uvm_page.c revision 1.126
1/*	$OpenBSD: uvm_page.c,v 1.126 2013/06/11 19:01:20 beck Exp $	*/
2/*	$NetBSD: uvm_page.c,v 1.44 2000/11/27 08:40:04 chs Exp $	*/
3
4/*
5 * Copyright (c) 1997 Charles D. Cranor and Washington University.
6 * Copyright (c) 1991, 1993, The Regents of the University of California.
7 *
8 * All rights reserved.
9 *
10 * This code is derived from software contributed to Berkeley by
11 * The Mach Operating System project at Carnegie-Mellon University.
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 Charles D. Cranor,
24 *      Washington University, the University of California, Berkeley and
25 *      its contributors.
26 * 4. Neither the name of the University nor the names of its contributors
27 *    may be used to endorse or promote products derived from this software
28 *    without specific prior written permission.
29 *
30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
40 * SUCH DAMAGE.
41 *
42 *	@(#)vm_page.c   8.3 (Berkeley) 3/21/94
43 * from: Id: uvm_page.c,v 1.1.2.18 1998/02/06 05:24:42 chs Exp
44 *
45 *
46 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
47 * All rights reserved.
48 *
49 * Permission to use, copy, modify and distribute this software and
50 * its documentation is hereby granted, provided that both the copyright
51 * notice and this permission notice appear in all copies of the
52 * software, derivative works or modified versions, and any portions
53 * thereof, and that both notices appear in supporting documentation.
54 *
55 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
56 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
57 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
58 *
59 * Carnegie Mellon requests users of this software to return to
60 *
61 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
62 *  School of Computer Science
63 *  Carnegie Mellon University
64 *  Pittsburgh PA 15213-3890
65 *
66 * any improvements or extensions that they make and grant Carnegie the
67 * rights to redistribute these changes.
68 */
69
70/*
71 * uvm_page.c: page ops.
72 */
73
74#include <sys/param.h>
75#include <sys/systm.h>
76#include <sys/sched.h>
77#include <sys/kernel.h>
78#include <sys/vnode.h>
79#include <sys/mount.h>
80#include <sys/proc.h>
81
82#include <uvm/uvm.h>
83
84/*
85 * for object trees
86 */
87RB_GENERATE(uvm_objtree, vm_page, objt, uvm_pagecmp);
88
89int
90uvm_pagecmp(struct vm_page *a, struct vm_page *b)
91{
92	return (a->offset < b->offset ? -1 : a->offset > b->offset);
93}
94
95/*
96 * global vars... XXXCDC: move to uvm. structure.
97 */
98
99/*
100 * physical memory config is stored in vm_physmem.
101 */
102
103struct vm_physseg vm_physmem[VM_PHYSSEG_MAX];	/* XXXCDC: uvm.physmem */
104int vm_nphysseg = 0;				/* XXXCDC: uvm.nphysseg */
105
106/*
107 * Some supported CPUs in a given architecture don't support all
108 * of the things necessary to do idle page zero'ing efficiently.
109 * We therefore provide a way to disable it from machdep code here.
110 */
111
112/*
113 * XXX disabled until we can find a way to do this without causing
114 * problems for either cpu caches or DMA latency.
115 */
116boolean_t vm_page_zero_enable = FALSE;
117
118/*
119 * local variables
120 */
121
122/*
123 * these variables record the values returned by vm_page_bootstrap,
124 * for debugging purposes.  The implementation of uvm_pageboot_alloc
125 * and pmap_startup here also uses them internally.
126 */
127
128static vaddr_t      virtual_space_start;
129static vaddr_t      virtual_space_end;
130
131/*
132 * local prototypes
133 */
134
135static void uvm_pageinsert(struct vm_page *);
136static void uvm_pageremove(struct vm_page *);
137
138/*
139 * inline functions
140 */
141
142/*
143 * uvm_pageinsert: insert a page in the object
144 *
145 * => caller must lock page queues XXX questionable
146 * => call should have already set pg's object and offset pointers
147 *    and bumped the version counter
148 */
149
150__inline static void
151uvm_pageinsert(struct vm_page *pg)
152{
153	struct vm_page	*dupe;
154
155	KASSERT((pg->pg_flags & PG_TABLED) == 0);
156	dupe = RB_INSERT(uvm_objtree, &pg->uobject->memt, pg);
157	/* not allowed to insert over another page */
158	KASSERT(dupe == NULL);
159	atomic_setbits_int(&pg->pg_flags, PG_TABLED);
160	pg->uobject->uo_npages++;
161}
162
163/*
164 * uvm_page_remove: remove page from object
165 *
166 * => caller must lock page queues
167 */
168
169static __inline void
170uvm_pageremove(struct vm_page *pg)
171{
172
173	KASSERT(pg->pg_flags & PG_TABLED);
174	RB_REMOVE(uvm_objtree, &pg->uobject->memt, pg);
175
176	atomic_clearbits_int(&pg->pg_flags, PG_TABLED);
177	pg->uobject->uo_npages--;
178	pg->uobject = NULL;
179	pg->pg_version++;
180}
181
182/*
183 * uvm_page_init: init the page system.   called from uvm_init().
184 *
185 * => we return the range of kernel virtual memory in kvm_startp/kvm_endp
186 */
187
188void
189uvm_page_init(vaddr_t *kvm_startp, vaddr_t *kvm_endp)
190{
191	vsize_t freepages, pagecount, n;
192	vm_page_t pagearray, curpg;
193	int lcv, i;
194	paddr_t paddr, pgno;
195	struct vm_physseg *seg;
196
197	/*
198	 * init the page queues and page queue locks
199	 */
200
201	TAILQ_INIT(&uvm.page_active);
202	TAILQ_INIT(&uvm.page_inactive_swp);
203	TAILQ_INIT(&uvm.page_inactive_obj);
204	mtx_init(&uvm.fpageqlock, IPL_VM);
205	uvm_pmr_init();
206
207	/*
208	 * allocate vm_page structures.
209	 */
210
211	/*
212	 * sanity check:
213	 * before calling this function the MD code is expected to register
214	 * some free RAM with the uvm_page_physload() function.   our job
215	 * now is to allocate vm_page structures for this memory.
216	 */
217
218	if (vm_nphysseg == 0)
219		panic("uvm_page_bootstrap: no memory pre-allocated");
220
221	/*
222	 * first calculate the number of free pages...
223	 *
224	 * note that we use start/end rather than avail_start/avail_end.
225	 * this allows us to allocate extra vm_page structures in case we
226	 * want to return some memory to the pool after booting.
227	 */
228
229	freepages = 0;
230	for (lcv = 0, seg = vm_physmem; lcv < vm_nphysseg ; lcv++, seg++)
231		freepages += (seg->end - seg->start);
232
233	/*
234	 * we now know we have (PAGE_SIZE * freepages) bytes of memory we can
235	 * use.   for each page of memory we use we need a vm_page structure.
236	 * thus, the total number of pages we can use is the total size of
237	 * the memory divided by the PAGE_SIZE plus the size of the vm_page
238	 * structure.   we add one to freepages as a fudge factor to avoid
239	 * truncation errors (since we can only allocate in terms of whole
240	 * pages).
241	 */
242
243	pagecount = (((paddr_t)freepages + 1) << PAGE_SHIFT) /
244	    (PAGE_SIZE + sizeof(struct vm_page));
245	pagearray = (vm_page_t)uvm_pageboot_alloc(pagecount *
246	    sizeof(struct vm_page));
247	memset(pagearray, 0, pagecount * sizeof(struct vm_page));
248
249	/*
250	 * init the vm_page structures and put them in the correct place.
251	 */
252
253	for (lcv = 0, seg = vm_physmem; lcv < vm_nphysseg ; lcv++, seg++) {
254		n = seg->end - seg->start;
255		if (n > pagecount) {
256			panic("uvm_page_init: lost %ld page(s) in init",
257			    (long)(n - pagecount));
258			    /* XXXCDC: shouldn't happen? */
259			/* n = pagecount; */
260		}
261
262		/* set up page array pointers */
263		seg->pgs = pagearray;
264		pagearray += n;
265		pagecount -= n;
266		seg->lastpg = seg->pgs + (n - 1);
267
268		/* init and free vm_pages (we've already zeroed them) */
269		pgno = seg->start;
270		paddr = ptoa(pgno);
271		for (i = 0, curpg = seg->pgs; i < n;
272		    i++, curpg++, pgno++, paddr += PAGE_SIZE) {
273			curpg->phys_addr = paddr;
274#ifdef __HAVE_VM_PAGE_MD
275			VM_MDPAGE_INIT(curpg);
276#endif
277			if (pgno >= seg->avail_start &&
278			    pgno <= seg->avail_end) {
279				uvmexp.npages++;
280			}
281		}
282
283		/*
284		 * Add pages to free pool.
285		 */
286		uvm_pmr_freepages(&seg->pgs[seg->avail_start - seg->start],
287		    seg->avail_end - seg->avail_start);
288	}
289
290	/*
291	 * pass up the values of virtual_space_start and
292	 * virtual_space_end (obtained by uvm_pageboot_alloc) to the upper
293	 * layers of the VM.
294	 */
295
296	*kvm_startp = round_page(virtual_space_start);
297	*kvm_endp = trunc_page(virtual_space_end);
298
299	/*
300	 * init locks for kernel threads
301	 */
302	mtx_init(&uvm.aiodoned_lock, IPL_BIO);
303
304	/*
305	 * init reserve thresholds
306	 * XXXCDC - values may need adjusting
307	 */
308	uvmexp.reserve_pagedaemon = 4;
309	uvmexp.reserve_kernel = 6;
310	uvmexp.anonminpct = 10;
311	uvmexp.vnodeminpct = 10;
312	uvmexp.vtextminpct = 5;
313	uvmexp.anonmin = uvmexp.anonminpct * 256 / 100;
314	uvmexp.vnodemin = uvmexp.vnodeminpct * 256 / 100;
315	uvmexp.vtextmin = uvmexp.vtextminpct * 256 / 100;
316
317  	/*
318	 * determine if we should zero pages in the idle loop.
319	 */
320
321	uvm.page_idle_zero = vm_page_zero_enable;
322
323	/*
324	 * done!
325	 */
326
327	uvm.page_init_done = TRUE;
328}
329
330/*
331 * uvm_setpagesize: set the page size
332 *
333 * => sets page_shift and page_mask from uvmexp.pagesize.
334 */
335
336void
337uvm_setpagesize(void)
338{
339	if (uvmexp.pagesize == 0)
340		uvmexp.pagesize = DEFAULT_PAGE_SIZE;
341	uvmexp.pagemask = uvmexp.pagesize - 1;
342	if ((uvmexp.pagemask & uvmexp.pagesize) != 0)
343		panic("uvm_setpagesize: page size not a power of two");
344	for (uvmexp.pageshift = 0; ; uvmexp.pageshift++)
345		if ((1 << uvmexp.pageshift) == uvmexp.pagesize)
346			break;
347}
348
349/*
350 * uvm_pageboot_alloc: steal memory from physmem for bootstrapping
351 */
352
353vaddr_t
354uvm_pageboot_alloc(vsize_t size)
355{
356#if defined(PMAP_STEAL_MEMORY)
357	vaddr_t addr;
358
359	/*
360	 * defer bootstrap allocation to MD code (it may want to allocate
361	 * from a direct-mapped segment).  pmap_steal_memory should round
362	 * off virtual_space_start/virtual_space_end.
363	 */
364
365	addr = pmap_steal_memory(size, &virtual_space_start,
366	    &virtual_space_end);
367
368	return(addr);
369
370#else /* !PMAP_STEAL_MEMORY */
371
372	static boolean_t initialized = FALSE;
373	vaddr_t addr, vaddr;
374	paddr_t paddr;
375
376	/* round to page size */
377	size = round_page(size);
378
379	/*
380	 * on first call to this function, initialize ourselves.
381	 */
382	if (initialized == FALSE) {
383		pmap_virtual_space(&virtual_space_start, &virtual_space_end);
384
385		/* round it the way we like it */
386		virtual_space_start = round_page(virtual_space_start);
387		virtual_space_end = trunc_page(virtual_space_end);
388
389		initialized = TRUE;
390	}
391
392	/*
393	 * allocate virtual memory for this request
394	 */
395	if (virtual_space_start == virtual_space_end ||
396	    (virtual_space_end - virtual_space_start) < size)
397		panic("uvm_pageboot_alloc: out of virtual space");
398
399	addr = virtual_space_start;
400
401#ifdef PMAP_GROWKERNEL
402	/*
403	 * If the kernel pmap can't map the requested space,
404	 * then allocate more resources for it.
405	 */
406	if (uvm_maxkaddr < (addr + size)) {
407		uvm_maxkaddr = pmap_growkernel(addr + size);
408		if (uvm_maxkaddr < (addr + size))
409			panic("uvm_pageboot_alloc: pmap_growkernel() failed");
410	}
411#endif
412
413	virtual_space_start += size;
414
415	/*
416	 * allocate and mapin physical pages to back new virtual pages
417	 */
418
419	for (vaddr = round_page(addr) ; vaddr < addr + size ;
420	    vaddr += PAGE_SIZE) {
421
422		if (!uvm_page_physget(&paddr))
423			panic("uvm_pageboot_alloc: out of memory");
424
425		/*
426		 * Note this memory is no longer managed, so using
427		 * pmap_kenter is safe.
428		 */
429		pmap_kenter_pa(vaddr, paddr, VM_PROT_READ|VM_PROT_WRITE);
430	}
431	pmap_update(pmap_kernel());
432	return(addr);
433#endif	/* PMAP_STEAL_MEMORY */
434}
435
436#if !defined(PMAP_STEAL_MEMORY)
437/*
438 * uvm_page_physget: "steal" one page from the vm_physmem structure.
439 *
440 * => attempt to allocate it off the end of a segment in which the "avail"
441 *    values match the start/end values.   if we can't do that, then we
442 *    will advance both values (making them equal, and removing some
443 *    vm_page structures from the non-avail area).
444 * => return false if out of memory.
445 */
446
447boolean_t
448uvm_page_physget(paddr_t *paddrp)
449{
450	int lcv;
451	struct vm_physseg *seg;
452
453	/* pass 1: try allocating from a matching end */
454#if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) || \
455	(VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH)
456	for (lcv = vm_nphysseg - 1, seg = vm_physmem + lcv; lcv >= 0;
457	    lcv--, seg--)
458#else
459	for (lcv = 0, seg = vm_physmem; lcv < vm_nphysseg ; lcv++, seg++)
460#endif
461	{
462		if (uvm.page_init_done == TRUE)
463			panic("uvm_page_physget: called _after_ bootstrap");
464
465		/* try from front */
466		if (seg->avail_start == seg->start &&
467		    seg->avail_start < seg->avail_end) {
468			*paddrp = ptoa(seg->avail_start);
469			seg->avail_start++;
470			seg->start++;
471			/* nothing left?   nuke it */
472			if (seg->avail_start == seg->end) {
473				if (vm_nphysseg == 1)
474				    panic("uvm_page_physget: out of memory!");
475				vm_nphysseg--;
476				for (; lcv < vm_nphysseg; lcv++, seg++)
477					/* structure copy */
478					seg[0] = seg[1];
479			}
480			return (TRUE);
481		}
482
483		/* try from rear */
484		if (seg->avail_end == seg->end &&
485		    seg->avail_start < seg->avail_end) {
486			*paddrp = ptoa(seg->avail_end - 1);
487			seg->avail_end--;
488			seg->end--;
489			/* nothing left?   nuke it */
490			if (seg->avail_end == seg->start) {
491				if (vm_nphysseg == 1)
492				    panic("uvm_page_physget: out of memory!");
493				vm_nphysseg--;
494				for (; lcv < vm_nphysseg ; lcv++, seg++)
495					/* structure copy */
496					seg[0] = seg[1];
497			}
498			return (TRUE);
499		}
500	}
501
502	/* pass2: forget about matching ends, just allocate something */
503#if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) || \
504	(VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH)
505	for (lcv = vm_nphysseg - 1, seg = vm_physmem + lcv; lcv >= 0;
506	    lcv--, seg--)
507#else
508	for (lcv = 0, seg = vm_physmem; lcv < vm_nphysseg ; lcv++, seg++)
509#endif
510	{
511
512		/* any room in this bank? */
513		if (seg->avail_start >= seg->avail_end)
514			continue;  /* nope */
515
516		*paddrp = ptoa(seg->avail_start);
517		seg->avail_start++;
518		/* truncate! */
519		seg->start = seg->avail_start;
520
521		/* nothing left?   nuke it */
522		if (seg->avail_start == seg->end) {
523			if (vm_nphysseg == 1)
524				panic("uvm_page_physget: out of memory!");
525			vm_nphysseg--;
526			for (; lcv < vm_nphysseg ; lcv++, seg++)
527				/* structure copy */
528				seg[0] = seg[1];
529		}
530		return (TRUE);
531	}
532
533	return (FALSE);        /* whoops! */
534}
535
536#endif /* PMAP_STEAL_MEMORY */
537
538/*
539 * uvm_page_physload: load physical memory into VM system
540 *
541 * => all args are PFs
542 * => all pages in start/end get vm_page structures
543 * => areas marked by avail_start/avail_end get added to the free page pool
544 * => we are limited to VM_PHYSSEG_MAX physical memory segments
545 */
546
547void
548uvm_page_physload(paddr_t start, paddr_t end, paddr_t avail_start,
549    paddr_t avail_end, int flags)
550{
551	int preload, lcv;
552	psize_t npages;
553	struct vm_page *pgs;
554	struct vm_physseg *ps, *seg;
555
556#ifdef DIAGNOSTIC
557	if (uvmexp.pagesize == 0)
558		panic("uvm_page_physload: page size not set!");
559
560	if (start >= end)
561		panic("uvm_page_physload: start >= end");
562#endif
563
564	/*
565	 * do we have room?
566	 */
567	if (vm_nphysseg == VM_PHYSSEG_MAX) {
568		printf("uvm_page_physload: unable to load physical memory "
569		    "segment\n");
570		printf("\t%d segments allocated, ignoring 0x%llx -> 0x%llx\n",
571		    VM_PHYSSEG_MAX, (long long)start, (long long)end);
572		printf("\tincrease VM_PHYSSEG_MAX\n");
573		return;
574	}
575
576	/*
577	 * check to see if this is a "preload" (i.e. uvm_mem_init hasn't been
578	 * called yet, so malloc is not available).
579	 */
580	for (lcv = 0, seg = vm_physmem; lcv < vm_nphysseg; lcv++, seg++) {
581		if (seg->pgs)
582			break;
583	}
584	preload = (lcv == vm_nphysseg);
585
586	/*
587	 * if VM is already running, attempt to malloc() vm_page structures
588	 */
589	if (!preload) {
590		/*
591		 * XXXCDC: need some sort of lockout for this case
592		 * right now it is only used by devices so it should be alright.
593		 */
594 		paddr_t paddr;
595
596 		npages = end - start;  /* # of pages */
597
598		pgs = (struct vm_page *)uvm_km_zalloc(kernel_map,
599		    npages * sizeof(*pgs));
600		if (pgs == NULL) {
601			printf("uvm_page_physload: can not malloc vm_page "
602			    "structs for segment\n");
603			printf("\tignoring 0x%lx -> 0x%lx\n", start, end);
604			return;
605		}
606		/* init phys_addr and free pages, XXX uvmexp.npages */
607		for (lcv = 0, paddr = ptoa(start); lcv < npages;
608		    lcv++, paddr += PAGE_SIZE) {
609			pgs[lcv].phys_addr = paddr;
610#ifdef __HAVE_VM_PAGE_MD
611			VM_MDPAGE_INIT(&pgs[lcv]);
612#endif
613			if (atop(paddr) >= avail_start &&
614			    atop(paddr) <= avail_end) {
615				if (flags & PHYSLOAD_DEVICE) {
616					atomic_setbits_int(&pgs[lcv].pg_flags,
617					    PG_DEV);
618					pgs[lcv].wire_count = 1;
619				} else {
620#if defined(VM_PHYSSEG_NOADD)
621		panic("uvm_page_physload: tried to add RAM after vm_mem_init");
622#endif
623				}
624			}
625		}
626
627		/*
628		 * Add pages to free pool.
629		 */
630		if ((flags & PHYSLOAD_DEVICE) == 0) {
631			uvm_pmr_freepages(&pgs[avail_start - start],
632			    avail_end - avail_start);
633		}
634
635		/* XXXCDC: need hook to tell pmap to rebuild pv_list, etc... */
636	} else {
637
638		/* gcc complains if these don't get init'd */
639		pgs = NULL;
640		npages = 0;
641
642	}
643
644	/*
645	 * now insert us in the proper place in vm_physmem[]
646	 */
647
648#if (VM_PHYSSEG_STRAT == VM_PSTRAT_RANDOM)
649
650	/* random: put it at the end (easy!) */
651	ps = &vm_physmem[vm_nphysseg];
652
653#elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH)
654
655	{
656		int x;
657		/* sort by address for binary search */
658		for (lcv = 0, seg = vm_physmem; lcv < vm_nphysseg; lcv++, seg++)
659			if (start < seg->start)
660				break;
661		ps = seg;
662		/* move back other entries, if necessary ... */
663		for (x = vm_nphysseg, seg = vm_physmem + x - 1; x > lcv;
664		    x--, seg--)
665			/* structure copy */
666			seg[1] = seg[0];
667	}
668
669#elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST)
670
671	{
672		int x;
673		/* sort by largest segment first */
674		for (lcv = 0, seg = vm_physmem; lcv < vm_nphysseg; lcv++, seg++)
675			if ((end - start) >
676			    (seg->end - seg->start))
677				break;
678		ps = &vm_physmem[lcv];
679		/* move back other entries, if necessary ... */
680		for (x = vm_nphysseg, seg = vm_physmem + x - 1; x > lcv;
681		    x--, seg--)
682			/* structure copy */
683			seg[1] = seg[0];
684	}
685
686#else
687
688	panic("uvm_page_physload: unknown physseg strategy selected!");
689
690#endif
691
692	ps->start = start;
693	ps->end = end;
694	ps->avail_start = avail_start;
695	ps->avail_end = avail_end;
696	if (preload) {
697		ps->pgs = NULL;
698	} else {
699		ps->pgs = pgs;
700		ps->lastpg = pgs + npages - 1;
701	}
702	vm_nphysseg++;
703
704	/*
705	 * done!
706	 */
707
708	return;
709}
710
711#ifdef DDB /* XXXCDC: TMP TMP TMP DEBUG DEBUG DEBUG */
712
713void uvm_page_physdump(void); /* SHUT UP GCC */
714
715/* call from DDB */
716void
717uvm_page_physdump(void)
718{
719	int lcv;
720	struct vm_physseg *seg;
721
722	printf("uvm_page_physdump: physical memory config [segs=%d of %d]:\n",
723	    vm_nphysseg, VM_PHYSSEG_MAX);
724	for (lcv = 0, seg = vm_physmem; lcv < vm_nphysseg ; lcv++, seg++)
725		printf("0x%llx->0x%llx [0x%llx->0x%llx]\n",
726		    (long long)seg->start,
727		    (long long)seg->end,
728		    (long long)seg->avail_start,
729		    (long long)seg->avail_end);
730	printf("STRATEGY = ");
731	switch (VM_PHYSSEG_STRAT) {
732	case VM_PSTRAT_RANDOM: printf("RANDOM\n"); break;
733	case VM_PSTRAT_BSEARCH: printf("BSEARCH\n"); break;
734	case VM_PSTRAT_BIGFIRST: printf("BIGFIRST\n"); break;
735	default: printf("<<UNKNOWN>>!!!!\n");
736	}
737}
738#endif
739
740void
741uvm_shutdown(void)
742{
743#ifdef UVM_SWAP_ENCRYPT
744	uvm_swap_finicrypt_all();
745#endif
746}
747
748/*
749 * Perform insert of a given page in the specified anon of obj.
750 * This is basically, uvm_pagealloc, but with the page already given.
751 */
752void
753uvm_pagealloc_pg(struct vm_page *pg, struct uvm_object *obj, voff_t off,
754    struct vm_anon *anon)
755{
756	int	flags;
757
758	flags = PG_BUSY | PG_FAKE;
759	pg->offset = off;
760	pg->uobject = obj;
761	pg->uanon = anon;
762
763	if (anon) {
764		anon->an_page = pg;
765		flags |= PQ_ANON;
766	} else if (obj)
767		uvm_pageinsert(pg);
768	atomic_setbits_int(&pg->pg_flags, flags);
769#if defined(UVM_PAGE_TRKOWN)
770	pg->owner_tag = NULL;
771#endif
772	UVM_PAGE_OWN(pg, "new alloc");
773}
774
775/*
776 * uvm_pglistalloc: allocate a list of pages
777 *
778 * => allocated pages are placed at the tail of rlist.  rlist is
779 *    assumed to be properly initialized by caller.
780 * => returns 0 on success or errno on failure
781 * => doesn't take into account clean non-busy pages on inactive list
782 *	that could be used(?)
783 * => params:
784 *	size		the size of the allocation, rounded to page size.
785 *	low		the low address of the allowed allocation range.
786 *	high		the high address of the allowed allocation range.
787 *	alignment	memory must be aligned to this power-of-two boundary.
788 *	boundary	no segment in the allocation may cross this
789 *			power-of-two boundary (relative to zero).
790 * => flags:
791 *	UVM_PLA_NOWAIT	fail if allocation fails
792 *	UVM_PLA_WAITOK	wait for memory to become avail
793 *	UVM_PLA_ZERO	return zeroed memory
794 */
795int
796uvm_pglistalloc(psize_t size, paddr_t low, paddr_t high, paddr_t alignment,
797    paddr_t boundary, struct pglist *rlist, int nsegs, int flags)
798{
799	KASSERT((alignment & (alignment - 1)) == 0);
800	KASSERT((boundary & (boundary - 1)) == 0);
801	KASSERT(!(flags & UVM_PLA_WAITOK) ^ !(flags & UVM_PLA_NOWAIT));
802
803	if (size == 0)
804		return (EINVAL);
805	size = atop(round_page(size));
806
807	/*
808	 * check to see if we need to generate some free pages waking
809	 * the pagedaemon.
810	 */
811	if ((uvmexp.free - BUFPAGES_DEFICIT) < uvmexp.freemin ||
812	    ((uvmexp.free - BUFPAGES_DEFICIT) < uvmexp.freetarg &&
813	    (uvmexp.inactive + BUFPAGES_INACT) < uvmexp.inactarg))
814		wakeup(&uvm.pagedaemon);
815
816	/*
817	 * XXX uvm_pglistalloc is currently only used for kernel
818	 * objects. Unlike the checks in uvm_pagealloc, below, here
819	 * we are always allowed to use the kernel reseve. However, we
820	 * have to enforce the pagedaemon reserve here or allocations
821	 * via this path could consume everything and we can't
822	 * recover in the page daemon.
823	 */
824 again:
825	if ((uvmexp.free <= uvmexp.reserve_pagedaemon + size &&
826	    !((curproc == uvm.pagedaemon_proc) ||
827		(curproc == syncerproc)))) {
828		if (flags & UVM_PLA_WAITOK) {
829			uvm_wait("uvm_pglistalloc");
830			goto again;
831		}
832		return (ENOMEM);
833	}
834
835	if ((high & PAGE_MASK) != PAGE_MASK) {
836		printf("uvm_pglistalloc: Upper boundary 0x%lx "
837		    "not on pagemask.\n", (unsigned long)high);
838	}
839
840	/*
841	 * Our allocations are always page granularity, so our alignment
842	 * must be, too.
843	 */
844	if (alignment < PAGE_SIZE)
845		alignment = PAGE_SIZE;
846
847	low = atop(roundup(low, alignment));
848	/*
849	 * high + 1 may result in overflow, in which case high becomes 0x0,
850	 * which is the 'don't care' value.
851	 * The only requirement in that case is that low is also 0x0, or the
852	 * low<high assert will fail.
853	 */
854	high = atop(high + 1);
855	alignment = atop(alignment);
856	if (boundary < PAGE_SIZE && boundary != 0)
857		boundary = PAGE_SIZE;
858	boundary = atop(boundary);
859
860	return uvm_pmr_getpages(size, low, high, alignment, boundary, nsegs,
861	    flags, rlist);
862}
863
864/*
865 * uvm_pglistfree: free a list of pages
866 *
867 * => pages should already be unmapped
868 */
869void
870uvm_pglistfree(struct pglist *list)
871{
872	uvm_pmr_freepageq(list);
873}
874
875/*
876 * interface used by the buffer cache to allocate a buffer at a time.
877 * The pages are allocated wired in DMA accessible memory
878 */
879int
880uvm_pagealloc_multi(struct uvm_object *obj, voff_t off, vsize_t size,
881    int flags)
882{
883	struct pglist    plist;
884	struct vm_page  *pg;
885	int              i, r;
886
887
888	TAILQ_INIT(&plist);
889	r = uvm_pglistalloc(size, dma_constraint.ucr_low,
890	    dma_constraint.ucr_high, 0, 0, &plist, atop(round_page(size)),
891	    flags);
892	if (r != 0)
893		return(r);
894	i = 0;
895	while ((pg = TAILQ_FIRST(&plist)) != NULL) {
896		pg->wire_count = 1;
897		atomic_setbits_int(&pg->pg_flags, PG_CLEAN | PG_FAKE);
898		KASSERT((pg->pg_flags & PG_DEV) == 0);
899		TAILQ_REMOVE(&plist, pg, pageq);
900		uvm_pagealloc_pg(pg, obj, off + ptoa(i++), NULL);
901	}
902	return(0);
903}
904
905/*
906 * interface used by the buffer cache to reallocate a buffer at a time.
907 * The pages are reallocated wired outside the DMA accessible region.
908 *
909 */
910int
911uvm_pagerealloc_multi(struct uvm_object *obj, voff_t off, vsize_t size,
912    int flags, struct uvm_constraint_range *where)
913{
914	struct pglist    plist;
915	struct vm_page  *pg, *tpg;
916	int              i,r;
917	voff_t		offset;
918
919
920	TAILQ_INIT(&plist);
921	if (size == 0)
922		panic("size 0 uvm_pagerealloc");
923	r = uvm_pglistalloc(size, where->ucr_low, where->ucr_high, 0,
924	    0, &plist, atop(round_page(size)), flags);
925	if (r != 0)
926		return(r);
927	i = 0;
928	while((pg = TAILQ_FIRST(&plist)) != NULL) {
929		offset = off + ptoa(i++);
930		tpg = uvm_pagelookup(obj, offset);
931		pg->wire_count = 1;
932		atomic_setbits_int(&pg->pg_flags, PG_CLEAN | PG_FAKE);
933		KASSERT((pg->pg_flags & PG_DEV) == 0);
934		TAILQ_REMOVE(&plist, pg, pageq);
935		uvm_pagecopy(tpg, pg);
936		uvm_pagefree(tpg);
937		uvm_pagealloc_pg(pg, obj, offset, NULL);
938	}
939	return(0);
940}
941
942/*
943 * uvm_pagealloc_strat: allocate vm_page from a particular free list.
944 *
945 * => return null if no pages free
946 * => wake up pagedaemon if number of free pages drops below low water mark
947 * => only one of obj or anon can be non-null
948 * => caller must activate/deactivate page if it is not wired.
949 */
950
951struct vm_page *
952uvm_pagealloc(struct uvm_object *obj, voff_t off, struct vm_anon *anon,
953    int flags)
954{
955	struct vm_page *pg;
956	struct pglist pgl;
957	int pmr_flags;
958	boolean_t use_reserve;
959
960	KASSERT(obj == NULL || anon == NULL);
961	KASSERT(off == trunc_page(off));
962
963	/*
964	 * check to see if we need to generate some free pages waking
965	 * the pagedaemon.
966	 */
967	if ((uvmexp.free - BUFPAGES_DEFICIT) < uvmexp.freemin ||
968	    ((uvmexp.free - BUFPAGES_DEFICIT) < uvmexp.freetarg &&
969	    (uvmexp.inactive + BUFPAGES_INACT) < uvmexp.inactarg))
970		wakeup(&uvm.pagedaemon);
971
972	/*
973	 * fail if any of these conditions is true:
974	 * [1]  there really are no free pages, or
975	 * [2]  only kernel "reserved" pages remain and
976	 *        the page isn't being allocated to a kernel object.
977	 * [3]  only pagedaemon "reserved" pages remain and
978	 *        the requestor isn't the pagedaemon.
979	 */
980
981	use_reserve = (flags & UVM_PGA_USERESERVE) ||
982		(obj && UVM_OBJ_IS_KERN_OBJECT(obj));
983	if ((uvmexp.free <= uvmexp.reserve_kernel && !use_reserve) ||
984	    (uvmexp.free <= uvmexp.reserve_pagedaemon &&
985	     !((curproc == uvm.pagedaemon_proc) ||
986	      (curproc == syncerproc))))
987		goto fail;
988
989	pmr_flags = UVM_PLA_NOWAIT;
990	if (flags & UVM_PGA_ZERO)
991		pmr_flags |= UVM_PLA_ZERO;
992	TAILQ_INIT(&pgl);
993	if (uvm_pmr_getpages(1, 0, 0, 1, 0, 1, pmr_flags, &pgl) != 0)
994		goto fail;
995
996	pg = TAILQ_FIRST(&pgl);
997	KASSERT(pg != NULL && TAILQ_NEXT(pg, pageq) == NULL);
998
999	uvm_pagealloc_pg(pg, obj, off, anon);
1000	KASSERT((pg->pg_flags & PG_DEV) == 0);
1001	if (flags & UVM_PGA_ZERO)
1002		atomic_clearbits_int(&pg->pg_flags, PG_CLEAN);
1003	else
1004		atomic_setbits_int(&pg->pg_flags, PG_CLEAN);
1005
1006	return(pg);
1007
1008 fail:
1009	return (NULL);
1010}
1011
1012/*
1013 * uvm_pagerealloc: reallocate a page from one object to another
1014 */
1015
1016void
1017uvm_pagerealloc(struct vm_page *pg, struct uvm_object *newobj, voff_t newoff)
1018{
1019
1020	/*
1021	 * remove it from the old object
1022	 */
1023
1024	if (pg->uobject) {
1025		uvm_pageremove(pg);
1026	}
1027
1028	/*
1029	 * put it in the new object
1030	 */
1031
1032	if (newobj) {
1033		pg->uobject = newobj;
1034		pg->offset = newoff;
1035		pg->pg_version++;
1036		uvm_pageinsert(pg);
1037	}
1038}
1039
1040
1041/*
1042 * uvm_pagefree: free page
1043 *
1044 * => erase page's identity (i.e. remove from object)
1045 * => put page on free list
1046 * => caller must lock page queues
1047 * => assumes all valid mappings of pg are gone
1048 */
1049
1050void
1051uvm_pagefree(struct vm_page *pg)
1052{
1053	int saved_loan_count = pg->loan_count;
1054	u_int flags_to_clear = 0;
1055
1056#ifdef DEBUG
1057	if (pg->uobject == (void *)0xdeadbeef &&
1058	    pg->uanon == (void *)0xdeadbeef) {
1059		panic("uvm_pagefree: freeing free page %p", pg);
1060	}
1061#endif
1062
1063	KASSERT((pg->pg_flags & PG_DEV) == 0);
1064
1065	/*
1066	 * if the page was an object page (and thus "TABLED"), remove it
1067	 * from the object.
1068	 */
1069
1070	if (pg->pg_flags & PG_TABLED) {
1071
1072		/*
1073		 * if the object page is on loan we are going to drop ownership.
1074		 * it is possible that an anon will take over as owner for this
1075		 * page later on.   the anon will want a !PG_CLEAN page so that
1076		 * it knows it needs to allocate swap if it wants to page the
1077		 * page out.
1078		 */
1079
1080		/* in case an anon takes over */
1081		if (saved_loan_count)
1082			atomic_clearbits_int(&pg->pg_flags, PG_CLEAN);
1083		uvm_pageremove(pg);
1084
1085		/*
1086		 * if our page was on loan, then we just lost control over it
1087		 * (in fact, if it was loaned to an anon, the anon may have
1088		 * already taken over ownership of the page by now and thus
1089		 * changed the loan_count [e.g. in uvmfault_anonget()]) we just
1090		 * return (when the last loan is dropped, then the page can be
1091		 * freed by whatever was holding the last loan).
1092		 */
1093
1094		if (saved_loan_count)
1095			return;
1096	} else if (saved_loan_count && pg->uanon) {
1097		/*
1098		 * if our page is owned by an anon and is loaned out to the
1099		 * kernel then we just want to drop ownership and return.
1100		 * the kernel must free the page when all its loans clear ...
1101		 * note that the kernel can't change the loan status of our
1102		 * page as long as we are holding PQ lock.
1103		 */
1104		atomic_clearbits_int(&pg->pg_flags, PQ_ANON);
1105		pg->uanon->an_page = NULL;
1106		pg->uanon = NULL;
1107		return;
1108	}
1109	KASSERT(saved_loan_count == 0);
1110
1111	/*
1112	 * now remove the page from the queues
1113	 */
1114
1115	if (pg->pg_flags & PQ_ACTIVE) {
1116		TAILQ_REMOVE(&uvm.page_active, pg, pageq);
1117		flags_to_clear |= PQ_ACTIVE;
1118		uvmexp.active--;
1119	}
1120	if (pg->pg_flags & PQ_INACTIVE) {
1121		if (pg->pg_flags & PQ_SWAPBACKED)
1122			TAILQ_REMOVE(&uvm.page_inactive_swp, pg, pageq);
1123		else
1124			TAILQ_REMOVE(&uvm.page_inactive_obj, pg, pageq);
1125		flags_to_clear |= PQ_INACTIVE;
1126		uvmexp.inactive--;
1127	}
1128
1129	/*
1130	 * if the page was wired, unwire it now.
1131	 */
1132
1133	if (pg->wire_count) {
1134		pg->wire_count = 0;
1135		uvmexp.wired--;
1136	}
1137	if (pg->uanon) {
1138		pg->uanon->an_page = NULL;
1139		pg->uanon = NULL;
1140		flags_to_clear |= PQ_ANON;
1141	}
1142
1143	/*
1144	 * Clean page state bits.
1145	 */
1146	flags_to_clear |= PQ_AOBJ; /* XXX: find culprit */
1147	flags_to_clear |= PQ_ENCRYPT|PG_ZERO|PG_FAKE|PG_BUSY|PG_RELEASED|
1148	    PG_CLEAN|PG_CLEANCHK;
1149	atomic_clearbits_int(&pg->pg_flags, flags_to_clear);
1150
1151	/*
1152	 * and put on free queue
1153	 */
1154
1155#ifdef DEBUG
1156	pg->uobject = (void *)0xdeadbeef;
1157	pg->offset = 0xdeadbeef;
1158	pg->uanon = (void *)0xdeadbeef;
1159#endif
1160
1161	uvm_pmr_freepages(pg, 1);
1162
1163	if (uvmexp.zeropages < UVM_PAGEZERO_TARGET)
1164		uvm.page_idle_zero = vm_page_zero_enable;
1165}
1166
1167/*
1168 * uvm_page_unbusy: unbusy an array of pages.
1169 *
1170 * => pages must either all belong to the same object, or all belong to anons.
1171 * => if pages are anon-owned, anons must have 0 refcount.
1172 */
1173
1174void
1175uvm_page_unbusy(struct vm_page **pgs, int npgs)
1176{
1177	struct vm_page *pg;
1178	struct uvm_object *uobj;
1179	int i;
1180
1181	for (i = 0; i < npgs; i++) {
1182		pg = pgs[i];
1183
1184		if (pg == NULL || pg == PGO_DONTCARE) {
1185			continue;
1186		}
1187		if (pg->pg_flags & PG_WANTED) {
1188			wakeup(pg);
1189		}
1190		if (pg->pg_flags & PG_RELEASED) {
1191			uobj = pg->uobject;
1192			if (uobj != NULL) {
1193				uvm_lock_pageq();
1194				pmap_page_protect(pg, VM_PROT_NONE);
1195				/* XXX won't happen right now */
1196				if (pg->pg_flags & PQ_AOBJ)
1197					uao_dropswap(uobj,
1198					    pg->offset >> PAGE_SHIFT);
1199				uvm_pagefree(pg);
1200				uvm_unlock_pageq();
1201			} else {
1202				atomic_clearbits_int(&pg->pg_flags, PG_BUSY);
1203				UVM_PAGE_OWN(pg, NULL);
1204				uvm_anfree(pg->uanon);
1205			}
1206		} else {
1207			atomic_clearbits_int(&pg->pg_flags, PG_WANTED|PG_BUSY);
1208			UVM_PAGE_OWN(pg, NULL);
1209		}
1210	}
1211}
1212
1213#if defined(UVM_PAGE_TRKOWN)
1214/*
1215 * uvm_page_own: set or release page ownership
1216 *
1217 * => this is a debugging function that keeps track of who sets PG_BUSY
1218 *	and where they do it.   it can be used to track down problems
1219 *	such a process setting "PG_BUSY" and never releasing it.
1220 * => if "tag" is NULL then we are releasing page ownership
1221 */
1222void
1223uvm_page_own(struct vm_page *pg, char *tag)
1224{
1225	/* gain ownership? */
1226	if (tag) {
1227		if (pg->owner_tag) {
1228			printf("uvm_page_own: page %p already owned "
1229			    "by proc %d [%s]\n", pg,
1230			     pg->owner, pg->owner_tag);
1231			panic("uvm_page_own");
1232		}
1233		pg->owner = (curproc) ? curproc->p_pid :  (pid_t) -1;
1234		pg->owner_tag = tag;
1235		return;
1236	}
1237
1238	/* drop ownership */
1239	if (pg->owner_tag == NULL) {
1240		printf("uvm_page_own: dropping ownership of an non-owned "
1241		    "page (%p)\n", pg);
1242		panic("uvm_page_own");
1243	}
1244	pg->owner_tag = NULL;
1245	return;
1246}
1247#endif
1248
1249/*
1250 * uvm_pageidlezero: zero free pages while the system is idle.
1251 *
1252 * => we do at least one iteration per call, if we are below the target.
1253 * => we loop until we either reach the target or whichqs indicates that
1254 *	there is a process ready to run.
1255 */
1256void
1257uvm_pageidlezero(void)
1258{
1259#if 0 /* disabled: need new code */
1260	struct vm_page *pg;
1261	struct pgfreelist *pgfl;
1262	int free_list;
1263
1264	do {
1265		uvm_lock_fpageq();
1266
1267		if (uvmexp.zeropages >= UVM_PAGEZERO_TARGET) {
1268			uvm.page_idle_zero = FALSE;
1269			uvm_unlock_fpageq();
1270			return;
1271		}
1272
1273		for (free_list = 0; free_list < VM_NFREELIST; free_list++) {
1274			pgfl = &uvm.page_free[free_list];
1275			if ((pg = TAILQ_FIRST(&pgfl->pgfl_queues[
1276			    PGFL_UNKNOWN])) != NULL)
1277				break;
1278		}
1279
1280		if (pg == NULL) {
1281			/*
1282			 * No non-zero'd pages; don't bother trying again
1283			 * until we know we have non-zero'd pages free.
1284			 */
1285			uvm.page_idle_zero = FALSE;
1286			uvm_unlock_fpageq();
1287			return;
1288		}
1289
1290		TAILQ_REMOVE(&pgfl->pgfl_queues[PGFL_UNKNOWN], pg, pageq);
1291		uvmexp.free--;
1292		uvm_unlock_fpageq();
1293
1294#ifdef PMAP_PAGEIDLEZERO
1295		if (PMAP_PAGEIDLEZERO(pg) == FALSE) {
1296			/*
1297			 * The machine-dependent code detected some
1298			 * reason for us to abort zeroing pages,
1299			 * probably because there is a process now
1300			 * ready to run.
1301			 */
1302			uvm_lock_fpageq();
1303			TAILQ_INSERT_HEAD(&pgfl->pgfl_queues[PGFL_UNKNOWN],
1304			    pg, pageq);
1305			uvmexp.free++;
1306			uvmexp.zeroaborts++;
1307			uvm_unlock_fpageq();
1308			return;
1309		}
1310#else
1311		/*
1312		 * XXX This will toast the cache unless the pmap_zero_page()
1313		 * XXX implementation does uncached access.
1314		 */
1315		pmap_zero_page(pg);
1316#endif
1317		atomic_setbits_int(&pg->pg_flags, PG_ZERO);
1318
1319		uvm_lock_fpageq();
1320		TAILQ_INSERT_HEAD(&pgfl->pgfl_queues[PGFL_ZEROS], pg, pageq);
1321		uvmexp.free++;
1322		uvmexp.zeropages++;
1323		uvm_unlock_fpageq();
1324	} while (curcpu_is_idle());
1325#endif /* 0 */
1326}
1327
1328/*
1329 * when VM_PHYSSEG_MAX is 1, we can simplify these functions
1330 */
1331
1332#if VM_PHYSSEG_MAX > 1
1333/*
1334 * vm_physseg_find: find vm_physseg structure that belongs to a PA
1335 */
1336int
1337vm_physseg_find(paddr_t pframe, int *offp)
1338{
1339	struct vm_physseg *seg;
1340
1341#if (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH)
1342	/* binary search for it */
1343	int	start, len, try;
1344
1345	/*
1346	 * if try is too large (thus target is less than than try) we reduce
1347	 * the length to trunc(len/2) [i.e. everything smaller than "try"]
1348	 *
1349	 * if the try is too small (thus target is greater than try) then
1350	 * we set the new start to be (try + 1).   this means we need to
1351	 * reduce the length to (round(len/2) - 1).
1352	 *
1353	 * note "adjust" below which takes advantage of the fact that
1354	 *  (round(len/2) - 1) == trunc((len - 1) / 2)
1355	 * for any value of len we may have
1356	 */
1357
1358	for (start = 0, len = vm_nphysseg ; len != 0 ; len = len / 2) {
1359		try = start + (len / 2);	/* try in the middle */
1360		seg = vm_physmem + try;
1361
1362		/* start past our try? */
1363		if (pframe >= seg->start) {
1364			/* was try correct? */
1365			if (pframe < seg->end) {
1366				if (offp)
1367					*offp = pframe - seg->start;
1368				return(try);            /* got it */
1369			}
1370			start = try + 1;	/* next time, start here */
1371			len--;			/* "adjust" */
1372		} else {
1373			/*
1374			 * pframe before try, just reduce length of
1375			 * region, done in "for" loop
1376			 */
1377		}
1378	}
1379	return(-1);
1380
1381#else
1382	/* linear search for it */
1383	int	lcv;
1384
1385	for (lcv = 0, seg = vm_physmem; lcv < vm_nphysseg ; lcv++, seg++) {
1386		if (pframe >= seg->start && pframe < seg->end) {
1387			if (offp)
1388				*offp = pframe - seg->start;
1389			return(lcv);		   /* got it */
1390		}
1391	}
1392	return(-1);
1393
1394#endif
1395}
1396
1397/*
1398 * PHYS_TO_VM_PAGE: find vm_page for a PA.   used by MI code to get vm_pages
1399 * back from an I/O mapping (ugh!).   used in some MD code as well.
1400 */
1401struct vm_page *
1402PHYS_TO_VM_PAGE(paddr_t pa)
1403{
1404	paddr_t pf = atop(pa);
1405	int	off;
1406	int	psi;
1407
1408	psi = vm_physseg_find(pf, &off);
1409
1410	return ((psi == -1) ? NULL : &vm_physmem[psi].pgs[off]);
1411}
1412#endif /* VM_PHYSSEG_MAX > 1 */
1413
1414/*
1415 * uvm_pagelookup: look up a page
1416 */
1417struct vm_page *
1418uvm_pagelookup(struct uvm_object *obj, voff_t off)
1419{
1420	/* XXX if stack is too much, handroll */
1421	struct vm_page pg;
1422
1423	pg.offset = off;
1424	return (RB_FIND(uvm_objtree, &obj->memt, &pg));
1425}
1426
1427/*
1428 * uvm_pagewire: wire the page, thus removing it from the daemon's grasp
1429 *
1430 * => caller must lock page queues
1431 */
1432void
1433uvm_pagewire(struct vm_page *pg)
1434{
1435	if (pg->wire_count == 0) {
1436		if (pg->pg_flags & PQ_ACTIVE) {
1437			TAILQ_REMOVE(&uvm.page_active, pg, pageq);
1438			atomic_clearbits_int(&pg->pg_flags, PQ_ACTIVE);
1439			uvmexp.active--;
1440		}
1441		if (pg->pg_flags & PQ_INACTIVE) {
1442			if (pg->pg_flags & PQ_SWAPBACKED)
1443				TAILQ_REMOVE(&uvm.page_inactive_swp, pg, pageq);
1444			else
1445				TAILQ_REMOVE(&uvm.page_inactive_obj, pg, pageq);
1446			atomic_clearbits_int(&pg->pg_flags, PQ_INACTIVE);
1447			uvmexp.inactive--;
1448		}
1449		uvmexp.wired++;
1450	}
1451	pg->wire_count++;
1452}
1453
1454/*
1455 * uvm_pageunwire: unwire the page.
1456 *
1457 * => activate if wire count goes to zero.
1458 * => caller must lock page queues
1459 */
1460void
1461uvm_pageunwire(struct vm_page *pg)
1462{
1463	pg->wire_count--;
1464	if (pg->wire_count == 0) {
1465		TAILQ_INSERT_TAIL(&uvm.page_active, pg, pageq);
1466		uvmexp.active++;
1467		atomic_setbits_int(&pg->pg_flags, PQ_ACTIVE);
1468		uvmexp.wired--;
1469	}
1470}
1471
1472/*
1473 * uvm_pagedeactivate: deactivate page -- no pmaps have access to page
1474 *
1475 * => caller must lock page queues
1476 * => caller must check to make sure page is not wired
1477 * => object that page belongs to must be locked (so we can adjust pg->flags)
1478 */
1479void
1480uvm_pagedeactivate(struct vm_page *pg)
1481{
1482	if (pg->pg_flags & PQ_ACTIVE) {
1483		TAILQ_REMOVE(&uvm.page_active, pg, pageq);
1484		atomic_clearbits_int(&pg->pg_flags, PQ_ACTIVE);
1485		uvmexp.active--;
1486	}
1487	if ((pg->pg_flags & PQ_INACTIVE) == 0) {
1488		KASSERT(pg->wire_count == 0);
1489		if (pg->pg_flags & PQ_SWAPBACKED)
1490			TAILQ_INSERT_TAIL(&uvm.page_inactive_swp, pg, pageq);
1491		else
1492			TAILQ_INSERT_TAIL(&uvm.page_inactive_obj, pg, pageq);
1493		atomic_setbits_int(&pg->pg_flags, PQ_INACTIVE);
1494		uvmexp.inactive++;
1495		pmap_clear_reference(pg);
1496		/*
1497		 * update the "clean" bit.  this isn't 100%
1498		 * accurate, and doesn't have to be.  we'll
1499		 * re-sync it after we zap all mappings when
1500		 * scanning the inactive list.
1501		 */
1502		if ((pg->pg_flags & PG_CLEAN) != 0 &&
1503		    pmap_is_modified(pg))
1504			atomic_clearbits_int(&pg->pg_flags, PG_CLEAN);
1505	}
1506}
1507
1508/*
1509 * uvm_pageactivate: activate page
1510 *
1511 * => caller must lock page queues
1512 */
1513void
1514uvm_pageactivate(struct vm_page *pg)
1515{
1516	if (pg->pg_flags & PQ_INACTIVE) {
1517		if (pg->pg_flags & PQ_SWAPBACKED)
1518			TAILQ_REMOVE(&uvm.page_inactive_swp, pg, pageq);
1519		else
1520			TAILQ_REMOVE(&uvm.page_inactive_obj, pg, pageq);
1521		atomic_clearbits_int(&pg->pg_flags, PQ_INACTIVE);
1522		uvmexp.inactive--;
1523	}
1524	if (pg->wire_count == 0) {
1525
1526		/*
1527		 * if page is already active, remove it from list so we
1528		 * can put it at tail.  if it wasn't active, then mark
1529		 * it active and bump active count
1530		 */
1531		if (pg->pg_flags & PQ_ACTIVE)
1532			TAILQ_REMOVE(&uvm.page_active, pg, pageq);
1533		else {
1534			atomic_setbits_int(&pg->pg_flags, PQ_ACTIVE);
1535			uvmexp.active++;
1536		}
1537
1538		TAILQ_INSERT_TAIL(&uvm.page_active, pg, pageq);
1539	}
1540}
1541
1542/*
1543 * uvm_pagezero: zero fill a page
1544 */
1545void
1546uvm_pagezero(struct vm_page *pg)
1547{
1548	atomic_clearbits_int(&pg->pg_flags, PG_CLEAN);
1549	pmap_zero_page(pg);
1550}
1551
1552/*
1553 * uvm_pagecopy: copy a page
1554 */
1555void
1556uvm_pagecopy(struct vm_page *src, struct vm_page *dst)
1557{
1558	atomic_clearbits_int(&dst->pg_flags, PG_CLEAN);
1559	pmap_copy_page(src, dst);
1560}
1561
1562/*
1563 * uvm_pagecount: count the number of physical pages in the address range.
1564 */
1565psize_t
1566uvm_pagecount(struct uvm_constraint_range* constraint)
1567{
1568	int lcv;
1569	psize_t sz;
1570	paddr_t low, high;
1571	paddr_t ps_low, ps_high;
1572
1573	/* Algorithm uses page numbers. */
1574	low = atop(constraint->ucr_low);
1575	high = atop(constraint->ucr_high);
1576
1577	sz = 0;
1578	for (lcv = 0; lcv < vm_nphysseg; lcv++) {
1579		ps_low = MAX(low, vm_physmem[lcv].avail_start);
1580		ps_high = MIN(high, vm_physmem[lcv].avail_end);
1581		if (ps_low < ps_high)
1582			sz += ps_high - ps_low;
1583	}
1584	return sz;
1585}
1586