1 /* $NetBSD: uvm_km.c,v 1.141 2016/07/27 16:45:00 maxv 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. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * @(#)vm_kern.c 8.3 (Berkeley) 1/12/94
37 * from: Id: uvm_km.c,v 1.1.2.14 1998/02/06 05:19:27 chs Exp
38 *
39 *
40 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
41 * All rights reserved.
42 *
43 * Permission to use, copy, modify and distribute this software and
44 * its documentation is hereby granted, provided that both the copyright
45 * notice and this permission notice appear in all copies of the
46 * software, derivative works or modified versions, and any portions
47 * thereof, and that both notices appear in supporting documentation.
48 *
49 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
50 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
51 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
52 *
53 * Carnegie Mellon requests users of this software to return to
54 *
55 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
56 * School of Computer Science
57 * Carnegie Mellon University
58 * Pittsburgh PA 15213-3890
59 *
60 * any improvements or extensions that they make and grant Carnegie the
61 * rights to redistribute these changes.
62 */
63
64 /*
65 * uvm_km.c: handle kernel memory allocation and management
66 */
67
68 /*
69 * overview of kernel memory management:
70 *
71 * the kernel virtual address space is mapped by "kernel_map." kernel_map
72 * starts at VM_MIN_KERNEL_ADDRESS and goes to VM_MAX_KERNEL_ADDRESS.
73 * note that VM_MIN_KERNEL_ADDRESS is equal to vm_map_min(kernel_map).
74 *
75 * the kernel_map has several "submaps." submaps can only appear in
76 * the kernel_map (user processes can't use them). submaps "take over"
77 * the management of a sub-range of the kernel's address space. submaps
78 * are typically allocated at boot time and are never released. kernel
79 * virtual address space that is mapped by a submap is locked by the
80 * submap's lock -- not the kernel_map's lock.
81 *
82 * thus, the useful feature of submaps is that they allow us to break
83 * up the locking and protection of the kernel address space into smaller
84 * chunks.
85 *
86 * the vm system has several standard kernel submaps/arenas, including:
87 * kmem_arena => used for kmem/pool (memoryallocators(9))
88 * pager_map => used to map "buf" structures into kernel space
89 * exec_map => used during exec to handle exec args
90 * etc...
91 *
92 * The kmem_arena is a "special submap", as it lives in a fixed map entry
93 * within the kernel_map and is controlled by vmem(9).
94 *
95 * the kernel allocates its private memory out of special uvm_objects whose
96 * reference count is set to UVM_OBJ_KERN (thus indicating that the objects
97 * are "special" and never die). all kernel objects should be thought of
98 * as large, fixed-sized, sparsely populated uvm_objects. each kernel
99 * object is equal to the size of kernel virtual address space (i.e. the
100 * value "VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS").
101 *
102 * note that just because a kernel object spans the entire kernel virtual
103 * address space doesn't mean that it has to be mapped into the entire space.
104 * large chunks of a kernel object's space go unused either because
105 * that area of kernel VM is unmapped, or there is some other type of
106 * object mapped into that range (e.g. a vnode). for submap's kernel
107 * objects, the only part of the object that can ever be populated is the
108 * offsets that are managed by the submap.
109 *
110 * note that the "offset" in a kernel object is always the kernel virtual
111 * address minus the VM_MIN_KERNEL_ADDRESS (aka vm_map_min(kernel_map)).
112 * example:
113 * suppose VM_MIN_KERNEL_ADDRESS is 0xf8000000 and the kernel does a
114 * uvm_km_alloc(kernel_map, PAGE_SIZE) [allocate 1 wired down page in the
115 * kernel map]. if uvm_km_alloc returns virtual address 0xf8235000,
116 * then that means that the page at offset 0x235000 in kernel_object is
117 * mapped at 0xf8235000.
118 *
119 * kernel object have one other special property: when the kernel virtual
120 * memory mapping them is unmapped, the backing memory in the object is
121 * freed right away. this is done with the uvm_km_pgremove() function.
122 * this has to be done because there is no backing store for kernel pages
123 * and no need to save them after they are no longer referenced.
124 *
125 * Generic arenas:
126 *
127 * kmem_arena:
128 * Main arena controlling the kernel KVA used by other arenas.
129 *
130 * kmem_va_arena:
131 * Implements quantum caching in order to speedup allocations and
132 * reduce fragmentation. The pool(9), unless created with a custom
133 * meta-data allocator, and kmem(9) subsystems use this arena.
134 *
135 * Arenas for meta-data allocations are used by vmem(9) and pool(9).
136 * These arenas cannot use quantum cache. However, kmem_va_meta_arena
137 * compensates this by importing larger chunks from kmem_arena.
138 *
139 * kmem_va_meta_arena:
140 * Space for meta-data.
141 *
142 * kmem_meta_arena:
143 * Imports from kmem_va_meta_arena. Allocations from this arena are
144 * backed with the pages.
145 *
146 * Arena stacking:
147 *
148 * kmem_arena
149 * kmem_va_arena
150 * kmem_va_meta_arena
151 * kmem_meta_arena
152 */
153
154 #include <sys/cdefs.h>
155 __KERNEL_RCSID(0, "$NetBSD: uvm_km.c,v 1.141 2016/07/27 16:45:00 maxv Exp $");
156
157 #include "opt_uvmhist.h"
158
159 #include "opt_kmempages.h"
160
161 #ifndef NKMEMPAGES
162 #define NKMEMPAGES 0
163 #endif
164
165 /*
166 * Defaults for lower and upper-bounds for the kmem_arena page count.
167 * Can be overridden by kernel config options.
168 */
169 #ifndef NKMEMPAGES_MIN
170 #define NKMEMPAGES_MIN NKMEMPAGES_MIN_DEFAULT
171 #endif
172
173 #ifndef NKMEMPAGES_MAX
174 #define NKMEMPAGES_MAX NKMEMPAGES_MAX_DEFAULT
175 #endif
176
177
178 #include <sys/param.h>
179 #include <sys/systm.h>
180 #include <sys/proc.h>
181 #include <sys/pool.h>
182 #include <sys/vmem.h>
183 #include <sys/vmem_impl.h>
184 #include <sys/kmem.h>
185
186 #include <uvm/uvm.h>
187
188 /*
189 * global data structures
190 */
191
192 struct vm_map *kernel_map = NULL;
193
194 /*
195 * local data structues
196 */
197
198 static struct vm_map kernel_map_store;
199 static struct vm_map_entry kernel_image_mapent_store;
200 static struct vm_map_entry kernel_kmem_mapent_store;
201
202 int nkmempages = 0;
203 vaddr_t kmembase;
204 vsize_t kmemsize;
205
206 static struct vmem kmem_arena_store;
207 vmem_t *kmem_arena = NULL;
208 static struct vmem kmem_va_arena_store;
209 vmem_t *kmem_va_arena;
210
211 /*
212 * kmeminit_nkmempages: calculate the size of kmem_arena.
213 */
214 void
kmeminit_nkmempages(void)215 kmeminit_nkmempages(void)
216 {
217 int npages;
218
219 if (nkmempages != 0) {
220 /*
221 * It's already been set (by us being here before)
222 * bail out now;
223 */
224 return;
225 }
226
227 #if defined(PMAP_MAP_POOLPAGE)
228 npages = (physmem / 4);
229 #else
230 npages = (physmem / 3) * 2;
231 #endif /* defined(PMAP_MAP_POOLPAGE) */
232
233 #ifndef NKMEMPAGES_MAX_UNLIMITED
234 if (npages > NKMEMPAGES_MAX)
235 npages = NKMEMPAGES_MAX;
236 #endif
237
238 if (npages < NKMEMPAGES_MIN)
239 npages = NKMEMPAGES_MIN;
240
241 nkmempages = npages;
242 }
243
244 /*
245 * uvm_km_bootstrap: init kernel maps and objects to reflect reality (i.e.
246 * KVM already allocated for text, data, bss, and static data structures).
247 *
248 * => KVM is defined by VM_MIN_KERNEL_ADDRESS/VM_MAX_KERNEL_ADDRESS.
249 * we assume that [vmin -> start] has already been allocated and that
250 * "end" is the end.
251 */
252
253 void
uvm_km_bootstrap(vaddr_t start,vaddr_t end)254 uvm_km_bootstrap(vaddr_t start, vaddr_t end)
255 {
256 bool kmem_arena_small;
257 vaddr_t base = VM_MIN_KERNEL_ADDRESS;
258 struct uvm_map_args args;
259 int error;
260
261 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
262 UVMHIST_LOG(maphist, "start=%"PRIxVADDR" end=%#"PRIxVADDR,
263 start, end, 0,0);
264
265 kmeminit_nkmempages();
266 kmemsize = (vsize_t)nkmempages * PAGE_SIZE;
267 kmem_arena_small = kmemsize < 64 * 1024 * 1024;
268
269 UVMHIST_LOG(maphist, "kmemsize=%#"PRIxVSIZE, kmemsize, 0,0,0);
270
271 /*
272 * next, init kernel memory objects.
273 */
274
275 /* kernel_object: for pageable anonymous kernel memory */
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_map_store, base, end, VM_MAP_PAGEABLE);
285 kernel_map_store.pmap = pmap_kernel();
286 if (start != base) {
287 error = uvm_map_prepare(&kernel_map_store,
288 base, start - base,
289 NULL, UVM_UNKNOWN_OFFSET, 0,
290 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE,
291 UVM_ADV_RANDOM, UVM_FLAG_FIXED), &args);
292 if (!error) {
293 kernel_image_mapent_store.flags =
294 UVM_MAP_KERNEL | UVM_MAP_STATIC | UVM_MAP_NOMERGE;
295 error = uvm_map_enter(&kernel_map_store, &args,
296 &kernel_image_mapent_store);
297 }
298
299 if (error)
300 panic(
301 "uvm_km_bootstrap: could not reserve space for kernel");
302
303 kmembase = args.uma_start + args.uma_size;
304 } else {
305 kmembase = base;
306 }
307
308 error = uvm_map_prepare(&kernel_map_store,
309 kmembase, kmemsize,
310 NULL, UVM_UNKNOWN_OFFSET, 0,
311 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE,
312 UVM_ADV_RANDOM, UVM_FLAG_FIXED), &args);
313 if (!error) {
314 kernel_kmem_mapent_store.flags =
315 UVM_MAP_KERNEL | UVM_MAP_STATIC | UVM_MAP_NOMERGE;
316 error = uvm_map_enter(&kernel_map_store, &args,
317 &kernel_kmem_mapent_store);
318 }
319
320 if (error)
321 panic("uvm_km_bootstrap: could not reserve kernel kmem");
322
323 /*
324 * install!
325 */
326
327 kernel_map = &kernel_map_store;
328
329 pool_subsystem_init();
330
331 kmem_arena = vmem_init(&kmem_arena_store, "kmem",
332 kmembase, kmemsize, PAGE_SIZE, NULL, NULL, NULL,
333 0, VM_NOSLEEP | VM_BOOTSTRAP, IPL_VM);
334 #ifdef PMAP_GROWKERNEL
335 /*
336 * kmem_arena VA allocations happen independently of uvm_map.
337 * grow kernel to accommodate the kmem_arena.
338 */
339 if (uvm_maxkaddr < kmembase + kmemsize) {
340 uvm_maxkaddr = pmap_growkernel(kmembase + kmemsize);
341 KASSERTMSG(uvm_maxkaddr >= kmembase + kmemsize,
342 "%#"PRIxVADDR" %#"PRIxVADDR" %#"PRIxVSIZE,
343 uvm_maxkaddr, kmembase, kmemsize);
344 }
345 #endif
346
347 vmem_subsystem_init(kmem_arena);
348
349 UVMHIST_LOG(maphist, "kmem vmem created (base=%#"PRIxVADDR
350 ", size=%#"PRIxVSIZE, kmembase, kmemsize, 0,0);
351
352 kmem_va_arena = vmem_init(&kmem_va_arena_store, "kva",
353 0, 0, PAGE_SIZE, vmem_alloc, vmem_free, kmem_arena,
354 (kmem_arena_small ? 4 : VMEM_QCACHE_IDX_MAX) * PAGE_SIZE,
355 VM_NOSLEEP, IPL_VM);
356
357 UVMHIST_LOG(maphist, "<- done", 0,0,0,0);
358 }
359
360 /*
361 * uvm_km_init: init the kernel maps virtual memory caches
362 * and start the pool/kmem allocator.
363 */
364 void
uvm_km_init(void)365 uvm_km_init(void)
366 {
367 kmem_init();
368 }
369
370 /*
371 * uvm_km_suballoc: allocate a submap in the kernel map. once a submap
372 * is allocated all references to that area of VM must go through it. this
373 * allows the locking of VAs in kernel_map to be broken up into regions.
374 *
375 * => if `fixed' is true, *vmin specifies where the region described
376 * pager_map => used to map "buf" structures into kernel space
377 * by the submap must start
378 * => if submap is non NULL we use that as the submap, otherwise we
379 * alloc a new map
380 */
381
382 struct vm_map *
uvm_km_suballoc(struct vm_map * map,vaddr_t * vmin,vaddr_t * vmax,vsize_t size,int flags,bool fixed,struct vm_map * submap)383 uvm_km_suballoc(struct vm_map *map, vaddr_t *vmin /* IN/OUT */,
384 vaddr_t *vmax /* OUT */, vsize_t size, int flags, bool fixed,
385 struct vm_map *submap)
386 {
387 int mapflags = UVM_FLAG_NOMERGE | (fixed ? UVM_FLAG_FIXED : 0);
388 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
389
390 KASSERT(vm_map_pmap(map) == pmap_kernel());
391
392 size = round_page(size); /* round up to pagesize */
393
394 /*
395 * first allocate a blank spot in the parent map
396 */
397
398 if (uvm_map(map, vmin, size, NULL, UVM_UNKNOWN_OFFSET, 0,
399 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE,
400 UVM_ADV_RANDOM, mapflags)) != 0) {
401 panic("%s: unable to allocate space in parent map", __func__);
402 }
403
404 /*
405 * set VM bounds (vmin is filled in by uvm_map)
406 */
407
408 *vmax = *vmin + size;
409
410 /*
411 * add references to pmap and create or init the submap
412 */
413
414 pmap_reference(vm_map_pmap(map));
415 if (submap == NULL) {
416 submap = kmem_alloc(sizeof(*submap), KM_SLEEP);
417 if (submap == NULL)
418 panic("uvm_km_suballoc: unable to create submap");
419 }
420 uvm_map_setup(submap, *vmin, *vmax, flags);
421 submap->pmap = vm_map_pmap(map);
422
423 /*
424 * now let uvm_map_submap plug in it...
425 */
426
427 if (uvm_map_submap(map, *vmin, *vmax, submap) != 0)
428 panic("uvm_km_suballoc: submap allocation failed");
429
430 return(submap);
431 }
432
433 /*
434 * uvm_km_pgremove: remove pages from a kernel uvm_object and KVA.
435 */
436
437 void
uvm_km_pgremove(vaddr_t startva,vaddr_t endva)438 uvm_km_pgremove(vaddr_t startva, vaddr_t endva)
439 {
440 struct uvm_object * const uobj = uvm_kernel_object;
441 const voff_t start = startva - vm_map_min(kernel_map);
442 const voff_t end = endva - vm_map_min(kernel_map);
443 struct vm_page *pg;
444 voff_t curoff, nextoff;
445 int swpgonlydelta = 0;
446 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
447
448 KASSERT(VM_MIN_KERNEL_ADDRESS <= startva);
449 KASSERT(startva < endva);
450 KASSERT(endva <= VM_MAX_KERNEL_ADDRESS);
451
452 mutex_enter(uobj->vmobjlock);
453 pmap_remove(pmap_kernel(), startva, endva);
454 for (curoff = start; curoff < end; curoff = nextoff) {
455 nextoff = curoff + PAGE_SIZE;
456 pg = uvm_pagelookup(uobj, curoff);
457 if (pg != NULL && pg->flags & PG_BUSY) {
458 pg->flags |= PG_WANTED;
459 UVM_UNLOCK_AND_WAIT(pg, uobj->vmobjlock, 0,
460 "km_pgrm", 0);
461 mutex_enter(uobj->vmobjlock);
462 nextoff = curoff;
463 continue;
464 }
465
466 /*
467 * free the swap slot, then the page.
468 */
469
470 if (pg == NULL &&
471 uao_find_swslot(uobj, curoff >> PAGE_SHIFT) > 0) {
472 swpgonlydelta++;
473 }
474 uao_dropswap(uobj, curoff >> PAGE_SHIFT);
475 if (pg != NULL) {
476 mutex_enter(&uvm_pageqlock);
477 uvm_pagefree(pg);
478 mutex_exit(&uvm_pageqlock);
479 }
480 }
481 mutex_exit(uobj->vmobjlock);
482
483 if (swpgonlydelta > 0) {
484 mutex_enter(&uvm_swap_data_lock);
485 KASSERT(uvmexp.swpgonly >= swpgonlydelta);
486 uvmexp.swpgonly -= swpgonlydelta;
487 mutex_exit(&uvm_swap_data_lock);
488 }
489 }
490
491
492 /*
493 * uvm_km_pgremove_intrsafe: like uvm_km_pgremove(), but for non object backed
494 * regions.
495 *
496 * => when you unmap a part of anonymous kernel memory you want to toss
497 * the pages right away. (this is called from uvm_unmap_...).
498 * => none of the pages will ever be busy, and none of them will ever
499 * be on the active or inactive queues (because they have no object).
500 */
501
502 void
uvm_km_pgremove_intrsafe(struct vm_map * map,vaddr_t start,vaddr_t end)503 uvm_km_pgremove_intrsafe(struct vm_map *map, vaddr_t start, vaddr_t end)
504 {
505 #define __PGRM_BATCH 16
506 struct vm_page *pg;
507 paddr_t pa[__PGRM_BATCH];
508 int npgrm, i;
509 vaddr_t va, batch_vastart;
510
511 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
512
513 KASSERT(VM_MAP_IS_KERNEL(map));
514 KASSERTMSG(vm_map_min(map) <= start,
515 "vm_map_min(map) [%#"PRIxVADDR"] <= start [%#"PRIxVADDR"]"
516 " (size=%#"PRIxVSIZE")",
517 vm_map_min(map), start, end - start);
518 KASSERT(start < end);
519 KASSERT(end <= vm_map_max(map));
520
521 for (va = start; va < end;) {
522 batch_vastart = va;
523 /* create a batch of at most __PGRM_BATCH pages to free */
524 for (i = 0;
525 i < __PGRM_BATCH && va < end;
526 va += PAGE_SIZE) {
527 if (!pmap_extract(pmap_kernel(), va, &pa[i])) {
528 continue;
529 }
530 i++;
531 }
532 npgrm = i;
533 /* now remove the mappings */
534 pmap_kremove(batch_vastart, va - batch_vastart);
535 /* and free the pages */
536 for (i = 0; i < npgrm; i++) {
537 pg = PHYS_TO_VM_PAGE(pa[i]);
538 KASSERT(pg);
539 KASSERT(pg->uobject == NULL && pg->uanon == NULL);
540 KASSERT((pg->flags & PG_BUSY) == 0);
541 uvm_pagefree(pg);
542 }
543 }
544 #undef __PGRM_BATCH
545 }
546
547 #if defined(DEBUG)
548 void
uvm_km_check_empty(struct vm_map * map,vaddr_t start,vaddr_t end)549 uvm_km_check_empty(struct vm_map *map, vaddr_t start, vaddr_t end)
550 {
551 struct vm_page *pg;
552 vaddr_t va;
553 paddr_t pa;
554 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
555
556 KDASSERT(VM_MAP_IS_KERNEL(map));
557 KDASSERT(vm_map_min(map) <= start);
558 KDASSERT(start < end);
559 KDASSERT(end <= vm_map_max(map));
560
561 for (va = start; va < end; va += PAGE_SIZE) {
562 if (pmap_extract(pmap_kernel(), va, &pa)) {
563 panic("uvm_km_check_empty: va %p has pa 0x%llx",
564 (void *)va, (long long)pa);
565 }
566 mutex_enter(uvm_kernel_object->vmobjlock);
567 pg = uvm_pagelookup(uvm_kernel_object,
568 va - vm_map_min(kernel_map));
569 mutex_exit(uvm_kernel_object->vmobjlock);
570 if (pg) {
571 panic("uvm_km_check_empty: "
572 "has page hashed at %p", (const void *)va);
573 }
574 }
575 }
576 #endif /* defined(DEBUG) */
577
578 /*
579 * uvm_km_alloc: allocate an area of kernel memory.
580 *
581 * => NOTE: we can return 0 even if we can wait if there is not enough
582 * free VM space in the map... caller should be prepared to handle
583 * this case.
584 * => we return KVA of memory allocated
585 */
586
587 vaddr_t
uvm_km_alloc(struct vm_map * map,vsize_t size,vsize_t align,uvm_flag_t flags)588 uvm_km_alloc(struct vm_map *map, vsize_t size, vsize_t align, uvm_flag_t flags)
589 {
590 vaddr_t kva, loopva;
591 vaddr_t offset;
592 vsize_t loopsize;
593 struct vm_page *pg;
594 struct uvm_object *obj;
595 int pgaflags;
596 vm_prot_t prot, vaprot;
597 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
598
599 KASSERT(vm_map_pmap(map) == pmap_kernel());
600 KASSERT((flags & UVM_KMF_TYPEMASK) == UVM_KMF_WIRED ||
601 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_PAGEABLE ||
602 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_VAONLY);
603 KASSERT((flags & UVM_KMF_VAONLY) != 0 || (flags & UVM_KMF_COLORMATCH) == 0);
604 KASSERT((flags & UVM_KMF_COLORMATCH) == 0 || (flags & UVM_KMF_VAONLY) != 0);
605
606 /*
607 * setup for call
608 */
609
610 kva = vm_map_min(map); /* hint */
611 size = round_page(size);
612 obj = (flags & UVM_KMF_PAGEABLE) ? uvm_kernel_object : NULL;
613 UVMHIST_LOG(maphist," (map=0x%x, obj=0x%x, size=0x%x, flags=%d)",
614 map, obj, size, flags);
615
616 /*
617 * allocate some virtual space
618 */
619
620 vaprot = (flags & UVM_KMF_EXEC) ? UVM_PROT_ALL : UVM_PROT_RW;
621 if (__predict_false(uvm_map(map, &kva, size, obj, UVM_UNKNOWN_OFFSET,
622 align, UVM_MAPFLAG(vaprot, UVM_PROT_ALL, UVM_INH_NONE,
623 UVM_ADV_RANDOM,
624 (flags & (UVM_KMF_TRYLOCK | UVM_KMF_NOWAIT | UVM_KMF_WAITVA
625 | UVM_KMF_COLORMATCH)))) != 0)) {
626 UVMHIST_LOG(maphist, "<- done (no VM)",0,0,0,0);
627 return(0);
628 }
629
630 /*
631 * if all we wanted was VA, return now
632 */
633
634 if (flags & (UVM_KMF_VAONLY | UVM_KMF_PAGEABLE)) {
635 UVMHIST_LOG(maphist,"<- done valloc (kva=0x%x)", kva,0,0,0);
636 return(kva);
637 }
638
639 /*
640 * recover object offset from virtual address
641 */
642
643 offset = kva - vm_map_min(kernel_map);
644 UVMHIST_LOG(maphist, " kva=0x%x, offset=0x%x", kva, offset,0,0);
645
646 /*
647 * now allocate and map in the memory... note that we are the only ones
648 * whom should ever get a handle on this area of VM.
649 */
650
651 loopva = kva;
652 loopsize = size;
653
654 pgaflags = UVM_FLAG_COLORMATCH;
655 if (flags & UVM_KMF_NOWAIT)
656 pgaflags |= UVM_PGA_USERESERVE;
657 if (flags & UVM_KMF_ZERO)
658 pgaflags |= UVM_PGA_ZERO;
659 prot = VM_PROT_READ | VM_PROT_WRITE;
660 if (flags & UVM_KMF_EXEC)
661 prot |= VM_PROT_EXECUTE;
662 while (loopsize) {
663 KASSERTMSG(!pmap_extract(pmap_kernel(), loopva, NULL),
664 "loopva=%#"PRIxVADDR, loopva);
665
666 pg = uvm_pagealloc_strat(NULL, offset, NULL, pgaflags,
667 #ifdef UVM_KM_VMFREELIST
668 UVM_PGA_STRAT_ONLY, UVM_KM_VMFREELIST
669 #else
670 UVM_PGA_STRAT_NORMAL, 0
671 #endif
672 );
673
674 /*
675 * out of memory?
676 */
677
678 if (__predict_false(pg == NULL)) {
679 if ((flags & UVM_KMF_NOWAIT) ||
680 ((flags & UVM_KMF_CANFAIL) && !uvm_reclaimable())) {
681 /* free everything! */
682 uvm_km_free(map, kva, size,
683 flags & UVM_KMF_TYPEMASK);
684 return (0);
685 } else {
686 uvm_wait("km_getwait2"); /* sleep here */
687 continue;
688 }
689 }
690
691 pg->flags &= ~PG_BUSY; /* new page */
692 UVM_PAGE_OWN(pg, NULL);
693
694 /*
695 * map it in
696 */
697
698 pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg),
699 prot, PMAP_KMPAGE);
700 loopva += PAGE_SIZE;
701 offset += PAGE_SIZE;
702 loopsize -= PAGE_SIZE;
703 }
704
705 pmap_update(pmap_kernel());
706
707 UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0);
708 return(kva);
709 }
710
711 /*
712 * uvm_km_protect: change the protection of an allocated area
713 */
714
715 int
uvm_km_protect(struct vm_map * map,vaddr_t addr,vsize_t size,vm_prot_t prot)716 uvm_km_protect(struct vm_map *map, vaddr_t addr, vsize_t size, vm_prot_t prot)
717 {
718 return uvm_map_protect(map, addr, addr + round_page(size), prot, false);
719 }
720
721 /*
722 * uvm_km_free: free an area of kernel memory
723 */
724
725 void
uvm_km_free(struct vm_map * map,vaddr_t addr,vsize_t size,uvm_flag_t flags)726 uvm_km_free(struct vm_map *map, vaddr_t addr, vsize_t size, uvm_flag_t flags)
727 {
728 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
729
730 KASSERT((flags & UVM_KMF_TYPEMASK) == UVM_KMF_WIRED ||
731 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_PAGEABLE ||
732 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_VAONLY);
733 KASSERT((addr & PAGE_MASK) == 0);
734 KASSERT(vm_map_pmap(map) == pmap_kernel());
735
736 size = round_page(size);
737
738 if (flags & UVM_KMF_PAGEABLE) {
739 uvm_km_pgremove(addr, addr + size);
740 } else if (flags & UVM_KMF_WIRED) {
741 /*
742 * Note: uvm_km_pgremove_intrsafe() extracts mapping, thus
743 * remove it after. See comment below about KVA visibility.
744 */
745 uvm_km_pgremove_intrsafe(map, addr, addr + size);
746 }
747
748 /*
749 * Note: uvm_unmap_remove() calls pmap_update() for us, before
750 * KVA becomes globally available.
751 */
752
753 uvm_unmap1(map, addr, addr + size, UVM_FLAG_VAONLY);
754 }
755
756 /* Sanity; must specify both or none. */
757 #if (defined(PMAP_MAP_POOLPAGE) || defined(PMAP_UNMAP_POOLPAGE)) && \
758 (!defined(PMAP_MAP_POOLPAGE) || !defined(PMAP_UNMAP_POOLPAGE))
759 #error Must specify MAP and UNMAP together.
760 #endif
761
762 int
uvm_km_kmem_alloc(vmem_t * vm,vmem_size_t size,vm_flag_t flags,vmem_addr_t * addr)763 uvm_km_kmem_alloc(vmem_t *vm, vmem_size_t size, vm_flag_t flags,
764 vmem_addr_t *addr)
765 {
766 struct vm_page *pg;
767 vmem_addr_t va;
768 int rc;
769 vaddr_t loopva;
770 vsize_t loopsize;
771
772 size = round_page(size);
773
774 #if defined(PMAP_MAP_POOLPAGE)
775 if (size == PAGE_SIZE) {
776 again:
777 #ifdef PMAP_ALLOC_POOLPAGE
778 pg = PMAP_ALLOC_POOLPAGE((flags & VM_SLEEP) ?
779 0 : UVM_PGA_USERESERVE);
780 #else
781 pg = uvm_pagealloc(NULL, 0, NULL,
782 (flags & VM_SLEEP) ? 0 : UVM_PGA_USERESERVE);
783 #endif /* PMAP_ALLOC_POOLPAGE */
784 if (__predict_false(pg == NULL)) {
785 if (flags & VM_SLEEP) {
786 uvm_wait("plpg");
787 goto again;
788 }
789 return ENOMEM;
790 }
791 va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg));
792 if (__predict_false(va == 0)) {
793 uvm_pagefree(pg);
794 return ENOMEM;
795 }
796 *addr = va;
797 return 0;
798 }
799 #endif /* PMAP_MAP_POOLPAGE */
800
801 rc = vmem_alloc(vm, size, flags, &va);
802 if (rc != 0)
803 return rc;
804
805 #ifdef PMAP_GROWKERNEL
806 /*
807 * These VA allocations happen independently of uvm_map
808 * so this allocation must not extend beyond the current limit.
809 */
810 KASSERTMSG(uvm_maxkaddr >= va + size,
811 "%#"PRIxVADDR" %#"PRIxPTR" %#zx",
812 uvm_maxkaddr, va, size);
813 #endif
814
815 loopva = va;
816 loopsize = size;
817
818 while (loopsize) {
819 #ifdef DIAGNOSTIC
820 paddr_t pa;
821 #endif
822 KASSERTMSG(!pmap_extract(pmap_kernel(), loopva, &pa),
823 "loopva=%#"PRIxVADDR" loopsize=%#"PRIxVSIZE
824 " pa=%#"PRIxPADDR" vmem=%p",
825 loopva, loopsize, pa, vm);
826
827 pg = uvm_pagealloc(NULL, loopva, NULL,
828 UVM_FLAG_COLORMATCH
829 | ((flags & VM_SLEEP) ? 0 : UVM_PGA_USERESERVE));
830 if (__predict_false(pg == NULL)) {
831 if (flags & VM_SLEEP) {
832 uvm_wait("plpg");
833 continue;
834 } else {
835 uvm_km_pgremove_intrsafe(kernel_map, va,
836 va + size);
837 vmem_free(vm, va, size);
838 return ENOMEM;
839 }
840 }
841
842 pg->flags &= ~PG_BUSY; /* new page */
843 UVM_PAGE_OWN(pg, NULL);
844 pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg),
845 VM_PROT_READ|VM_PROT_WRITE, PMAP_KMPAGE);
846
847 loopva += PAGE_SIZE;
848 loopsize -= PAGE_SIZE;
849 }
850 pmap_update(pmap_kernel());
851
852 *addr = va;
853
854 return 0;
855 }
856
857 void
uvm_km_kmem_free(vmem_t * vm,vmem_addr_t addr,size_t size)858 uvm_km_kmem_free(vmem_t *vm, vmem_addr_t addr, size_t size)
859 {
860
861 size = round_page(size);
862 #if defined(PMAP_UNMAP_POOLPAGE)
863 if (size == PAGE_SIZE) {
864 paddr_t pa;
865
866 pa = PMAP_UNMAP_POOLPAGE(addr);
867 uvm_pagefree(PHYS_TO_VM_PAGE(pa));
868 return;
869 }
870 #endif /* PMAP_UNMAP_POOLPAGE */
871 uvm_km_pgremove_intrsafe(kernel_map, addr, addr + size);
872 pmap_update(pmap_kernel());
873
874 vmem_free(vm, addr, size);
875 }
876
877 bool
uvm_km_va_starved_p(void)878 uvm_km_va_starved_p(void)
879 {
880 vmem_size_t total;
881 vmem_size_t free;
882
883 if (kmem_arena == NULL)
884 return false;
885
886 total = vmem_size(kmem_arena, VMEM_ALLOC|VMEM_FREE);
887 free = vmem_size(kmem_arena, VMEM_FREE);
888
889 return (free < (total / 10));
890 }
891