xref: /netbsd-src/sys/uvm/uvm_page.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: uvm_page.c,v 1.155 2010/04/25 15:54:14 ad Exp $	*/
2 
3 /*
4  * Copyright (c) 2010 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*
30  * Copyright (c) 1997 Charles D. Cranor and Washington University.
31  * Copyright (c) 1991, 1993, The Regents of the University of California.
32  *
33  * All rights reserved.
34  *
35  * This code is derived from software contributed to Berkeley by
36  * The Mach Operating System project at Carnegie-Mellon University.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  * 3. All advertising materials mentioning features or use of this software
47  *    must display the following acknowledgement:
48  *	This product includes software developed by Charles D. Cranor,
49  *      Washington University, the University of California, Berkeley and
50  *      its contributors.
51  * 4. Neither the name of the University nor the names of its contributors
52  *    may be used to endorse or promote products derived from this software
53  *    without specific prior written permission.
54  *
55  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
56  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
57  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
58  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
59  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
60  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
61  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
62  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
63  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
64  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
65  * SUCH DAMAGE.
66  *
67  *	@(#)vm_page.c   8.3 (Berkeley) 3/21/94
68  * from: Id: uvm_page.c,v 1.1.2.18 1998/02/06 05:24:42 chs Exp
69  *
70  *
71  * Copyright (c) 1987, 1990 Carnegie-Mellon University.
72  * All rights reserved.
73  *
74  * Permission to use, copy, modify and distribute this software and
75  * its documentation is hereby granted, provided that both the copyright
76  * notice and this permission notice appear in all copies of the
77  * software, derivative works or modified versions, and any portions
78  * thereof, and that both notices appear in supporting documentation.
79  *
80  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
81  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
82  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
83  *
84  * Carnegie Mellon requests users of this software to return to
85  *
86  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
87  *  School of Computer Science
88  *  Carnegie Mellon University
89  *  Pittsburgh PA 15213-3890
90  *
91  * any improvements or extensions that they make and grant Carnegie the
92  * rights to redistribute these changes.
93  */
94 
95 /*
96  * uvm_page.c: page ops.
97  */
98 
99 #include <sys/cdefs.h>
100 __KERNEL_RCSID(0, "$NetBSD: uvm_page.c,v 1.155 2010/04/25 15:54:14 ad Exp $");
101 
102 #include "opt_ddb.h"
103 #include "opt_uvmhist.h"
104 #include "opt_readahead.h"
105 
106 #include <sys/param.h>
107 #include <sys/systm.h>
108 #include <sys/malloc.h>
109 #include <sys/sched.h>
110 #include <sys/kernel.h>
111 #include <sys/vnode.h>
112 #include <sys/proc.h>
113 #include <sys/atomic.h>
114 #include <sys/cpu.h>
115 
116 #include <uvm/uvm.h>
117 #include <uvm/uvm_ddb.h>
118 #include <uvm/uvm_pdpolicy.h>
119 
120 /*
121  * global vars... XXXCDC: move to uvm. structure.
122  */
123 
124 /*
125  * physical memory config is stored in vm_physmem.
126  */
127 
128 struct vm_physseg vm_physmem[VM_PHYSSEG_MAX];	/* XXXCDC: uvm.physmem */
129 int vm_nphysseg = 0;				/* XXXCDC: uvm.nphysseg */
130 
131 /*
132  * Some supported CPUs in a given architecture don't support all
133  * of the things necessary to do idle page zero'ing efficiently.
134  * We therefore provide a way to enable it from machdep code here.
135  */
136 bool vm_page_zero_enable = false;
137 
138 /*
139  * number of pages per-CPU to reserve for the kernel.
140  */
141 int vm_page_reserve_kernel = 5;
142 
143 /*
144  * physical memory size;
145  */
146 int physmem;
147 
148 /*
149  * local variables
150  */
151 
152 /*
153  * these variables record the values returned by vm_page_bootstrap,
154  * for debugging purposes.  The implementation of uvm_pageboot_alloc
155  * and pmap_startup here also uses them internally.
156  */
157 
158 static vaddr_t      virtual_space_start;
159 static vaddr_t      virtual_space_end;
160 
161 /*
162  * we allocate an initial number of page colors in uvm_page_init(),
163  * and remember them.  We may re-color pages as cache sizes are
164  * discovered during the autoconfiguration phase.  But we can never
165  * free the initial set of buckets, since they are allocated using
166  * uvm_pageboot_alloc().
167  */
168 
169 static bool have_recolored_pages /* = false */;
170 
171 MALLOC_DEFINE(M_VMPAGE, "VM page", "VM page");
172 
173 #ifdef DEBUG
174 vaddr_t uvm_zerocheckkva;
175 #endif /* DEBUG */
176 
177 /*
178  * local prototypes
179  */
180 
181 static void uvm_pageinsert(struct uvm_object *, struct vm_page *);
182 static void uvm_pageremove(struct uvm_object *, struct vm_page *);
183 
184 /*
185  * per-object tree of pages
186  */
187 
188 static signed int
189 uvm_page_compare_nodes(const struct rb_node *n1, const struct rb_node *n2)
190 {
191 	const struct vm_page *pg1 = (const void *)n1;
192 	const struct vm_page *pg2 = (const void *)n2;
193 	const voff_t a = pg1->offset;
194 	const voff_t b = pg2->offset;
195 
196 	if (a < b)
197 		return 1;
198 	if (a > b)
199 		return -1;
200 	return 0;
201 }
202 
203 static signed int
204 uvm_page_compare_key(const struct rb_node *n, const void *key)
205 {
206 	const struct vm_page *pg = (const void *)n;
207 	const voff_t a = pg->offset;
208 	const voff_t b = *(const voff_t *)key;
209 
210 	if (a < b)
211 		return 1;
212 	if (a > b)
213 		return -1;
214 	return 0;
215 }
216 
217 const struct rb_tree_ops uvm_page_tree_ops = {
218 	.rbto_compare_nodes = uvm_page_compare_nodes,
219 	.rbto_compare_key = uvm_page_compare_key,
220 };
221 
222 /*
223  * inline functions
224  */
225 
226 /*
227  * uvm_pageinsert: insert a page in the object.
228  *
229  * => caller must lock object
230  * => caller must lock page queues
231  * => call should have already set pg's object and offset pointers
232  *    and bumped the version counter
233  */
234 
235 static inline void
236 uvm_pageinsert_list(struct uvm_object *uobj, struct vm_page *pg,
237     struct vm_page *where)
238 {
239 
240 	KASSERT(uobj == pg->uobject);
241 	KASSERT(mutex_owned(&uobj->vmobjlock));
242 	KASSERT((pg->flags & PG_TABLED) == 0);
243 	KASSERT(where == NULL || (where->flags & PG_TABLED));
244 	KASSERT(where == NULL || (where->uobject == uobj));
245 
246 	if (UVM_OBJ_IS_VNODE(uobj)) {
247 		if (uobj->uo_npages == 0) {
248 			struct vnode *vp = (struct vnode *)uobj;
249 
250 			vholdl(vp);
251 		}
252 		if (UVM_OBJ_IS_VTEXT(uobj)) {
253 			atomic_inc_uint(&uvmexp.execpages);
254 		} else {
255 			atomic_inc_uint(&uvmexp.filepages);
256 		}
257 	} else if (UVM_OBJ_IS_AOBJ(uobj)) {
258 		atomic_inc_uint(&uvmexp.anonpages);
259 	}
260 
261 	if (where)
262 		TAILQ_INSERT_AFTER(&uobj->memq, where, pg, listq.queue);
263 	else
264 		TAILQ_INSERT_TAIL(&uobj->memq, pg, listq.queue);
265 	pg->flags |= PG_TABLED;
266 	uobj->uo_npages++;
267 }
268 
269 
270 static inline void
271 uvm_pageinsert_tree(struct uvm_object *uobj, struct vm_page *pg)
272 {
273 	bool success;
274 
275 	KASSERT(uobj == pg->uobject);
276 	success = rb_tree_insert_node(&uobj->rb_tree, &pg->rb_node);
277 	KASSERT(success);
278 }
279 
280 static inline void
281 uvm_pageinsert(struct uvm_object *uobj, struct vm_page *pg)
282 {
283 
284 	KDASSERT(uobj != NULL);
285 	uvm_pageinsert_tree(uobj, pg);
286 	uvm_pageinsert_list(uobj, pg, NULL);
287 }
288 
289 /*
290  * uvm_page_remove: remove page from object.
291  *
292  * => caller must lock object
293  * => caller must lock page queues
294  */
295 
296 static inline void
297 uvm_pageremove_list(struct uvm_object *uobj, struct vm_page *pg)
298 {
299 
300 	KASSERT(uobj == pg->uobject);
301 	KASSERT(mutex_owned(&uobj->vmobjlock));
302 	KASSERT(pg->flags & PG_TABLED);
303 
304 	if (UVM_OBJ_IS_VNODE(uobj)) {
305 		if (uobj->uo_npages == 1) {
306 			struct vnode *vp = (struct vnode *)uobj;
307 
308 			holdrelel(vp);
309 		}
310 		if (UVM_OBJ_IS_VTEXT(uobj)) {
311 			atomic_dec_uint(&uvmexp.execpages);
312 		} else {
313 			atomic_dec_uint(&uvmexp.filepages);
314 		}
315 	} else if (UVM_OBJ_IS_AOBJ(uobj)) {
316 		atomic_dec_uint(&uvmexp.anonpages);
317 	}
318 
319 	/* object should be locked */
320 	uobj->uo_npages--;
321 	TAILQ_REMOVE(&uobj->memq, pg, listq.queue);
322 	pg->flags &= ~PG_TABLED;
323 	pg->uobject = NULL;
324 }
325 
326 static inline void
327 uvm_pageremove_tree(struct uvm_object *uobj, struct vm_page *pg)
328 {
329 
330 	KASSERT(uobj == pg->uobject);
331 	rb_tree_remove_node(&uobj->rb_tree, &pg->rb_node);
332 }
333 
334 static inline void
335 uvm_pageremove(struct uvm_object *uobj, struct vm_page *pg)
336 {
337 
338 	KDASSERT(uobj != NULL);
339 	uvm_pageremove_tree(uobj, pg);
340 	uvm_pageremove_list(uobj, pg);
341 }
342 
343 static void
344 uvm_page_init_buckets(struct pgfreelist *pgfl)
345 {
346 	int color, i;
347 
348 	for (color = 0; color < uvmexp.ncolors; color++) {
349 		for (i = 0; i < PGFL_NQUEUES; i++) {
350 			LIST_INIT(&pgfl->pgfl_buckets[color].pgfl_queues[i]);
351 		}
352 	}
353 }
354 
355 /*
356  * uvm_page_init: init the page system.   called from uvm_init().
357  *
358  * => we return the range of kernel virtual memory in kvm_startp/kvm_endp
359  */
360 
361 void
362 uvm_page_init(vaddr_t *kvm_startp, vaddr_t *kvm_endp)
363 {
364 	static struct uvm_cpu boot_cpu;
365 	psize_t freepages, pagecount, bucketcount, n;
366 	struct pgflbucket *bucketarray, *cpuarray;
367 	struct vm_page *pagearray;
368 	int lcv;
369 	u_int i;
370 	paddr_t paddr;
371 
372 	KASSERT(ncpu <= 1);
373 	CTASSERT(sizeof(pagearray->offset) >= sizeof(struct uvm_cpu *));
374 
375 	/*
376 	 * init the page queues and page queue locks, except the free
377 	 * list; we allocate that later (with the initial vm_page
378 	 * structures).
379 	 */
380 
381 	uvm.cpus[0] = &boot_cpu;
382 	curcpu()->ci_data.cpu_uvm = &boot_cpu;
383 	uvm_reclaim_init();
384 	uvmpdpol_init();
385 	mutex_init(&uvm_pageqlock, MUTEX_DRIVER, IPL_NONE);
386 	mutex_init(&uvm_fpageqlock, MUTEX_DRIVER, IPL_VM);
387 
388 	/*
389 	 * allocate vm_page structures.
390 	 */
391 
392 	/*
393 	 * sanity check:
394 	 * before calling this function the MD code is expected to register
395 	 * some free RAM with the uvm_page_physload() function.   our job
396 	 * now is to allocate vm_page structures for this memory.
397 	 */
398 
399 	if (vm_nphysseg == 0)
400 		panic("uvm_page_bootstrap: no memory pre-allocated");
401 
402 	/*
403 	 * first calculate the number of free pages...
404 	 *
405 	 * note that we use start/end rather than avail_start/avail_end.
406 	 * this allows us to allocate extra vm_page structures in case we
407 	 * want to return some memory to the pool after booting.
408 	 */
409 
410 	freepages = 0;
411 	for (lcv = 0 ; lcv < vm_nphysseg ; lcv++)
412 		freepages += (vm_physmem[lcv].end - vm_physmem[lcv].start);
413 
414 	/*
415 	 * Let MD code initialize the number of colors, or default
416 	 * to 1 color if MD code doesn't care.
417 	 */
418 	if (uvmexp.ncolors == 0)
419 		uvmexp.ncolors = 1;
420 	uvmexp.colormask = uvmexp.ncolors - 1;
421 
422 	/*
423 	 * we now know we have (PAGE_SIZE * freepages) bytes of memory we can
424 	 * use.   for each page of memory we use we need a vm_page structure.
425 	 * thus, the total number of pages we can use is the total size of
426 	 * the memory divided by the PAGE_SIZE plus the size of the vm_page
427 	 * structure.   we add one to freepages as a fudge factor to avoid
428 	 * truncation errors (since we can only allocate in terms of whole
429 	 * pages).
430 	 */
431 
432 	bucketcount = uvmexp.ncolors * VM_NFREELIST;
433 	pagecount = ((freepages + 1) << PAGE_SHIFT) /
434 	    (PAGE_SIZE + sizeof(struct vm_page));
435 
436 	bucketarray = (void *)uvm_pageboot_alloc((bucketcount *
437 	    sizeof(struct pgflbucket) * 2) + (pagecount *
438 	    sizeof(struct vm_page)));
439 	cpuarray = bucketarray + bucketcount;
440 	pagearray = (struct vm_page *)(bucketarray + bucketcount * 2);
441 
442 	for (lcv = 0; lcv < VM_NFREELIST; lcv++) {
443 		uvm.page_free[lcv].pgfl_buckets =
444 		    (bucketarray + (lcv * uvmexp.ncolors));
445 		uvm_page_init_buckets(&uvm.page_free[lcv]);
446 		uvm.cpus[0]->page_free[lcv].pgfl_buckets =
447 		    (cpuarray + (lcv * uvmexp.ncolors));
448 		uvm_page_init_buckets(&uvm.cpus[0]->page_free[lcv]);
449 	}
450 	memset(pagearray, 0, pagecount * sizeof(struct vm_page));
451 
452 	/*
453 	 * init the vm_page structures and put them in the correct place.
454 	 */
455 
456 	for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) {
457 		n = vm_physmem[lcv].end - vm_physmem[lcv].start;
458 
459 		/* set up page array pointers */
460 		vm_physmem[lcv].pgs = pagearray;
461 		pagearray += n;
462 		pagecount -= n;
463 		vm_physmem[lcv].lastpg = vm_physmem[lcv].pgs + (n - 1);
464 
465 		/* init and free vm_pages (we've already zeroed them) */
466 		paddr = ctob(vm_physmem[lcv].start);
467 		for (i = 0 ; i < n ; i++, paddr += PAGE_SIZE) {
468 			vm_physmem[lcv].pgs[i].phys_addr = paddr;
469 #ifdef __HAVE_VM_PAGE_MD
470 			VM_MDPAGE_INIT(&vm_physmem[lcv].pgs[i]);
471 #endif
472 			if (atop(paddr) >= vm_physmem[lcv].avail_start &&
473 			    atop(paddr) <= vm_physmem[lcv].avail_end) {
474 				uvmexp.npages++;
475 				/* add page to free pool */
476 				uvm_pagefree(&vm_physmem[lcv].pgs[i]);
477 			}
478 		}
479 	}
480 
481 	/*
482 	 * pass up the values of virtual_space_start and
483 	 * virtual_space_end (obtained by uvm_pageboot_alloc) to the upper
484 	 * layers of the VM.
485 	 */
486 
487 	*kvm_startp = round_page(virtual_space_start);
488 	*kvm_endp = trunc_page(virtual_space_end);
489 #ifdef DEBUG
490 	/*
491 	 * steal kva for uvm_pagezerocheck().
492 	 */
493 	uvm_zerocheckkva = *kvm_startp;
494 	*kvm_startp += PAGE_SIZE;
495 #endif /* DEBUG */
496 
497 	/*
498 	 * init various thresholds.
499 	 */
500 
501 	uvmexp.reserve_pagedaemon = 1;
502 	uvmexp.reserve_kernel = vm_page_reserve_kernel;
503 
504 	/*
505 	 * determine if we should zero pages in the idle loop.
506 	 */
507 
508 	uvm.cpus[0]->page_idle_zero = vm_page_zero_enable;
509 
510 	/*
511 	 * done!
512 	 */
513 
514 	uvm.page_init_done = true;
515 }
516 
517 /*
518  * uvm_setpagesize: set the page size
519  *
520  * => sets page_shift and page_mask from uvmexp.pagesize.
521  */
522 
523 void
524 uvm_setpagesize(void)
525 {
526 
527 	/*
528 	 * If uvmexp.pagesize is 0 at this point, we expect PAGE_SIZE
529 	 * to be a constant (indicated by being a non-zero value).
530 	 */
531 	if (uvmexp.pagesize == 0) {
532 		if (PAGE_SIZE == 0)
533 			panic("uvm_setpagesize: uvmexp.pagesize not set");
534 		uvmexp.pagesize = PAGE_SIZE;
535 	}
536 	uvmexp.pagemask = uvmexp.pagesize - 1;
537 	if ((uvmexp.pagemask & uvmexp.pagesize) != 0)
538 		panic("uvm_setpagesize: page size not a power of two");
539 	for (uvmexp.pageshift = 0; ; uvmexp.pageshift++)
540 		if ((1 << uvmexp.pageshift) == uvmexp.pagesize)
541 			break;
542 }
543 
544 /*
545  * uvm_pageboot_alloc: steal memory from physmem for bootstrapping
546  */
547 
548 vaddr_t
549 uvm_pageboot_alloc(vsize_t size)
550 {
551 	static bool initialized = false;
552 	vaddr_t addr;
553 #if !defined(PMAP_STEAL_MEMORY)
554 	vaddr_t vaddr;
555 	paddr_t paddr;
556 #endif
557 
558 	/*
559 	 * on first call to this function, initialize ourselves.
560 	 */
561 	if (initialized == false) {
562 		pmap_virtual_space(&virtual_space_start, &virtual_space_end);
563 
564 		/* round it the way we like it */
565 		virtual_space_start = round_page(virtual_space_start);
566 		virtual_space_end = trunc_page(virtual_space_end);
567 
568 		initialized = true;
569 	}
570 
571 	/* round to page size */
572 	size = round_page(size);
573 
574 #if defined(PMAP_STEAL_MEMORY)
575 
576 	/*
577 	 * defer bootstrap allocation to MD code (it may want to allocate
578 	 * from a direct-mapped segment).  pmap_steal_memory should adjust
579 	 * virtual_space_start/virtual_space_end if necessary.
580 	 */
581 
582 	addr = pmap_steal_memory(size, &virtual_space_start,
583 	    &virtual_space_end);
584 
585 	return(addr);
586 
587 #else /* !PMAP_STEAL_MEMORY */
588 
589 	/*
590 	 * allocate virtual memory for this request
591 	 */
592 	if (virtual_space_start == virtual_space_end ||
593 	    (virtual_space_end - virtual_space_start) < size)
594 		panic("uvm_pageboot_alloc: out of virtual space");
595 
596 	addr = virtual_space_start;
597 
598 #ifdef PMAP_GROWKERNEL
599 	/*
600 	 * If the kernel pmap can't map the requested space,
601 	 * then allocate more resources for it.
602 	 */
603 	if (uvm_maxkaddr < (addr + size)) {
604 		uvm_maxkaddr = pmap_growkernel(addr + size);
605 		if (uvm_maxkaddr < (addr + size))
606 			panic("uvm_pageboot_alloc: pmap_growkernel() failed");
607 	}
608 #endif
609 
610 	virtual_space_start += size;
611 
612 	/*
613 	 * allocate and mapin physical pages to back new virtual pages
614 	 */
615 
616 	for (vaddr = round_page(addr) ; vaddr < addr + size ;
617 	    vaddr += PAGE_SIZE) {
618 
619 		if (!uvm_page_physget(&paddr))
620 			panic("uvm_pageboot_alloc: out of memory");
621 
622 		/*
623 		 * Note this memory is no longer managed, so using
624 		 * pmap_kenter is safe.
625 		 */
626 		pmap_kenter_pa(vaddr, paddr, VM_PROT_READ|VM_PROT_WRITE, 0);
627 	}
628 	pmap_update(pmap_kernel());
629 	return(addr);
630 #endif	/* PMAP_STEAL_MEMORY */
631 }
632 
633 #if !defined(PMAP_STEAL_MEMORY)
634 /*
635  * uvm_page_physget: "steal" one page from the vm_physmem structure.
636  *
637  * => attempt to allocate it off the end of a segment in which the "avail"
638  *    values match the start/end values.   if we can't do that, then we
639  *    will advance both values (making them equal, and removing some
640  *    vm_page structures from the non-avail area).
641  * => return false if out of memory.
642  */
643 
644 /* subroutine: try to allocate from memory chunks on the specified freelist */
645 static bool uvm_page_physget_freelist(paddr_t *, int);
646 
647 static bool
648 uvm_page_physget_freelist(paddr_t *paddrp, int freelist)
649 {
650 	int lcv, x;
651 
652 	/* pass 1: try allocating from a matching end */
653 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST)
654 	for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--)
655 #else
656 	for (lcv = 0 ; lcv < vm_nphysseg ; lcv++)
657 #endif
658 	{
659 
660 		if (uvm.page_init_done == true)
661 			panic("uvm_page_physget: called _after_ bootstrap");
662 
663 		if (vm_physmem[lcv].free_list != freelist)
664 			continue;
665 
666 		/* try from front */
667 		if (vm_physmem[lcv].avail_start == vm_physmem[lcv].start &&
668 		    vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) {
669 			*paddrp = ctob(vm_physmem[lcv].avail_start);
670 			vm_physmem[lcv].avail_start++;
671 			vm_physmem[lcv].start++;
672 			/* nothing left?   nuke it */
673 			if (vm_physmem[lcv].avail_start ==
674 			    vm_physmem[lcv].end) {
675 				if (vm_nphysseg == 1)
676 				    panic("uvm_page_physget: out of memory!");
677 				vm_nphysseg--;
678 				for (x = lcv ; x < vm_nphysseg ; x++)
679 					/* structure copy */
680 					vm_physmem[x] = vm_physmem[x+1];
681 			}
682 			return (true);
683 		}
684 
685 		/* try from rear */
686 		if (vm_physmem[lcv].avail_end == vm_physmem[lcv].end &&
687 		    vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) {
688 			*paddrp = ctob(vm_physmem[lcv].avail_end - 1);
689 			vm_physmem[lcv].avail_end--;
690 			vm_physmem[lcv].end--;
691 			/* nothing left?   nuke it */
692 			if (vm_physmem[lcv].avail_end ==
693 			    vm_physmem[lcv].start) {
694 				if (vm_nphysseg == 1)
695 				    panic("uvm_page_physget: out of memory!");
696 				vm_nphysseg--;
697 				for (x = lcv ; x < vm_nphysseg ; x++)
698 					/* structure copy */
699 					vm_physmem[x] = vm_physmem[x+1];
700 			}
701 			return (true);
702 		}
703 	}
704 
705 	/* pass2: forget about matching ends, just allocate something */
706 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST)
707 	for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--)
708 #else
709 	for (lcv = 0 ; lcv < vm_nphysseg ; lcv++)
710 #endif
711 	{
712 
713 		/* any room in this bank? */
714 		if (vm_physmem[lcv].avail_start >= vm_physmem[lcv].avail_end)
715 			continue;  /* nope */
716 
717 		*paddrp = ctob(vm_physmem[lcv].avail_start);
718 		vm_physmem[lcv].avail_start++;
719 		/* truncate! */
720 		vm_physmem[lcv].start = vm_physmem[lcv].avail_start;
721 
722 		/* nothing left?   nuke it */
723 		if (vm_physmem[lcv].avail_start == vm_physmem[lcv].end) {
724 			if (vm_nphysseg == 1)
725 				panic("uvm_page_physget: out of memory!");
726 			vm_nphysseg--;
727 			for (x = lcv ; x < vm_nphysseg ; x++)
728 				/* structure copy */
729 				vm_physmem[x] = vm_physmem[x+1];
730 		}
731 		return (true);
732 	}
733 
734 	return (false);        /* whoops! */
735 }
736 
737 bool
738 uvm_page_physget(paddr_t *paddrp)
739 {
740 	int i;
741 
742 	/* try in the order of freelist preference */
743 	for (i = 0; i < VM_NFREELIST; i++)
744 		if (uvm_page_physget_freelist(paddrp, i) == true)
745 			return (true);
746 	return (false);
747 }
748 #endif /* PMAP_STEAL_MEMORY */
749 
750 /*
751  * uvm_page_physload: load physical memory into VM system
752  *
753  * => all args are PFs
754  * => all pages in start/end get vm_page structures
755  * => areas marked by avail_start/avail_end get added to the free page pool
756  * => we are limited to VM_PHYSSEG_MAX physical memory segments
757  */
758 
759 void
760 uvm_page_physload(paddr_t start, paddr_t end, paddr_t avail_start,
761     paddr_t avail_end, int free_list)
762 {
763 	int preload, lcv;
764 	psize_t npages;
765 	struct vm_page *pgs;
766 	struct vm_physseg *ps;
767 
768 	if (uvmexp.pagesize == 0)
769 		panic("uvm_page_physload: page size not set!");
770 	if (free_list >= VM_NFREELIST || free_list < VM_FREELIST_DEFAULT)
771 		panic("uvm_page_physload: bad free list %d", free_list);
772 	if (start >= end)
773 		panic("uvm_page_physload: start >= end");
774 
775 	/*
776 	 * do we have room?
777 	 */
778 
779 	if (vm_nphysseg == VM_PHYSSEG_MAX) {
780 		printf("uvm_page_physload: unable to load physical memory "
781 		    "segment\n");
782 		printf("\t%d segments allocated, ignoring 0x%llx -> 0x%llx\n",
783 		    VM_PHYSSEG_MAX, (long long)start, (long long)end);
784 		printf("\tincrease VM_PHYSSEG_MAX\n");
785 		return;
786 	}
787 
788 	/*
789 	 * check to see if this is a "preload" (i.e. uvm_mem_init hasn't been
790 	 * called yet, so malloc is not available).
791 	 */
792 
793 	for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) {
794 		if (vm_physmem[lcv].pgs)
795 			break;
796 	}
797 	preload = (lcv == vm_nphysseg);
798 
799 	/*
800 	 * if VM is already running, attempt to malloc() vm_page structures
801 	 */
802 
803 	if (!preload) {
804 #if defined(VM_PHYSSEG_NOADD)
805 		panic("uvm_page_physload: tried to add RAM after vm_mem_init");
806 #else
807 		/* XXXCDC: need some sort of lockout for this case */
808 		paddr_t paddr;
809 		npages = end - start;  /* # of pages */
810 		pgs = malloc(sizeof(struct vm_page) * npages,
811 		    M_VMPAGE, M_NOWAIT);
812 		if (pgs == NULL) {
813 			printf("uvm_page_physload: can not malloc vm_page "
814 			    "structs for segment\n");
815 			printf("\tignoring 0x%lx -> 0x%lx\n", start, end);
816 			return;
817 		}
818 		/* zero data, init phys_addr and free_list, and free pages */
819 		memset(pgs, 0, sizeof(struct vm_page) * npages);
820 		for (lcv = 0, paddr = ctob(start) ;
821 				 lcv < npages ; lcv++, paddr += PAGE_SIZE) {
822 			pgs[lcv].phys_addr = paddr;
823 			pgs[lcv].free_list = free_list;
824 			if (atop(paddr) >= avail_start &&
825 			    atop(paddr) <= avail_end)
826 				uvm_pagefree(&pgs[lcv]);
827 		}
828 		/* XXXCDC: incomplete: need to update uvmexp.free, what else? */
829 		/* XXXCDC: need hook to tell pmap to rebuild pv_list, etc... */
830 #endif
831 	} else {
832 		pgs = NULL;
833 		npages = 0;
834 	}
835 
836 	/*
837 	 * now insert us in the proper place in vm_physmem[]
838 	 */
839 
840 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_RANDOM)
841 	/* random: put it at the end (easy!) */
842 	ps = &vm_physmem[vm_nphysseg];
843 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH)
844 	{
845 		int x;
846 		/* sort by address for binary search */
847 		for (lcv = 0 ; lcv < vm_nphysseg ; lcv++)
848 			if (start < vm_physmem[lcv].start)
849 				break;
850 		ps = &vm_physmem[lcv];
851 		/* move back other entries, if necessary ... */
852 		for (x = vm_nphysseg ; x > lcv ; x--)
853 			/* structure copy */
854 			vm_physmem[x] = vm_physmem[x - 1];
855 	}
856 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST)
857 	{
858 		int x;
859 		/* sort by largest segment first */
860 		for (lcv = 0 ; lcv < vm_nphysseg ; lcv++)
861 			if ((end - start) >
862 			    (vm_physmem[lcv].end - vm_physmem[lcv].start))
863 				break;
864 		ps = &vm_physmem[lcv];
865 		/* move back other entries, if necessary ... */
866 		for (x = vm_nphysseg ; x > lcv ; x--)
867 			/* structure copy */
868 			vm_physmem[x] = vm_physmem[x - 1];
869 	}
870 #else
871 	panic("uvm_page_physload: unknown physseg strategy selected!");
872 #endif
873 
874 	ps->start = start;
875 	ps->end = end;
876 	ps->avail_start = avail_start;
877 	ps->avail_end = avail_end;
878 	if (preload) {
879 		ps->pgs = NULL;
880 	} else {
881 		ps->pgs = pgs;
882 		ps->lastpg = pgs + npages - 1;
883 	}
884 	ps->free_list = free_list;
885 	vm_nphysseg++;
886 
887 	if (!preload) {
888 		uvmpdpol_reinit();
889 	}
890 }
891 
892 /*
893  * uvm_page_recolor: Recolor the pages if the new bucket count is
894  * larger than the old one.
895  */
896 
897 void
898 uvm_page_recolor(int newncolors)
899 {
900 	struct pgflbucket *bucketarray, *cpuarray, *oldbucketarray;
901 	struct pgfreelist gpgfl, pgfl;
902 	struct vm_page *pg;
903 	vsize_t bucketcount;
904 	int lcv, color, i, ocolors;
905 	struct uvm_cpu *ucpu;
906 
907 	if (newncolors <= uvmexp.ncolors)
908 		return;
909 
910 	if (uvm.page_init_done == false) {
911 		uvmexp.ncolors = newncolors;
912 		return;
913 	}
914 
915 	bucketcount = newncolors * VM_NFREELIST;
916 	bucketarray = malloc(bucketcount * sizeof(struct pgflbucket) * 2,
917 	    M_VMPAGE, M_NOWAIT);
918 	cpuarray = bucketarray + bucketcount;
919 	if (bucketarray == NULL) {
920 		printf("WARNING: unable to allocate %ld page color buckets\n",
921 		    (long) bucketcount);
922 		return;
923 	}
924 
925 	mutex_spin_enter(&uvm_fpageqlock);
926 
927 	/* Make sure we should still do this. */
928 	if (newncolors <= uvmexp.ncolors) {
929 		mutex_spin_exit(&uvm_fpageqlock);
930 		free(bucketarray, M_VMPAGE);
931 		return;
932 	}
933 
934 	oldbucketarray = uvm.page_free[0].pgfl_buckets;
935 	ocolors = uvmexp.ncolors;
936 
937 	uvmexp.ncolors = newncolors;
938 	uvmexp.colormask = uvmexp.ncolors - 1;
939 
940 	ucpu = curcpu()->ci_data.cpu_uvm;
941 	for (lcv = 0; lcv < VM_NFREELIST; lcv++) {
942 		gpgfl.pgfl_buckets = (bucketarray + (lcv * newncolors));
943 		pgfl.pgfl_buckets = (cpuarray + (lcv * uvmexp.ncolors));
944 		uvm_page_init_buckets(&gpgfl);
945 		uvm_page_init_buckets(&pgfl);
946 		for (color = 0; color < ocolors; color++) {
947 			for (i = 0; i < PGFL_NQUEUES; i++) {
948 				while ((pg = LIST_FIRST(&uvm.page_free[
949 				    lcv].pgfl_buckets[color].pgfl_queues[i]))
950 				    != NULL) {
951 					LIST_REMOVE(pg, pageq.list); /* global */
952 					LIST_REMOVE(pg, listq.list); /* cpu */
953 					LIST_INSERT_HEAD(&gpgfl.pgfl_buckets[
954 					    VM_PGCOLOR_BUCKET(pg)].pgfl_queues[
955 					    i], pg, pageq.list);
956 					LIST_INSERT_HEAD(&pgfl.pgfl_buckets[
957 					    VM_PGCOLOR_BUCKET(pg)].pgfl_queues[
958 					    i], pg, listq.list);
959 				}
960 			}
961 		}
962 		uvm.page_free[lcv].pgfl_buckets = gpgfl.pgfl_buckets;
963 		ucpu->page_free[lcv].pgfl_buckets = pgfl.pgfl_buckets;
964 	}
965 
966 	if (have_recolored_pages) {
967 		mutex_spin_exit(&uvm_fpageqlock);
968 		free(oldbucketarray, M_VMPAGE);
969 		return;
970 	}
971 
972 	have_recolored_pages = true;
973 	mutex_spin_exit(&uvm_fpageqlock);
974 }
975 
976 /*
977  * uvm_cpu_attach: initialize per-CPU data structures.
978  */
979 
980 void
981 uvm_cpu_attach(struct cpu_info *ci)
982 {
983 	struct pgflbucket *bucketarray;
984 	struct pgfreelist pgfl;
985 	struct uvm_cpu *ucpu;
986 	vsize_t bucketcount;
987 	int lcv;
988 
989 	if (CPU_IS_PRIMARY(ci)) {
990 		/* Already done in uvm_page_init(). */
991 		return;
992 	}
993 
994 	/* Add more reserve pages for this CPU. */
995 	uvmexp.reserve_kernel += vm_page_reserve_kernel;
996 
997 	/* Configure this CPU's free lists. */
998 	bucketcount = uvmexp.ncolors * VM_NFREELIST;
999 	bucketarray = malloc(bucketcount * sizeof(struct pgflbucket),
1000 	    M_VMPAGE, M_WAITOK);
1001 	ucpu = kmem_zalloc(sizeof(*ucpu), KM_SLEEP);
1002 	uvm.cpus[cpu_index(ci)] = ucpu;
1003 	ci->ci_data.cpu_uvm = ucpu;
1004 	for (lcv = 0; lcv < VM_NFREELIST; lcv++) {
1005 		pgfl.pgfl_buckets = (bucketarray + (lcv * uvmexp.ncolors));
1006 		uvm_page_init_buckets(&pgfl);
1007 		ucpu->page_free[lcv].pgfl_buckets = pgfl.pgfl_buckets;
1008 	}
1009 }
1010 
1011 /*
1012  * uvm_pagealloc_pgfl: helper routine for uvm_pagealloc_strat
1013  */
1014 
1015 static struct vm_page *
1016 uvm_pagealloc_pgfl(struct uvm_cpu *ucpu, int flist, int try1, int try2,
1017     int *trycolorp)
1018 {
1019 	struct pgflist *freeq;
1020 	struct vm_page *pg;
1021 	int color, trycolor = *trycolorp;
1022 	struct pgfreelist *gpgfl, *pgfl;
1023 
1024 	KASSERT(mutex_owned(&uvm_fpageqlock));
1025 
1026 	color = trycolor;
1027 	pgfl = &ucpu->page_free[flist];
1028 	gpgfl = &uvm.page_free[flist];
1029 	do {
1030 		/* cpu, try1 */
1031 		if ((pg = LIST_FIRST((freeq =
1032 		    &pgfl->pgfl_buckets[color].pgfl_queues[try1]))) != NULL) {
1033 			VM_FREE_PAGE_TO_CPU(pg)->pages[try1]--;
1034 		    	uvmexp.cpuhit++;
1035 			goto gotit;
1036 		}
1037 		/* global, try1 */
1038 		if ((pg = LIST_FIRST((freeq =
1039 		    &gpgfl->pgfl_buckets[color].pgfl_queues[try1]))) != NULL) {
1040 			VM_FREE_PAGE_TO_CPU(pg)->pages[try1]--;
1041 		    	uvmexp.cpumiss++;
1042 			goto gotit;
1043 		}
1044 		/* cpu, try2 */
1045 		if ((pg = LIST_FIRST((freeq =
1046 		    &pgfl->pgfl_buckets[color].pgfl_queues[try2]))) != NULL) {
1047 			VM_FREE_PAGE_TO_CPU(pg)->pages[try2]--;
1048 		    	uvmexp.cpuhit++;
1049 			goto gotit;
1050 		}
1051 		/* global, try2 */
1052 		if ((pg = LIST_FIRST((freeq =
1053 		    &gpgfl->pgfl_buckets[color].pgfl_queues[try2]))) != NULL) {
1054 			VM_FREE_PAGE_TO_CPU(pg)->pages[try2]--;
1055 		    	uvmexp.cpumiss++;
1056 			goto gotit;
1057 		}
1058 		color = (color + 1) & uvmexp.colormask;
1059 	} while (color != trycolor);
1060 
1061 	return (NULL);
1062 
1063  gotit:
1064 	LIST_REMOVE(pg, pageq.list);	/* global list */
1065 	LIST_REMOVE(pg, listq.list);	/* per-cpu list */
1066 	uvmexp.free--;
1067 
1068 	/* update zero'd page count */
1069 	if (pg->flags & PG_ZERO)
1070 		uvmexp.zeropages--;
1071 
1072 	if (color == trycolor)
1073 		uvmexp.colorhit++;
1074 	else {
1075 		uvmexp.colormiss++;
1076 		*trycolorp = color;
1077 	}
1078 
1079 	return (pg);
1080 }
1081 
1082 /*
1083  * uvm_pagealloc_strat: allocate vm_page from a particular free list.
1084  *
1085  * => return null if no pages free
1086  * => wake up pagedaemon if number of free pages drops below low water mark
1087  * => if obj != NULL, obj must be locked (to put in obj's tree)
1088  * => if anon != NULL, anon must be locked (to put in anon)
1089  * => only one of obj or anon can be non-null
1090  * => caller must activate/deactivate page if it is not wired.
1091  * => free_list is ignored if strat == UVM_PGA_STRAT_NORMAL.
1092  * => policy decision: it is more important to pull a page off of the
1093  *	appropriate priority free list than it is to get a zero'd or
1094  *	unknown contents page.  This is because we live with the
1095  *	consequences of a bad free list decision for the entire
1096  *	lifetime of the page, e.g. if the page comes from memory that
1097  *	is slower to access.
1098  */
1099 
1100 struct vm_page *
1101 uvm_pagealloc_strat(struct uvm_object *obj, voff_t off, struct vm_anon *anon,
1102     int flags, int strat, int free_list)
1103 {
1104 	int lcv, try1, try2, zeroit = 0, color;
1105 	struct uvm_cpu *ucpu;
1106 	struct vm_page *pg;
1107 	lwp_t *l;
1108 
1109 	KASSERT(obj == NULL || anon == NULL);
1110 	KASSERT(anon == NULL || off == 0);
1111 	KASSERT(off == trunc_page(off));
1112 	KASSERT(obj == NULL || mutex_owned(&obj->vmobjlock));
1113 	KASSERT(anon == NULL || mutex_owned(&anon->an_lock));
1114 
1115 	mutex_spin_enter(&uvm_fpageqlock);
1116 
1117 	/*
1118 	 * This implements a global round-robin page coloring
1119 	 * algorithm.
1120 	 *
1121 	 * XXXJRT: What about virtually-indexed caches?
1122 	 */
1123 
1124 	ucpu = curcpu()->ci_data.cpu_uvm;
1125 	color = ucpu->page_free_nextcolor;
1126 
1127 	/*
1128 	 * check to see if we need to generate some free pages waking
1129 	 * the pagedaemon.
1130 	 */
1131 
1132 	uvm_kick_pdaemon();
1133 
1134 	/*
1135 	 * fail if any of these conditions is true:
1136 	 * [1]  there really are no free pages, or
1137 	 * [2]  only kernel "reserved" pages remain and
1138 	 *        reserved pages have not been requested.
1139 	 * [3]  only pagedaemon "reserved" pages remain and
1140 	 *        the requestor isn't the pagedaemon.
1141 	 * we make kernel reserve pages available if called by a
1142 	 * kernel thread or a realtime thread.
1143 	 */
1144 	l = curlwp;
1145 	if (__predict_true(l != NULL) && lwp_eprio(l) >= PRI_KTHREAD) {
1146 		flags |= UVM_PGA_USERESERVE;
1147 	}
1148 	if ((uvmexp.free <= uvmexp.reserve_kernel &&
1149 	    (flags & UVM_PGA_USERESERVE) == 0) ||
1150 	    (uvmexp.free <= uvmexp.reserve_pagedaemon &&
1151 	     curlwp != uvm.pagedaemon_lwp))
1152 		goto fail;
1153 
1154 #if PGFL_NQUEUES != 2
1155 #error uvm_pagealloc_strat needs to be updated
1156 #endif
1157 
1158 	/*
1159 	 * If we want a zero'd page, try the ZEROS queue first, otherwise
1160 	 * we try the UNKNOWN queue first.
1161 	 */
1162 	if (flags & UVM_PGA_ZERO) {
1163 		try1 = PGFL_ZEROS;
1164 		try2 = PGFL_UNKNOWN;
1165 	} else {
1166 		try1 = PGFL_UNKNOWN;
1167 		try2 = PGFL_ZEROS;
1168 	}
1169 
1170  again:
1171 	switch (strat) {
1172 	case UVM_PGA_STRAT_NORMAL:
1173 		/* Check freelists: descending priority (ascending id) order */
1174 		for (lcv = 0; lcv < VM_NFREELIST; lcv++) {
1175 			pg = uvm_pagealloc_pgfl(ucpu, lcv,
1176 			    try1, try2, &color);
1177 			if (pg != NULL)
1178 				goto gotit;
1179 		}
1180 
1181 		/* No pages free! */
1182 		goto fail;
1183 
1184 	case UVM_PGA_STRAT_ONLY:
1185 	case UVM_PGA_STRAT_FALLBACK:
1186 		/* Attempt to allocate from the specified free list. */
1187 		KASSERT(free_list >= 0 && free_list < VM_NFREELIST);
1188 		pg = uvm_pagealloc_pgfl(ucpu, free_list,
1189 		    try1, try2, &color);
1190 		if (pg != NULL)
1191 			goto gotit;
1192 
1193 		/* Fall back, if possible. */
1194 		if (strat == UVM_PGA_STRAT_FALLBACK) {
1195 			strat = UVM_PGA_STRAT_NORMAL;
1196 			goto again;
1197 		}
1198 
1199 		/* No pages free! */
1200 		goto fail;
1201 
1202 	default:
1203 		panic("uvm_pagealloc_strat: bad strat %d", strat);
1204 		/* NOTREACHED */
1205 	}
1206 
1207  gotit:
1208 	/*
1209 	 * We now know which color we actually allocated from; set
1210 	 * the next color accordingly.
1211 	 */
1212 
1213 	ucpu->page_free_nextcolor = (color + 1) & uvmexp.colormask;
1214 
1215 	/*
1216 	 * update allocation statistics and remember if we have to
1217 	 * zero the page
1218 	 */
1219 
1220 	if (flags & UVM_PGA_ZERO) {
1221 		if (pg->flags & PG_ZERO) {
1222 			uvmexp.pga_zerohit++;
1223 			zeroit = 0;
1224 		} else {
1225 			uvmexp.pga_zeromiss++;
1226 			zeroit = 1;
1227 		}
1228 		if (ucpu->pages[PGFL_ZEROS] < ucpu->pages[PGFL_UNKNOWN]) {
1229 			ucpu->page_idle_zero = vm_page_zero_enable;
1230 		}
1231 	}
1232 	KASSERT(pg->pqflags == PQ_FREE);
1233 
1234 	pg->offset = off;
1235 	pg->uobject = obj;
1236 	pg->uanon = anon;
1237 	pg->flags = PG_BUSY|PG_CLEAN|PG_FAKE;
1238 	if (anon) {
1239 		anon->an_page = pg;
1240 		pg->pqflags = PQ_ANON;
1241 		atomic_inc_uint(&uvmexp.anonpages);
1242 	} else {
1243 		if (obj) {
1244 			uvm_pageinsert(obj, pg);
1245 		}
1246 		pg->pqflags = 0;
1247 	}
1248 	mutex_spin_exit(&uvm_fpageqlock);
1249 
1250 #if defined(UVM_PAGE_TRKOWN)
1251 	pg->owner_tag = NULL;
1252 #endif
1253 	UVM_PAGE_OWN(pg, "new alloc");
1254 
1255 	if (flags & UVM_PGA_ZERO) {
1256 		/*
1257 		 * A zero'd page is not clean.  If we got a page not already
1258 		 * zero'd, then we have to zero it ourselves.
1259 		 */
1260 		pg->flags &= ~PG_CLEAN;
1261 		if (zeroit)
1262 			pmap_zero_page(VM_PAGE_TO_PHYS(pg));
1263 	}
1264 
1265 	return(pg);
1266 
1267  fail:
1268 	mutex_spin_exit(&uvm_fpageqlock);
1269 	return (NULL);
1270 }
1271 
1272 /*
1273  * uvm_pagereplace: replace a page with another
1274  *
1275  * => object must be locked
1276  */
1277 
1278 void
1279 uvm_pagereplace(struct vm_page *oldpg, struct vm_page *newpg)
1280 {
1281 	struct uvm_object *uobj = oldpg->uobject;
1282 
1283 	KASSERT((oldpg->flags & PG_TABLED) != 0);
1284 	KASSERT(uobj != NULL);
1285 	KASSERT((newpg->flags & PG_TABLED) == 0);
1286 	KASSERT(newpg->uobject == NULL);
1287 	KASSERT(mutex_owned(&uobj->vmobjlock));
1288 
1289 	newpg->uobject = uobj;
1290 	newpg->offset = oldpg->offset;
1291 
1292 	uvm_pageremove_tree(uobj, oldpg);
1293 	uvm_pageinsert_tree(uobj, newpg);
1294 	uvm_pageinsert_list(uobj, newpg, oldpg);
1295 	uvm_pageremove_list(uobj, oldpg);
1296 }
1297 
1298 /*
1299  * uvm_pagerealloc: reallocate a page from one object to another
1300  *
1301  * => both objects must be locked
1302  */
1303 
1304 void
1305 uvm_pagerealloc(struct vm_page *pg, struct uvm_object *newobj, voff_t newoff)
1306 {
1307 	/*
1308 	 * remove it from the old object
1309 	 */
1310 
1311 	if (pg->uobject) {
1312 		uvm_pageremove(pg->uobject, pg);
1313 	}
1314 
1315 	/*
1316 	 * put it in the new object
1317 	 */
1318 
1319 	if (newobj) {
1320 		pg->uobject = newobj;
1321 		pg->offset = newoff;
1322 		uvm_pageinsert(newobj, pg);
1323 	}
1324 }
1325 
1326 #ifdef DEBUG
1327 /*
1328  * check if page is zero-filled
1329  *
1330  *  - called with free page queue lock held.
1331  */
1332 void
1333 uvm_pagezerocheck(struct vm_page *pg)
1334 {
1335 	int *p, *ep;
1336 
1337 	KASSERT(uvm_zerocheckkva != 0);
1338 	KASSERT(mutex_owned(&uvm_fpageqlock));
1339 
1340 	/*
1341 	 * XXX assuming pmap_kenter_pa and pmap_kremove never call
1342 	 * uvm page allocator.
1343 	 *
1344 	 * it might be better to have "CPU-local temporary map" pmap interface.
1345 	 */
1346 	pmap_kenter_pa(uvm_zerocheckkva, VM_PAGE_TO_PHYS(pg), VM_PROT_READ, 0);
1347 	p = (int *)uvm_zerocheckkva;
1348 	ep = (int *)((char *)p + PAGE_SIZE);
1349 	pmap_update(pmap_kernel());
1350 	while (p < ep) {
1351 		if (*p != 0)
1352 			panic("PG_ZERO page isn't zero-filled");
1353 		p++;
1354 	}
1355 	pmap_kremove(uvm_zerocheckkva, PAGE_SIZE);
1356 	/*
1357 	 * pmap_update() is not necessary here because no one except us
1358 	 * uses this VA.
1359 	 */
1360 }
1361 #endif /* DEBUG */
1362 
1363 /*
1364  * uvm_pagefree: free page
1365  *
1366  * => erase page's identity (i.e. remove from object)
1367  * => put page on free list
1368  * => caller must lock owning object (either anon or uvm_object)
1369  * => caller must lock page queues
1370  * => assumes all valid mappings of pg are gone
1371  */
1372 
1373 void
1374 uvm_pagefree(struct vm_page *pg)
1375 {
1376 	struct pgflist *pgfl;
1377 	struct uvm_cpu *ucpu;
1378 	int index, color, queue;
1379 	bool iszero;
1380 
1381 #ifdef DEBUG
1382 	if (pg->uobject == (void *)0xdeadbeef &&
1383 	    pg->uanon == (void *)0xdeadbeef) {
1384 		panic("uvm_pagefree: freeing free page %p", pg);
1385 	}
1386 #endif /* DEBUG */
1387 
1388 	KASSERT((pg->flags & PG_PAGEOUT) == 0);
1389 	KASSERT(!(pg->pqflags & PQ_FREE));
1390 	KASSERT(mutex_owned(&uvm_pageqlock) || !uvmpdpol_pageisqueued_p(pg));
1391 	KASSERT(pg->uobject == NULL || mutex_owned(&pg->uobject->vmobjlock));
1392 	KASSERT(pg->uobject != NULL || pg->uanon == NULL ||
1393 		mutex_owned(&pg->uanon->an_lock));
1394 
1395 	/*
1396 	 * if the page is loaned, resolve the loan instead of freeing.
1397 	 */
1398 
1399 	if (pg->loan_count) {
1400 		KASSERT(pg->wire_count == 0);
1401 
1402 		/*
1403 		 * if the page is owned by an anon then we just want to
1404 		 * drop anon ownership.  the kernel will free the page when
1405 		 * it is done with it.  if the page is owned by an object,
1406 		 * remove it from the object and mark it dirty for the benefit
1407 		 * of possible anon owners.
1408 		 *
1409 		 * regardless of previous ownership, wakeup any waiters,
1410 		 * unbusy the page, and we're done.
1411 		 */
1412 
1413 		if (pg->uobject != NULL) {
1414 			uvm_pageremove(pg->uobject, pg);
1415 			pg->flags &= ~PG_CLEAN;
1416 		} else if (pg->uanon != NULL) {
1417 			if ((pg->pqflags & PQ_ANON) == 0) {
1418 				pg->loan_count--;
1419 			} else {
1420 				pg->pqflags &= ~PQ_ANON;
1421 				atomic_dec_uint(&uvmexp.anonpages);
1422 			}
1423 			pg->uanon->an_page = NULL;
1424 			pg->uanon = NULL;
1425 		}
1426 		if (pg->flags & PG_WANTED) {
1427 			wakeup(pg);
1428 		}
1429 		pg->flags &= ~(PG_WANTED|PG_BUSY|PG_RELEASED|PG_PAGER1);
1430 #ifdef UVM_PAGE_TRKOWN
1431 		pg->owner_tag = NULL;
1432 #endif
1433 		if (pg->loan_count) {
1434 			KASSERT(pg->uobject == NULL);
1435 			if (pg->uanon == NULL) {
1436 				uvm_pagedequeue(pg);
1437 			}
1438 			return;
1439 		}
1440 	}
1441 
1442 	/*
1443 	 * remove page from its object or anon.
1444 	 */
1445 
1446 	if (pg->uobject != NULL) {
1447 		uvm_pageremove(pg->uobject, pg);
1448 	} else if (pg->uanon != NULL) {
1449 		pg->uanon->an_page = NULL;
1450 		atomic_dec_uint(&uvmexp.anonpages);
1451 	}
1452 
1453 	/*
1454 	 * now remove the page from the queues.
1455 	 */
1456 
1457 	uvm_pagedequeue(pg);
1458 
1459 	/*
1460 	 * if the page was wired, unwire it now.
1461 	 */
1462 
1463 	if (pg->wire_count) {
1464 		pg->wire_count = 0;
1465 		uvmexp.wired--;
1466 	}
1467 
1468 	/*
1469 	 * and put on free queue
1470 	 */
1471 
1472 	iszero = (pg->flags & PG_ZERO);
1473 	index = uvm_page_lookup_freelist(pg);
1474 	color = VM_PGCOLOR_BUCKET(pg);
1475 	queue = (iszero ? PGFL_ZEROS : PGFL_UNKNOWN);
1476 
1477 #ifdef DEBUG
1478 	pg->uobject = (void *)0xdeadbeef;
1479 	pg->uanon = (void *)0xdeadbeef;
1480 #endif
1481 
1482 	mutex_spin_enter(&uvm_fpageqlock);
1483 	pg->pqflags = PQ_FREE;
1484 
1485 #ifdef DEBUG
1486 	if (iszero)
1487 		uvm_pagezerocheck(pg);
1488 #endif /* DEBUG */
1489 
1490 
1491 	/* global list */
1492 	pgfl = &uvm.page_free[index].pgfl_buckets[color].pgfl_queues[queue];
1493 	LIST_INSERT_HEAD(pgfl, pg, pageq.list);
1494 	uvmexp.free++;
1495 	if (iszero) {
1496 		uvmexp.zeropages++;
1497 	}
1498 
1499 	/* per-cpu list */
1500 	ucpu = curcpu()->ci_data.cpu_uvm;
1501 	pg->offset = (uintptr_t)ucpu;
1502 	pgfl = &ucpu->page_free[index].pgfl_buckets[color].pgfl_queues[queue];
1503 	LIST_INSERT_HEAD(pgfl, pg, listq.list);
1504 	ucpu->pages[queue]++;
1505 	if (ucpu->pages[PGFL_ZEROS] < ucpu->pages[PGFL_UNKNOWN]) {
1506 		ucpu->page_idle_zero = vm_page_zero_enable;
1507 	}
1508 
1509 	mutex_spin_exit(&uvm_fpageqlock);
1510 }
1511 
1512 /*
1513  * uvm_page_unbusy: unbusy an array of pages.
1514  *
1515  * => pages must either all belong to the same object, or all belong to anons.
1516  * => if pages are object-owned, object must be locked.
1517  * => if pages are anon-owned, anons must be locked.
1518  * => caller must lock page queues if pages may be released.
1519  * => caller must make sure that anon-owned pages are not PG_RELEASED.
1520  */
1521 
1522 void
1523 uvm_page_unbusy(struct vm_page **pgs, int npgs)
1524 {
1525 	struct vm_page *pg;
1526 	int i;
1527 	UVMHIST_FUNC("uvm_page_unbusy"); UVMHIST_CALLED(ubchist);
1528 
1529 	for (i = 0; i < npgs; i++) {
1530 		pg = pgs[i];
1531 		if (pg == NULL || pg == PGO_DONTCARE) {
1532 			continue;
1533 		}
1534 
1535 		KASSERT(pg->uobject == NULL ||
1536 		    mutex_owned(&pg->uobject->vmobjlock));
1537 		KASSERT(pg->uobject != NULL ||
1538 		    (pg->uanon != NULL && mutex_owned(&pg->uanon->an_lock)));
1539 
1540 		KASSERT(pg->flags & PG_BUSY);
1541 		KASSERT((pg->flags & PG_PAGEOUT) == 0);
1542 		if (pg->flags & PG_WANTED) {
1543 			wakeup(pg);
1544 		}
1545 		if (pg->flags & PG_RELEASED) {
1546 			UVMHIST_LOG(ubchist, "releasing pg %p", pg,0,0,0);
1547 			KASSERT(pg->uobject != NULL ||
1548 			    (pg->uanon != NULL && pg->uanon->an_ref > 0));
1549 			pg->flags &= ~PG_RELEASED;
1550 			uvm_pagefree(pg);
1551 		} else {
1552 			UVMHIST_LOG(ubchist, "unbusying pg %p", pg,0,0,0);
1553 			KASSERT((pg->flags & PG_FAKE) == 0);
1554 			pg->flags &= ~(PG_WANTED|PG_BUSY);
1555 			UVM_PAGE_OWN(pg, NULL);
1556 		}
1557 	}
1558 }
1559 
1560 #if defined(UVM_PAGE_TRKOWN)
1561 /*
1562  * uvm_page_own: set or release page ownership
1563  *
1564  * => this is a debugging function that keeps track of who sets PG_BUSY
1565  *	and where they do it.   it can be used to track down problems
1566  *	such a process setting "PG_BUSY" and never releasing it.
1567  * => page's object [if any] must be locked
1568  * => if "tag" is NULL then we are releasing page ownership
1569  */
1570 void
1571 uvm_page_own(struct vm_page *pg, const char *tag)
1572 {
1573 	struct uvm_object *uobj;
1574 	struct vm_anon *anon;
1575 
1576 	KASSERT((pg->flags & (PG_PAGEOUT|PG_RELEASED)) == 0);
1577 
1578 	uobj = pg->uobject;
1579 	anon = pg->uanon;
1580 	if (uobj != NULL) {
1581 		KASSERT(mutex_owned(&uobj->vmobjlock));
1582 	} else if (anon != NULL) {
1583 		KASSERT(mutex_owned(&anon->an_lock));
1584 	}
1585 
1586 	KASSERT((pg->flags & PG_WANTED) == 0);
1587 
1588 	/* gain ownership? */
1589 	if (tag) {
1590 		KASSERT((pg->flags & PG_BUSY) != 0);
1591 		if (pg->owner_tag) {
1592 			printf("uvm_page_own: page %p already owned "
1593 			    "by proc %d [%s]\n", pg,
1594 			    pg->owner, pg->owner_tag);
1595 			panic("uvm_page_own");
1596 		}
1597 		pg->owner = (curproc) ? curproc->p_pid :  (pid_t) -1;
1598 		pg->lowner = (curlwp) ? curlwp->l_lid :  (lwpid_t) -1;
1599 		pg->owner_tag = tag;
1600 		return;
1601 	}
1602 
1603 	/* drop ownership */
1604 	KASSERT((pg->flags & PG_BUSY) == 0);
1605 	if (pg->owner_tag == NULL) {
1606 		printf("uvm_page_own: dropping ownership of an non-owned "
1607 		    "page (%p)\n", pg);
1608 		panic("uvm_page_own");
1609 	}
1610 	if (!uvmpdpol_pageisqueued_p(pg)) {
1611 		KASSERT((pg->uanon == NULL && pg->uobject == NULL) ||
1612 		    pg->wire_count > 0);
1613 	} else {
1614 		KASSERT(pg->wire_count == 0);
1615 	}
1616 	pg->owner_tag = NULL;
1617 }
1618 #endif
1619 
1620 /*
1621  * uvm_pageidlezero: zero free pages while the system is idle.
1622  *
1623  * => try to complete one color bucket at a time, to reduce our impact
1624  *	on the CPU cache.
1625  * => we loop until we either reach the target or there is a lwp ready
1626  *      to run, or MD code detects a reason to break early.
1627  */
1628 void
1629 uvm_pageidlezero(void)
1630 {
1631 	struct vm_page *pg;
1632 	struct pgfreelist *pgfl, *gpgfl;
1633 	struct uvm_cpu *ucpu;
1634 	int free_list, firstbucket, nextbucket;
1635 
1636 	ucpu = curcpu()->ci_data.cpu_uvm;
1637 	if (!ucpu->page_idle_zero ||
1638 	    ucpu->pages[PGFL_UNKNOWN] < uvmexp.ncolors) {
1639 	    	ucpu->page_idle_zero = false;
1640 		return;
1641 	}
1642 	mutex_enter(&uvm_fpageqlock);
1643 	firstbucket = ucpu->page_free_nextcolor;
1644 	nextbucket = firstbucket;
1645 	do {
1646 		for (free_list = 0; free_list < VM_NFREELIST; free_list++) {
1647 			if (sched_curcpu_runnable_p()) {
1648 				goto quit;
1649 			}
1650 			pgfl = &ucpu->page_free[free_list];
1651 			gpgfl = &uvm.page_free[free_list];
1652 			while ((pg = LIST_FIRST(&pgfl->pgfl_buckets[
1653 			    nextbucket].pgfl_queues[PGFL_UNKNOWN])) != NULL) {
1654 				if (sched_curcpu_runnable_p()) {
1655 					goto quit;
1656 				}
1657 				LIST_REMOVE(pg, pageq.list); /* global list */
1658 				LIST_REMOVE(pg, listq.list); /* per-cpu list */
1659 				ucpu->pages[PGFL_UNKNOWN]--;
1660 				uvmexp.free--;
1661 				KASSERT(pg->pqflags == PQ_FREE);
1662 				pg->pqflags = 0;
1663 				mutex_spin_exit(&uvm_fpageqlock);
1664 #ifdef PMAP_PAGEIDLEZERO
1665 				if (!PMAP_PAGEIDLEZERO(VM_PAGE_TO_PHYS(pg))) {
1666 
1667 					/*
1668 					 * The machine-dependent code detected
1669 					 * some reason for us to abort zeroing
1670 					 * pages, probably because there is a
1671 					 * process now ready to run.
1672 					 */
1673 
1674 					mutex_spin_enter(&uvm_fpageqlock);
1675 					pg->pqflags = PQ_FREE;
1676 					LIST_INSERT_HEAD(&gpgfl->pgfl_buckets[
1677 					    nextbucket].pgfl_queues[
1678 					    PGFL_UNKNOWN], pg, pageq.list);
1679 					LIST_INSERT_HEAD(&pgfl->pgfl_buckets[
1680 					    nextbucket].pgfl_queues[
1681 					    PGFL_UNKNOWN], pg, listq.list);
1682 					ucpu->pages[PGFL_UNKNOWN]++;
1683 					uvmexp.free++;
1684 					uvmexp.zeroaborts++;
1685 					goto quit;
1686 				}
1687 #else
1688 				pmap_zero_page(VM_PAGE_TO_PHYS(pg));
1689 #endif /* PMAP_PAGEIDLEZERO */
1690 				pg->flags |= PG_ZERO;
1691 
1692 				mutex_spin_enter(&uvm_fpageqlock);
1693 				pg->pqflags = PQ_FREE;
1694 				LIST_INSERT_HEAD(&gpgfl->pgfl_buckets[
1695 				    nextbucket].pgfl_queues[PGFL_ZEROS],
1696 				    pg, pageq.list);
1697 				LIST_INSERT_HEAD(&pgfl->pgfl_buckets[
1698 				    nextbucket].pgfl_queues[PGFL_ZEROS],
1699 				    pg, listq.list);
1700 				ucpu->pages[PGFL_ZEROS]++;
1701 				uvmexp.free++;
1702 				uvmexp.zeropages++;
1703 			}
1704 		}
1705 		if (ucpu->pages[PGFL_UNKNOWN] < uvmexp.ncolors) {
1706 			break;
1707 		}
1708 		nextbucket = (nextbucket + 1) & uvmexp.colormask;
1709 	} while (nextbucket != firstbucket);
1710 	ucpu->page_idle_zero = false;
1711  quit:
1712 	mutex_spin_exit(&uvm_fpageqlock);
1713 }
1714 
1715 /*
1716  * uvm_pagelookup: look up a page
1717  *
1718  * => caller should lock object to keep someone from pulling the page
1719  *	out from under it
1720  */
1721 
1722 struct vm_page *
1723 uvm_pagelookup(struct uvm_object *obj, voff_t off)
1724 {
1725 	struct vm_page *pg;
1726 
1727 	KASSERT(mutex_owned(&obj->vmobjlock));
1728 
1729 	pg = (struct vm_page *)rb_tree_find_node(&obj->rb_tree, &off);
1730 
1731 	KASSERT(pg == NULL || obj->uo_npages != 0);
1732 	KASSERT(pg == NULL || (pg->flags & (PG_RELEASED|PG_PAGEOUT)) == 0 ||
1733 		(pg->flags & PG_BUSY) != 0);
1734 	return(pg);
1735 }
1736 
1737 /*
1738  * uvm_pagewire: wire the page, thus removing it from the daemon's grasp
1739  *
1740  * => caller must lock page queues
1741  */
1742 
1743 void
1744 uvm_pagewire(struct vm_page *pg)
1745 {
1746 	KASSERT(mutex_owned(&uvm_pageqlock));
1747 #if defined(READAHEAD_STATS)
1748 	if ((pg->pqflags & PQ_READAHEAD) != 0) {
1749 		uvm_ra_hit.ev_count++;
1750 		pg->pqflags &= ~PQ_READAHEAD;
1751 	}
1752 #endif /* defined(READAHEAD_STATS) */
1753 	if (pg->wire_count == 0) {
1754 		uvm_pagedequeue(pg);
1755 		uvmexp.wired++;
1756 	}
1757 	pg->wire_count++;
1758 }
1759 
1760 /*
1761  * uvm_pageunwire: unwire the page.
1762  *
1763  * => activate if wire count goes to zero.
1764  * => caller must lock page queues
1765  */
1766 
1767 void
1768 uvm_pageunwire(struct vm_page *pg)
1769 {
1770 	KASSERT(mutex_owned(&uvm_pageqlock));
1771 	pg->wire_count--;
1772 	if (pg->wire_count == 0) {
1773 		uvm_pageactivate(pg);
1774 		uvmexp.wired--;
1775 	}
1776 }
1777 
1778 /*
1779  * uvm_pagedeactivate: deactivate page
1780  *
1781  * => caller must lock page queues
1782  * => caller must check to make sure page is not wired
1783  * => object that page belongs to must be locked (so we can adjust pg->flags)
1784  * => caller must clear the reference on the page before calling
1785  */
1786 
1787 void
1788 uvm_pagedeactivate(struct vm_page *pg)
1789 {
1790 
1791 	KASSERT(mutex_owned(&uvm_pageqlock));
1792 	KASSERT(pg->wire_count != 0 || uvmpdpol_pageisqueued_p(pg));
1793 	uvmpdpol_pagedeactivate(pg);
1794 }
1795 
1796 /*
1797  * uvm_pageactivate: activate page
1798  *
1799  * => caller must lock page queues
1800  */
1801 
1802 void
1803 uvm_pageactivate(struct vm_page *pg)
1804 {
1805 
1806 	KASSERT(mutex_owned(&uvm_pageqlock));
1807 #if defined(READAHEAD_STATS)
1808 	if ((pg->pqflags & PQ_READAHEAD) != 0) {
1809 		uvm_ra_hit.ev_count++;
1810 		pg->pqflags &= ~PQ_READAHEAD;
1811 	}
1812 #endif /* defined(READAHEAD_STATS) */
1813 	if (pg->wire_count != 0) {
1814 		return;
1815 	}
1816 	uvmpdpol_pageactivate(pg);
1817 }
1818 
1819 /*
1820  * uvm_pagedequeue: remove a page from any paging queue
1821  */
1822 
1823 void
1824 uvm_pagedequeue(struct vm_page *pg)
1825 {
1826 
1827 	if (uvmpdpol_pageisqueued_p(pg)) {
1828 		KASSERT(mutex_owned(&uvm_pageqlock));
1829 	}
1830 
1831 	uvmpdpol_pagedequeue(pg);
1832 }
1833 
1834 /*
1835  * uvm_pageenqueue: add a page to a paging queue without activating.
1836  * used where a page is not really demanded (yet).  eg. read-ahead
1837  */
1838 
1839 void
1840 uvm_pageenqueue(struct vm_page *pg)
1841 {
1842 
1843 	KASSERT(mutex_owned(&uvm_pageqlock));
1844 	if (pg->wire_count != 0) {
1845 		return;
1846 	}
1847 	uvmpdpol_pageenqueue(pg);
1848 }
1849 
1850 /*
1851  * uvm_pagezero: zero fill a page
1852  *
1853  * => if page is part of an object then the object should be locked
1854  *	to protect pg->flags.
1855  */
1856 
1857 void
1858 uvm_pagezero(struct vm_page *pg)
1859 {
1860 	pg->flags &= ~PG_CLEAN;
1861 	pmap_zero_page(VM_PAGE_TO_PHYS(pg));
1862 }
1863 
1864 /*
1865  * uvm_pagecopy: copy a page
1866  *
1867  * => if page is part of an object then the object should be locked
1868  *	to protect pg->flags.
1869  */
1870 
1871 void
1872 uvm_pagecopy(struct vm_page *src, struct vm_page *dst)
1873 {
1874 
1875 	dst->flags &= ~PG_CLEAN;
1876 	pmap_copy_page(VM_PAGE_TO_PHYS(src), VM_PAGE_TO_PHYS(dst));
1877 }
1878 
1879 /*
1880  * uvm_pageismanaged: test it see that a page (specified by PA) is managed.
1881  */
1882 
1883 bool
1884 uvm_pageismanaged(paddr_t pa)
1885 {
1886 
1887 	return (vm_physseg_find(atop(pa), NULL) != -1);
1888 }
1889 
1890 /*
1891  * uvm_page_lookup_freelist: look up the free list for the specified page
1892  */
1893 
1894 int
1895 uvm_page_lookup_freelist(struct vm_page *pg)
1896 {
1897 	int lcv;
1898 
1899 	lcv = vm_physseg_find(atop(VM_PAGE_TO_PHYS(pg)), NULL);
1900 	KASSERT(lcv != -1);
1901 	return (vm_physmem[lcv].free_list);
1902 }
1903 
1904 #if defined(DDB) || defined(DEBUGPRINT)
1905 
1906 /*
1907  * uvm_page_printit: actually print the page
1908  */
1909 
1910 static const char page_flagbits[] = UVM_PGFLAGBITS;
1911 static const char page_pqflagbits[] = UVM_PQFLAGBITS;
1912 
1913 void
1914 uvm_page_printit(struct vm_page *pg, bool full,
1915     void (*pr)(const char *, ...))
1916 {
1917 	struct vm_page *tpg;
1918 	struct uvm_object *uobj;
1919 	struct pgflist *pgl;
1920 	char pgbuf[128];
1921 	char pqbuf[128];
1922 
1923 	(*pr)("PAGE %p:\n", pg);
1924 	snprintb(pgbuf, sizeof(pgbuf), page_flagbits, pg->flags);
1925 	snprintb(pqbuf, sizeof(pqbuf), page_pqflagbits, pg->pqflags);
1926 	(*pr)("  flags=%s, pqflags=%s, wire_count=%d, pa=0x%lx\n",
1927 	    pgbuf, pqbuf, pg->wire_count, (long)VM_PAGE_TO_PHYS(pg));
1928 	(*pr)("  uobject=%p, uanon=%p, offset=0x%llx loan_count=%d\n",
1929 	    pg->uobject, pg->uanon, (long long)pg->offset, pg->loan_count);
1930 #if defined(UVM_PAGE_TRKOWN)
1931 	if (pg->flags & PG_BUSY)
1932 		(*pr)("  owning process = %d, tag=%s\n",
1933 		    pg->owner, pg->owner_tag);
1934 	else
1935 		(*pr)("  page not busy, no owner\n");
1936 #else
1937 	(*pr)("  [page ownership tracking disabled]\n");
1938 #endif
1939 
1940 	if (!full)
1941 		return;
1942 
1943 	/* cross-verify object/anon */
1944 	if ((pg->pqflags & PQ_FREE) == 0) {
1945 		if (pg->pqflags & PQ_ANON) {
1946 			if (pg->uanon == NULL || pg->uanon->an_page != pg)
1947 			    (*pr)("  >>> ANON DOES NOT POINT HERE <<< (%p)\n",
1948 				(pg->uanon) ? pg->uanon->an_page : NULL);
1949 			else
1950 				(*pr)("  anon backpointer is OK\n");
1951 		} else {
1952 			uobj = pg->uobject;
1953 			if (uobj) {
1954 				(*pr)("  checking object list\n");
1955 				TAILQ_FOREACH(tpg, &uobj->memq, listq.queue) {
1956 					if (tpg == pg) {
1957 						break;
1958 					}
1959 				}
1960 				if (tpg)
1961 					(*pr)("  page found on object list\n");
1962 				else
1963 			(*pr)("  >>> PAGE NOT FOUND ON OBJECT LIST! <<<\n");
1964 			}
1965 		}
1966 	}
1967 
1968 	/* cross-verify page queue */
1969 	if (pg->pqflags & PQ_FREE) {
1970 		int fl = uvm_page_lookup_freelist(pg);
1971 		int color = VM_PGCOLOR_BUCKET(pg);
1972 		pgl = &uvm.page_free[fl].pgfl_buckets[color].pgfl_queues[
1973 		    ((pg)->flags & PG_ZERO) ? PGFL_ZEROS : PGFL_UNKNOWN];
1974 	} else {
1975 		pgl = NULL;
1976 	}
1977 
1978 	if (pgl) {
1979 		(*pr)("  checking pageq list\n");
1980 		LIST_FOREACH(tpg, pgl, pageq.list) {
1981 			if (tpg == pg) {
1982 				break;
1983 			}
1984 		}
1985 		if (tpg)
1986 			(*pr)("  page found on pageq list\n");
1987 		else
1988 			(*pr)("  >>> PAGE NOT FOUND ON PAGEQ LIST! <<<\n");
1989 	}
1990 }
1991 
1992 /*
1993  * uvm_pages_printthem - print a summary of all managed pages
1994  */
1995 
1996 void
1997 uvm_page_printall(void (*pr)(const char *, ...))
1998 {
1999 	unsigned i;
2000 	struct vm_page *pg;
2001 
2002 	(*pr)("%18s %4s %4s %18s %18s"
2003 #ifdef UVM_PAGE_TRKOWN
2004 	    " OWNER"
2005 #endif
2006 	    "\n", "PAGE", "FLAG", "PQ", "UOBJECT", "UANON");
2007 	for (i = 0; i < vm_nphysseg; i++) {
2008 		for (pg = vm_physmem[i].pgs; pg <= vm_physmem[i].lastpg; pg++) {
2009 			(*pr)("%18p %04x %04x %18p %18p",
2010 			    pg, pg->flags, pg->pqflags, pg->uobject,
2011 			    pg->uanon);
2012 #ifdef UVM_PAGE_TRKOWN
2013 			if (pg->flags & PG_BUSY)
2014 				(*pr)(" %d [%s]", pg->owner, pg->owner_tag);
2015 #endif
2016 			(*pr)("\n");
2017 		}
2018 	}
2019 }
2020 
2021 #endif /* DDB || DEBUGPRINT */
2022