1/*-
2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * The Mach Operating System project at Carnegie-Mellon University.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * from: @(#)vm_kern.c 8.3 (Berkeley) 1/12/94
33 *
34 *
35 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
36 * All rights reserved.
37 *
38 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
39 *
40 * Permission to use, copy, modify and distribute this software and
41 * its documentation is hereby granted, provided that both the copyright
42 * notice and this permission notice appear in all copies of the
43 * software, derivative works or modified versions, and any portions
44 * thereof, and that both notices appear in supporting documentation.
45 *
46 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
47 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
48 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
49 *
50 * Carnegie Mellon requests users of this software to return to
51 *
52 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
53 * School of Computer Science
54 * Carnegie Mellon University
55 * Pittsburgh PA 15213-3890
56 *
57 * any improvements or extensions that they make and grant Carnegie the
58 * rights to redistribute these changes.
59 */
60
61/*
62 * Kernel memory management.
63 */
64
65#include <sys/cdefs.h>
| 1/*-
2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * The Mach Operating System project at Carnegie-Mellon University.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * from: @(#)vm_kern.c 8.3 (Berkeley) 1/12/94
33 *
34 *
35 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
36 * All rights reserved.
37 *
38 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
39 *
40 * Permission to use, copy, modify and distribute this software and
41 * its documentation is hereby granted, provided that both the copyright
42 * notice and this permission notice appear in all copies of the
43 * software, derivative works or modified versions, and any portions
44 * thereof, and that both notices appear in supporting documentation.
45 *
46 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
47 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
48 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
49 *
50 * Carnegie Mellon requests users of this software to return to
51 *
52 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
53 * School of Computer Science
54 * Carnegie Mellon University
55 * Pittsburgh PA 15213-3890
56 *
57 * any improvements or extensions that they make and grant Carnegie the
58 * rights to redistribute these changes.
59 */
60
61/*
62 * Kernel memory management.
63 */
64
65#include <sys/cdefs.h>
|
66__FBSDID("$FreeBSD: head/sys/vm/vm_kern.c 226843 2011-10-27 16:39:17Z alc $");
| 66__FBSDID("$FreeBSD: head/sys/vm/vm_kern.c 230623 2012-01-27 20:18:31Z kmacy $");
|
67
68#include <sys/param.h>
69#include <sys/systm.h>
70#include <sys/kernel.h> /* for ticks and hz */
71#include <sys/eventhandler.h>
72#include <sys/lock.h>
73#include <sys/mutex.h>
74#include <sys/proc.h>
75#include <sys/malloc.h>
76#include <sys/sysctl.h>
77
78#include <vm/vm.h>
79#include <vm/vm_param.h>
80#include <vm/pmap.h>
81#include <vm/vm_map.h>
82#include <vm/vm_object.h>
83#include <vm/vm_page.h>
84#include <vm/vm_pageout.h>
85#include <vm/vm_extern.h>
86#include <vm/uma.h>
87
88vm_map_t kernel_map=0;
89vm_map_t kmem_map=0;
90vm_map_t exec_map=0;
91vm_map_t pipe_map;
92vm_map_t buffer_map=0;
93
94const void *zero_region;
95CTASSERT((ZERO_REGION_SIZE & PAGE_MASK) == 0);
96
97/*
98 * kmem_alloc_nofault:
99 *
100 * Allocate a virtual address range with no underlying object and
101 * no initial mapping to physical memory. Any mapping from this
102 * range to physical memory must be explicitly created prior to
103 * its use, typically with pmap_qenter(). Any attempt to create
104 * a mapping on demand through vm_fault() will result in a panic.
105 */
106vm_offset_t
107kmem_alloc_nofault(map, size)
108 vm_map_t map;
109 vm_size_t size;
110{
111 vm_offset_t addr;
112 int result;
113
114 size = round_page(size);
115 addr = vm_map_min(map);
116 result = vm_map_find(map, NULL, 0, &addr, size, VMFS_ANY_SPACE,
117 VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
118 if (result != KERN_SUCCESS) {
119 return (0);
120 }
121 return (addr);
122}
123
124/*
125 * kmem_alloc_nofault_space:
126 *
127 * Allocate a virtual address range with no underlying object and
128 * no initial mapping to physical memory within the specified
129 * address space. Any mapping from this range to physical memory
130 * must be explicitly created prior to its use, typically with
131 * pmap_qenter(). Any attempt to create a mapping on demand
132 * through vm_fault() will result in a panic.
133 */
134vm_offset_t
135kmem_alloc_nofault_space(map, size, find_space)
136 vm_map_t map;
137 vm_size_t size;
138 int find_space;
139{
140 vm_offset_t addr;
141 int result;
142
143 size = round_page(size);
144 addr = vm_map_min(map);
145 result = vm_map_find(map, NULL, 0, &addr, size, find_space,
146 VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
147 if (result != KERN_SUCCESS) {
148 return (0);
149 }
150 return (addr);
151}
152
153/*
154 * Allocate wired-down memory in the kernel's address map
155 * or a submap.
156 */
157vm_offset_t
158kmem_alloc(map, size)
159 vm_map_t map;
160 vm_size_t size;
161{
162 vm_offset_t addr;
163 vm_offset_t offset;
164 vm_offset_t i;
165
166 size = round_page(size);
167
168 /*
169 * Use the kernel object for wired-down kernel pages. Assume that no
170 * region of the kernel object is referenced more than once.
171 */
172
173 /*
174 * Locate sufficient space in the map. This will give us the final
175 * virtual address for the new memory, and thus will tell us the
176 * offset within the kernel map.
177 */
178 vm_map_lock(map);
179 if (vm_map_findspace(map, vm_map_min(map), size, &addr)) {
180 vm_map_unlock(map);
181 return (0);
182 }
183 offset = addr - VM_MIN_KERNEL_ADDRESS;
184 vm_object_reference(kernel_object);
185 vm_map_insert(map, kernel_object, offset, addr, addr + size,
186 VM_PROT_ALL, VM_PROT_ALL, 0);
187 vm_map_unlock(map);
188
189 /*
190 * Guarantee that there are pages already in this object before
191 * calling vm_map_wire. This is to prevent the following
192 * scenario:
193 *
194 * 1) Threads have swapped out, so that there is a pager for the
195 * kernel_object. 2) The kmsg zone is empty, and so we are
196 * kmem_allocing a new page for it. 3) vm_map_wire calls vm_fault;
197 * there is no page, but there is a pager, so we call
198 * pager_data_request. But the kmsg zone is empty, so we must
199 * kmem_alloc. 4) goto 1 5) Even if the kmsg zone is not empty: when
200 * we get the data back from the pager, it will be (very stale)
201 * non-zero data. kmem_alloc is defined to return zero-filled memory.
202 *
203 * We're intentionally not activating the pages we allocate to prevent a
204 * race with page-out. vm_map_wire will wire the pages.
205 */
206 VM_OBJECT_LOCK(kernel_object);
207 for (i = 0; i < size; i += PAGE_SIZE) {
208 vm_page_t mem;
209
210 mem = vm_page_grab(kernel_object, OFF_TO_IDX(offset + i),
211 VM_ALLOC_NOBUSY | VM_ALLOC_ZERO | VM_ALLOC_RETRY);
212 mem->valid = VM_PAGE_BITS_ALL;
213 KASSERT((mem->oflags & VPO_UNMANAGED) != 0,
214 ("kmem_alloc: page %p is managed", mem));
215 }
216 VM_OBJECT_UNLOCK(kernel_object);
217
218 /*
219 * And finally, mark the data as non-pageable.
220 */
221 (void) vm_map_wire(map, addr, addr + size,
222 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
223
224 return (addr);
225}
226
227/*
228 * kmem_free:
229 *
230 * Release a region of kernel virtual memory allocated
231 * with kmem_alloc, and return the physical pages
232 * associated with that region.
233 *
234 * This routine may not block on kernel maps.
235 */
236void
237kmem_free(map, addr, size)
238 vm_map_t map;
239 vm_offset_t addr;
240 vm_size_t size;
241{
242
243 (void) vm_map_remove(map, trunc_page(addr), round_page(addr + size));
244}
245
246/*
247 * kmem_suballoc:
248 *
249 * Allocates a map to manage a subrange
250 * of the kernel virtual address space.
251 *
252 * Arguments are as follows:
253 *
254 * parent Map to take range from
255 * min, max Returned endpoints of map
256 * size Size of range to find
257 * superpage_align Request that min is superpage aligned
258 */
259vm_map_t
260kmem_suballoc(vm_map_t parent, vm_offset_t *min, vm_offset_t *max,
261 vm_size_t size, boolean_t superpage_align)
262{
263 int ret;
264 vm_map_t result;
265
266 size = round_page(size);
267
268 *min = vm_map_min(parent);
269 ret = vm_map_find(parent, NULL, 0, min, size, superpage_align ?
270 VMFS_ALIGNED_SPACE : VMFS_ANY_SPACE, VM_PROT_ALL, VM_PROT_ALL,
271 MAP_ACC_NO_CHARGE);
272 if (ret != KERN_SUCCESS)
273 panic("kmem_suballoc: bad status return of %d", ret);
274 *max = *min + size;
275 result = vm_map_create(vm_map_pmap(parent), *min, *max);
276 if (result == NULL)
277 panic("kmem_suballoc: cannot create submap");
278 if (vm_map_submap(parent, *min, *max, result) != KERN_SUCCESS)
279 panic("kmem_suballoc: unable to change range to submap");
280 return (result);
281}
282
283/*
284 * kmem_malloc:
285 *
286 * Allocate wired-down memory in the kernel's address map for the higher
287 * level kernel memory allocator (kern/kern_malloc.c). We cannot use
288 * kmem_alloc() because we may need to allocate memory at interrupt
289 * level where we cannot block (canwait == FALSE).
290 *
291 * This routine has its own private kernel submap (kmem_map) and object
292 * (kmem_object). This, combined with the fact that only malloc uses
293 * this routine, ensures that we will never block in map or object waits.
294 *
295 * We don't worry about expanding the map (adding entries) since entries
296 * for wired maps are statically allocated.
297 *
298 * `map' is ONLY allowed to be kmem_map or one of the mbuf submaps to
299 * which we never free.
300 */
301vm_offset_t
302kmem_malloc(map, size, flags)
303 vm_map_t map;
304 vm_size_t size;
305 int flags;
306{
307 vm_offset_t addr;
308 int i, rv;
309
310 size = round_page(size);
311 addr = vm_map_min(map);
312
313 /*
314 * Locate sufficient space in the map. This will give us the final
315 * virtual address for the new memory, and thus will tell us the
316 * offset within the kernel map.
317 */
318 vm_map_lock(map);
319 if (vm_map_findspace(map, vm_map_min(map), size, &addr)) {
320 vm_map_unlock(map);
321 if ((flags & M_NOWAIT) == 0) {
322 for (i = 0; i < 8; i++) {
323 EVENTHANDLER_INVOKE(vm_lowmem, 0);
324 uma_reclaim();
325 vm_map_lock(map);
326 if (vm_map_findspace(map, vm_map_min(map),
327 size, &addr) == 0) {
328 break;
329 }
330 vm_map_unlock(map);
331 tsleep(&i, 0, "nokva", (hz / 4) * (i + 1));
332 }
333 if (i == 8) {
334 panic("kmem_malloc(%ld): kmem_map too small: %ld total allocated",
335 (long)size, (long)map->size);
336 }
337 } else {
338 return (0);
339 }
340 }
341
342 rv = kmem_back(map, addr, size, flags);
343 vm_map_unlock(map);
344 return (rv == KERN_SUCCESS ? addr : 0);
345}
346
347/*
348 * kmem_back:
349 *
350 * Allocate physical pages for the specified virtual address range.
351 */
352int
353kmem_back(vm_map_t map, vm_offset_t addr, vm_size_t size, int flags)
354{
355 vm_offset_t offset, i;
356 vm_map_entry_t entry;
357 vm_page_t m;
358 int pflags;
359 boolean_t found;
360
361 KASSERT(vm_map_locked(map), ("kmem_back: map %p is not locked", map));
362 offset = addr - VM_MIN_KERNEL_ADDRESS;
363 vm_object_reference(kmem_object);
364 vm_map_insert(map, kmem_object, offset, addr, addr + size,
365 VM_PROT_ALL, VM_PROT_ALL, 0);
366
367 /*
368 * Assert: vm_map_insert() will never be able to extend the
369 * previous entry so vm_map_lookup_entry() will find a new
370 * entry exactly corresponding to this address range and it
371 * will have wired_count == 0.
372 */
373 found = vm_map_lookup_entry(map, addr, &entry);
374 KASSERT(found && entry->start == addr && entry->end == addr + size &&
375 entry->wired_count == 0 && (entry->eflags & MAP_ENTRY_IN_TRANSITION)
376 == 0, ("kmem_back: entry not found or misaligned"));
377
378 if ((flags & (M_NOWAIT|M_USE_RESERVE)) == M_NOWAIT)
379 pflags = VM_ALLOC_INTERRUPT | VM_ALLOC_WIRED;
380 else
381 pflags = VM_ALLOC_SYSTEM | VM_ALLOC_WIRED;
382
383 if (flags & M_ZERO)
384 pflags |= VM_ALLOC_ZERO;
| 67
68#include <sys/param.h>
69#include <sys/systm.h>
70#include <sys/kernel.h> /* for ticks and hz */
71#include <sys/eventhandler.h>
72#include <sys/lock.h>
73#include <sys/mutex.h>
74#include <sys/proc.h>
75#include <sys/malloc.h>
76#include <sys/sysctl.h>
77
78#include <vm/vm.h>
79#include <vm/vm_param.h>
80#include <vm/pmap.h>
81#include <vm/vm_map.h>
82#include <vm/vm_object.h>
83#include <vm/vm_page.h>
84#include <vm/vm_pageout.h>
85#include <vm/vm_extern.h>
86#include <vm/uma.h>
87
88vm_map_t kernel_map=0;
89vm_map_t kmem_map=0;
90vm_map_t exec_map=0;
91vm_map_t pipe_map;
92vm_map_t buffer_map=0;
93
94const void *zero_region;
95CTASSERT((ZERO_REGION_SIZE & PAGE_MASK) == 0);
96
97/*
98 * kmem_alloc_nofault:
99 *
100 * Allocate a virtual address range with no underlying object and
101 * no initial mapping to physical memory. Any mapping from this
102 * range to physical memory must be explicitly created prior to
103 * its use, typically with pmap_qenter(). Any attempt to create
104 * a mapping on demand through vm_fault() will result in a panic.
105 */
106vm_offset_t
107kmem_alloc_nofault(map, size)
108 vm_map_t map;
109 vm_size_t size;
110{
111 vm_offset_t addr;
112 int result;
113
114 size = round_page(size);
115 addr = vm_map_min(map);
116 result = vm_map_find(map, NULL, 0, &addr, size, VMFS_ANY_SPACE,
117 VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
118 if (result != KERN_SUCCESS) {
119 return (0);
120 }
121 return (addr);
122}
123
124/*
125 * kmem_alloc_nofault_space:
126 *
127 * Allocate a virtual address range with no underlying object and
128 * no initial mapping to physical memory within the specified
129 * address space. Any mapping from this range to physical memory
130 * must be explicitly created prior to its use, typically with
131 * pmap_qenter(). Any attempt to create a mapping on demand
132 * through vm_fault() will result in a panic.
133 */
134vm_offset_t
135kmem_alloc_nofault_space(map, size, find_space)
136 vm_map_t map;
137 vm_size_t size;
138 int find_space;
139{
140 vm_offset_t addr;
141 int result;
142
143 size = round_page(size);
144 addr = vm_map_min(map);
145 result = vm_map_find(map, NULL, 0, &addr, size, find_space,
146 VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
147 if (result != KERN_SUCCESS) {
148 return (0);
149 }
150 return (addr);
151}
152
153/*
154 * Allocate wired-down memory in the kernel's address map
155 * or a submap.
156 */
157vm_offset_t
158kmem_alloc(map, size)
159 vm_map_t map;
160 vm_size_t size;
161{
162 vm_offset_t addr;
163 vm_offset_t offset;
164 vm_offset_t i;
165
166 size = round_page(size);
167
168 /*
169 * Use the kernel object for wired-down kernel pages. Assume that no
170 * region of the kernel object is referenced more than once.
171 */
172
173 /*
174 * Locate sufficient space in the map. This will give us the final
175 * virtual address for the new memory, and thus will tell us the
176 * offset within the kernel map.
177 */
178 vm_map_lock(map);
179 if (vm_map_findspace(map, vm_map_min(map), size, &addr)) {
180 vm_map_unlock(map);
181 return (0);
182 }
183 offset = addr - VM_MIN_KERNEL_ADDRESS;
184 vm_object_reference(kernel_object);
185 vm_map_insert(map, kernel_object, offset, addr, addr + size,
186 VM_PROT_ALL, VM_PROT_ALL, 0);
187 vm_map_unlock(map);
188
189 /*
190 * Guarantee that there are pages already in this object before
191 * calling vm_map_wire. This is to prevent the following
192 * scenario:
193 *
194 * 1) Threads have swapped out, so that there is a pager for the
195 * kernel_object. 2) The kmsg zone is empty, and so we are
196 * kmem_allocing a new page for it. 3) vm_map_wire calls vm_fault;
197 * there is no page, but there is a pager, so we call
198 * pager_data_request. But the kmsg zone is empty, so we must
199 * kmem_alloc. 4) goto 1 5) Even if the kmsg zone is not empty: when
200 * we get the data back from the pager, it will be (very stale)
201 * non-zero data. kmem_alloc is defined to return zero-filled memory.
202 *
203 * We're intentionally not activating the pages we allocate to prevent a
204 * race with page-out. vm_map_wire will wire the pages.
205 */
206 VM_OBJECT_LOCK(kernel_object);
207 for (i = 0; i < size; i += PAGE_SIZE) {
208 vm_page_t mem;
209
210 mem = vm_page_grab(kernel_object, OFF_TO_IDX(offset + i),
211 VM_ALLOC_NOBUSY | VM_ALLOC_ZERO | VM_ALLOC_RETRY);
212 mem->valid = VM_PAGE_BITS_ALL;
213 KASSERT((mem->oflags & VPO_UNMANAGED) != 0,
214 ("kmem_alloc: page %p is managed", mem));
215 }
216 VM_OBJECT_UNLOCK(kernel_object);
217
218 /*
219 * And finally, mark the data as non-pageable.
220 */
221 (void) vm_map_wire(map, addr, addr + size,
222 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
223
224 return (addr);
225}
226
227/*
228 * kmem_free:
229 *
230 * Release a region of kernel virtual memory allocated
231 * with kmem_alloc, and return the physical pages
232 * associated with that region.
233 *
234 * This routine may not block on kernel maps.
235 */
236void
237kmem_free(map, addr, size)
238 vm_map_t map;
239 vm_offset_t addr;
240 vm_size_t size;
241{
242
243 (void) vm_map_remove(map, trunc_page(addr), round_page(addr + size));
244}
245
246/*
247 * kmem_suballoc:
248 *
249 * Allocates a map to manage a subrange
250 * of the kernel virtual address space.
251 *
252 * Arguments are as follows:
253 *
254 * parent Map to take range from
255 * min, max Returned endpoints of map
256 * size Size of range to find
257 * superpage_align Request that min is superpage aligned
258 */
259vm_map_t
260kmem_suballoc(vm_map_t parent, vm_offset_t *min, vm_offset_t *max,
261 vm_size_t size, boolean_t superpage_align)
262{
263 int ret;
264 vm_map_t result;
265
266 size = round_page(size);
267
268 *min = vm_map_min(parent);
269 ret = vm_map_find(parent, NULL, 0, min, size, superpage_align ?
270 VMFS_ALIGNED_SPACE : VMFS_ANY_SPACE, VM_PROT_ALL, VM_PROT_ALL,
271 MAP_ACC_NO_CHARGE);
272 if (ret != KERN_SUCCESS)
273 panic("kmem_suballoc: bad status return of %d", ret);
274 *max = *min + size;
275 result = vm_map_create(vm_map_pmap(parent), *min, *max);
276 if (result == NULL)
277 panic("kmem_suballoc: cannot create submap");
278 if (vm_map_submap(parent, *min, *max, result) != KERN_SUCCESS)
279 panic("kmem_suballoc: unable to change range to submap");
280 return (result);
281}
282
283/*
284 * kmem_malloc:
285 *
286 * Allocate wired-down memory in the kernel's address map for the higher
287 * level kernel memory allocator (kern/kern_malloc.c). We cannot use
288 * kmem_alloc() because we may need to allocate memory at interrupt
289 * level where we cannot block (canwait == FALSE).
290 *
291 * This routine has its own private kernel submap (kmem_map) and object
292 * (kmem_object). This, combined with the fact that only malloc uses
293 * this routine, ensures that we will never block in map or object waits.
294 *
295 * We don't worry about expanding the map (adding entries) since entries
296 * for wired maps are statically allocated.
297 *
298 * `map' is ONLY allowed to be kmem_map or one of the mbuf submaps to
299 * which we never free.
300 */
301vm_offset_t
302kmem_malloc(map, size, flags)
303 vm_map_t map;
304 vm_size_t size;
305 int flags;
306{
307 vm_offset_t addr;
308 int i, rv;
309
310 size = round_page(size);
311 addr = vm_map_min(map);
312
313 /*
314 * Locate sufficient space in the map. This will give us the final
315 * virtual address for the new memory, and thus will tell us the
316 * offset within the kernel map.
317 */
318 vm_map_lock(map);
319 if (vm_map_findspace(map, vm_map_min(map), size, &addr)) {
320 vm_map_unlock(map);
321 if ((flags & M_NOWAIT) == 0) {
322 for (i = 0; i < 8; i++) {
323 EVENTHANDLER_INVOKE(vm_lowmem, 0);
324 uma_reclaim();
325 vm_map_lock(map);
326 if (vm_map_findspace(map, vm_map_min(map),
327 size, &addr) == 0) {
328 break;
329 }
330 vm_map_unlock(map);
331 tsleep(&i, 0, "nokva", (hz / 4) * (i + 1));
332 }
333 if (i == 8) {
334 panic("kmem_malloc(%ld): kmem_map too small: %ld total allocated",
335 (long)size, (long)map->size);
336 }
337 } else {
338 return (0);
339 }
340 }
341
342 rv = kmem_back(map, addr, size, flags);
343 vm_map_unlock(map);
344 return (rv == KERN_SUCCESS ? addr : 0);
345}
346
347/*
348 * kmem_back:
349 *
350 * Allocate physical pages for the specified virtual address range.
351 */
352int
353kmem_back(vm_map_t map, vm_offset_t addr, vm_size_t size, int flags)
354{
355 vm_offset_t offset, i;
356 vm_map_entry_t entry;
357 vm_page_t m;
358 int pflags;
359 boolean_t found;
360
361 KASSERT(vm_map_locked(map), ("kmem_back: map %p is not locked", map));
362 offset = addr - VM_MIN_KERNEL_ADDRESS;
363 vm_object_reference(kmem_object);
364 vm_map_insert(map, kmem_object, offset, addr, addr + size,
365 VM_PROT_ALL, VM_PROT_ALL, 0);
366
367 /*
368 * Assert: vm_map_insert() will never be able to extend the
369 * previous entry so vm_map_lookup_entry() will find a new
370 * entry exactly corresponding to this address range and it
371 * will have wired_count == 0.
372 */
373 found = vm_map_lookup_entry(map, addr, &entry);
374 KASSERT(found && entry->start == addr && entry->end == addr + size &&
375 entry->wired_count == 0 && (entry->eflags & MAP_ENTRY_IN_TRANSITION)
376 == 0, ("kmem_back: entry not found or misaligned"));
377
378 if ((flags & (M_NOWAIT|M_USE_RESERVE)) == M_NOWAIT)
379 pflags = VM_ALLOC_INTERRUPT | VM_ALLOC_WIRED;
380 else
381 pflags = VM_ALLOC_SYSTEM | VM_ALLOC_WIRED;
382
383 if (flags & M_ZERO)
384 pflags |= VM_ALLOC_ZERO;
|
| 385 if (flags & M_NODUMP)
386 pflags |= VM_ALLOC_NODUMP;
|
385
386 VM_OBJECT_LOCK(kmem_object);
387 for (i = 0; i < size; i += PAGE_SIZE) {
388retry:
389 m = vm_page_alloc(kmem_object, OFF_TO_IDX(offset + i), pflags);
390
391 /*
392 * Ran out of space, free everything up and return. Don't need
393 * to lock page queues here as we know that the pages we got
394 * aren't on any queues.
395 */
396 if (m == NULL) {
397 if ((flags & M_NOWAIT) == 0) {
398 VM_OBJECT_UNLOCK(kmem_object);
399 entry->eflags |= MAP_ENTRY_IN_TRANSITION;
400 vm_map_unlock(map);
401 VM_WAIT;
402 vm_map_lock(map);
403 KASSERT(
404(entry->eflags & (MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_NEEDS_WAKEUP)) ==
405 MAP_ENTRY_IN_TRANSITION,
406 ("kmem_back: volatile entry"));
407 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION;
408 VM_OBJECT_LOCK(kmem_object);
409 goto retry;
410 }
411 /*
412 * Free the pages before removing the map entry.
413 * They are already marked busy. Calling
414 * vm_map_delete before the pages has been freed or
415 * unbusied will cause a deadlock.
416 */
417 while (i != 0) {
418 i -= PAGE_SIZE;
419 m = vm_page_lookup(kmem_object,
420 OFF_TO_IDX(offset + i));
421 vm_page_unwire(m, 0);
422 vm_page_free(m);
423 }
424 VM_OBJECT_UNLOCK(kmem_object);
425 vm_map_delete(map, addr, addr + size);
426 return (KERN_NO_SPACE);
427 }
428 if (flags & M_ZERO && (m->flags & PG_ZERO) == 0)
429 pmap_zero_page(m);
430 m->valid = VM_PAGE_BITS_ALL;
431 KASSERT((m->oflags & VPO_UNMANAGED) != 0,
432 ("kmem_malloc: page %p is managed", m));
433 }
434 VM_OBJECT_UNLOCK(kmem_object);
435
436 /*
437 * Mark map entry as non-pageable. Repeat the assert.
438 */
439 KASSERT(entry->start == addr && entry->end == addr + size &&
440 entry->wired_count == 0,
441 ("kmem_back: entry not found or misaligned after allocation"));
442 entry->wired_count = 1;
443
444 /*
445 * At this point, the kmem_object must be unlocked because
446 * vm_map_simplify_entry() calls vm_object_deallocate(), which
447 * locks the kmem_object.
448 */
449 vm_map_simplify_entry(map, entry);
450
451 /*
452 * Loop thru pages, entering them in the pmap.
453 */
454 VM_OBJECT_LOCK(kmem_object);
455 for (i = 0; i < size; i += PAGE_SIZE) {
456 m = vm_page_lookup(kmem_object, OFF_TO_IDX(offset + i));
457 /*
458 * Because this is kernel_pmap, this call will not block.
459 */
460 pmap_enter(kernel_pmap, addr + i, VM_PROT_ALL, m, VM_PROT_ALL,
461 TRUE);
462 vm_page_wakeup(m);
463 }
464 VM_OBJECT_UNLOCK(kmem_object);
465
466 return (KERN_SUCCESS);
467}
468
469/*
470 * kmem_alloc_wait:
471 *
472 * Allocates pageable memory from a sub-map of the kernel. If the submap
473 * has no room, the caller sleeps waiting for more memory in the submap.
474 *
475 * This routine may block.
476 */
477vm_offset_t
478kmem_alloc_wait(map, size)
479 vm_map_t map;
480 vm_size_t size;
481{
482 vm_offset_t addr;
483
484 size = round_page(size);
485 if (!swap_reserve(size))
486 return (0);
487
488 for (;;) {
489 /*
490 * To make this work for more than one map, use the map's lock
491 * to lock out sleepers/wakers.
492 */
493 vm_map_lock(map);
494 if (vm_map_findspace(map, vm_map_min(map), size, &addr) == 0)
495 break;
496 /* no space now; see if we can ever get space */
497 if (vm_map_max(map) - vm_map_min(map) < size) {
498 vm_map_unlock(map);
499 swap_release(size);
500 return (0);
501 }
502 map->needs_wakeup = TRUE;
503 vm_map_unlock_and_wait(map, 0);
504 }
505 vm_map_insert(map, NULL, 0, addr, addr + size, VM_PROT_ALL,
506 VM_PROT_ALL, MAP_ACC_CHARGED);
507 vm_map_unlock(map);
508 return (addr);
509}
510
511/*
512 * kmem_free_wakeup:
513 *
514 * Returns memory to a submap of the kernel, and wakes up any processes
515 * waiting for memory in that map.
516 */
517void
518kmem_free_wakeup(map, addr, size)
519 vm_map_t map;
520 vm_offset_t addr;
521 vm_size_t size;
522{
523
524 vm_map_lock(map);
525 (void) vm_map_delete(map, trunc_page(addr), round_page(addr + size));
526 if (map->needs_wakeup) {
527 map->needs_wakeup = FALSE;
528 vm_map_wakeup(map);
529 }
530 vm_map_unlock(map);
531}
532
533static void
534kmem_init_zero_region(void)
535{
536 vm_offset_t addr, i;
537 vm_page_t m;
538 int error;
539
540 /*
541 * Map a single physical page of zeros to a larger virtual range.
542 * This requires less looping in places that want large amounts of
543 * zeros, while not using much more physical resources.
544 */
545 addr = kmem_alloc_nofault(kernel_map, ZERO_REGION_SIZE);
546 m = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL |
547 VM_ALLOC_NOOBJ | VM_ALLOC_WIRED | VM_ALLOC_ZERO);
548 if ((m->flags & PG_ZERO) == 0)
549 pmap_zero_page(m);
550 for (i = 0; i < ZERO_REGION_SIZE; i += PAGE_SIZE)
551 pmap_qenter(addr + i, &m, 1);
552 error = vm_map_protect(kernel_map, addr, addr + ZERO_REGION_SIZE,
553 VM_PROT_READ, TRUE);
554 KASSERT(error == 0, ("error=%d", error));
555
556 zero_region = (const void *)addr;
557}
558
559/*
560 * kmem_init:
561 *
562 * Create the kernel map; insert a mapping covering kernel text,
563 * data, bss, and all space allocated thus far (`boostrap' data). The
564 * new map will thus map the range between VM_MIN_KERNEL_ADDRESS and
565 * `start' as allocated, and the range between `start' and `end' as free.
566 */
567void
568kmem_init(start, end)
569 vm_offset_t start, end;
570{
571 vm_map_t m;
572
573 m = vm_map_create(kernel_pmap, VM_MIN_KERNEL_ADDRESS, end);
574 m->system_map = 1;
575 vm_map_lock(m);
576 /* N.B.: cannot use kgdb to debug, starting with this assignment ... */
577 kernel_map = m;
578 (void) vm_map_insert(m, NULL, (vm_ooffset_t) 0,
579#ifdef __amd64__
580 KERNBASE,
581#else
582 VM_MIN_KERNEL_ADDRESS,
583#endif
584 start, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
585 /* ... and ending with the completion of the above `insert' */
586 vm_map_unlock(m);
587
588 kmem_init_zero_region();
589}
590
591#ifdef DIAGNOSTIC
592/*
593 * Allow userspace to directly trigger the VM drain routine for testing
594 * purposes.
595 */
596static int
597debug_vm_lowmem(SYSCTL_HANDLER_ARGS)
598{
599 int error, i;
600
601 i = 0;
602 error = sysctl_handle_int(oidp, &i, 0, req);
603 if (error)
604 return (error);
605 if (i)
606 EVENTHANDLER_INVOKE(vm_lowmem, 0);
607 return (0);
608}
609
610SYSCTL_PROC(_debug, OID_AUTO, vm_lowmem, CTLTYPE_INT | CTLFLAG_RW, 0, 0,
611 debug_vm_lowmem, "I", "set to trigger vm_lowmem event");
612#endif
| 387
388 VM_OBJECT_LOCK(kmem_object);
389 for (i = 0; i < size; i += PAGE_SIZE) {
390retry:
391 m = vm_page_alloc(kmem_object, OFF_TO_IDX(offset + i), pflags);
392
393 /*
394 * Ran out of space, free everything up and return. Don't need
395 * to lock page queues here as we know that the pages we got
396 * aren't on any queues.
397 */
398 if (m == NULL) {
399 if ((flags & M_NOWAIT) == 0) {
400 VM_OBJECT_UNLOCK(kmem_object);
401 entry->eflags |= MAP_ENTRY_IN_TRANSITION;
402 vm_map_unlock(map);
403 VM_WAIT;
404 vm_map_lock(map);
405 KASSERT(
406(entry->eflags & (MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_NEEDS_WAKEUP)) ==
407 MAP_ENTRY_IN_TRANSITION,
408 ("kmem_back: volatile entry"));
409 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION;
410 VM_OBJECT_LOCK(kmem_object);
411 goto retry;
412 }
413 /*
414 * Free the pages before removing the map entry.
415 * They are already marked busy. Calling
416 * vm_map_delete before the pages has been freed or
417 * unbusied will cause a deadlock.
418 */
419 while (i != 0) {
420 i -= PAGE_SIZE;
421 m = vm_page_lookup(kmem_object,
422 OFF_TO_IDX(offset + i));
423 vm_page_unwire(m, 0);
424 vm_page_free(m);
425 }
426 VM_OBJECT_UNLOCK(kmem_object);
427 vm_map_delete(map, addr, addr + size);
428 return (KERN_NO_SPACE);
429 }
430 if (flags & M_ZERO && (m->flags & PG_ZERO) == 0)
431 pmap_zero_page(m);
432 m->valid = VM_PAGE_BITS_ALL;
433 KASSERT((m->oflags & VPO_UNMANAGED) != 0,
434 ("kmem_malloc: page %p is managed", m));
435 }
436 VM_OBJECT_UNLOCK(kmem_object);
437
438 /*
439 * Mark map entry as non-pageable. Repeat the assert.
440 */
441 KASSERT(entry->start == addr && entry->end == addr + size &&
442 entry->wired_count == 0,
443 ("kmem_back: entry not found or misaligned after allocation"));
444 entry->wired_count = 1;
445
446 /*
447 * At this point, the kmem_object must be unlocked because
448 * vm_map_simplify_entry() calls vm_object_deallocate(), which
449 * locks the kmem_object.
450 */
451 vm_map_simplify_entry(map, entry);
452
453 /*
454 * Loop thru pages, entering them in the pmap.
455 */
456 VM_OBJECT_LOCK(kmem_object);
457 for (i = 0; i < size; i += PAGE_SIZE) {
458 m = vm_page_lookup(kmem_object, OFF_TO_IDX(offset + i));
459 /*
460 * Because this is kernel_pmap, this call will not block.
461 */
462 pmap_enter(kernel_pmap, addr + i, VM_PROT_ALL, m, VM_PROT_ALL,
463 TRUE);
464 vm_page_wakeup(m);
465 }
466 VM_OBJECT_UNLOCK(kmem_object);
467
468 return (KERN_SUCCESS);
469}
470
471/*
472 * kmem_alloc_wait:
473 *
474 * Allocates pageable memory from a sub-map of the kernel. If the submap
475 * has no room, the caller sleeps waiting for more memory in the submap.
476 *
477 * This routine may block.
478 */
479vm_offset_t
480kmem_alloc_wait(map, size)
481 vm_map_t map;
482 vm_size_t size;
483{
484 vm_offset_t addr;
485
486 size = round_page(size);
487 if (!swap_reserve(size))
488 return (0);
489
490 for (;;) {
491 /*
492 * To make this work for more than one map, use the map's lock
493 * to lock out sleepers/wakers.
494 */
495 vm_map_lock(map);
496 if (vm_map_findspace(map, vm_map_min(map), size, &addr) == 0)
497 break;
498 /* no space now; see if we can ever get space */
499 if (vm_map_max(map) - vm_map_min(map) < size) {
500 vm_map_unlock(map);
501 swap_release(size);
502 return (0);
503 }
504 map->needs_wakeup = TRUE;
505 vm_map_unlock_and_wait(map, 0);
506 }
507 vm_map_insert(map, NULL, 0, addr, addr + size, VM_PROT_ALL,
508 VM_PROT_ALL, MAP_ACC_CHARGED);
509 vm_map_unlock(map);
510 return (addr);
511}
512
513/*
514 * kmem_free_wakeup:
515 *
516 * Returns memory to a submap of the kernel, and wakes up any processes
517 * waiting for memory in that map.
518 */
519void
520kmem_free_wakeup(map, addr, size)
521 vm_map_t map;
522 vm_offset_t addr;
523 vm_size_t size;
524{
525
526 vm_map_lock(map);
527 (void) vm_map_delete(map, trunc_page(addr), round_page(addr + size));
528 if (map->needs_wakeup) {
529 map->needs_wakeup = FALSE;
530 vm_map_wakeup(map);
531 }
532 vm_map_unlock(map);
533}
534
535static void
536kmem_init_zero_region(void)
537{
538 vm_offset_t addr, i;
539 vm_page_t m;
540 int error;
541
542 /*
543 * Map a single physical page of zeros to a larger virtual range.
544 * This requires less looping in places that want large amounts of
545 * zeros, while not using much more physical resources.
546 */
547 addr = kmem_alloc_nofault(kernel_map, ZERO_REGION_SIZE);
548 m = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL |
549 VM_ALLOC_NOOBJ | VM_ALLOC_WIRED | VM_ALLOC_ZERO);
550 if ((m->flags & PG_ZERO) == 0)
551 pmap_zero_page(m);
552 for (i = 0; i < ZERO_REGION_SIZE; i += PAGE_SIZE)
553 pmap_qenter(addr + i, &m, 1);
554 error = vm_map_protect(kernel_map, addr, addr + ZERO_REGION_SIZE,
555 VM_PROT_READ, TRUE);
556 KASSERT(error == 0, ("error=%d", error));
557
558 zero_region = (const void *)addr;
559}
560
561/*
562 * kmem_init:
563 *
564 * Create the kernel map; insert a mapping covering kernel text,
565 * data, bss, and all space allocated thus far (`boostrap' data). The
566 * new map will thus map the range between VM_MIN_KERNEL_ADDRESS and
567 * `start' as allocated, and the range between `start' and `end' as free.
568 */
569void
570kmem_init(start, end)
571 vm_offset_t start, end;
572{
573 vm_map_t m;
574
575 m = vm_map_create(kernel_pmap, VM_MIN_KERNEL_ADDRESS, end);
576 m->system_map = 1;
577 vm_map_lock(m);
578 /* N.B.: cannot use kgdb to debug, starting with this assignment ... */
579 kernel_map = m;
580 (void) vm_map_insert(m, NULL, (vm_ooffset_t) 0,
581#ifdef __amd64__
582 KERNBASE,
583#else
584 VM_MIN_KERNEL_ADDRESS,
585#endif
586 start, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
587 /* ... and ending with the completion of the above `insert' */
588 vm_map_unlock(m);
589
590 kmem_init_zero_region();
591}
592
593#ifdef DIAGNOSTIC
594/*
595 * Allow userspace to directly trigger the VM drain routine for testing
596 * purposes.
597 */
598static int
599debug_vm_lowmem(SYSCTL_HANDLER_ARGS)
600{
601 int error, i;
602
603 i = 0;
604 error = sysctl_handle_int(oidp, &i, 0, req);
605 if (error)
606 return (error);
607 if (i)
608 EVENTHANDLER_INVOKE(vm_lowmem, 0);
609 return (0);
610}
611
612SYSCTL_PROC(_debug, OID_AUTO, vm_lowmem, CTLTYPE_INT | CTLFLAG_RW, 0, 0,
613 debug_vm_lowmem, "I", "set to trigger vm_lowmem event");
614#endif
|