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1.1 root 1: /*
2: * Copyright (c) 1991 Regents of the University of California.
3: * 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: * 3. All advertising materials mentioning features or use of this software
17: * must display the following acknowledgement:
18: * This product includes software developed by the University of
19: * California, Berkeley and its contributors.
20: * 4. 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_pager.c 7.4 (Berkeley) 5/7/91
37: *
38: *
39: * Copyright (c) 1987, 1990 Carnegie-Mellon University.
40: * All rights reserved.
41: *
42: * Authors: Avadis Tevanian, Jr., Michael Wayne Young
43: *
44: * Permission to use, copy, modify and distribute this software and
45: * its documentation is hereby granted, provided that both the copyright
46: * notice and this permission notice appear in all copies of the
47: * software, derivative works or modified versions, and any portions
48: * thereof, and that both notices appear in supporting documentation.
49: *
50: * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
51: * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
52: * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
53: *
54: * Carnegie Mellon requests users of this software to return to
55: *
56: * Software Distribution Coordinator or [email protected]
57: * School of Computer Science
58: * Carnegie Mellon University
59: * Pittsburgh PA 15213-3890
60: *
61: * any improvements or extensions that they make and grant Carnegie the
62: * rights to redistribute these changes.
63: */
64:
65: /*
66: * Paging space routine stubs. Emulates a matchmaker-like interface
67: * for builtin pagers.
68: */
69:
70: #include "param.h"
71: #include "malloc.h"
72:
73: #include "vm.h"
74: #include "vm_page.h"
75: #include "vm_kern.h"
76:
77: #include "swappager.h"
78:
79: #if NSWAPPAGER > 0
80: extern struct pagerops swappagerops;
81: #else
82: #define swappagerops NULL
83: #endif
84: #include "vnodepager.h"
85: #if NVNODEPAGER > 0
86: extern struct pagerops vnodepagerops;
87: #else
88: #define vnodepagerops NULL
89: #endif
90: #include "devpager.h"
91: #if NDEVPAGER > 0
92: extern struct pagerops devicepagerops;
93: #else
94: #define devicepagerops NULL
95: #endif
96:
97: struct pagerops *pagertab[] = {
98: &swappagerops, /* PG_SWAP */
99: &vnodepagerops, /* PG_VNODE */
100: &devicepagerops, /* PG_DEV */
101: };
102: int npagers = sizeof (pagertab) / sizeof (pagertab[0]);
103:
104: struct pagerops *dfltpagerops = NULL; /* default pager */
105:
106: /*
107: * Kernel address space for mapping pages.
108: * Used by pagers where KVAs are needed for IO.
109: */
110: #define PAGER_MAP_SIZE (256 * PAGE_SIZE)
111: vm_map_t pager_map;
112: vm_offset_t pager_sva, pager_eva;
113:
114: void
115: vm_pager_init()
116: {
117: struct pagerops **pgops;
118:
119: /*
120: * Allocate a kernel submap for tracking get/put page mappings
121: */
122: pager_map = kmem_suballoc(kernel_map, &pager_sva, &pager_eva,
123: PAGER_MAP_SIZE, FALSE);
124: /*
125: * Initialize known pagers
126: */
127: for (pgops = pagertab; pgops < &pagertab[npagers]; pgops++)
128: (*(*pgops)->pgo_init)();
129: if (dfltpagerops == NULL)
130: panic("no default pager");
131: }
132:
133: /*
134: * Allocate an instance of a pager of the given type.
135: */
136: vm_pager_t
137: vm_pager_allocate(type, handle, size, prot)
138: int type;
139: caddr_t handle;
140: vm_size_t size;
141: vm_prot_t prot;
142: {
143: vm_pager_t pager;
144: struct pagerops *ops;
145:
146: ops = (type == PG_DFLT) ? dfltpagerops : pagertab[type];
147: return((*ops->pgo_alloc)(handle, size, prot));
148: }
149:
150: void
151: vm_pager_deallocate(pager)
152: vm_pager_t pager;
153: {
154: if (pager == NULL)
155: panic("vm_pager_deallocate: null pager");
156:
157: VM_PAGER_DEALLOC(pager);
158: }
159:
160: vm_pager_get(pager, m, sync)
161: vm_pager_t pager;
162: vm_page_t m;
163: boolean_t sync;
164: {
165: extern boolean_t vm_page_zero_fill();
166:
167: if (pager == NULL)
168: return(vm_page_zero_fill(m) ? VM_PAGER_OK : VM_PAGER_FAIL);
169: return(VM_PAGER_GET(pager, m, sync));
170: }
171:
172: vm_pager_put(pager, m, sync)
173: vm_pager_t pager;
174: vm_page_t m;
175: boolean_t sync;
176: {
177: if (pager == NULL)
178: panic("vm_pager_put: null pager");
179: return(VM_PAGER_PUT(pager, m, sync));
180: }
181:
182: boolean_t
183: vm_pager_has_page(pager, offset)
184: vm_pager_t pager;
185: vm_offset_t offset;
186: {
187: if (pager == NULL)
188: panic("vm_pager_has_page");
189: return(VM_PAGER_HASPAGE(pager, offset));
190: }
191:
192: /*
193: * Called by pageout daemon before going back to sleep.
194: * Gives pagers a chance to clean up any completed async pageing operations.
195: */
196: void
197: vm_pager_sync()
198: {
199: struct pagerops **pgops;
200:
201: for (pgops = pagertab; pgops < &pagertab[npagers]; pgops++)
202: (*(*pgops)->pgo_putpage)(NULL, NULL, FALSE);
203: }
204:
205: vm_offset_t
206: vm_pager_map_page(m)
207: vm_page_t m;
208: {
209: vm_offset_t kva;
210:
211: #ifdef DEBUG
212: if (!m->busy || m->active)
213: panic("vm_pager_map_page: page active or not busy");
214: if (m->pagerowned)
215: printf("vm_pager_map_page: page %x already in pager\n", m);
216: #endif
217: kva = kmem_alloc_wait(pager_map, PAGE_SIZE);
218: #ifdef DEBUG
219: m->pagerowned = 1;
220: #endif
221: pmap_enter(vm_map_pmap(pager_map), kva, VM_PAGE_TO_PHYS(m),
222: VM_PROT_DEFAULT, TRUE);
223: return(kva);
224: }
225:
226: void
227: vm_pager_unmap_page(kva)
228: vm_offset_t kva;
229: {
230: #ifdef DEBUG
231: vm_page_t m;
232:
233: m = PHYS_TO_VM_PAGE(pmap_extract(vm_map_pmap(pager_map), kva));
234: #endif
235: pmap_remove(vm_map_pmap(pager_map), kva, kva + PAGE_SIZE);
236: kmem_free_wakeup(pager_map, kva, PAGE_SIZE);
237: #ifdef DEBUG
238: if (m->pagerowned)
239: m->pagerowned = 0;
240: else
241: printf("vm_pager_unmap_page: page %x(%x/%x) not owned\n",
242: m, kva, VM_PAGE_TO_PHYS(m));
243: #endif
244: }
245:
246: vm_pager_t
247: vm_pager_lookup(list, handle)
248: register queue_head_t *list;
249: caddr_t handle;
250: {
251: register vm_pager_t pager;
252:
253: pager = (vm_pager_t) queue_first(list);
254: while (!queue_end(list, (queue_entry_t)pager)) {
255: if (pager->pg_handle == handle)
256: return(pager);
257: pager = (vm_pager_t) queue_next(&pager->pg_list);
258: }
259: return(NULL);
260: }
261:
262: /*
263: * This routine gains a reference to the object.
264: * Explicit deallocation is necessary.
265: */
266: pager_cache(object, should_cache)
267: vm_object_t object;
268: boolean_t should_cache;
269: {
270: if (object == NULL)
271: return(KERN_INVALID_ARGUMENT);
272:
273: vm_object_cache_lock();
274: vm_object_lock(object);
275: object->can_persist = should_cache;
276: vm_object_unlock(object);
277: vm_object_cache_unlock();
278:
279: vm_object_deallocate(object);
280:
281: return(KERN_SUCCESS);
282: }
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