xref: /netbsd-src/sys/uvm/uvm_km.c (revision aaf4ece63a859a04e37cf3a7229b5fab0157cc06)
1 /*	$NetBSD: uvm_km.c,v 1.84 2005/12/11 12:25:29 christos 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 1.84 2005/12/11 12:25:29 christos 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 
149 struct vm_map *kernel_map = NULL;
150 
151 /*
152  * local data structues
153  */
154 
155 static struct vm_map_kernel	kernel_map_store;
156 static 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 
168 static void *km_vacache_alloc(struct pool *, int);
169 static void km_vacache_free(struct pool *, void *);
170 static 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 
177 static void *
178 km_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) ? 0 : UVM_FLAG_TRYLOCK | UVM_FLAG_NOWAIT))))
192 		return NULL;
193 
194 	return (void *)va;
195 }
196 
197 static void
198 km_vacache_free(struct pool *pp, void *v)
199 {
200 	vaddr_t va = (vaddr_t)v;
201 	size_t size = pp->pr_alloc->pa_pagesz;
202 	struct vm_map *map;
203 
204 	map = KM_VACACHE_POOL_TO_MAP(pp);
205 	uvm_unmap1(map, va, va + size, UVM_FLAG_QUANTUM|UVM_FLAG_VAONLY);
206 }
207 
208 /*
209  * km_vacache_init: initialize kva cache.
210  */
211 
212 static void
213 km_vacache_init(struct vm_map *map, const char *name, size_t size)
214 {
215 	struct vm_map_kernel *vmk;
216 	struct pool *pp;
217 	struct pool_allocator *pa;
218 
219 	KASSERT(VM_MAP_IS_KERNEL(map));
220 	KASSERT(size < (vm_map_max(map) - vm_map_min(map)) / 2); /* sanity */
221 
222 	vmk = vm_map_to_kernel(map);
223 	pp = &vmk->vmk_vacache;
224 	pa = &vmk->vmk_vacache_allocator;
225 	memset(pa, 0, sizeof(*pa));
226 	pa->pa_alloc = km_vacache_alloc;
227 	pa->pa_free = km_vacache_free;
228 	pa->pa_pagesz = (unsigned int)size;
229 	pool_init(pp, PAGE_SIZE, 0, 0, PR_NOTOUCH | PR_RECURSIVE, name, pa);
230 
231 	/* XXX for now.. */
232 	pool_sethiwat(pp, 0);
233 }
234 
235 void
236 uvm_km_vacache_init(struct vm_map *map, const char *name, size_t size)
237 {
238 
239 	map->flags |= VM_MAP_VACACHE;
240 	if (size == 0)
241 		size = KM_VACACHE_SIZE;
242 	km_vacache_init(map, name, size);
243 }
244 
245 #else /* !defined(PMAP_MAP_POOLPAGE) */
246 
247 void
248 uvm_km_vacache_init(struct vm_map *map, const char *name, size_t size)
249 {
250 
251 	/* nothing */
252 }
253 
254 #endif /* !defined(PMAP_MAP_POOLPAGE) */
255 
256 /*
257  * uvm_km_init: init kernel maps and objects to reflect reality (i.e.
258  * KVM already allocated for text, data, bss, and static data structures).
259  *
260  * => KVM is defined by VM_MIN_KERNEL_ADDRESS/VM_MAX_KERNEL_ADDRESS.
261  *    we assume that [vmin -> start] has already been allocated and that
262  *    "end" is the end.
263  */
264 
265 void
266 uvm_km_init(vaddr_t start, vaddr_t end)
267 {
268 	vaddr_t base = VM_MIN_KERNEL_ADDRESS;
269 
270 	/*
271 	 * next, init kernel memory objects.
272 	 */
273 
274 	/* kernel_object: for pageable anonymous kernel memory */
275 	uao_init();
276 	uvm.kernel_object = uao_create(VM_MAX_KERNEL_ADDRESS -
277 				 VM_MIN_KERNEL_ADDRESS, UAO_FLAG_KERNOBJ);
278 
279 	/*
280 	 * init the map and reserve any space that might already
281 	 * have been allocated kernel space before installing.
282 	 */
283 
284 	uvm_map_setup_kernel(&kernel_map_store, base, end, VM_MAP_PAGEABLE);
285 	kernel_map_store.vmk_map.pmap = pmap_kernel();
286 	if (start != base) {
287 		int error;
288 		struct uvm_map_args args;
289 
290 		error = uvm_map_prepare(&kernel_map_store.vmk_map,
291 		    base, start - base,
292 		    NULL, UVM_UNKNOWN_OFFSET, 0,
293 		    UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE,
294 		    		UVM_ADV_RANDOM, UVM_FLAG_FIXED), &args);
295 		if (!error) {
296 			kernel_first_mapent_store.flags =
297 			    UVM_MAP_KERNEL | UVM_MAP_FIRST;
298 			error = uvm_map_enter(&kernel_map_store.vmk_map, &args,
299 			    &kernel_first_mapent_store);
300 		}
301 
302 		if (error)
303 			panic(
304 			    "uvm_km_init: could not reserve space for kernel");
305 	}
306 
307 	/*
308 	 * install!
309 	 */
310 
311 	kernel_map = &kernel_map_store.vmk_map;
312 	uvm_km_vacache_init(kernel_map, "kvakernel", 0);
313 }
314 
315 /*
316  * uvm_km_suballoc: allocate a submap in the kernel map.   once a submap
317  * is allocated all references to that area of VM must go through it.  this
318  * allows the locking of VAs in kernel_map to be broken up into regions.
319  *
320  * => if `fixed' is true, *vmin specifies where the region described
321  *      by the submap must start
322  * => if submap is non NULL we use that as the submap, otherwise we
323  *	alloc a new map
324  */
325 
326 struct vm_map *
327 uvm_km_suballoc(struct vm_map *map, vaddr_t *vmin /* IN/OUT */,
328     vaddr_t *vmax /* OUT */, vsize_t size, int flags, boolean_t fixed,
329     struct vm_map_kernel *submap)
330 {
331 	int mapflags = UVM_FLAG_NOMERGE | (fixed ? UVM_FLAG_FIXED : 0);
332 
333 	KASSERT(vm_map_pmap(map) == pmap_kernel());
334 
335 	size = round_page(size);	/* round up to pagesize */
336 
337 	/*
338 	 * first allocate a blank spot in the parent map
339 	 */
340 
341 	if (uvm_map(map, vmin, size, NULL, UVM_UNKNOWN_OFFSET, 0,
342 	    UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE,
343 	    UVM_ADV_RANDOM, mapflags)) != 0) {
344 	       panic("uvm_km_suballoc: unable to allocate space in parent map");
345 	}
346 
347 	/*
348 	 * set VM bounds (vmin is filled in by uvm_map)
349 	 */
350 
351 	*vmax = *vmin + size;
352 
353 	/*
354 	 * add references to pmap and create or init the submap
355 	 */
356 
357 	pmap_reference(vm_map_pmap(map));
358 	if (submap == NULL) {
359 		submap = malloc(sizeof(*submap), M_VMMAP, M_WAITOK);
360 		if (submap == NULL)
361 			panic("uvm_km_suballoc: unable to create submap");
362 	}
363 	uvm_map_setup_kernel(submap, *vmin, *vmax, flags);
364 	submap->vmk_map.pmap = vm_map_pmap(map);
365 
366 	/*
367 	 * now let uvm_map_submap plug in it...
368 	 */
369 
370 	if (uvm_map_submap(map, *vmin, *vmax, &submap->vmk_map) != 0)
371 		panic("uvm_km_suballoc: submap allocation failed");
372 
373 	return(&submap->vmk_map);
374 }
375 
376 /*
377  * uvm_km_pgremove: remove pages from a kernel uvm_object.
378  *
379  * => when you unmap a part of anonymous kernel memory you want to toss
380  *    the pages right away.    (this gets called from uvm_unmap_...).
381  */
382 
383 void
384 uvm_km_pgremove(vaddr_t startva, vaddr_t endva)
385 {
386 	struct uvm_object * const uobj = uvm.kernel_object;
387 	const voff_t start = startva - vm_map_min(kernel_map);
388 	const voff_t end = endva - vm_map_min(kernel_map);
389 	struct vm_page *pg;
390 	voff_t curoff, nextoff;
391 	int swpgonlydelta = 0;
392 	UVMHIST_FUNC("uvm_km_pgremove"); UVMHIST_CALLED(maphist);
393 
394 	KASSERT(VM_MIN_KERNEL_ADDRESS <= startva);
395 	KASSERT(startva < endva);
396 	KASSERT(endva < VM_MAX_KERNEL_ADDRESS);
397 
398 	simple_lock(&uobj->vmobjlock);
399 
400 	for (curoff = start; curoff < end; curoff = nextoff) {
401 		nextoff = curoff + PAGE_SIZE;
402 		pg = uvm_pagelookup(uobj, curoff);
403 		if (pg != NULL && pg->flags & PG_BUSY) {
404 			pg->flags |= PG_WANTED;
405 			UVM_UNLOCK_AND_WAIT(pg, &uobj->vmobjlock, 0,
406 				    "km_pgrm", 0);
407 			simple_lock(&uobj->vmobjlock);
408 			nextoff = curoff;
409 			continue;
410 		}
411 
412 		/*
413 		 * free the swap slot, then the page.
414 		 */
415 
416 		if (pg == NULL &&
417 		    uao_find_swslot(uobj, curoff >> PAGE_SHIFT) > 0) {
418 			swpgonlydelta++;
419 		}
420 		uao_dropswap(uobj, curoff >> PAGE_SHIFT);
421 		if (pg != NULL) {
422 			uvm_lock_pageq();
423 			uvm_pagefree(pg);
424 			uvm_unlock_pageq();
425 		}
426 	}
427 	simple_unlock(&uobj->vmobjlock);
428 
429 	if (swpgonlydelta > 0) {
430 		simple_lock(&uvm.swap_data_lock);
431 		KASSERT(uvmexp.swpgonly >= swpgonlydelta);
432 		uvmexp.swpgonly -= swpgonlydelta;
433 		simple_unlock(&uvm.swap_data_lock);
434 	}
435 }
436 
437 
438 /*
439  * uvm_km_pgremove_intrsafe: like uvm_km_pgremove(), but for non object backed
440  *    regions.
441  *
442  * => when you unmap a part of anonymous kernel memory you want to toss
443  *    the pages right away.    (this is called from uvm_unmap_...).
444  * => none of the pages will ever be busy, and none of them will ever
445  *    be on the active or inactive queues (because they have no object).
446  */
447 
448 void
449 uvm_km_pgremove_intrsafe(vaddr_t start, vaddr_t end)
450 {
451 	struct vm_page *pg;
452 	paddr_t pa;
453 	UVMHIST_FUNC("uvm_km_pgremove_intrsafe"); UVMHIST_CALLED(maphist);
454 
455 	KASSERT(VM_MIN_KERNEL_ADDRESS <= start);
456 	KASSERT(start < end);
457 	KASSERT(end < VM_MAX_KERNEL_ADDRESS);
458 
459 	for (; start < end; start += PAGE_SIZE) {
460 		if (!pmap_extract(pmap_kernel(), start, &pa)) {
461 			continue;
462 		}
463 		pg = PHYS_TO_VM_PAGE(pa);
464 		KASSERT(pg);
465 		KASSERT(pg->uobject == NULL && pg->uanon == NULL);
466 		uvm_pagefree(pg);
467 	}
468 }
469 
470 #if defined(DEBUG)
471 void
472 uvm_km_check_empty(vaddr_t start, vaddr_t end, boolean_t intrsafe)
473 {
474 	vaddr_t va;
475 	paddr_t pa;
476 
477 	KDASSERT(VM_MIN_KERNEL_ADDRESS <= start);
478 	KDASSERT(start < end);
479 	KDASSERT(end < VM_MAX_KERNEL_ADDRESS);
480 
481 	for (va = start; va < end; va += PAGE_SIZE) {
482 		if (pmap_extract(pmap_kernel(), va, &pa)) {
483 			panic("uvm_km_check_empty: va %p has pa 0x%llx",
484 			    (void *)va, (long long)pa);
485 		}
486 		if (!intrsafe) {
487 			const struct vm_page *pg;
488 
489 			simple_lock(&uvm.kernel_object->vmobjlock);
490 			pg = uvm_pagelookup(uvm.kernel_object,
491 			    va - vm_map_min(kernel_map));
492 			simple_unlock(&uvm.kernel_object->vmobjlock);
493 			if (pg) {
494 				panic("uvm_km_check_empty: "
495 				    "has page hashed at %p", (const void *)va);
496 			}
497 		}
498 	}
499 }
500 #endif /* defined(DEBUG) */
501 
502 /*
503  * uvm_km_alloc: allocate an area of kernel memory.
504  *
505  * => NOTE: we can return 0 even if we can wait if there is not enough
506  *	free VM space in the map... caller should be prepared to handle
507  *	this case.
508  * => we return KVA of memory allocated
509  */
510 
511 vaddr_t
512 uvm_km_alloc(struct vm_map *map, vsize_t size, vsize_t align, uvm_flag_t flags)
513 {
514 	vaddr_t kva, loopva;
515 	vaddr_t offset;
516 	vsize_t loopsize;
517 	struct vm_page *pg;
518 	struct uvm_object *obj;
519 	int pgaflags;
520 	UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
521 
522 	KASSERT(vm_map_pmap(map) == pmap_kernel());
523 	KASSERT((flags & UVM_KMF_TYPEMASK) == UVM_KMF_WIRED ||
524 		(flags & UVM_KMF_TYPEMASK) == UVM_KMF_PAGEABLE ||
525 		(flags & UVM_KMF_TYPEMASK) == UVM_KMF_VAONLY);
526 
527 	/*
528 	 * setup for call
529 	 */
530 
531 	kva = vm_map_min(map);	/* hint */
532 	size = round_page(size);
533 	obj = (flags & UVM_KMF_PAGEABLE) ? uvm.kernel_object : NULL;
534 	UVMHIST_LOG(maphist,"  (map=0x%x, obj=0x%x, size=0x%x, flags=%d)",
535 		    map, obj, size, flags);
536 
537 	/*
538 	 * allocate some virtual space
539 	 */
540 
541 	if (__predict_false(uvm_map(map, &kva, size, obj, UVM_UNKNOWN_OFFSET,
542 	    align, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE,
543 	    UVM_ADV_RANDOM,
544 	    (flags & (UVM_KMF_TRYLOCK | UVM_KMF_NOWAIT | UVM_KMF_WAITVA))
545 	    | UVM_FLAG_QUANTUM)) != 0)) {
546 		UVMHIST_LOG(maphist, "<- done (no VM)",0,0,0,0);
547 		return(0);
548 	}
549 
550 	/*
551 	 * if all we wanted was VA, return now
552 	 */
553 
554 	if (flags & (UVM_KMF_VAONLY | UVM_KMF_PAGEABLE)) {
555 		UVMHIST_LOG(maphist,"<- done valloc (kva=0x%x)", kva,0,0,0);
556 		return(kva);
557 	}
558 
559 	/*
560 	 * recover object offset from virtual address
561 	 */
562 
563 	offset = kva - vm_map_min(kernel_map);
564 	UVMHIST_LOG(maphist, "  kva=0x%x, offset=0x%x", kva, offset,0,0);
565 
566 	/*
567 	 * now allocate and map in the memory... note that we are the only ones
568 	 * whom should ever get a handle on this area of VM.
569 	 */
570 
571 	loopva = kva;
572 	loopsize = size;
573 
574 	pgaflags = UVM_PGA_USERESERVE;
575 	if (flags & UVM_KMF_ZERO)
576 		pgaflags |= UVM_PGA_ZERO;
577 	while (loopsize) {
578 		KASSERT(!pmap_extract(pmap_kernel(), loopva, NULL));
579 
580 		pg = uvm_pagealloc(NULL, offset, NULL, pgaflags);
581 
582 		/*
583 		 * out of memory?
584 		 */
585 
586 		if (__predict_false(pg == NULL)) {
587 			if ((flags & UVM_KMF_NOWAIT) ||
588 			    ((flags & UVM_KMF_CANFAIL) && !uvm_reclaimable())) {
589 				/* free everything! */
590 				uvm_km_free(map, kva, size,
591 				    flags & UVM_KMF_TYPEMASK);
592 				return (0);
593 			} else {
594 				uvm_wait("km_getwait2");	/* sleep here */
595 				continue;
596 			}
597 		}
598 
599 		pg->flags &= ~PG_BUSY;	/* new page */
600 		UVM_PAGE_OWN(pg, NULL);
601 
602 		/*
603 		 * map it in
604 		 */
605 
606 		pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg),
607 		    VM_PROT_READ | VM_PROT_WRITE);
608 		loopva += PAGE_SIZE;
609 		offset += PAGE_SIZE;
610 		loopsize -= PAGE_SIZE;
611 	}
612 
613        	pmap_update(pmap_kernel());
614 
615 	UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0);
616 	return(kva);
617 }
618 
619 /*
620  * uvm_km_free: free an area of kernel memory
621  */
622 
623 void
624 uvm_km_free(struct vm_map *map, vaddr_t addr, vsize_t size, uvm_flag_t flags)
625 {
626 
627 	KASSERT((flags & UVM_KMF_TYPEMASK) == UVM_KMF_WIRED ||
628 		(flags & UVM_KMF_TYPEMASK) == UVM_KMF_PAGEABLE ||
629 		(flags & UVM_KMF_TYPEMASK) == UVM_KMF_VAONLY);
630 	KASSERT((addr & PAGE_MASK) == 0);
631 	KASSERT(vm_map_pmap(map) == pmap_kernel());
632 
633 	size = round_page(size);
634 
635 	if (flags & UVM_KMF_PAGEABLE) {
636 		uvm_km_pgremove(addr, addr + size);
637 		pmap_remove(pmap_kernel(), addr, addr + size);
638 	} else if (flags & UVM_KMF_WIRED) {
639 		uvm_km_pgremove_intrsafe(addr, addr + size);
640 		pmap_kremove(addr, size);
641 	}
642 
643 	uvm_unmap1(map, addr, addr + size, UVM_FLAG_QUANTUM|UVM_FLAG_VAONLY);
644 }
645 
646 /* Sanity; must specify both or none. */
647 #if (defined(PMAP_MAP_POOLPAGE) || defined(PMAP_UNMAP_POOLPAGE)) && \
648     (!defined(PMAP_MAP_POOLPAGE) || !defined(PMAP_UNMAP_POOLPAGE))
649 #error Must specify MAP and UNMAP together.
650 #endif
651 
652 /*
653  * uvm_km_alloc_poolpage: allocate a page for the pool allocator
654  *
655  * => if the pmap specifies an alternate mapping method, we use it.
656  */
657 
658 /* ARGSUSED */
659 vaddr_t
660 uvm_km_alloc_poolpage_cache(struct vm_map *map, boolean_t waitok)
661 {
662 #if defined(PMAP_MAP_POOLPAGE)
663 	return uvm_km_alloc_poolpage(map, waitok);
664 #else
665 	struct vm_page *pg;
666 	struct pool *pp = &vm_map_to_kernel(map)->vmk_vacache;
667 	vaddr_t va;
668 	int s = 0xdeadbeaf; /* XXX: gcc */
669 	const boolean_t intrsafe = (map->flags & VM_MAP_INTRSAFE) != 0;
670 
671 	if ((map->flags & VM_MAP_VACACHE) == 0)
672 		return uvm_km_alloc_poolpage(map, waitok);
673 
674 	if (intrsafe)
675 		s = splvm();
676 	va = (vaddr_t)pool_get(pp, waitok ? PR_WAITOK : PR_NOWAIT);
677 	if (intrsafe)
678 		splx(s);
679 	if (va == 0)
680 		return 0;
681 	KASSERT(!pmap_extract(pmap_kernel(), va, NULL));
682 again:
683 	pg = uvm_pagealloc(NULL, 0, NULL, UVM_PGA_USERESERVE);
684 	if (__predict_false(pg == NULL)) {
685 		if (waitok) {
686 			uvm_wait("plpg");
687 			goto again;
688 		} else {
689 			if (intrsafe)
690 				s = splvm();
691 			pool_put(pp, (void *)va);
692 			if (intrsafe)
693 				splx(s);
694 			return 0;
695 		}
696 	}
697 	pmap_kenter_pa(va, VM_PAGE_TO_PHYS(pg), VM_PROT_READ|VM_PROT_WRITE);
698 	pmap_update(pmap_kernel());
699 
700 	return va;
701 #endif /* PMAP_MAP_POOLPAGE */
702 }
703 
704 vaddr_t
705 uvm_km_alloc_poolpage(struct vm_map *map, boolean_t waitok)
706 {
707 #if defined(PMAP_MAP_POOLPAGE)
708 	struct vm_page *pg;
709 	vaddr_t va;
710 
711  again:
712 	pg = uvm_pagealloc(NULL, 0, NULL, UVM_PGA_USERESERVE);
713 	if (__predict_false(pg == NULL)) {
714 		if (waitok) {
715 			uvm_wait("plpg");
716 			goto again;
717 		} else
718 			return (0);
719 	}
720 	va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg));
721 	if (__predict_false(va == 0))
722 		uvm_pagefree(pg);
723 	return (va);
724 #else
725 	vaddr_t va;
726 	int s = 0xdeadbeaf; /* XXX: gcc */
727 	const boolean_t intrsafe = (map->flags & VM_MAP_INTRSAFE) != 0;
728 
729 	if (intrsafe)
730 		s = splvm();
731 	va = uvm_km_alloc(map, PAGE_SIZE, 0,
732 	    (waitok ? 0 : UVM_KMF_NOWAIT | UVM_KMF_TRYLOCK) | UVM_KMF_WIRED);
733 	if (intrsafe)
734 		splx(s);
735 	return (va);
736 #endif /* PMAP_MAP_POOLPAGE */
737 }
738 
739 /*
740  * uvm_km_free_poolpage: free a previously allocated pool page
741  *
742  * => if the pmap specifies an alternate unmapping method, we use it.
743  */
744 
745 /* ARGSUSED */
746 void
747 uvm_km_free_poolpage_cache(struct vm_map *map, vaddr_t addr)
748 {
749 #if defined(PMAP_UNMAP_POOLPAGE)
750 	uvm_km_free_poolpage(map, addr);
751 #else
752 	struct pool *pp;
753 	int s = 0xdeadbeaf; /* XXX: gcc */
754 	const boolean_t intrsafe = (map->flags & VM_MAP_INTRSAFE) != 0;
755 
756 	if ((map->flags & VM_MAP_VACACHE) == 0) {
757 		uvm_km_free_poolpage(map, addr);
758 		return;
759 	}
760 
761 	KASSERT(pmap_extract(pmap_kernel(), addr, NULL));
762 	uvm_km_pgremove_intrsafe(addr, addr + PAGE_SIZE);
763 	pmap_kremove(addr, PAGE_SIZE);
764 #if defined(DEBUG)
765 	pmap_update(pmap_kernel());
766 #endif
767 	KASSERT(!pmap_extract(pmap_kernel(), addr, NULL));
768 	pp = &vm_map_to_kernel(map)->vmk_vacache;
769 	if (intrsafe)
770 		s = splvm();
771 	pool_put(pp, (void *)addr);
772 	if (intrsafe)
773 		splx(s);
774 #endif
775 }
776 
777 /* ARGSUSED */
778 void
779 uvm_km_free_poolpage(struct vm_map *map, vaddr_t addr)
780 {
781 #if defined(PMAP_UNMAP_POOLPAGE)
782 	paddr_t pa;
783 
784 	pa = PMAP_UNMAP_POOLPAGE(addr);
785 	uvm_pagefree(PHYS_TO_VM_PAGE(pa));
786 #else
787 	int s = 0xdeadbeaf; /* XXX: gcc */
788 	const boolean_t intrsafe = (map->flags & VM_MAP_INTRSAFE) != 0;
789 
790 	if (intrsafe)
791 		s = splvm();
792 	uvm_km_free(map, addr, PAGE_SIZE, UVM_KMF_WIRED);
793 	if (intrsafe)
794 		splx(s);
795 #endif /* PMAP_UNMAP_POOLPAGE */
796 }
797