uvm_km.c revision 1.96
1/*	$NetBSD: uvm_km.c,v 1.96 2007/07/21 20:52:59 ad Exp $	*/
2
3/*
4 * Copyright (c) 1997 Charles D. Cranor and Washington University.
5 * Copyright (c) 1991, 1993, The Regents of the University of California.
6 *
7 * All rights reserved.
8 *
9 * This code is derived from software contributed to Berkeley by
10 * The Mach Operating System project at Carnegie-Mellon University.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 *    notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 *    notice, this list of conditions and the following disclaimer in the
19 *    documentation and/or other materials provided with the distribution.
20 * 3. All advertising materials mentioning features or use of this software
21 *    must display the following acknowledgement:
22 *	This product includes software developed by Charles D. Cranor,
23 *      Washington University, the University of California, Berkeley and
24 *      its contributors.
25 * 4. Neither the name of the University nor the names of its contributors
26 *    may be used to endorse or promote products derived from this software
27 *    without specific prior written permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
32 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 * SUCH DAMAGE.
40 *
41 *	@(#)vm_kern.c   8.3 (Berkeley) 1/12/94
42 * from: Id: uvm_km.c,v 1.1.2.14 1998/02/06 05:19:27 chs Exp
43 *
44 *
45 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
46 * All rights reserved.
47 *
48 * Permission to use, copy, modify and distribute this software and
49 * its documentation is hereby granted, provided that both the copyright
50 * notice and this permission notice appear in all copies of the
51 * software, derivative works or modified versions, and any portions
52 * thereof, and that both notices appear in supporting documentation.
53 *
54 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
55 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
56 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
57 *
58 * Carnegie Mellon requests users of this software to return to
59 *
60 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
61 *  School of Computer Science
62 *  Carnegie Mellon University
63 *  Pittsburgh PA 15213-3890
64 *
65 * any improvements or extensions that they make and grant Carnegie the
66 * rights to redistribute these changes.
67 */
68
69/*
70 * uvm_km.c: handle kernel memory allocation and management
71 */
72
73/*
74 * overview of kernel memory management:
75 *
76 * the kernel virtual address space is mapped by "kernel_map."   kernel_map
77 * starts at VM_MIN_KERNEL_ADDRESS and goes to VM_MAX_KERNEL_ADDRESS.
78 * note that VM_MIN_KERNEL_ADDRESS is equal to vm_map_min(kernel_map).
79 *
80 * the kernel_map has several "submaps."   submaps can only appear in
81 * the kernel_map (user processes can't use them).   submaps "take over"
82 * the management of a sub-range of the kernel's address space.  submaps
83 * are typically allocated at boot time and are never released.   kernel
84 * virtual address space that is mapped by a submap is locked by the
85 * submap's lock -- not the kernel_map's lock.
86 *
87 * thus, the useful feature of submaps is that they allow us to break
88 * up the locking and protection of the kernel address space into smaller
89 * chunks.
90 *
91 * the vm system has several standard kernel submaps, including:
92 *   kmem_map => contains only wired kernel memory for the kernel
93 *		malloc.   *** access to kmem_map must be protected
94 *		by splvm() because we are allowed to call malloc()
95 *		at interrupt time ***
96 *   mb_map => memory for large mbufs,  *** protected by splvm ***
97 *   pager_map => used to map "buf" structures into kernel space
98 *   exec_map => used during exec to handle exec args
99 *   etc...
100 *
101 * the kernel allocates its private memory out of special uvm_objects whose
102 * reference count is set to UVM_OBJ_KERN (thus indicating that the objects
103 * are "special" and never die).   all kernel objects should be thought of
104 * as large, fixed-sized, sparsely populated uvm_objects.   each kernel
105 * object is equal to the size of kernel virtual address space (i.e. the
106 * value "VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS").
107 *
108 * note that just because a kernel object spans the entire kernel virutal
109 * address space doesn't mean that it has to be mapped into the entire space.
110 * large chunks of a kernel object's space go unused either because
111 * that area of kernel VM is unmapped, or there is some other type of
112 * object mapped into that range (e.g. a vnode).    for submap's kernel
113 * objects, the only part of the object that can ever be populated is the
114 * offsets that are managed by the submap.
115 *
116 * note that the "offset" in a kernel object is always the kernel virtual
117 * address minus the VM_MIN_KERNEL_ADDRESS (aka vm_map_min(kernel_map)).
118 * example:
119 *   suppose VM_MIN_KERNEL_ADDRESS is 0xf8000000 and the kernel does a
120 *   uvm_km_alloc(kernel_map, PAGE_SIZE) [allocate 1 wired down page in the
121 *   kernel map].    if uvm_km_alloc returns virtual address 0xf8235000,
122 *   then that means that the page at offset 0x235000 in kernel_object is
123 *   mapped at 0xf8235000.
124 *
125 * kernel object have one other special property: when the kernel virtual
126 * memory mapping them is unmapped, the backing memory in the object is
127 * freed right away.   this is done with the uvm_km_pgremove() function.
128 * this has to be done because there is no backing store for kernel pages
129 * and no need to save them after they are no longer referenced.
130 */
131
132#include <sys/cdefs.h>
133__KERNEL_RCSID(0, "$NetBSD: uvm_km.c,v 1.96 2007/07/21 20:52:59 ad Exp $");
134
135#include "opt_uvmhist.h"
136
137#include <sys/param.h>
138#include <sys/malloc.h>
139#include <sys/systm.h>
140#include <sys/proc.h>
141#include <sys/pool.h>
142
143#include <uvm/uvm.h>
144
145/*
146 * global data structures
147 */
148
149struct vm_map *kernel_map = NULL;
150
151/*
152 * local data structues
153 */
154
155static struct vm_map_kernel	kernel_map_store;
156static struct vm_map_entry	kernel_first_mapent_store;
157
158#if !defined(PMAP_MAP_POOLPAGE)
159
160/*
161 * kva cache
162 *
163 * XXX maybe it's better to do this at the uvm_map layer.
164 */
165
166#define	KM_VACACHE_SIZE	(32 * PAGE_SIZE) /* XXX tune */
167
168static void *km_vacache_alloc(struct pool *, int);
169static void km_vacache_free(struct pool *, void *);
170static void km_vacache_init(struct vm_map *, const char *, size_t);
171
172/* XXX */
173#define	KM_VACACHE_POOL_TO_MAP(pp) \
174	((struct vm_map *)((char *)(pp) - \
175	    offsetof(struct vm_map_kernel, vmk_vacache)))
176
177static void *
178km_vacache_alloc(struct pool *pp, int flags)
179{
180	vaddr_t va;
181	size_t size;
182	struct vm_map *map;
183	size = pp->pr_alloc->pa_pagesz;
184
185	map = KM_VACACHE_POOL_TO_MAP(pp);
186
187	va = vm_map_min(map); /* hint */
188	if (uvm_map(map, &va, size, NULL, UVM_UNKNOWN_OFFSET, size,
189	    UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE,
190	    UVM_ADV_RANDOM, UVM_FLAG_QUANTUM |
191	    ((flags & PR_WAITOK) ? UVM_FLAG_WAITVA :
192	    UVM_FLAG_TRYLOCK | UVM_FLAG_NOWAIT))))
193		return NULL;
194
195	return (void *)va;
196}
197
198static void
199km_vacache_free(struct pool *pp, void *v)
200{
201	vaddr_t va = (vaddr_t)v;
202	size_t size = pp->pr_alloc->pa_pagesz;
203	struct vm_map *map;
204
205	map = KM_VACACHE_POOL_TO_MAP(pp);
206	uvm_unmap1(map, va, va + size, UVM_FLAG_QUANTUM|UVM_FLAG_VAONLY);
207}
208
209/*
210 * km_vacache_init: initialize kva cache.
211 */
212
213static void
214km_vacache_init(struct vm_map *map, const char *name, size_t size)
215{
216	struct vm_map_kernel *vmk;
217	struct pool *pp;
218	struct pool_allocator *pa;
219	int ipl;
220
221	KASSERT(VM_MAP_IS_KERNEL(map));
222	KASSERT(size < (vm_map_max(map) - vm_map_min(map)) / 2); /* sanity */
223
224	vmk = vm_map_to_kernel(map);
225	pp = &vmk->vmk_vacache;
226	pa = &vmk->vmk_vacache_allocator;
227	memset(pa, 0, sizeof(*pa));
228	pa->pa_alloc = km_vacache_alloc;
229	pa->pa_free = km_vacache_free;
230	pa->pa_pagesz = (unsigned int)size;
231	pa->pa_backingmap = map;
232	pa->pa_backingmapptr = NULL;
233
234	if ((map->flags & VM_MAP_INTRSAFE) != 0)
235		ipl = IPL_VM;
236	else
237		ipl = IPL_NONE;
238
239	pool_init(pp, PAGE_SIZE, 0, 0, PR_NOTOUCH | PR_RECURSIVE, name, pa,
240	    ipl);
241}
242
243void
244uvm_km_vacache_init(struct vm_map *map, const char *name, size_t size)
245{
246
247	map->flags |= VM_MAP_VACACHE;
248	if (size == 0)
249		size = KM_VACACHE_SIZE;
250	km_vacache_init(map, name, size);
251}
252
253#else /* !defined(PMAP_MAP_POOLPAGE) */
254
255void
256uvm_km_vacache_init(struct vm_map *map, const char *name, size_t size)
257{
258
259	/* nothing */
260}
261
262#endif /* !defined(PMAP_MAP_POOLPAGE) */
263
264void
265uvm_km_va_drain(struct vm_map *map, uvm_flag_t flags)
266{
267	struct vm_map_kernel *vmk = vm_map_to_kernel(map);
268	const bool intrsafe = (map->flags & VM_MAP_INTRSAFE) != 0;
269	int s = 0xdeadbeaf; /* XXX: gcc */
270
271	if (intrsafe) {
272		s = splvm();
273	}
274	callback_run_roundrobin(&vmk->vmk_reclaim_callback, NULL);
275	if (intrsafe) {
276		splx(s);
277	}
278}
279
280/*
281 * uvm_km_init: init kernel maps and objects to reflect reality (i.e.
282 * KVM already allocated for text, data, bss, and static data structures).
283 *
284 * => KVM is defined by VM_MIN_KERNEL_ADDRESS/VM_MAX_KERNEL_ADDRESS.
285 *    we assume that [vmin -> start] has already been allocated and that
286 *    "end" is the end.
287 */
288
289void
290uvm_km_init(vaddr_t start, vaddr_t end)
291{
292	vaddr_t base = VM_MIN_KERNEL_ADDRESS;
293
294	/*
295	 * next, init kernel memory objects.
296	 */
297
298	/* kernel_object: for pageable anonymous kernel memory */
299	uao_init();
300	uvm_kernel_object = uao_create(VM_MAX_KERNEL_ADDRESS -
301				 VM_MIN_KERNEL_ADDRESS, UAO_FLAG_KERNOBJ);
302
303	/*
304	 * init the map and reserve any space that might already
305	 * have been allocated kernel space before installing.
306	 */
307
308	uvm_map_setup_kernel(&kernel_map_store, base, end, VM_MAP_PAGEABLE);
309	kernel_map_store.vmk_map.pmap = pmap_kernel();
310	if (start != base) {
311		int error;
312		struct uvm_map_args args;
313
314		error = uvm_map_prepare(&kernel_map_store.vmk_map,
315		    base, start - base,
316		    NULL, UVM_UNKNOWN_OFFSET, 0,
317		    UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE,
318		    		UVM_ADV_RANDOM, UVM_FLAG_FIXED), &args);
319		if (!error) {
320			kernel_first_mapent_store.flags =
321			    UVM_MAP_KERNEL | UVM_MAP_FIRST;
322			error = uvm_map_enter(&kernel_map_store.vmk_map, &args,
323			    &kernel_first_mapent_store);
324		}
325
326		if (error)
327			panic(
328			    "uvm_km_init: could not reserve space for kernel");
329	}
330
331	/*
332	 * install!
333	 */
334
335	kernel_map = &kernel_map_store.vmk_map;
336	uvm_km_vacache_init(kernel_map, "kvakernel", 0);
337}
338
339/*
340 * uvm_km_suballoc: allocate a submap in the kernel map.   once a submap
341 * is allocated all references to that area of VM must go through it.  this
342 * allows the locking of VAs in kernel_map to be broken up into regions.
343 *
344 * => if `fixed' is true, *vmin specifies where the region described
345 *      by the submap must start
346 * => if submap is non NULL we use that as the submap, otherwise we
347 *	alloc a new map
348 */
349
350struct vm_map *
351uvm_km_suballoc(struct vm_map *map, vaddr_t *vmin /* IN/OUT */,
352    vaddr_t *vmax /* OUT */, vsize_t size, int flags, bool fixed,
353    struct vm_map_kernel *submap)
354{
355	int mapflags = UVM_FLAG_NOMERGE | (fixed ? UVM_FLAG_FIXED : 0);
356
357	KASSERT(vm_map_pmap(map) == pmap_kernel());
358
359	size = round_page(size);	/* round up to pagesize */
360	size += uvm_mapent_overhead(size, flags);
361
362	/*
363	 * first allocate a blank spot in the parent map
364	 */
365
366	if (uvm_map(map, vmin, size, NULL, UVM_UNKNOWN_OFFSET, 0,
367	    UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE,
368	    UVM_ADV_RANDOM, mapflags)) != 0) {
369	       panic("uvm_km_suballoc: unable to allocate space in parent map");
370	}
371
372	/*
373	 * set VM bounds (vmin is filled in by uvm_map)
374	 */
375
376	*vmax = *vmin + size;
377
378	/*
379	 * add references to pmap and create or init the submap
380	 */
381
382	pmap_reference(vm_map_pmap(map));
383	if (submap == NULL) {
384		submap = malloc(sizeof(*submap), M_VMMAP, M_WAITOK);
385		if (submap == NULL)
386			panic("uvm_km_suballoc: unable to create submap");
387	}
388	uvm_map_setup_kernel(submap, *vmin, *vmax, flags);
389	submap->vmk_map.pmap = vm_map_pmap(map);
390
391	/*
392	 * now let uvm_map_submap plug in it...
393	 */
394
395	if (uvm_map_submap(map, *vmin, *vmax, &submap->vmk_map) != 0)
396		panic("uvm_km_suballoc: submap allocation failed");
397
398	return(&submap->vmk_map);
399}
400
401/*
402 * uvm_km_pgremove: remove pages from a kernel uvm_object.
403 *
404 * => when you unmap a part of anonymous kernel memory you want to toss
405 *    the pages right away.    (this gets called from uvm_unmap_...).
406 */
407
408void
409uvm_km_pgremove(vaddr_t startva, vaddr_t endva)
410{
411	struct uvm_object * const uobj = uvm_kernel_object;
412	const voff_t start = startva - vm_map_min(kernel_map);
413	const voff_t end = endva - vm_map_min(kernel_map);
414	struct vm_page *pg;
415	voff_t curoff, nextoff;
416	int swpgonlydelta = 0;
417	UVMHIST_FUNC("uvm_km_pgremove"); UVMHIST_CALLED(maphist);
418
419	KASSERT(VM_MIN_KERNEL_ADDRESS <= startva);
420	KASSERT(startva < endva);
421	KASSERT(endva <= VM_MAX_KERNEL_ADDRESS);
422
423	simple_lock(&uobj->vmobjlock);
424
425	for (curoff = start; curoff < end; curoff = nextoff) {
426		nextoff = curoff + PAGE_SIZE;
427		pg = uvm_pagelookup(uobj, curoff);
428		if (pg != NULL && pg->flags & PG_BUSY) {
429			pg->flags |= PG_WANTED;
430			UVM_UNLOCK_AND_WAIT(pg, &uobj->vmobjlock, 0,
431				    "km_pgrm", 0);
432			simple_lock(&uobj->vmobjlock);
433			nextoff = curoff;
434			continue;
435		}
436
437		/*
438		 * free the swap slot, then the page.
439		 */
440
441		if (pg == NULL &&
442		    uao_find_swslot(uobj, curoff >> PAGE_SHIFT) > 0) {
443			swpgonlydelta++;
444		}
445		uao_dropswap(uobj, curoff >> PAGE_SHIFT);
446		if (pg != NULL) {
447			uvm_lock_pageq();
448			uvm_pagefree(pg);
449			uvm_unlock_pageq();
450		}
451	}
452	simple_unlock(&uobj->vmobjlock);
453
454	if (swpgonlydelta > 0) {
455		mutex_enter(&uvm_swap_data_lock);
456		KASSERT(uvmexp.swpgonly >= swpgonlydelta);
457		uvmexp.swpgonly -= swpgonlydelta;
458		mutex_exit(&uvm_swap_data_lock);
459	}
460}
461
462
463/*
464 * uvm_km_pgremove_intrsafe: like uvm_km_pgremove(), but for non object backed
465 *    regions.
466 *
467 * => when you unmap a part of anonymous kernel memory you want to toss
468 *    the pages right away.    (this is called from uvm_unmap_...).
469 * => none of the pages will ever be busy, and none of them will ever
470 *    be on the active or inactive queues (because they have no object).
471 */
472
473void
474uvm_km_pgremove_intrsafe(vaddr_t start, vaddr_t end)
475{
476	struct vm_page *pg;
477	paddr_t pa;
478	UVMHIST_FUNC("uvm_km_pgremove_intrsafe"); UVMHIST_CALLED(maphist);
479
480	KASSERT(VM_MIN_KERNEL_ADDRESS <= start);
481	KASSERT(start < end);
482	KASSERT(end <= VM_MAX_KERNEL_ADDRESS);
483
484	for (; start < end; start += PAGE_SIZE) {
485		if (!pmap_extract(pmap_kernel(), start, &pa)) {
486			continue;
487		}
488		pg = PHYS_TO_VM_PAGE(pa);
489		KASSERT(pg);
490		KASSERT(pg->uobject == NULL && pg->uanon == NULL);
491		uvm_pagefree(pg);
492	}
493}
494
495#if defined(DEBUG)
496void
497uvm_km_check_empty(vaddr_t start, vaddr_t end, bool intrsafe)
498{
499	vaddr_t va;
500	paddr_t pa;
501
502	KDASSERT(VM_MIN_KERNEL_ADDRESS <= start);
503	KDASSERT(start < end);
504	KDASSERT(end <= VM_MAX_KERNEL_ADDRESS);
505
506	for (va = start; va < end; va += PAGE_SIZE) {
507		if (pmap_extract(pmap_kernel(), va, &pa)) {
508			panic("uvm_km_check_empty: va %p has pa 0x%llx",
509			    (void *)va, (long long)pa);
510		}
511		if (!intrsafe) {
512			const struct vm_page *pg;
513
514			simple_lock(&uvm_kernel_object->vmobjlock);
515			pg = uvm_pagelookup(uvm_kernel_object,
516			    va - vm_map_min(kernel_map));
517			simple_unlock(&uvm_kernel_object->vmobjlock);
518			if (pg) {
519				panic("uvm_km_check_empty: "
520				    "has page hashed at %p", (const void *)va);
521			}
522		}
523	}
524}
525#endif /* defined(DEBUG) */
526
527/*
528 * uvm_km_alloc: allocate an area of kernel memory.
529 *
530 * => NOTE: we can return 0 even if we can wait if there is not enough
531 *	free VM space in the map... caller should be prepared to handle
532 *	this case.
533 * => we return KVA of memory allocated
534 */
535
536vaddr_t
537uvm_km_alloc(struct vm_map *map, vsize_t size, vsize_t align, uvm_flag_t flags)
538{
539	vaddr_t kva, loopva;
540	vaddr_t offset;
541	vsize_t loopsize;
542	struct vm_page *pg;
543	struct uvm_object *obj;
544	int pgaflags;
545	vm_prot_t prot;
546	UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
547
548	KASSERT(vm_map_pmap(map) == pmap_kernel());
549	KASSERT((flags & UVM_KMF_TYPEMASK) == UVM_KMF_WIRED ||
550		(flags & UVM_KMF_TYPEMASK) == UVM_KMF_PAGEABLE ||
551		(flags & UVM_KMF_TYPEMASK) == UVM_KMF_VAONLY);
552
553	/*
554	 * setup for call
555	 */
556
557	kva = vm_map_min(map);	/* hint */
558	size = round_page(size);
559	obj = (flags & UVM_KMF_PAGEABLE) ? uvm_kernel_object : NULL;
560	UVMHIST_LOG(maphist,"  (map=0x%x, obj=0x%x, size=0x%x, flags=%d)",
561		    map, obj, size, flags);
562
563	/*
564	 * allocate some virtual space
565	 */
566
567	if (__predict_false(uvm_map(map, &kva, size, obj, UVM_UNKNOWN_OFFSET,
568	    align, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE,
569	    UVM_ADV_RANDOM,
570	    (flags & (UVM_KMF_TRYLOCK | UVM_KMF_NOWAIT | UVM_KMF_WAITVA))
571	    | UVM_FLAG_QUANTUM)) != 0)) {
572		UVMHIST_LOG(maphist, "<- done (no VM)",0,0,0,0);
573		return(0);
574	}
575
576	/*
577	 * if all we wanted was VA, return now
578	 */
579
580	if (flags & (UVM_KMF_VAONLY | UVM_KMF_PAGEABLE)) {
581		UVMHIST_LOG(maphist,"<- done valloc (kva=0x%x)", kva,0,0,0);
582		return(kva);
583	}
584
585	/*
586	 * recover object offset from virtual address
587	 */
588
589	offset = kva - vm_map_min(kernel_map);
590	UVMHIST_LOG(maphist, "  kva=0x%x, offset=0x%x", kva, offset,0,0);
591
592	/*
593	 * now allocate and map in the memory... note that we are the only ones
594	 * whom should ever get a handle on this area of VM.
595	 */
596
597	loopva = kva;
598	loopsize = size;
599
600	pgaflags = UVM_PGA_USERESERVE;
601	if (flags & UVM_KMF_ZERO)
602		pgaflags |= UVM_PGA_ZERO;
603	prot = VM_PROT_READ | VM_PROT_WRITE;
604	if (flags & UVM_KMF_EXEC)
605		prot |= VM_PROT_EXECUTE;
606	while (loopsize) {
607		KASSERT(!pmap_extract(pmap_kernel(), loopva, NULL));
608
609		pg = uvm_pagealloc(NULL, offset, NULL, pgaflags);
610
611		/*
612		 * out of memory?
613		 */
614
615		if (__predict_false(pg == NULL)) {
616			if ((flags & UVM_KMF_NOWAIT) ||
617			    ((flags & UVM_KMF_CANFAIL) && !uvm_reclaimable())) {
618				/* free everything! */
619				uvm_km_free(map, kva, size,
620				    flags & UVM_KMF_TYPEMASK);
621				return (0);
622			} else {
623				uvm_wait("km_getwait2");	/* sleep here */
624				continue;
625			}
626		}
627
628		pg->flags &= ~PG_BUSY;	/* new page */
629		UVM_PAGE_OWN(pg, NULL);
630
631		/*
632		 * map it in
633		 */
634
635		pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), prot);
636		loopva += PAGE_SIZE;
637		offset += PAGE_SIZE;
638		loopsize -= PAGE_SIZE;
639	}
640
641       	pmap_update(pmap_kernel());
642
643	UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0);
644	return(kva);
645}
646
647/*
648 * uvm_km_free: free an area of kernel memory
649 */
650
651void
652uvm_km_free(struct vm_map *map, vaddr_t addr, vsize_t size, uvm_flag_t flags)
653{
654
655	KASSERT((flags & UVM_KMF_TYPEMASK) == UVM_KMF_WIRED ||
656		(flags & UVM_KMF_TYPEMASK) == UVM_KMF_PAGEABLE ||
657		(flags & UVM_KMF_TYPEMASK) == UVM_KMF_VAONLY);
658	KASSERT((addr & PAGE_MASK) == 0);
659	KASSERT(vm_map_pmap(map) == pmap_kernel());
660
661	size = round_page(size);
662
663	if (flags & UVM_KMF_PAGEABLE) {
664		uvm_km_pgremove(addr, addr + size);
665		pmap_remove(pmap_kernel(), addr, addr + size);
666	} else if (flags & UVM_KMF_WIRED) {
667		uvm_km_pgremove_intrsafe(addr, addr + size);
668		pmap_kremove(addr, size);
669	}
670
671	uvm_unmap1(map, addr, addr + size, UVM_FLAG_QUANTUM|UVM_FLAG_VAONLY);
672}
673
674/* Sanity; must specify both or none. */
675#if (defined(PMAP_MAP_POOLPAGE) || defined(PMAP_UNMAP_POOLPAGE)) && \
676    (!defined(PMAP_MAP_POOLPAGE) || !defined(PMAP_UNMAP_POOLPAGE))
677#error Must specify MAP and UNMAP together.
678#endif
679
680/*
681 * uvm_km_alloc_poolpage: allocate a page for the pool allocator
682 *
683 * => if the pmap specifies an alternate mapping method, we use it.
684 */
685
686/* ARGSUSED */
687vaddr_t
688uvm_km_alloc_poolpage_cache(struct vm_map *map, bool waitok)
689{
690#if defined(PMAP_MAP_POOLPAGE)
691	return uvm_km_alloc_poolpage(map, waitok);
692#else
693	struct vm_page *pg;
694	struct pool *pp = &vm_map_to_kernel(map)->vmk_vacache;
695	vaddr_t va;
696	int s = 0xdeadbeaf; /* XXX: gcc */
697	const bool intrsafe = (map->flags & VM_MAP_INTRSAFE) != 0;
698
699	if ((map->flags & VM_MAP_VACACHE) == 0)
700		return uvm_km_alloc_poolpage(map, waitok);
701
702	if (intrsafe)
703		s = splvm();
704	va = (vaddr_t)pool_get(pp, waitok ? PR_WAITOK : PR_NOWAIT);
705	if (intrsafe)
706		splx(s);
707	if (va == 0)
708		return 0;
709	KASSERT(!pmap_extract(pmap_kernel(), va, NULL));
710again:
711	pg = uvm_pagealloc(NULL, 0, NULL, UVM_PGA_USERESERVE);
712	if (__predict_false(pg == NULL)) {
713		if (waitok) {
714			uvm_wait("plpg");
715			goto again;
716		} else {
717			if (intrsafe)
718				s = splvm();
719			pool_put(pp, (void *)va);
720			if (intrsafe)
721				splx(s);
722			return 0;
723		}
724	}
725	pmap_kenter_pa(va, VM_PAGE_TO_PHYS(pg), VM_PROT_READ|VM_PROT_WRITE);
726	pmap_update(pmap_kernel());
727
728	return va;
729#endif /* PMAP_MAP_POOLPAGE */
730}
731
732vaddr_t
733uvm_km_alloc_poolpage(struct vm_map *map, bool waitok)
734{
735#if defined(PMAP_MAP_POOLPAGE)
736	struct vm_page *pg;
737	vaddr_t va;
738
739 again:
740	pg = uvm_pagealloc(NULL, 0, NULL, UVM_PGA_USERESERVE);
741	if (__predict_false(pg == NULL)) {
742		if (waitok) {
743			uvm_wait("plpg");
744			goto again;
745		} else
746			return (0);
747	}
748	va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg));
749	if (__predict_false(va == 0))
750		uvm_pagefree(pg);
751	return (va);
752#else
753	vaddr_t va;
754	int s = 0xdeadbeaf; /* XXX: gcc */
755	const bool intrsafe = (map->flags & VM_MAP_INTRSAFE) != 0;
756
757	if (intrsafe)
758		s = splvm();
759	va = uvm_km_alloc(map, PAGE_SIZE, 0,
760	    (waitok ? 0 : UVM_KMF_NOWAIT | UVM_KMF_TRYLOCK) | UVM_KMF_WIRED);
761	if (intrsafe)
762		splx(s);
763	return (va);
764#endif /* PMAP_MAP_POOLPAGE */
765}
766
767/*
768 * uvm_km_free_poolpage: free a previously allocated pool page
769 *
770 * => if the pmap specifies an alternate unmapping method, we use it.
771 */
772
773/* ARGSUSED */
774void
775uvm_km_free_poolpage_cache(struct vm_map *map, vaddr_t addr)
776{
777#if defined(PMAP_UNMAP_POOLPAGE)
778	uvm_km_free_poolpage(map, addr);
779#else
780	struct pool *pp;
781	int s = 0xdeadbeaf; /* XXX: gcc */
782	const bool intrsafe = (map->flags & VM_MAP_INTRSAFE) != 0;
783
784	if ((map->flags & VM_MAP_VACACHE) == 0) {
785		uvm_km_free_poolpage(map, addr);
786		return;
787	}
788
789	KASSERT(pmap_extract(pmap_kernel(), addr, NULL));
790	uvm_km_pgremove_intrsafe(addr, addr + PAGE_SIZE);
791	pmap_kremove(addr, PAGE_SIZE);
792#if defined(DEBUG)
793	pmap_update(pmap_kernel());
794#endif
795	KASSERT(!pmap_extract(pmap_kernel(), addr, NULL));
796	pp = &vm_map_to_kernel(map)->vmk_vacache;
797	if (intrsafe)
798		s = splvm();
799	pool_put(pp, (void *)addr);
800	if (intrsafe)
801		splx(s);
802#endif
803}
804
805/* ARGSUSED */
806void
807uvm_km_free_poolpage(struct vm_map *map, vaddr_t addr)
808{
809#if defined(PMAP_UNMAP_POOLPAGE)
810	paddr_t pa;
811
812	pa = PMAP_UNMAP_POOLPAGE(addr);
813	uvm_pagefree(PHYS_TO_VM_PAGE(pa));
814#else
815	int s = 0xdeadbeaf; /* XXX: gcc */
816	const bool intrsafe = (map->flags & VM_MAP_INTRSAFE) != 0;
817
818	if (intrsafe)
819		s = splvm();
820	uvm_km_free(map, addr, PAGE_SIZE, UVM_KMF_WIRED);
821	if (intrsafe)
822		splx(s);
823#endif /* PMAP_UNMAP_POOLPAGE */
824}
825