful
617 * to do an entire invltlb for checking a single mapping.
618 */
619
620static unsigned *
621pmap_pte_quick(pmap, va)
622	register pmap_t pmap;
623	vm_offset_t va;
624{
625	unsigned pde, newpf;
626	if ((pde = (unsigned) pmap->pm_pdir[va >> PDRSHIFT]) != 0) {
627		unsigned frame = (unsigned) pmap->pm_pdir[PTDPTDI] & PG_FRAME;
628		unsigned index = i386_btop(va);
629		/* are we current address space or kernel? */
630		if ((pmap == kernel_pmap) ||
631			(frame == (((unsigned) PTDpde) & PG_FRAME))) {
632			return (unsigned *) PTmap + index;
633		}
634		newpf = pde & PG_FRAME;
635		if ( ((* (unsigned *) PMAP1) & PG_FRAME) != newpf) {
636			* (unsigned *) PMAP1 = newpf | PG_RW | PG_V;
637			invltlb_1pg((vm_offset_t) PADDR1);
638		}
639		return PADDR1 + ((unsigned) index & (NPTEPG - 1));
640	}
641	return (0);
642}
643
644/*
645 *	Routine:	pmap_extract
646 *	Function:
647 *		Extract the physical page address associated
648 *		with the given map/virtual_address pair.
649 */
650vm_offset_t
651pmap_extract(pmap, va)
652	register pmap_t pmap;
653	vm_offset_t va;
654{
655	vm_offset_t rtval;
656	vm_offset_t pdirindex;
657	pdirindex = va >> PDRSHIFT;
658	if (pmap && (rtval = (unsigned) pmap->pm_pdir[pdirindex])) {
659		unsigned *pte;
660		if ((rtval & PG_PS) != 0) {
661			rtval &= ~(NBPDR - 1);
662			rtval |= va & (NBPDR - 1);
663			return rtval;
664		}
665		pte = get_ptbase(pmap) + i386_btop(va);
666		rtval = ((*pte & PG_FRAME) | (va & PAGE_MASK));
667		return rtval;
668	}
669	return 0;
670
671}
672
673/***************************************************
674 * Low level mapping routines.....
675 ***************************************************/
676
677/*
678 * add a wired page to the kva
679 * note that in order for the mapping to take effect -- you
680 * should do a invltlb after doing the pmap_kenter...
681 */
682PMAP_INLINE void
683pmap_kenter(va, pa)
684	vm_offset_t va;
685	register vm_offset_t pa;
686{
687	register unsigned *pte;
688	unsigned npte, opte;
689
690	npte = pa | PG_RW | PG_V | pgeflag;
691	pte = (unsigned *)vtopte(va);
692	opte = *pte;
693	*pte = npte;
694	/*if (opte)*/
695		invltlb_1pg(va);	/* XXX what about SMP? */
696}
697
698/*
699 * remove a page from the kernel pagetables
700 */
701PMAP_INLINE void
702pmap_kremove(va)
703	vm_offset_t va;
704{
705	register unsigned *pte;
706
707	pte = (unsigned *)vtopte(va);
708	*pte = 0;
709	invltlb_1pg(va);	/* XXX what about SMP? */
710}
711
712/*
713 *	Used to map a range of physical addresses into kernel
714 *	virtual address space.
715 *
716 *	The value passed in '*virt' is a suggested virtual address for
717 *	the mapping. Architectures which can support a direct-mapped
718 *	physical to virtual region can return the appropriate address
719 *	within that region, leaving '*virt' unchanged. Other
720 *	architectures should map the pages starting at '*virt' and
721 *	update '*virt' with the first usable address after the mapped
722 *	region.
723 */
724vm_offset_t
725pmap_map(virt, start, end, prot)
726	vm_offset_t *virt;
727	vm_offset_t start;
728	vm_offset_t end;
729	int prot;
730{
731	vm_offset_t sva = *virt;
732	vm_offset_t va = sva;
733	while (start < end) {
734		pmap_kenter(va, start);
735		va += PAGE_SIZE;
736		start += PAGE_SIZE;
737	}
738	*virt = va;
739	return (sva);
740}
741
742
743/*
744 * Add a list of wired pages to the kva
745 * this routine is only used for temporary
746 * kernel mappings that do not need to have
747 * page modification or references recorded.
748 * Note that old mappings are simply written
749 * over.  The page *must* be wired.
750 */
751void
752pmap_qenter(va, m, count)
753	vm_offset_t va;
754	vm_page_t *m;
755	int count;
756{
757	int i;
758
759	for (i = 0; i < count; i++) {
760		vm_offset_t tva = va + i * PAGE_SIZE;
761		pmap_kenter(tva, VM_PAGE_TO_PHYS(m[i]));
762	}
763}
764
765/*
766 * this routine jerks page mappings from the
767 * kernel -- it is meant only for temporary mappings.
768 */
769void
770pmap_qremove(va, count)
771	vm_offset_t va;
772	int count;
773{
774	vm_offset_t end_va;
775
776	end_va = va + count*PAGE_SIZE;
777
778	while (va < end_va) {
779		unsigned *pte;
780
781		pte = (unsigned *)vtopte(va);
782		*pte = 0;
783#ifdef SMP
784		cpu_invlpg((void *)va);
785#else
786		invltlb_1pg(va);
787#endif
788		va += PAGE_SIZE;
789	}
790#ifdef SMP
791	smp_invltlb();
792#endif
793}
794
795static vm_page_t
796pmap_page_lookup(object, pindex)
797	vm_object_t object;
798	vm_pindex_t pindex;
799{
800	vm_page_t m;
801retry:
802	m = vm_page_lookup(object, pindex);
803	if (m && vm_page_sleep_busy(m, FALSE, "pplookp"))
804		goto retry;
805	return m;
806}
807
808/*
809 * Create the UPAGES for a new process.
810 * This routine directly affects the fork perf for a process.
811 */
812void
813pmap_new_proc(p)
814	struct proc *p;
815{
816#ifdef I386_CPU
817	int updateneeded;
818#endif
819	int i;
820	vm_object_t upobj;
821	vm_page_t m;
822	struct user *up;
823	unsigned *ptek, oldpte;
824
825	/*
826	 * allocate object for the upages
827	 */
828	if ((upobj = p->p_upages_obj) == NULL) {
829		upobj = vm_object_allocate( OBJT_DEFAULT, UPAGES);
830		p->p_upages_obj = upobj;
831	}
832
833	/* get a kernel virtual address for the UPAGES for this proc */
834	if ((up = p->p_addr) == NULL) {
835		up = (struct user *) kmem_alloc_nofault(kernel_map,
836				UPAGES * PAGE_SIZE);
837		if (up == NULL)
838			panic("pmap_new_proc: u_map allocation failed");
839		p->p_addr = up;
840	}
841
842	ptek = (unsigned *) vtopte((vm_offset_t) up);
843
844#ifdef I386_CPU
845	updateneeded = 0;
846#endif
847	for(i=0;i<UPAGES;i++) {
848		/*
849		 * Get a kernel stack page
850		 */
851		m = vm_page_grab(upobj, i, VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
852
853		/*
854		 * Wire the page
855		 */
856		m->wire_count++;
857		cnt.v_wire_count++;
858
859		oldpte = *(ptek + i);
860		/*
861		 * Enter the page into the kernel address space.
862		 */
863		*(ptek + i) = VM_PAGE_TO_PHYS(m) | PG_RW | PG_V | pgeflag;
864		if (oldpte) {
865#ifdef I386_CPU
866			updateneeded = 1;
867#else
868			invlpg((vm_offset_t) up + i * PAGE_SIZE);
869#endif
870		}
871
872		vm_page_wakeup(m);
873		vm_page_flag_clear(m, PG_ZERO);
874		vm_page_flag_set(m, PG_MAPPED | PG_WRITEABLE);
875		m->valid = VM_PAGE_BITS_ALL;
876	}
877#ifdef I386_CPU
878	if (updateneeded)
879		invltlb();
880#endif
881}
882
883/*
884 * Dispose the UPAGES for a process that has exited.
885 * This routine directly impacts the exit perf of a process.
886 */
887void
888pmap_dispose_proc(p)
889	struct proc *p;
890{
891	int i;
892	vm_object_t upobj;
893	vm_page_t m;
894	unsigned *ptek, oldpte;
895
896	upobj = p->p_upages_obj;
897
898	ptek = (unsigned *) vtopte((vm_offset_t) p->p_addr);
899	for(i=0;i<UPAGES;i++) {
900
901		if ((m = vm_page_lookup(upobj, i)) == NULL)
902			panic("pmap_dispose_proc: upage already missing???");
903
904		vm_page_busy(m);
905
906		oldpte = *(ptek + i);
907		*(ptek + i) = 0;
908#ifndef I386_CPU
909		invlpg((vm_offset_t) p->p_addr + i * PAGE_SIZE);
910#endif
911		vm_page_unwire(m, 0);
912		vm_page_free(m);
913	}
914#ifdef I386_CPU
915	invltlb();
916#endif
917}
918
919/*
920 * Allow the UPAGES for a process to be prejudicially paged out.
921 */
922void
923pmap_swapout_proc(p)
924	struct proc *p;
925{
926	int i;
927	vm_object_t upobj;
928	vm_page_t m;
929
930	upobj = p->p_upages_obj;
931	/*
932	 * let the upages be paged
933	 */
934	for(i=0;i<UPAGES;i++) {
935		if ((m = vm_page_lookup(upobj, i)) == NULL)
936			panic("pmap_swapout_proc: upage already missing???");
937		vm_page_dirty(m);
938		vm_page_unwire(m, 0);
939		pmap_kremove( (vm_offset_t) p->p_addr + PAGE_SIZE * i);
940	}
941}
942
943/*
944 * Bring the UPAGES for a specified process back in.
945 */
946void
947pmap_swapin_proc(p)
948	struct proc *p;
949{
950	int i,rv;
951	vm_object_t upobj;
952	vm_page_t m;
953
954	upobj = p->p_upages_obj;
955	for(i=0;i<UPAGES;i++) {
956
957		m = vm_page_grab(upobj, i, VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
958
959		pmap_kenter(((vm_offset_t) p->p_addr) + i * PAGE_SIZE,
960			VM_PAGE_TO_PHYS(m));
961
962		if (m->valid != VM_PAGE_BITS_ALL) {
963			rv = vm_pager_get_pages(upobj, &m, 1, 0);
964			if (rv != VM_PAGER_OK)
965				panic("pmap_swapin_proc: cannot get upages for proc: %d\n", p->p_pid);
966			m = vm_page_lookup(upobj, i);
967			m->valid = VM_PAGE_BITS_ALL;
968		}
969
970		vm_page_wire(m);
971		vm_page_wakeup(m);
972		vm_page_flag_set(m, PG_MAPPED | PG_WRITEABLE);
973	}
974}
975
976/***************************************************
977 * Page table page management routines.....
978 ***************************************************/
979
980/*
981 * This routine unholds page table pages, and if the hold count
982 * drops to zero, then it decrements the wire count.
983 */
984static int
985_pmap_unwire_pte_hold(pmap_t pmap, vm_page_t m) {
986
987	while (vm_page_sleep_busy(m, FALSE, "pmuwpt"))
988		;
989
990	if (m->hold_count == 0) {
991		vm_offset_t pteva;
992		/*
993		 * unmap the page table page
994		 */
995		pmap->pm_pdir[m->pindex] = 0;
996		--pmap->pm_stats.resident_count;
997		if ((((unsigned)pmap->pm_pdir[PTDPTDI]) & PG_FRAME) ==
998			(((unsigned) PTDpde) & PG_FRAME)) {
999			/*
1000			 * Do a invltlb to make the invalidated mapping
1001			 * take effect immediately.
1002			 */
1003			pteva = UPT_MIN_ADDRESS + i386_ptob(m->pindex);
1004			pmap_TLB_invalidate(pmap, pteva);
1005		}
1006
1007		if (pmap->pm_ptphint == m)
1008			pmap->pm_ptphint = NULL;
1009
1010		/*
1011		 * If the page is finally unwired, simply free it.
1012		 */
1013		--m->wire_count;
1014		if (m->wire_count == 0) {
1015
1016			vm_page_flash(m);
1017			vm_page_busy(m);
1018			vm_page_free_zero(m);
1019			--cnt.v_wire_count;
1020		}
1021		return 1;
1022	}
1023	return 0;
1024}
1025
1026static PMAP_INLINE int
1027pmap_unwire_pte_hold(pmap_t pmap, vm_page_t m)
1028{
1029	vm_page_unhold(m);
1030	if (m->hold_count == 0)
1031		return _pmap_unwire_pte_hold(pmap, m);
1032	else
1033		return 0;
1034}
1035
1036/*
1037 * After removing a page table entry, this routine is used to
1038 * conditionally free the page, and manage the hold/wire counts.
1039 */
1040static int
1041pmap_unuse_pt(pmap, va, mpte)
1042	pmap_t pmap;
1043	vm_offset_t va;
1044	vm_page_t mpte;
1045{
1046	unsigned ptepindex;
1047	if (va >= UPT_MIN_ADDRESS)
1048		return 0;
1049
1050	if (mpte == NULL) {
1051		ptepindex = (va >> PDRSHIFT);
1052		if (pmap->pm_ptphint &&
1053			(pmap->pm_ptphint->pindex == ptepindex)) {
1054			mpte = pmap->pm_ptphint;
1055		} else {
1056			mpte = pmap_page_lookup( pmap->pm_pteobj, ptepindex);
1057			pmap->pm_ptphint = mpte;
1058		}
1059	}
1060
1061	return pmap_unwire_pte_hold(pmap, mpte);
1062}
1063
1064void
1065pmap_pinit0(pmap)
1066	struct pmap *pmap;
1067{
1068	pmap->pm_pdir =
1069		(pd_entry_t *)kmem_alloc_pageable(kernel_map, PAGE_SIZE);
1070	pmap_kenter((vm_offset_t) pmap->pm_pdir, (vm_offset_t) IdlePTD);
1071	pmap->pm_count = 1;
1072	pmap->pm_active = 0;
1073	pmap->pm_ptphint = NULL;
1074	TAILQ_INIT(&pmap->pm_pvlist);
1075	bzero(&pmap->pm_stats, sizeof pmap->pm_stats);
1076	LIST_INSERT_HEAD(&allpmaps, pmap, pm_list);
1077}
1078
1079/*
1080 * Initialize a preallocated and zeroed pmap structure,
1081 * such as one in a vmspace structure.
1082 */
1083void
1084pmap_pinit(pmap)
1085	register struct pmap *pmap;
1086{
1087	vm_page_t ptdpg;
1088
1089	/*
1090	 * No need to allocate page table space yet but we do need a valid
1091	 * page directory table.
1092	 */
1093	if (pmap->pm_pdir == NULL)
1094		pmap->pm_pdir =
1095			(pd_entry_t *)kmem_alloc_pageable(kernel_map, PAGE_SIZE);
1096
1097	/*
1098	 * allocate object for the ptes
1099	 */
1100	if (pmap->pm_pteobj == NULL)
1101		pmap->pm_pteobj = vm_object_allocate( OBJT_DEFAULT, PTDPTDI + 1);
1102
1103	/*
1104	 * allocate the page directory page
1105	 */
1106	ptdpg = vm_page_grab( pmap->pm_pteobj, PTDPTDI,
1107			VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
1108
1109	ptdpg->wire_count = 1;
1110	++cnt.v_wire_count;
1111
1112
1113	vm_page_flag_clear(ptdpg, PG_MAPPED | PG_BUSY); /* not usually mapped*/
1114	ptdpg->valid = VM_PAGE_BITS_ALL;
1115
1116	pmap_kenter((vm_offset_t) pmap->pm_pdir, VM_PAGE_TO_PHYS(ptdpg));
1117	if ((ptdpg->flags & PG_ZERO) == 0)
1118		bzero(pmap->pm_pdir, PAGE_SIZE);
1119
1120	LIST_INSERT_HEAD(&allpmaps, pmap, pm_list);
1121	/* Wire in kernel global address entries. */
1122	/* XXX copies current process, does not fill in MPPTDI */
1123	bcopy(PTD + KPTDI, pmap->pm_pdir + KPTDI, nkpt * PTESIZE);
1124#ifdef SMP
1125	pmap->pm_pdir[MPPTDI] = PTD[MPPTDI];
1126#endif
1127
1128	/* install self-referential address mapping entry */
1129	*(unsigned *) (pmap->pm_pdir + PTDPTDI) =
1130		VM_PAGE_TO_PHYS(ptdpg) | PG_V | PG_RW | PG_A | PG_M;
1131
1132	pmap->pm_count = 1;
1133	pmap->pm_active = 0;
1134	pmap->pm_ptphint = NULL;
1135	TAILQ_INIT(&pmap->pm_pvlist);
1136	bzero(&pmap->pm_stats, sizeof pmap->pm_stats);
1137}
1138
1139/*
1140 * Wire in kernel global address entries.  To avoid a race condition
1141 * between pmap initialization and pmap_growkernel, this procedure
1142 * should be called after the vmspace is attached to the process
1143 * but before this pmap is activated.
1144 */
1145void
1146pmap_pinit2(pmap)
1147	struct pmap *pmap;
1148{
1149	/* XXX: Remove this stub when no longer called */
1150}
1151
1152static int
1153pmap_release_free_page(pmap, p)
1154	struct pmap *pmap;
1155	vm_page_t p;
1156{
1157	unsigned *pde = (unsigned *) pmap->pm_pdir;
1158	/*
1159	 * This code optimizes the case of freeing non-busy
1160	 * page-table pages.  Those pages are zero now, and
1161	 * might as well be placed directly into the zero queue.
1162	 */
1163	if (vm_page_sleep_busy(p, FALSE, "pmaprl"))
1164		return 0;
1165
1166	vm_page_busy(p);
1167
1168	/*
1169	 * Remove the page table page from the processes address space.
1170	 */
1171	pde[p->pindex] = 0;
1172	pmap->pm_stats.resident_count--;
1173
1174	if (p->hold_count)  {
1175		panic("pmap_release: freeing held page table page");
1176	}
1177	/*
1178	 * Page directory pages need to have the kernel
1179	 * stuff cleared, so they can go into the zero queue also.
1180	 */
1181	if (p->pindex == PTDPTDI) {
1182		bzero(pde + KPTDI, nkpt * PTESIZE);
1183#ifdef SMP
1184		pde[MPPTDI] = 0;
1185#endif
1186		pde[APTDPTDI] = 0;
1187		pmap_kremove((vm_offset_t) pmap->pm_pdir);
1188	}
1189
1190	if (pmap->pm_ptphint && (pmap->pm_ptphint->pindex == p->pindex))
1191		pmap->pm_ptphint = NULL;
1192
1193	p->wire_count--;
1194	cnt.v_wire_count--;
1195	vm_page_free_zero(p);
1196	return 1;
1197}
1198
1199/*
1200 * this routine is called if the page table page is not
1201 * mapped correctly.
1202 */
1203static vm_page_t
1204_pmap_allocpte(pmap, ptepindex)
1205	pmap_t	pmap;
1206	unsigned ptepindex;
1207{
1208	vm_offset_t pteva, ptepa;
1209	vm_page_t m;
1210
1211	/*
1212	 * Find or fabricate a new pagetable page
1213	 */
1214	m = vm_page_grab(pmap->pm_pteobj, ptepindex,
1215			VM_ALLOC_ZERO | VM_ALLOC_RETRY);
1216
1217	KASSERT(m->queue == PQ_NONE,
1218		("_pmap_allocpte: %p->queue != PQ_NONE", m));
1219
1220	if (m->wire_count == 0)
1221		cnt.v_wire_count++;
1222	m->wire_count++;
1223
1224	/*
1225	 * Increment the hold count for the page table page
1226	 * (denoting a new mapping.)
1227	 */
1228	m->hold_count++;
1229
1230	/*
1231	 * Map the pagetable page into the process address space, if
1232	 * it isn't already there.
1233	 */
1234
1235	pmap->pm_stats.resident_count++;
1236
1237	ptepa = VM_PAGE_TO_PHYS(m);
1238	pmap->pm_pdir[ptepindex] =
1239		(pd_entry_t) (ptepa | PG_U | PG_RW | PG_V | PG_A | PG_M);
1240
1241	/*
1242	 * Set the page table hint
1243	 */
1244	pmap->pm_ptphint = m;
1245
1246	/*
1247	 * Try to use the new mapping, but if we cannot, then
1248	 * do it with the routine that maps the page explicitly.
1249	 */
1250	if ((m->flags & PG_ZERO) == 0) {
1251		if ((((unsigned)pmap->pm_pdir[PTDPTDI]) & PG_FRAME) ==
1252			(((unsigned) PTDpde) & PG_FRAME)) {
1253			pteva = UPT_MIN_ADDRESS + i386_ptob(ptepindex);
1254			bzero((caddr_t) pteva, PAGE_SIZE);
1255		} else {
1256			pmap_zero_page(ptepa);
1257		}
1258	}
1259
1260	m->valid = VM_PAGE_BITS_ALL;
1261	vm_page_flag_clear(m, PG_ZERO);
1262	vm_page_flag_set(m, PG_MAPPED);
1263	vm_page_wakeup(m);
1264
1265	return m;
1266}
1267
1268static vm_page_t
1269pmap_allocpte(pmap, va)
1270	pmap_t	pmap;
1271	vm_offset_t va;
1272{
1273	unsigned ptepindex;
1274	vm_offset_t ptepa;
1275	vm_page_t m;
1276
1277	/*
1278	 * Calculate pagetable page index
1279	 */
1280	ptepindex = va >> PDRSHIFT;
1281
1282	/*
1283	 * Get the page directory entry
1284	 */
1285	ptepa = (vm_offset_t) pmap->pm_pdir[ptepindex];
1286
1287	/*
1288	 * This supports switching from a 4MB page to a
1289	 * normal 4K page.
1290	 */
1291	if (ptepa & PG_PS) {
1292		pmap->pm_pdir[ptepindex] = 0;
1293		ptepa = 0;
1294		invltlb();
1295	}
1296
1297	/*
1298	 * If the page table page is mapped, we just increment the
1299	 * hold count, and activate it.
1300	 */
1301	if (ptepa) {
1302		/*
1303		 * In order to get the page table page, try the
1304		 * hint first.
1305		 */
1306		if (pmap->pm_ptphint &&
1307			(pmap->pm_ptphint->pindex == ptepindex)) {
1308			m = pmap->pm_ptphint;
1309		} else {
1310			m = pmap_page_lookup( pmap->pm_pteobj, ptepindex);
1311			pmap->pm_ptphint = m;
1312		}
1313		m->hold_count++;
1314		return m;
1315	}
1316	/*
1317	 * Here if the pte page isn't mapped, or if it has been deallocated.
1318	 */
1319	return _pmap_allocpte(pmap, ptepindex);
1320}
1321
1322
1323/***************************************************
1324* Pmap allocation/deallocation routines.
1325 ***************************************************/
1326
1327/*
1328 * Release any resources held by the given physical map.
1329 * Called when a pmap initialized by pmap_pinit is being released.
1330 * Should only be called if the map contains no valid mappings.
1331 */
1332void
1333pmap_release(pmap)
1334	register struct pmap *pmap;
1335{
1336	vm_page_t p,n,ptdpg;
1337	vm_object_t object = pmap->pm_pteobj;
1338	int curgeneration;
1339
1340#if defined(DIAGNOSTIC)
1341	if (object->ref_count != 1)
1342		panic("pmap_release: pteobj reference count != 1");
1343#endif
1344
1345	ptdpg = NULL;
1346	LIST_REMOVE(pmap, pm_list);
1347retry:
1348	curgeneration = object->generation;
1349	for (p = TAILQ_FIRST(&object->memq); p != NULL; p = n) {
1350		n = TAILQ_NEXT(p, listq);
1351		if (p->pindex == PTDPTDI) {
1352			ptdpg = p;
1353			continue;
1354		}
1355		while (1) {
1356			if (!pmap_release_free_page(pmap, p) &&
1357				(object->generation != curgeneration))
1358				goto retry;
1359		}
1360	}
1361
1362	if (ptdpg && !pmap_release_free_page(pmap, ptdpg))
1363		goto retry;
1364}
1365
1366/*
1367 * grow the number of kernel page table entries, if needed
1368 */
1369void
1370pmap_growkernel(vm_offset_t addr)
1371{
1372	struct pmap *pmap;
1373	int s;
1374	vm_offset_t ptppaddr;
1375	vm_page_t nkpg;
1376	pd_entry_t newpdir;
1377
1378	s = splhigh();
1379	if (kernel_vm_end == 0) {
1380		kernel_vm_end = KERNBASE;
1381		nkpt = 0;
1382		while (pdir_pde(PTD, kernel_vm_end)) {
1383			kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1);
1384			nkpt++;
1385		}
1386	}
1387	addr = (addr + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1);
1388	while (kernel_vm_end < addr) {
1389		if (pdir_pde(PTD, kernel_vm_end)) {
1390			kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1);
1391			continue;
1392		}
1393
1394		/*
1395		 * This index is bogus, but out of the way
1396		 */
1397		nkpg = vm_page_alloc(kptobj, nkpt, VM_ALLOC_SYSTEM);
1398		if (!nkpg)
1399			panic("pmap_growkernel: no memory to grow kernel");
1400
1401		nkpt++;
1402
1403		vm_page_wire(nkpg);
1404		ptppaddr = VM_PAGE_TO_PHYS(nkpg);
1405		pmap_zero_page(ptppaddr);
1406		newpdir = (pd_entry_t) (ptppaddr | PG_V | PG_RW | PG_A | PG_M);
1407		pdir_pde(PTD, kernel_vm_end) = newpdir;
1408
1409		LIST_FOREACH(pmap, &allpmaps, pm_list) {
1410			*pmap_pde(pmap, kernel_vm_end) = newpdir;
1411		}
1412		kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1);
1413	}
1414	splx(s);
1415}
1416
1417/*
1418 *	Retire the given physical map from service.
1419 *	Should only be called if the map contains
1420 *	no valid mappings.
1421 */
1422void
1423pmap_destroy(pmap)
1424	register pmap_t pmap;
1425{
1426	int count;
1427
1428	if (pmap == NULL)
1429		return;
1430
1431	count = --pmap->pm_count;
1432	if (count == 0) {
1433		pmap_release(pmap);
1434		panic("destroying a pmap is not yet implemented");
1435	}
1436}
1437
1438/*
1439 *	Add a reference to the specified pmap.
1440 */
1441void
1442pmap_reference(pmap)
1443	pmap_t pmap;
1444{
1445	if (pmap != NULL) {
1446		pmap->pm_count++;
1447	}
1448}
1449
1450/***************************************************
1451* page management routines.
1452 ***************************************************/
1453
1454/*
1455 * free the pv_entry back to the free list
1456 */
1457static PMAP_INLINE void
1458free_pv_entry(pv)
1459	pv_entry_t pv;
1460{
1461	pv_entry_count--;
1462	zfree(pvzone, pv);
1463}
1464
1465/*
1466 * get a new pv_entry, allocating a block from the system
1467 * when needed.
1468 * the memory allocation is performed bypassing the malloc code
1469 * because of the possibility of allocations at interrupt time.
1470 */
1471static pv_entry_t
1472get_pv_entry(void)
1473{
1474	pv_entry_count++;
1475	if (pv_entry_high_water &&
1476		(pv_entry_count > pv_entry_high_water) &&
1477		(pmap_pagedaemon_waken == 0)) {
1478		pmap_pagedaemon_waken = 1;
1479		wakeup (&vm_pages_needed);
1480	}
1481	return zalloc(pvzone);
1482}
1483
1484/*
1485 * This routine is very drastic, but can save the system
1486 * in a pinch.
1487 */
1488void
1489pmap_collect()
1490{
1491	int i;
1492	vm_page_t m;
1493	static int warningdone=0;
1494
1495	if (pmap_pagedaemon_waken == 0)
1496		return;
1497
1498	if (warningdone < 5) {
1499		printf("pmap_collect: collecting pv entries -- suggest increasing PMAP_SHPGPERPROC\n");
1500		warningdone++;
1501	}
1502
1503	for(i = 0; i < vm_page_array_size; i++) {
1504		m = &vm_page_array[i];
1505		if (m->wire_count || m->hold_count || m->busy ||
1506		    (m->flags & PG_BUSY))
1507			continue;
1508		pmap_remove_all(m);
1509	}
1510	pmap_pagedaemon_waken = 0;
1511}
1512
1513
1514/*
1515 * If it is the first entry on the list, it is actually
1516 * in the header and we must copy the following entry up
1517 * to the header.  Otherwise we must search the list for
1518 * the entry.  In either case we free the now unused entry.
1519 */
1520
1521static int
1522pmap_remove_entry(pmap, m, va)
1523	struct pmap *pmap;
1524	vm_page_t m;
1525	vm_offset_t va;
1526{
1527	pv_entry_t pv;
1528	int rtval;
1529	int s;
1530
1531	s = splvm();
1532	if (m->md.pv_list_count < pmap->pm_stats.resident_count) {
1533		for (pv = TAILQ_FIRST(&m->md.pv_list);
1534			pv;
1535			pv = TAILQ_NEXT(pv, pv_list)) {
1536			if (pmap == pv->pv_pmap && va == pv->pv_va)
1537				break;
1538		}
1539	} else {
1540		for (pv = TAILQ_FIRST(&pmap->pm_pvlist);
1541			pv;
1542			pv = TAILQ_NEXT(pv, pv_plist)) {
1543			if (va == pv->pv_va)
1544				break;
1545		}
1546	}
1547
1548	rtval = 0;
1549	if (pv) {
1550
1551		rtval = pmap_unuse_pt(pmap, va, pv->pv_ptem);
1552		TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
1553		m->md.pv_list_count--;
1554		if (TAILQ_FIRST(&m->md.pv_list) == NULL)
1555			vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE);
1556
1557		TAILQ_REMOVE(&pmap->pm_pvlist, pv, pv_plist);
1558		free_pv_entry(pv);
1559	}
1560
1561	splx(s);
1562	return rtval;
1563}
1564
1565/*
1566 * Create a pv entry for page at pa for
1567 * (pmap, va).
1568 */
1569static void
1570pmap_insert_entry(pmap, va, mpte, m)
1571	pmap_t pmap;
1572	vm_offset_t va;
1573	vm_page_t mpte;
1574	vm_page_t m;
1575{
1576
1577	int s;
1578	pv_entry_t pv;
1579
1580	s = splvm();
1581	pv = get_pv_entry();
1582	pv->pv_va = va;
1583	pv->pv_pmap = pmap;
1584	pv->pv_ptem = mpte;
1585
1586	TAILQ_INSERT_TAIL(&pmap->pm_pvlist, pv, pv_plist);
1587	TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list);
1588	m->md.pv_list_count++;
1589
1590	splx(s);
1591}
1592
1593/*
1594 * pmap_remove_pte: do the things to unmap a page in a process
1595 */
1596static int
1597pmap_remove_pte(pmap, ptq, va)
1598	struct pmap *pmap;
1599	unsigned *ptq;
1600	vm_offset_t va;
1601{
1602	unsigned oldpte;
1603	vm_page_t m;
1604
1605	oldpte = atomic_readandclear_int(ptq);
1606	if (oldpte & PG_W)
1607		pmap->pm_stats.wired_count -= 1;
1608	/*
1609	 * Machines that don't support invlpg, also don't support
1610	 * PG_G.
1611	 */
1612	if (oldpte & PG_G)
1613		invlpg(va);
1614	pmap->pm_stats.resident_count -= 1;
1615	if (oldpte & PG_MANAGED) {
1616		m = PHYS_TO_VM_PAGE(oldpte);
1617		if (oldpte & PG_M) {
1618#if defined(PMAP_DIAGNOSTIC)
1619			if (pmap_nw_modified((pt_entry_t) oldpte)) {
1620				printf(
1621	"pmap_remove: modified page not writable: va: 0x%x, pte: 0x%x\n",
1622				    va, oldpte);
1623			}
1624#endif
1625			if (pmap_track_modified(va))
1626				vm_page_dirty(m);
1627		}
1628		if (oldpte & PG_A)
1629			vm_page_flag_set(m, PG_REFERENCED);
1630		return pmap_remove_entry(pmap, m, va);
1631	} else {
1632		return pmap_unuse_pt(pmap, va, NULL);
1633	}
1634
1635	return 0;
1636}
1637
1638/*
1639 * Remove a single page from a process address space
1640 */
1641static void
1642pmap_remove_page(pmap, va)
1643	struct pmap *pmap;
1644	register vm_offset_t va;
1645{
1646	register unsigned *ptq;
1647
1648	/*
1649	 * if there is no pte for this address, just skip it!!!
1650	 */
1651	if (*pmap_pde(pmap, va) == 0) {
1652		return;
1653	}
1654
1655	/*
1656	 * get a local va for mappings for this pmap.
1657	 */
1658	ptq = get_ptbase(pmap) + i386_btop(va);
1659	if (*ptq) {
1660		(void) pmap_remove_pte(pmap, ptq, va);
1661		pmap_TLB_invalidate(pmap, va);
1662	}
1663	return;
1664}
1665
1666/*
1667 *	Remove the given range of addresses from the specified map.
1668 *
1669 *	It is assumed that the start and end are properly
1670 *	rounded to the page size.
1671 */
1672void
1673pmap_remove(pmap, sva, eva)
1674	struct pmap *pmap;
1675	register vm_offset_t sva;
1676	register vm_offset_t eva;
1677{
1678	register unsigned *ptbase;
1679	vm_offset_t pdnxt;
1680	vm_offset_t ptpaddr;
1681	vm_offset_t sindex, eindex;
1682	int anyvalid;
1683
1684	if (pmap == NULL)
1685		return;
1686
1687	if (pmap->pm_stats.resident_count == 0)
1688		return;
1689
1690	/*
1691	 * special handling of removing one page.  a very
1692	 * common operation and easy to short circuit some
1693	 * code.
1694	 */
1695	if (((sva + PAGE_SIZE) == eva) &&
1696		(((unsigned) pmap->pm_pdir[(sva >> PDRSHIFT)] & PG_PS) == 0)) {
1697		pmap_remove_page(pmap, sva);
1698		return;
1699	}
1700
1701	anyvalid = 0;
1702
1703	/*
1704	 * Get a local virtual address for the mappings that are being
1705	 * worked with.
1706	 */
1707	ptbase = get_ptbase(pmap);
1708
1709	sindex = i386_btop(sva);
1710	eindex = i386_btop(eva);
1711
1712	for (; sindex < eindex; sindex = pdnxt) {
1713		unsigned pdirindex;
1714
1715		/*
1716		 * Calculate index for next page table.
1717		 */
1718		pdnxt = ((sindex + NPTEPG) & ~(NPTEPG - 1));
1719		if (pmap->pm_stats.resident_count == 0)
1720			break;
1721
1722		pdirindex = sindex / NPDEPG;
1723		if (((ptpaddr = (unsigned) pmap->pm_pdir[pdirindex]) & PG_PS) != 0) {
1724			pmap->pm_pdir[pdirindex] = 0;
1725			pmap->pm_stats.resident_count -= NBPDR / PAGE_SIZE;
1726			anyvalid++;
1727			continue;
1728		}
1729
1730		/*
1731		 * Weed out invalid mappings. Note: we assume that the page
1732		 * directory table is always allocated, and in kernel virtual.
1733		 */
1734		if (ptpaddr == 0)
1735			continue;
1736
1737		/*
1738		 * Limit our scan to either the end of the va represented
1739		 * by the current page table page, or to the end of the
1740		 * range being removed.
1741		 */
1742		if (pdnxt > eindex) {
1743			pdnxt = eindex;
1744		}
1745
1746		for ( ;sindex != pdnxt; sindex++) {
1747			vm_offset_t va;
1748			if (ptbase[sindex] == 0) {
1749				continue;
1750			}
1751			va = i386_ptob(sindex);
1752
1753			anyvalid++;
1754			if (pmap_remove_pte(pmap,
1755				ptbase + sindex, va))
1756				break;
1757		}
1758	}
1759
1760	if (anyvalid)
1761		pmap_TLB_invalidate_all(pmap);
1762}
1763
1764/*
1765 *	Routine:	pmap_remove_all
1766 *	Function:
1767 *		Removes this physical page from
1768 *		all physical maps in which it resides.
1769 *		Reflects back modify bits to the pager.
1770 *
1771 *	Notes:
1772 *		Original versions of this routine were very
1773 *		inefficient because they iteratively called
1774 *		pmap_remove (slow...)
1775 */
1776
1777static void
1778pmap_remove_all(m)
1779	vm_page_t m;
1780{
1781	register pv_entry_t pv;
1782	register unsigned *pte, tpte;
1783	int s;
1784
1785#if defined(PMAP_DIAGNOSTIC)
1786	/*
1787	 * XXX this makes pmap_page_protect(NONE) illegal for non-managed
1788	 * pages!
1789	 */
1790	if (!pmap_initialized || (m->flags & PG_FICTITIOUS)) {
1791		panic("pmap_page_protect: illegal for unmanaged page, va: 0x%x", VM_PAGE_TO_PHYS(m));
1792	}
1793#endif
1794
1795	s = splvm();
1796	while ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) {
1797		pv->pv_pmap->pm_stats.resident_count--;
1798
1799		pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va);
1800
1801		tpte = atomic_readandclear_int(pte);
1802		if (tpte & PG_W)
1803			pv->pv_pmap->pm_stats.wired_count--;
1804
1805		if (tpte & PG_A)
1806			vm_page_flag_set(m, PG_REFERENCED);
1807
1808		/*
1809		 * Update the vm_page_t clean and reference bits.
1810		 */
1811		if (tpte & PG_M) {
1812#if defined(PMAP_DIAGNOSTIC)
1813			if (pmap_nw_modified((pt_entry_t) tpte)) {
1814				printf(
1815	"pmap_remove_all: modified page not writable: va: 0x%x, pte: 0x%x\n",
1816				    pv->pv_va, tpte);
1817			}
1818#endif
1819			if (pmap_track_modified(pv->pv_va))
1820				vm_page_dirty(m);
1821		}
1822		pmap_TLB_invalidate(pv->pv_pmap, pv->pv_va);
1823
1824		TAILQ_REMOVE(&pv->pv_pmap->pm_pvlist, pv, pv_plist);
1825		TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
1826		m->md.pv_list_count--;
1827		pmap_unuse_pt(pv->pv_pmap, pv->pv_va, pv->pv_ptem);
1828		free_pv_entry(pv);
1829	}
1830
1831	vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE);
1832
1833	splx(s);
1834}
1835
1836/*
1837 *	Set the physical protection on the
1838 *	specified range of this map as requested.
1839 */
1840void
1841pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
1842{
1843	register unsigned *ptbase;
1844	vm_offset_t pdnxt, ptpaddr;
1845	vm_pindex_t sindex, eindex;
1846	int anychanged;
1847
1848	if (pmap == NULL)
1849		return;
1850
1851	if ((prot & VM_PROT_READ) == VM_PROT_NONE) {
1852		pmap_remove(pmap, sva, eva);
1853		return;
1854	}
1855
1856	if (prot & VM_PROT_WRITE)
1857		return;
1858
1859	anychanged = 0;
1860
1861	ptbase = get_ptbase(pmap);
1862
1863	sindex = i386_btop(sva);
1864	eindex = i386_btop(eva);
1865
1866	for (; sindex < eindex; sindex = pdnxt) {
1867
1868		unsigned pdirindex;
1869
1870		pdnxt = ((sindex + NPTEPG) & ~(NPTEPG - 1));
1871
1872		pdirindex = sindex / NPDEPG;
1873		if (((ptpaddr = (unsigned) pmap->pm_pdir[pdirindex]) & PG_PS) != 0) {
1874			(unsigned) pmap->pm_pdir[pdirindex] &= ~(PG_M|PG_RW);
1875			pmap->pm_stats.resident_count -= NBPDR / PAGE_SIZE;
1876			anychanged++;
1877			continue;
1878		}
1879
1880		/*
1881		 * Weed out invalid mappings. Note: we assume that the page
1882		 * directory table is always allocated, and in kernel virtual.
1883		 */
1884		if (ptpaddr == 0)
1885			continue;
1886
1887		if (pdnxt > eindex) {
1888			pdnxt = eindex;
1889		}
1890
1891		for (; sindex != pdnxt; sindex++) {
1892
1893			unsigned pbits;
1894			vm_page_t m;
1895
1896			pbits = ptbase[sindex];
1897
1898			if (pbits & PG_MANAGED) {
1899				m = NULL;
1900				if (pbits & PG_A) {
1901					m = PHYS_TO_VM_PAGE(pbits);
1902					vm_page_flag_set(m, PG_REFERENCED);
1903					pbits &= ~PG_A;
1904				}
1905				if (pbits & PG_M) {
1906					if (pmap_track_modified(i386_ptob(sindex))) {
1907						if (m == NULL)
1908							m = PHYS_TO_VM_PAGE(pbits);
1909						vm_page_dirty(m);
1910						pbits &= ~PG_M;
1911					}
1912				}
1913			}
1914
1915			pbits &= ~PG_RW;
1916
1917			if (pbits != ptbase[sindex]) {
1918				ptbase[sindex] = pbits;
1919				anychanged = 1;
1920			}
1921		}
1922	}
1923	if (anychanged)
1924		pmap_TLB_invalidate_all(pmap);
1925}
1926
1927/*
1928 *	Insert the given physical page (p) at
1929 *	the specified virtual address (v) in the
1930 *	target physical map with the protection requested.
1931 *
1932 *	If specified, the page will be wired down, meaning
1933 *	that the related pte can not be reclaimed.
1934 *
1935 *	NB:  This is the only routine which MAY NOT lazy-evaluate
1936 *	or lose information.  That is, this routine must actually
1937 *	insert this page into the given map NOW.
1938 */
1939void
1940pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot,
1941	   boolean_t wired)
1942{
1943	vm_offset_t pa;
1944	register unsigned *pte;
1945	vm_offset_t opa;
1946	vm_offset_t origpte, newpte;
1947	vm_page_t mpte;
1948
1949	if (pmap == NULL)
1950		return;
1951
1952	va &= PG_FRAME;
1953#ifdef PMAP_DIAGNOSTIC
1954	if (va > VM_MAX_KERNEL_ADDRESS)
1955		panic("pmap_enter: toobig");
1956	if ((va >= UPT_MIN_ADDRESS) && (va < UPT_MAX_ADDRESS))
1957		panic("pmap_enter: invalid to pmap_enter page table pages (va: 0x%x)", va);
1958#endif
1959
1960	mpte = NULL;
1961	/*
1962	 * In the case that a page table page is not
1963	 * resident, we are creating it here.
1964	 */
1965	if (va < UPT_MIN_ADDRESS) {
1966		mpte = pmap_allocpte(pmap, va);
1967	}
1968#if 0 && defined(PMAP_DIAGNOSTIC)
1969	else {
1970		vm_offset_t *pdeaddr = (vm_offset_t *)pmap_pde(pmap, va);
1971		if (((origpte = (vm_offset_t) *pdeaddr) & PG_V) == 0) {
1972			panic("pmap_enter: invalid kernel page table page(0), pdir=%p, pde=%p, va=%p\n",
1973				pmap->pm_pdir[PTDPTDI], origpte, va);
1974		}
1975		if (smp_active) {
1976			pdeaddr = (vm_offset_t *) IdlePTDS[PCPU_GET(cpuid)];
1977			if (((newpte = pdeaddr[va >> PDRSHIFT]) & PG_V) == 0) {
1978				if ((vm_offset_t) my_idlePTD != (vm_offset_t) vtophys(pdeaddr))
1979					printf("pde mismatch: %x, %x\n", my_idlePTD, pdeaddr);
1980				printf("cpuid: %d, pdeaddr: 0x%x\n", PCPU_GET(cpuid), pdeaddr);
1981				panic("pmap_enter: invalid kernel page table page(1), pdir=%p, npde=%p, pde=%p, va=%p\n",
1982					pmap->pm_pdir[PTDPTDI], newpte, origpte, va);
1983			}
1984		}
1985	}
1986#endif
1987
1988	pte = pmap_pte(pmap, va);
1989
1990	/*
1991	 * Page Directory table entry not valid, we need a new PT page
1992	 */
1993	if (pte == NULL) {
1994		panic("pmap_enter: invalid page directory, pdir=%p, va=0x%x\n",
1995			(void *)pmap->pm_pdir[PTDPTDI], va);
1996	}
1997
1998	pa = VM_PAGE_TO_PHYS(m) & PG_FRAME;
1999	origpte = *(vm_offset_t *)pte;
2000	opa = origpte & PG_FRAME;
2001
2002	if (origpte & PG_PS)
2003		panic("pmap_enter: attempted pmap_enter on 4MB page");
2004
2005	/*
2006	 * Mapping has not changed, must be protection or wiring change.
2007	 */
2008	if (origpte && (opa == pa)) {
2009		/*
2010		 * Wiring change, just update stats. We don't worry about
2011		 * wiring PT pages as they remain resident as long as there
2012		 * are valid mappings in them. Hence, if a user page is wired,
2013		 * the PT page will be also.
2014		 */
2015		if (wired && ((origpte & PG_W) == 0))
2016			pmap->pm_stats.wired_count++;
2017		else if (!wired && (origpte & PG_W))
2018			pmap->pm_stats.wired_count--;
2019
2020#if defined(PMAP_DIAGNOSTIC)
2021		if (pmap_nw_modified((pt_entry_t) origpte)) {
2022			printf(
2023	"pmap_enter: modified page not writable: va: 0x%x, pte: 0x%x\n",
2024			    va, origpte);
2025		}
2026#endif
2027
2028		/*
2029		 * Remove extra pte reference
2030		 */
2031		if (mpte)
2032			mpte->hold_count--;
2033
2034		if ((prot & VM_PROT_WRITE) && (origpte & PG_V)) {
2035			if ((origpte & PG_RW) == 0) {
2036				*pte |= PG_RW;
2037#ifdef SMP
2038				cpu_invlpg((void *)va);
2039				if (pmap->pm_active & PCPU_GET(other_cpus))
2040					smp_invltlb();
2041#else
2042				invltlb_1pg(va);
2043#endif
2044			}
2045			return;
2046		}
2047
2048		/*
2049		 * We might be turning off write access to the page,
2050		 * so we go ahead and sense modify status.
2051		 */
2052		if (origpte & PG_MANAGED) {
2053			if ((origpte & PG_M) && pmap_track_modified(va)) {
2054				vm_page_t om;
2055				om = PHYS_TO_VM_PAGE(opa);
2056				vm_page_dirty(om);
2057			}
2058			pa |= PG_MANAGED;
2059		}
2060		goto validate;
2061	}
2062	/*
2063	 * Mapping has changed, invalidate old range and fall through to
2064	 * handle validating new mapping.
2065	 */
2066	if (opa) {
2067		int err;
2068		err = pmap_remove_pte(pmap, pte, va);
2069		if (err)
2070			panic("pmap_enter: pte vanished, va: 0x%x", va);
2071	}
2072
2073	/*
2074	 * Enter on the PV list if part of our managed memory. Note that we
2075	 * raise IPL while manipulating pv_table since pmap_enter can be
2076	 * called at interrupt time.
2077	 */
2078	if (pmap_initialized &&
2079	    (m->flags & (PG_FICTITIOUS|PG_UNMANAGED)) == 0) {
2080		pmap_insert_entry(pmap, va, mpte, m);
2081		pa |= PG_MANAGED;
2082	}
2083
2084	/*
2085	 * Increment counters
2086	 */
2087	pmap->pm_stats.resident_count++;
2088	if (wired)
2089		pmap->pm_stats.wired_count++;
2090
2091validate:
2092	/*
2093	 * Now validate mapping with desired protection/wiring.
2094	 */
2095	newpte = (vm_offset_t) (pa | pte_prot(pmap, prot) | PG_V);
2096
2097	if (wired)
2098		newpte |= PG_W;
2099	if (va < UPT_MIN_ADDRESS)
2100		newpte |= PG_U;
2101	if (pmap == kernel_pmap)
2102		newpte |= pgeflag;
2103
2104	/*
2105	 * if the mapping or permission bits are different, we need
2106	 * to update the pte.
2107	 */
2108	if ((origpte & ~(PG_M|PG_A)) != newpte) {
2109		*pte = newpte | PG_A;
2110		/*if (origpte)*/ {
2111#ifdef SMP
2112			cpu_invlpg((void *)va);
2113			if (pmap->pm_active & PCPU_GET(other_cpus))
2114				smp_invltlb();
2115#else
2116			invltlb_1pg(va);
2117#endif
2118		}
2119	}
2120}
2121
2122/*
2123 * this code makes some *MAJOR* assumptions:
2124 * 1. Current pmap & pmap exists.
2125 * 2. Not wired.
2126 * 3. Read access.
2127 * 4. No page table pages.
2128 * 5. Tlbflush is deferred to calling procedure.
2129 * 6. Page IS managed.
2130 * but is *MUCH* faster than pmap_enter...
2131 */
2132
2133static vm_page_t
2134pmap_enter_quick(pmap, va, m, mpte)
2135	register pmap_t pmap;
2136	vm_offset_t va;
2137	vm_page_t m;
2138	vm_page_t mpte;
2139{
2140	unsigned *pte;
2141	vm_offset_t pa;
2142
2143	/*
2144	 * In the case that a page table page is not
2145	 * resident, we are creating it here.
2146	 */
2147	if (va < UPT_MIN_ADDRESS) {
2148		unsigned ptepindex;
2149		vm_offset_t ptepa;
2150
2151		/*
2152		 * Calculate pagetable page index
2153		 */
2154		ptepindex = va >> PDRSHIFT;
2155		if (mpte && (mpte->pindex == ptepindex)) {
2156			mpte->hold_count++;
2157		} else {
2158retry:
2159			/*
2160			 * Get the page directory entry
2161			 */
2162			ptepa = (vm_offset_t) pmap->pm_pdir[ptepindex];
2163
2164			/*
2165			 * If the page table page is mapped, we just increment
2166			 * the hold count, and activate it.
2167			 */
2168			if (ptepa) {
2169				if (ptepa & PG_PS)
2170					panic("pmap_enter_quick: unexpected mapping into 4MB page");
2171				if (pmap->pm_ptphint &&
2172					(pmap->pm_ptphint->pindex == ptepindex)) {
2173					mpte = pmap->pm_ptphint;
2174				} else {
2175					mpte = pmap_page_lookup( pmap->pm_pteobj, ptepindex);
2176					pmap->pm_ptphint = mpte;
2177				}
2178				if (mpte == NULL)
2179					goto retry;
2180				mpte->hold_count++;
2181			} else {
2182				mpte = _pmap_allocpte(pmap, ptepindex);
2183			}
2184		}
2185	} else {
2186		mpte = NULL;
2187	}
2188
2189	/*
2190	 * This call to vtopte makes the assumption that we are
2191	 * entering the page into the current pmap.  In order to support
2192	 * quick entry into any pmap, one would likely use pmap_pte_quick.
2193	 * But that isn't as quick as vtopte.
2194	 */
2195	pte = (unsigned *)vtopte(va);
2196	if (*pte) {
2197		if (mpte)
2198			pmap_unwire_pte_hold(pmap, mpte);
2199		return 0;
2200	}
2201
2202	/*
2203	 * Enter on the PV list if part of our managed memory. Note that we
2204	 * raise IPL while manipulating pv_table since pmap_enter can be
2205	 * called at interrupt time.
2206	 */
2207	if ((m->flags & (PG_FICTITIOUS|PG_UNMANAGED)) == 0)
2208		pmap_insert_entry(pmap, va, mpte, m);
2209
2210	/*
2211	 * Increment counters
2212	 */
2213	pmap->pm_stats.resident_count++;
2214
2215	pa = VM_PAGE_TO_PHYS(m);
2216
2217	/*
2218	 * Now validate mapping with RO protection
2219	 */
2220	if (m->flags & (PG_FICTITIOUS|PG_UNMANAGED))
2221		*pte = pa | PG_V | PG_U;
2222	else
2223		*pte = pa | PG_V | PG_U | PG_MANAGED;
2224
2225	return mpte;
2226}
2227
2228/*
2229 * Make a temporary mapping for a physical address.  This is only intended
2230 * to be used for panic dumps.
2231 */
2232void *
2233pmap_kenter_temporary(vm_offset_t pa, int i)
2234{
2235	pmap_kenter((vm_offset_t)crashdumpmap + (i * PAGE_SIZE), pa);
2236	return ((void *)crashdumpmap);
2237}
2238
2239#define MAX_INIT_PT (96)
2240/*
2241 * pmap_object_init_pt preloads the ptes for a given object
2242 * into the specified pmap.  This eliminates the blast of soft
2243 * faults on process startup and immediately after an mmap.
2244 */
2245void
2246pmap_object_init_pt(pmap, addr, object, pindex, size, limit)
2247	pmap_t pmap;
2248	vm_offset_t addr;
2249	vm_object_t object;
2250	vm_pindex_t pindex;
2251	vm_size_t size;
2252	int limit;
2253{
2254	vm_offset_t tmpidx;
2255	int psize;
2256	vm_page_t p, mpte;
2257	int objpgs;
2258
2259	if (pmap == NULL || object == NULL)
2260		return;
2261
2262	/*
2263	 * This code maps large physical mmap regions into the
2264	 * processor address space.  Note that some shortcuts
2265	 * are taken, but the code works.
2266	 */
2267	if (pseflag &&
2268		(object->type == OBJT_DEVICE) &&
2269		((addr & (NBPDR - 1)) == 0) &&
2270		((size & (NBPDR - 1)) == 0) ) {
2271		int i;
2272		vm_page_t m[1];
2273		unsigned int ptepindex;
2274		int npdes;
2275		vm_offset_t ptepa;
2276
2277		if (pmap->pm_pdir[ptepindex = (addr >> PDRSHIFT)])
2278			return;
2279
2280retry:
2281		p = vm_page_lookup(object, pindex);
2282		if (p && vm_page_sleep_busy(p, FALSE, "init4p"))
2283			goto retry;
2284
2285		if (p == NULL) {
2286			p = vm_page_alloc(object, pindex, VM_ALLOC_NORMAL);
2287			if (p == NULL)
2288				return;
2289			m[0] = p;
2290
2291			if (vm_pager_get_pages(object, m, 1, 0) != VM_PAGER_OK) {
2292				vm_page_free(p);
2293				return;
2294			}
2295
2296			p = vm_page_lookup(object, pindex);
2297			vm_page_wakeup(p);
2298		}
2299
2300		ptepa = (vm_offset_t) VM_PAGE_TO_PHYS(p);
2301		if (ptepa & (NBPDR - 1)) {
2302			return;
2303		}
2304
2305		p->valid = VM_PAGE_BITS_ALL;
2306
2307		pmap->pm_stats.resident_count += size >> PAGE_SHIFT;
2308		npdes = size >> PDRSHIFT;
2309		for(i=0;i<npdes;i++) {
2310			pmap->pm_pdir[ptepindex] =
2311				(pd_entry_t) (ptepa | PG_U | PG_RW | PG_V | PG_PS);
2312			ptepa += NBPDR;
2313			ptepindex += 1;
2314		}
2315		vm_page_flag_set(p, PG_MAPPED);
2316		invltlb();
2317		return;
2318	}
2319
2320	psize = i386_btop(size);
2321
2322	if ((object->type != OBJT_VNODE) ||
2323		(limit && (psize > MAX_INIT_PT) &&
2324			(object->resident_page_count > MAX_INIT_PT))) {
2325		return;
2326	}
2327
2328	if (psize + pindex > object->size) {
2329		if (object->size < pindex)
2330			return;
2331		psize = object->size - pindex;
2332	}
2333
2334	mpte = NULL;
2335	/*
2336	 * if we are processing a major portion of the object, then scan the
2337	 * entire thing.
2338	 */
2339	if (psize > (object->resident_page_count >> 2)) {
2340		objpgs = psize;
2341
2342		for (p = TAILQ_FIRST(&object->memq);
2343		    ((objpgs > 0) && (p != NULL));
2344		    p = TAILQ_NEXT(p, listq)) {
2345
2346			tmpidx = p->pindex;
2347			if (tmpidx < pindex) {
2348				continue;
2349			}
2350			tmpidx -= pindex;
2351			if (tmpidx >= psize) {
2352				continue;
2353			}
2354			if (((p->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) &&
2355				(p->busy == 0) &&
2356			    (p->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) {
2357				if ((p->queue - p->pc) == PQ_CACHE)
2358					vm_page_deactivate(p);
2359				vm_page_busy(p);
2360				mpte = pmap_enter_quick(pmap,
2361					addr + i386_ptob(tmpidx), p, mpte);
2362				vm_page_flag_set(p, PG_MAPPED);
2363				vm_page_wakeup(p);
2364			}
2365			objpgs -= 1;
2366		}
2367	} else {
2368		/*
2369		 * else lookup the pages one-by-one.
2370		 */
2371		for (tmpidx = 0; tmpidx < psize; tmpidx += 1) {
2372			p = vm_page_lookup(object, tmpidx + pindex);
2373			if (p &&
2374			    ((p->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) &&
2375				(p->busy == 0) &&
2376			    (p->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) {
2377				if ((p->queue - p->pc) == PQ_CACHE)
2378					vm_page_deactivate(p);
2379				vm_page_busy(p);
2380				mpte = pmap_enter_quick(pmap,
2381					addr + i386_ptob(tmpidx), p, mpte);
2382				vm_page_flag_set(p, PG_MAPPED);
2383				vm_page_wakeup(p);
2384			}
2385		}
2386	}
2387	return;
2388}
2389
2390/*
2391 * pmap_prefault provides a quick way of clustering
2392 * pagefaults into a processes address space.  It is a "cousin"
2393 * of pmap_object_init_pt, except it runs at page fault time instead
2394 * of mmap time.
2395 */
2396#define PFBAK 4
2397#define PFFOR 4
2398#define PAGEORDER_SIZE (PFBAK+PFFOR)
2399
2400static int pmap_prefault_pageorder[] = {
2401	-PAGE_SIZE, PAGE_SIZE,
2402	-2 * PAGE_SIZE, 2 * PAGE_SIZE,
2403	-3 * PAGE_SIZE, 3 * PAGE_SIZE
2404	-4 * PAGE_SIZE, 4 * PAGE_SIZE
2405};
2406
2407void
2408pmap_prefault(pmap, addra, entry)
2409	pmap_t pmap;
2410	vm_offset_t addra;
2411	vm_map_entry_t entry;
2412{
2413	int i;
2414	vm_offset_t starta;
2415	vm_offset_t addr;
2416	vm_pindex_t pindex;
2417	vm_page_t m, mpte;
2418	vm_object_t object;
2419
2420	if (!curproc || (pmap != vmspace_pmap(curproc->p_vmspace)))
2421		return;
2422
2423	object = entry->object.vm_object;
2424
2425	starta = addra - PFBAK * PAGE_SIZE;
2426	if (starta < entry->start) {
2427		starta = entry->start;
2428	} else if (starta > addra) {
2429		starta = 0;
2430	}
2431
2432	mpte = NULL;
2433	for (i = 0; i < PAGEORDER_SIZE; i++) {
2434		vm_object_t lobject;
2435		unsigned *pte;
2436
2437		addr = addra + pmap_prefault_pageorder[i];
2438		if (addr > addra + (PFFOR * PAGE_SIZE))
2439			addr = 0;
2440
2441		if (addr < starta || addr >= entry->end)
2442			continue;
2443
2444		if ((*pmap_pde(pmap, addr)) == NULL)
2445			continue;
2446
2447		pte = (unsigned *) vtopte(addr);
2448		if (*pte)
2449			continue;
2450
2451		pindex = ((addr - entry->start) + entry->offset) >> PAGE_SHIFT;
2452		lobject = object;
2453		for (m = vm_page_lookup(lobject, pindex);
2454		    (!m && (lobject->type == OBJT_DEFAULT) && (lobject->backing_object));
2455		    lobject = lobject->backing_object) {
2456			if (lobject->backing_object_offset & PAGE_MASK)
2457				break;
2458			pindex += (lobject->backing_object_offset >> PAGE_SHIFT);
2459			m = vm_page_lookup(lobject->backing_object, pindex);
2460		}
2461
2462		/*
2463		 * give-up when a page is not in memory
2464		 */
2465		if (m == NULL)
2466			break;
2467
2468		if (((m->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) &&
2469			(m->busy == 0) &&
2470		    (m->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) {
2471
2472			if ((m->queue - m->pc) == PQ_CACHE) {
2473				vm_page_deactivate(m);
2474			}
2475			vm_page_busy(m);
2476			mpte = pmap_enter_quick(pmap, addr, m, mpte);
2477			vm_page_flag_set(m, PG_MAPPED);
2478			vm_page_wakeup(m);
2479		}
2480	}
2481}
2482
2483/*
2484 *	Routine:	pmap_change_wiring
2485 *	Function:	Change the wiring attribute for a map/virtual-address
2486 *			pair.
2487 *	In/out conditions:
2488 *			The mapping must already exist in the pmap.
2489 */
2490void
2491pmap_change_wiring(pmap, va, wired)
2492	register pmap_t pmap;
2493	vm_offset_t va;
2494	boolean_t wired;
2495{
2496	register unsigned *pte;
2497
2498	if (pmap == NULL)
2499		return;
2500
2501	pte = pmap_pte(pmap, va);
2502
2503	if (wired && !pmap_pte_w(pte))
2504		pmap->pm_stats.wired_count++;
2505	else if (!wired && pmap_pte_w(pte))
2506		pmap->pm_stats.wired_count--;
2507
2508	/*
2509	 * Wiring is not a hardware characteristic so there is no need to
2510	 * invalidate TLB.
2511	 */
2512	pmap_pte_set_w(pte, wired);
2513}
2514
2515
2516
2517/*
2518 *	Copy the range specified by src_addr/len
2519 *	from the source map to the range dst_addr/len
2520 *	in the destination map.
2521 *
2522 *	This routine is only advisory and need not do anything.
2523 */
2524
2525void
2526pmap_copy(dst_pmap, src_pmap, dst_addr, len, src_addr)
2527	pmap_t dst_pmap, src_pmap;
2528	vm_offset_t dst_addr;
2529	vm_size_t len;
2530	vm_offset_t src_addr;
2531{
2532	vm_offset_t addr;
2533	vm_offset_t end_addr = src_addr + len;
2534	vm_offset_t pdnxt;
2535	unsigned src_frame, dst_frame;
2536	vm_page_t m;
2537
2538	if (dst_addr != src_addr)
2539		return;
2540
2541	src_frame = ((unsigned) src_pmap->pm_pdir[PTDPTDI]) & PG_FRAME;
2542	if (src_frame != (((unsigned) PTDpde) & PG_FRAME)) {
2543		return;
2544	}
2545
2546	dst_frame = ((unsigned) dst_pmap->pm_pdir[PTDPTDI]) & PG_FRAME;
2547	if (dst_frame != (((unsigned) APTDpde) & PG_FRAME)) {
2548		APTDpde = (pd_entry_t) (dst_frame | PG_RW | PG_V);
2549#if defined(SMP)
2550		/* The page directory is not shared between CPUs */
2551		cpu_invltlb();
2552#else
2553		invltlb();
2554#endif
2555	}
2556
2557	for(addr = src_addr; addr < end_addr; addr = pdnxt) {
2558		unsigned *src_pte, *dst_pte;
2559		vm_page_t dstmpte, srcmpte;
2560		vm_offset_t srcptepaddr;
2561		unsigned ptepindex;
2562
2563		if (addr >= UPT_MIN_ADDRESS)
2564			panic("pmap_copy: invalid to pmap_copy page tables\n");
2565
2566		/*
2567		 * Don't let optional prefaulting of pages make us go
2568		 * way below the low water mark of free pages or way
2569		 * above high water mark of used pv entries.
2570		 */
2571		if (cnt.v_free_count < cnt.v_free_reserved ||
2572		    pv_entry_count > pv_entry_high_water)
2573			break;
2574
2575		pdnxt = ((addr + PAGE_SIZE*NPTEPG) & ~(PAGE_SIZE*NPTEPG - 1));
2576		ptepindex = addr >> PDRSHIFT;
2577
2578		srcptepaddr = (vm_offset_t) src_pmap->pm_pdir[ptepindex];
2579		if (srcptepaddr == 0)
2580			continue;
2581
2582		if (srcptepaddr & PG_PS) {
2583			if (dst_pmap->pm_pdir[ptepindex] == 0) {
2584				dst_pmap->pm_pdir[ptepindex] = (pd_entry_t) srcptepaddr;
2585				dst_pmap->pm_stats.resident_count += NBPDR / PAGE_SIZE;
2586			}
2587			continue;
2588		}
2589
2590		srcmpte = vm_page_lookup(src_pmap->pm_pteobj, ptepindex);
2591		if ((srcmpte == NULL) ||
2592			(srcmpte->hold_count == 0) || (srcmpte->flags & PG_BUSY))
2593			continue;
2594
2595		if (pdnxt > end_addr)
2596			pdnxt = end_addr;
2597
2598		src_pte = (unsigned *) vtopte(addr);
2599		dst_pte = (unsigned *) avtopte(addr);
2600		while (addr < pdnxt) {
2601			unsigned ptetemp;
2602			ptetemp = *src_pte;
2603			/*
2604			 * we only virtual copy managed pages
2605			 */
2606			if ((ptetemp & PG_MANAGED) != 0) {
2607				/*
2608				 * We have to check after allocpte for the
2609				 * pte still being around...  allocpte can
2610				 * block.
2611				 */
2612				dstmpte = pmap_allocpte(dst_pmap, addr);
2613				if ((*dst_pte == 0) && (ptetemp = *src_pte)) {
2614					/*
2615					 * Clear the modified and
2616					 * accessed (referenced) bits
2617					 * during the copy.
2618					 */
2619					m = PHYS_TO_VM_PAGE(ptetemp);
2620					*dst_pte = ptetemp & ~(PG_M | PG_A);
2621					dst_pmap->pm_stats.resident_count++;
2622					pmap_insert_entry(dst_pmap, addr,
2623						dstmpte, m);
2624	 			} else {
2625					pmap_unwire_pte_hold(dst_pmap, dstmpte);
2626				}
2627				if (dstmpte->hold_count >= srcmpte->hold_count)
2628					break;
2629			}
2630			addr += PAGE_SIZE;
2631			src_pte++;
2632			dst_pte++;
2633		}
2634	}
2635}
2636
2637/*
2638 *	Routine:	pmap_kernel
2639 *	Function:
2640 *		Returns the physical map handle for the kernel.
2641 */
2642pmap_t
2643pmap_kernel()
2644{
2645	return (kernel_pmap);
2646}
2647
2648/*
2649 *	pmap_zero_page zeros the specified hardware page by mapping
2650 *	the page into KVM and using bzero to clear its contents.
2651 */
2652void
2653pmap_zero_page(phys)
2654	vm_offset_t phys;
2655{
2656
2657	if (*(int *) CMAP2)
2658		panic("pmap_zero_page: CMAP2 busy");
2659
2660	*(int *) CMAP2 = PG_V | PG_RW | (phys & PG_FRAME) | PG_A | PG_M;
2661	invltlb_1pg((vm_offset_t)CADDR2);
2662
2663#if defined(I686_CPU)
2664	if (cpu_class == CPUCLASS_686)
2665		i686_pagezero(CADDR2);
2666	else
2667#endif
2668		bzero(CADDR2, PAGE_SIZE);
2669	*(int *) CMAP2 = 0;
2670}
2671
2672/*
2673 *	pmap_zero_page_area zeros the specified hardware page by mapping
2674 *	the page into KVM and using bzero to clear its contents.
2675 *
2676 *	off and size may not cover an area beyond a single hardware page.
2677 */
2678void
2679pmap_zero_page_area(phys, off, size)
2680	vm_offset_t phys;
2681	int off;
2682	int size;
2683{
2684
2685	if (*(int *) CMAP2)
2686		panic("pmap_zero_page: CMAP2 busy");
2687
2688	*(int *) CMAP2 = PG_V | PG_RW | (phys & PG_FRAME) | PG_A | PG_M;
2689	invltlb_1pg((vm_offset_t)CADDR2);
2690
2691#if defined(I686_CPU)
2692	if (cpu_class == CPUCLASS_686 && off == 0 && size == PAGE_SIZE)
2693		i686_pagezero(CADDR2);
2694	else
2695#endif
2696		bzero((char *)CADDR2 + off, size);
2697	*(int *) CMAP2 = 0;
2698}
2699
2700/*
2701 *	pmap_copy_page copies the specified (machine independent)
2702 *	page by mapping the page into virtual memory and using
2703 *	bcopy to copy the page, one machine dependent page at a
2704 *	time.
2705 */
2706void
2707pmap_copy_page(src, dst)
2708	vm_offset_t src;
2709	vm_offset_t dst;
2710{
2711
2712	if (*(int *) CMAP1)
2713		panic("pmap_copy_page: CMAP1 busy");
2714	if (*(int *) CMAP2)
2715		panic("pmap_copy_page: CMAP2 busy");
2716
2717	*(int *) CMAP1 = PG_V | (src & PG_FRAME) | PG_A;
2718	*(int *) CMAP2 = PG_V | PG_RW | (dst & PG_FRAME) | PG_A | PG_M;
2719#ifdef I386_CPU
2720	invltlb();
2721#else
2722	invlpg((u_int)CADDR1);
2723	invlpg((u_int)CADDR2);
2724#endif
2725
2726	bcopy(CADDR1, CADDR2, PAGE_SIZE);
2727
2728	*(int *) CMAP1 = 0;
2729	*(int *) CMAP2 = 0;
2730}
2731
2732
2733/*
2734 *	Routine:	pmap_pageable
2735 *	Function:
2736 *		Make the specified pages (by pmap, offset)
2737 *		pageable (or not) as requested.
2738 *
2739 *		A page which is not pageable may not take
2740 *		a fault; therefore, its page table entry
2741 *		must remain valid for the duration.
2742 *
2743 *		This routine is merely advisory; pmap_enter
2744 *		will specify that these pages are to be wired
2745 *		down (or not) as appropriate.
2746 */
2747void
2748pmap_pageable(pmap, sva, eva, pageable)
2749	pmap_t pmap;
2750	vm_offset_t sva, eva;
2751	boolean_t pageable;
2752{
2753}
2754
2755/*
2756 * this routine returns true if a physical page resides
2757 * in the given pmap.
2758 */
2759boolean_t
2760pmap_page_exists(pmap, m)
2761	pmap_t pmap;
2762	vm_page_t m;
2763{
2764	register pv_entry_t pv;
2765	int s;
2766
2767	if (!pmap_initialized || (m->flags & PG_FICTITIOUS))
2768		return FALSE;
2769
2770	s = splvm();
2771
2772	/*
2773	 * Not found, check current mappings returning immediately if found.
2774	 */
2775	for (pv = TAILQ_FIRST(&m->md.pv_list);
2776		pv;
2777		pv = TAILQ_NEXT(pv, pv_list)) {
2778		if (pv->pv_pmap == pmap) {
2779			splx(s);
2780			return TRUE;
2781		}
2782	}
2783	splx(s);
2784	return (FALSE);
2785}
2786
2787#define PMAP_REMOVE_PAGES_CURPROC_ONLY
2788/*
2789 * Remove all pages from specified address space
2790 * this aids process exit speeds.  Also, this code
2791 * is special cased for current process only, but
2792 * can have the more generic (and slightly slower)
2793 * mode enabled.  This is much faster than pmap_remove
2794 * in the case of running down an entire address space.
2795 */
2796void
2797pmap_remove_pages(pmap, sva, eva)
2798	pmap_t pmap;
2799	vm_offset_t sva, eva;
2800{
2801	unsigned *pte, tpte;
2802	pv_entry_t pv, npv;
2803	int s;
2804	vm_page_t m;
2805
2806#ifdef PMAP_REMOVE_PAGES_CURPROC_ONLY
2807	if (!curproc || (pmap != vmspace_pmap(curproc->p_vmspace))) {
2808		printf("warning: pmap_remove_pages called with non-current pmap\n");
2809		return;
2810	}
2811#endif
2812
2813	s = splvm();
2814	for(pv = TAILQ_FIRST(&pmap->pm_pvlist);
2815		pv;
2816		pv = npv) {
2817
2818		if (pv->pv_va >= eva || pv->pv_va < sva) {
2819			npv = TAILQ_NEXT(pv, pv_plist);
2820			continue;
2821		}
2822
2823#ifdef PMAP_REMOVE_PAGES_CURPROC_ONLY
2824		pte = (unsigned *)vtopte(pv->pv_va);
2825#else
2826		pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va);
2827#endif
2828		tpte = *pte;
2829
2830/*
2831 * We cannot remove wired pages from a process' mapping at this time
2832 */
2833		if (tpte & PG_W) {
2834			npv = TAILQ_NEXT(pv, pv_plist);
2835			continue;
2836		}
2837		*pte = 0;
2838
2839		m = PHYS_TO_VM_PAGE(tpte);
2840
2841		KASSERT(m < &vm_page_array[vm_page_array_size],
2842			("pmap_remove_pages: bad tpte %x", tpte));
2843
2844		pv->pv_pmap->pm_stats.resident_count--;
2845
2846		/*
2847		 * Update the vm_page_t clean and reference bits.
2848		 */
2849		if (tpte & PG_M) {
2850			vm_page_dirty(m);
2851		}
2852
2853
2854		npv = TAILQ_NEXT(pv, pv_plist);
2855		TAILQ_REMOVE(&pv->pv_pmap->pm_pvlist, pv, pv_plist);
2856
2857		m->md.pv_list_count--;
2858		TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
2859		if (TAILQ_FIRST(&m->md.pv_list) == NULL) {
2860			vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE);
2861		}
2862
2863		pmap_unuse_pt(pv->pv_pmap, pv->pv_va, pv->pv_ptem);
2864		free_pv_entry(pv);
2865	}
2866	splx(s);
2867	pmap_TLB_invalidate_all(pmap);
2868}
2869
2870/*
2871 * pmap_testbit tests bits in pte's
2872 * note that the testbit/changebit routines are inline,
2873 * and a lot of things compile-time evaluate.
2874 */
2875static boolean_t
2876pmap_testbit(m, bit)
2877	vm_page_t m;
2878	int bit;
2879{
2880	pv_entry_t pv;
2881	unsigned *pte;
2882	int s;
2883
2884	if (!pmap_initialized || (m->flags & PG_FICTITIOUS))
2885		return FALSE;
2886
2887	if (TAILQ_FIRST(&m->md.pv_list) == NULL)
2888		return FALSE;
2889
2890	s = splvm();
2891
2892	for (pv = TAILQ_FIRST(&m->md.pv_list);
2893		pv;
2894		pv = TAILQ_NEXT(pv, pv_list)) {
2895
2896		/*
2897		 * if the bit being tested is the modified bit, then
2898		 * mark clean_map and ptes as never
2899		 * modified.
2900		 */
2901		if (bit & (PG_A|PG_M)) {
2902			if (!pmap_track_modified(pv->pv_va))
2903				continue;
2904		}
2905
2906#if defined(PMAP_DIAGNOSTIC)
2907		if (!pv->pv_pmap) {
2908			printf("Null pmap (tb) at va: 0x%x\n", pv->pv_va);
2909			continue;
2910		}
2911#endif
2912		pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va);
2913		if (*pte & bit) {
2914			splx(s);
2915			return TRUE;
2916		}
2917	}
2918	splx(s);
2919	return (FALSE);
2920}
2921
2922/*
2923 * this routine is used to modify bits in ptes
2924 */
2925static __inline void
2926pmap_changebit(m, bit, setem)
2927	vm_page_t m;
2928	int bit;
2929	boolean_t setem;
2930{
2931	register pv_entry_t pv;
2932	register unsigned *pte;
2933	int s;
2934
2935	if (!pmap_initialized || (m->flags & PG_FICTITIOUS))
2936		return;
2937
2938	s = splvm();
2939
2940	/*
2941	 * Loop over all current mappings setting/clearing as appropos If
2942	 * setting RO do we need to clear the VAC?
2943	 */
2944	for (pv = TAILQ_FIRST(&m->md.pv_list);
2945		pv;
2946		pv = TAILQ_NEXT(pv, pv_list)) {
2947
2948		/*
2949		 * don't write protect pager mappings
2950		 */
2951		if (!setem && (bit == PG_RW)) {
2952			if (!pmap_track_modified(pv->pv_va))
2953				continue;
2954		}
2955
2956#if defined(PMAP_DIAGNOSTIC)
2957		if (!pv->pv_pmap) {
2958			printf("Null pmap (cb) at va: 0x%x\n", pv->pv_va);
2959			continue;
2960		}
2961#endif
2962
2963		pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va);
2964
2965		if (setem) {
2966			*(int *)pte |= bit;
2967			pmap_TLB_invalidate(pv->pv_pmap, pv->pv_va);
2968		} else {
2969			vm_offset_t pbits = *(vm_offset_t *)pte;
2970			if (pbits & bit) {
2971				if (bit == PG_RW) {
2972					if (pbits & PG_M) {
2973						vm_page_dirty(m);
2974					}
2975					*(int *)pte = pbits & ~(PG_M|PG_RW);
2976				} else {
2977					*(int *)pte = pbits & ~bit;
2978				}
2979				pmap_TLB_invalidate(pv->pv_pmap, pv->pv_va);
2980			}
2981		}
2982	}
2983	splx(s);
2984}
2985
2986/*
2987 *      pmap_page_protect:
2988 *
2989 *      Lower the permission for all mappings to a given page.
2990 */
2991void
2992pmap_page_protect(vm_page_t m, vm_prot_t prot)
2993{
2994	if ((prot & VM_PROT_WRITE) == 0) {
2995		if (prot & (VM_PROT_READ | VM_PROT_EXECUTE)) {
2996			pmap_changebit(m, PG_RW, FALSE);
2997		} else {
2998			pmap_remove_all(m);
2999		}
3000	}
3001}
3002
3003vm_offset_t
3004pmap_phys_address(ppn)
3005	int ppn;
3006{
3007	return (i386_ptob(ppn));
3008}
3009
3010/*
3011 *	pmap_ts_referenced:
3012 *
3013 *	Return the count of reference bits for a page, clearing all of them.
3014 */
3015int
3016pmap_ts_referenced(vm_page_t m)
3017{
3018	register pv_entry_t pv, pvf, pvn;
3019	unsigned *pte;
3020	int s;
3021	int rtval = 0;
3022
3023	if (!pmap_initialized || (m->flags & PG_FICTITIOUS))
3024		return (rtval);
3025
3026	s = splvm();
3027
3028	if ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) {
3029
3030		pvf = pv;
3031
3032		do {
3033			pvn = TAILQ_NEXT(pv, pv_list);
3034
3035			TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
3036
3037			TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list);
3038
3039			if (!pmap_track_modified(pv->pv_va))
3040				continue;
3041
3042			pte = pmap_pte_quick(pv->pv_pmap, pv->pv_va);
3043
3044			if (pte && (*pte & PG_A)) {
3045				*pte &= ~PG_A;
3046
3047				pmap_TLB_invalidate(pv->pv_pmap, pv->pv_va);
3048
3049				rtval++;
3050				if (rtval > 4) {
3051					break;
3052				}
3053			}
3054		} while ((pv = pvn) != NULL && pv != pvf);
3055	}
3056	splx(s);
3057
3058	return (rtval);
3059}
3060
3061/*
3062 *	pmap_is_modified:
3063 *
3064 *	Return whether or not the specified physical page was modified
3065 *	in any physical maps.
3066 */
3067boolean_t
3068pmap_is_modified(vm_page_t m)
3069{
3070	return pmap_testbit(m, PG_M);
3071}
3072
3073/*
3074 *	Clear the modify bits on the specified physical page.
3075 */
3076void
3077pmap_clear_modify(vm_page_t m)
3078{
3079	pmap_changebit(m, PG_M, FALSE);
3080}
3081
3082/*
3083 *	pmap_clear_reference:
3084 *
3085 *	Clear the reference bit on the specified physical page.
3086 */
3087void
3088pmap_clear_reference(vm_page_t m)
3089{
3090	pmap_changebit(m, PG_A, FALSE);
3091}
3092
3093/*
3094 * Miscellaneous support routines follow
3095 */
3096
3097static void
3098i386_protection_init()
3099{
3100	register int *kp, prot;
3101
3102	kp = protection_codes;
3103	for (prot = 0; prot < 8; prot++) {
3104		switch (prot) {
3105		case VM_PROT_NONE | VM_PROT_NONE | VM_PROT_NONE:
3106			/*
3107			 * Read access is also 0. There isn't any execute bit,
3108			 * so just make it readable.
3109			 */
3110		case VM_PROT_READ | VM_PROT_NONE | VM_PROT_NONE:
3111		case VM_PROT_READ | VM_PROT_NONE | VM_PROT_EXECUTE:
3112		case VM_PROT_NONE | VM_PROT_NONE | VM_PROT_EXECUTE:
3113			*kp++ = 0;
3114			break;
3115		case VM_PROT_NONE | VM_PROT_WRITE | VM_PROT_NONE:
3116		case VM_PROT_NONE | VM_PROT_WRITE | VM_PROT_EXECUTE:
3117		case VM_PROT_READ | VM_PROT_WRITE | VM_PROT_NONE:
3118		case VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE:
3119			*kp++ = PG_RW;
3120			break;
3121		}
3122	}
3123}
3124
3125/*
3126 * Map a set of physical memory pages into the kernel virtual
3127 * address space. Return a pointer to where it is mapped. This
3128 * routine is intended to be used for mapping device memory,
3129 * NOT real memory.
3130 */
3131void *
3132pmap_mapdev(pa, size)
3133	vm_offset_t pa;
3134	vm_size_t size;
3135{
3136	vm_offset_t va, tmpva, offset;
3137	unsigned *pte;
3138
3139	offset = pa & PAGE_MASK;
3140	size = roundup(offset + size, PAGE_SIZE);
3141
3142	va = kmem_alloc_pageable(kernel_map, size);
3143	if (!va)
3144		panic("pmap_mapdev: Couldn't alloc kernel virtual memory");
3145
3146	pa = pa & PG_FRAME;
3147	for (tmpva = va; size > 0;) {
3148		pte = (unsigned *)vtopte(tmpva);
3149		*pte = pa | PG_RW | PG_V | pgeflag;
3150		size -= PAGE_SIZE;
3151		tmpva += PAGE_SIZE;
3152		pa += PAGE_SIZE;
3153	}
3154	invltlb();
3155
3156	return ((void *)(va + offset));
3157}
3158
3159void
3160pmap_unmapdev(va, size)
3161	vm_offset_t va;
3162	vm_size_t size;
3163{
3164	vm_offset_t base, offset;
3165
3166	base = va & PG_FRAME;
3167	offset = va & PAGE_MASK;
3168	size = roundup(offset + size, PAGE_SIZE);
3169	kmem_free(kernel_map, base, size);
3170}
3171
3172/*
3173 * perform the pmap work for mincore
3174 */
3175int
3176pmap_mincore(pmap, addr)
3177	pmap_t pmap;
3178	vm_offset_t addr;
3179{
3180
3181	unsigned *ptep, pte;
3182	vm_page_t m;
3183	int val = 0;
3184
3185	ptep = pmap_pte(pmap, addr);
3186	if (ptep == 0) {
3187		return 0;
3188	}
3189
3190	if ((pte = *ptep) != 0) {
3191		vm_offset_t pa;
3192
3193		val = MINCORE_INCORE;
3194		if ((pte & PG_MANAGED) == 0)
3195			return val;
3196
3197		pa = pte & PG_FRAME;
3198
3199		m = PHYS_TO_VM_PAGE(pa);
3200
3201		/*
3202		 * Modified by us
3203		 */
3204		if (pte & PG_M)
3205			val |= MINCORE_MODIFIED|MINCORE_MODIFIED_OTHER;
3206		/*
3207		 * Modified by someone
3208		 */
3209		else if (m->dirty || pmap_is_modified(m))
3210			val |= MINCORE_MODIFIED_OTHER;
3211		/*
3212		 * Referenced by us
3213		 */
3214		if (pte & PG_A)
3215			val |= MINCORE_REFERENCED|MINCORE_REFERENCED_OTHER;
3216
3217		/*
3218		 * Referenced by someone
3219		 */
3220		else if ((m->flags & PG_REFERENCED) || pmap_ts_referenced(m)) {
3221			val |= MINCORE_REFERENCED_OTHER;
3222			vm_page_flag_set(m, PG_REFERENCED);
3223		}
3224	}
3225	return val;
3226}
3227
3228void
3229pmap_activate(struct proc *p)
3230{
3231	pmap_t	pmap;
3232
3233	pmap = vmspace_pmap(p->p_vmspace);
3234#if defined(SMP)
3235	pmap->pm_active |= 1 << PCPU_GET(cpuid);
3236#else
3237	pmap->pm_active |= 1;
3238#endif
3239#if defined(SWTCH_OPTIM_STATS)
3240	tlb_flush_count++;
3241#endif
3242	load_cr3(p->p_addr->u_pcb.pcb_cr3 = vtophys(pmap->pm_pdir));
3243}
3244
3245vm_offset_t
3246pmap_addr_hint(vm_object_t obj, vm_offset_t addr, vm_size_t size)
3247{
3248
3249	if ((obj == NULL) || (size < NBPDR) || (obj->type != OBJT_DEVICE)) {
3250		return addr;
3251	}
3252
3253	addr = (addr + (NBPDR - 1)) & ~(NBPDR - 1);
3254	return addr;
3255}
3256
3257
3258#if defined(PMAP_DEBUG)
3259pmap_pid_dump(int pid)
3260{
3261	pmap_t pmap;
3262	struct proc *p;
3263	int npte = 0;
3264	int index;
3265
3266	sx_slock(&allproc_lock);
3267	LIST_FOREACH(p, &allproc, p_list) {
3268		if (p->p_pid != pid)
3269			continue;
3270
3271		if (p->p_vmspace) {
3272			int i,j;
3273			index = 0;
3274			pmap = vmspace_pmap(p->p_vmspace);
3275			for(i=0;i<1024;i++) {
3276				pd_entry_t *pde;
3277				unsigned *pte;
3278				unsigned base = i << PDRSHIFT;
3279
3280				pde = &pmap->pm_pdir[i];
3281				if (pde && pmap_pde_v(pde)) {
3282					for(j=0;j<1024;j++) {
3283						unsigned va = base + (j << PAGE_SHIFT);
3284						if (va >= (vm_offset_t) VM_MIN_KERNEL_ADDRESS) {
3285							if (index) {
3286								index = 0;
3287								printf("\n");
3288							}
3289							sx_sunlock(&allproc_lock);
3290							return npte;
3291						}
3292						pte = pmap_pte_quick( pmap, va);
3293						if (pte && pmap_pte_v(pte)) {
3294							vm_offset_t pa;
3295							vm_page_t m;
3296							pa = *(int *)pte;
3297							m = PHYS_TO_VM_PAGE(pa);
3298							printf("va: 0x%x, pt: 0x%x, h: %d, w: %d, f: 0x%x",
3299								va, pa, m->hold_count, m->wire_count, m->flags);
3300							npte++;
3301							index++;
3302							if (index >= 2) {
3303								index = 0;
3304								printf("\n");
3305							} else {
3306								printf(" ");
3307							}
3308						}
3309					}
3310				}
3311			}
3312		}
3313	}
3314	sx_sunlock(&allproc_lock);
3315	return npte;
3316}
3317#endif
3318
3319#if defined(DEBUG)
3320
3321static void	pads __P((pmap_t pm));
3322void		pmap_pvdump __P((vm_offset_t pa));
3323
3324/* print address space of pmap*/
3325static void
3326pads(pm)
3327	pmap_t pm;
3328{
3329	unsigned va, i, j;
3330	unsigned *ptep;
3331
3332	if (pm == kernel_pmap)
3333		return;
3334	for (i = 0; i < 1024; i++)
3335		if (pm->pm_pdir[i])
3336			for (j = 0; j < 1024; j++) {
3337				va = (i << PDRSHIFT) + (j << PAGE_SHIFT);
3338				if (pm == kernel_pmap && va < KERNBASE)
3339					continue;
3340				if (pm != kernel_pmap && va > UPT_MAX_ADDRESS)
3341					continue;
3342				ptep = pmap_pte_quick(pm, va);
3343				if (pmap_pte_v(ptep))
3344					printf("%x:%x ", va, *(int *) ptep);
3345			};
3346
3347}
3348
3349void
3350pmap_pvdump(pa)
3351	vm_offset_t pa;
3352{
3353	register pv_entry_t pv;
3354	vm_page_t m;
3355
3356	printf("pa %x", pa);
3357	m = PHYS_TO_VM_PAGE(pa);
3358	for (pv = TAILQ_FIRST(&m->md.pv_list);
3359		pv;
3360		pv = TAILQ_NEXT(pv, pv_list)) {
3361#ifdef used_to_be
3362		printf(" -> pmap %p, va %x, flags %x",
3363		    (void *)pv->pv_pmap, pv->pv_va, pv->pv_flags);
3364#endif
3365		printf(" -> pmap %p, va %x", (void *)pv->pv_pmap, pv->pv_va);
3366		pads(pv->pv_pmap);
3367	}
3368	printf(" ");
3369}
3370#endif
3371