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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: *
1.1.1.3 ! root 36: * from: @(#)vm_pager.c 7.4 (Berkeley) 5/7/91
! 37: * vm_pager.c,v 1.4.2.1 1993/07/24 21:34:02 cgd Exp
1.1 root 38: *
39: *
40: * Copyright (c) 1987, 1990 Carnegie-Mellon University.
41: * All rights reserved.
42: *
43: * Authors: Avadis Tevanian, Jr., Michael Wayne Young
44: *
45: * Permission to use, copy, modify and distribute this software and
46: * its documentation is hereby granted, provided that both the copyright
47: * notice and this permission notice appear in all copies of the
48: * software, derivative works or modified versions, and any portions
49: * thereof, and that both notices appear in supporting documentation.
50: *
51: * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
52: * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
53: * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
54: *
55: * Carnegie Mellon requests users of this software to return to
56: *
57: * Software Distribution Coordinator or [email protected]
58: * School of Computer Science
59: * Carnegie Mellon University
60: * Pittsburgh PA 15213-3890
61: *
62: * any improvements or extensions that they make and grant Carnegie the
63: * rights to redistribute these changes.
64: */
65:
66: /*
67: * Paging space routine stubs. Emulates a matchmaker-like interface
68: * for builtin pagers.
69: */
70:
71: #include "param.h"
72: #include "malloc.h"
73:
74: #include "vm.h"
75: #include "vm_page.h"
76: #include "vm_kern.h"
77:
78: #include "swappager.h"
79: #if NSWAPPAGER > 0
80: extern struct pagerops swappagerops;
81: #endif
82: #include "vnodepager.h"
83: #if NVNODEPAGER > 0
84: extern struct pagerops vnodepagerops;
85: #endif
86: #include "devpager.h"
87: #if NDEVPAGER > 0
88: extern struct pagerops devicepagerops;
89: #endif
90:
91: struct pagerops *pagertab[] = {
1.1.1.3 ! root 92: #if NSWAPPAGER > 0
1.1 root 93: &swappagerops, /* PG_SWAP */
1.1.1.3 ! root 94: #else
! 95: NULL, /* no swappager */
! 96: #endif
! 97: #if NVNODEPAGER > 0
1.1 root 98: &vnodepagerops, /* PG_VNODE */
1.1.1.3 ! root 99: #else
! 100: NULL, /* no vnodepager */
! 101: #endif
! 102: #if NDEVPAGER > 0
1.1 root 103: &devicepagerops, /* PG_DEV */
1.1.1.3 ! root 104: #else
! 105: NULL, /* no devpager */
! 106: #endif
1.1 root 107: };
108: int npagers = sizeof (pagertab) / sizeof (pagertab[0]);
109:
110: struct pagerops *dfltpagerops = NULL; /* default pager */
111:
112: /*
113: * Kernel address space for mapping pages.
114: * Used by pagers where KVAs are needed for IO.
115: */
116: #define PAGER_MAP_SIZE (256 * PAGE_SIZE)
117: vm_map_t pager_map;
118: vm_offset_t pager_sva, pager_eva;
119:
120: void
121: vm_pager_init()
122: {
123: struct pagerops **pgops;
124:
125: /*
126: * Allocate a kernel submap for tracking get/put page mappings
127: */
128: pager_map = kmem_suballoc(kernel_map, &pager_sva, &pager_eva,
129: PAGER_MAP_SIZE, FALSE);
130: /*
131: * Initialize known pagers
132: */
133: for (pgops = pagertab; pgops < &pagertab[npagers]; pgops++)
1.1.1.3 ! root 134: if (*pgops) (*(*pgops)->pgo_init)();
1.1 root 135: if (dfltpagerops == NULL)
136: panic("no default pager");
137: }
138:
139: /*
140: * Allocate an instance of a pager of the given type.
141: */
142: vm_pager_t
143: vm_pager_allocate(type, handle, size, prot)
144: int type;
145: caddr_t handle;
146: vm_size_t size;
147: vm_prot_t prot;
148: {
149: vm_pager_t pager;
150: struct pagerops *ops;
151:
152: ops = (type == PG_DFLT) ? dfltpagerops : pagertab[type];
153: return((*ops->pgo_alloc)(handle, size, prot));
154: }
155:
156: void
157: vm_pager_deallocate(pager)
158: vm_pager_t pager;
159: {
160: if (pager == NULL)
161: panic("vm_pager_deallocate: null pager");
162:
163: VM_PAGER_DEALLOC(pager);
164: }
165:
166: vm_pager_get(pager, m, sync)
167: vm_pager_t pager;
168: vm_page_t m;
169: boolean_t sync;
170: {
171: extern boolean_t vm_page_zero_fill();
172:
173: if (pager == NULL)
174: return(vm_page_zero_fill(m) ? VM_PAGER_OK : VM_PAGER_FAIL);
175: return(VM_PAGER_GET(pager, m, sync));
176: }
177:
178: vm_pager_put(pager, m, sync)
179: vm_pager_t pager;
180: vm_page_t m;
181: boolean_t sync;
182: {
183: if (pager == NULL)
184: panic("vm_pager_put: null pager");
185: return(VM_PAGER_PUT(pager, m, sync));
186: }
187:
188: boolean_t
189: vm_pager_has_page(pager, offset)
190: vm_pager_t pager;
191: vm_offset_t offset;
192: {
193: if (pager == NULL)
194: panic("vm_pager_has_page");
195: return(VM_PAGER_HASPAGE(pager, offset));
196: }
197:
198: /*
199: * Called by pageout daemon before going back to sleep.
200: * Gives pagers a chance to clean up any completed async pageing operations.
201: */
202: void
203: vm_pager_sync()
204: {
205: struct pagerops **pgops;
206:
207: for (pgops = pagertab; pgops < &pagertab[npagers]; pgops++)
1.1.1.3 ! root 208: if (*pgops) (*(*pgops)->pgo_putpage)(NULL, NULL, FALSE);
1.1 root 209: }
210:
211: vm_offset_t
212: vm_pager_map_page(m)
213: vm_page_t m;
214: {
215: vm_offset_t kva;
216:
217: #ifdef DEBUG
218: if (!m->busy || m->active)
219: panic("vm_pager_map_page: page active or not busy");
220: if (m->pagerowned)
221: printf("vm_pager_map_page: page %x already in pager\n", m);
222: #endif
223: kva = kmem_alloc_wait(pager_map, PAGE_SIZE);
224: #ifdef DEBUG
225: m->pagerowned = 1;
226: #endif
227: pmap_enter(vm_map_pmap(pager_map), kva, VM_PAGE_TO_PHYS(m),
228: VM_PROT_DEFAULT, TRUE);
229: return(kva);
230: }
231:
232: void
233: vm_pager_unmap_page(kva)
234: vm_offset_t kva;
235: {
236: #ifdef DEBUG
237: vm_page_t m;
238:
239: m = PHYS_TO_VM_PAGE(pmap_extract(vm_map_pmap(pager_map), kva));
240: #endif
241: kmem_free_wakeup(pager_map, kva, PAGE_SIZE);
242: #ifdef DEBUG
243: if (m->pagerowned)
244: m->pagerowned = 0;
245: else
246: printf("vm_pager_unmap_page: page %x(%x/%x) not owned\n",
247: m, kva, VM_PAGE_TO_PHYS(m));
248: #endif
249: }
250:
251: vm_pager_t
252: vm_pager_lookup(list, handle)
253: register queue_head_t *list;
254: caddr_t handle;
255: {
256: register vm_pager_t pager;
257:
258: pager = (vm_pager_t) queue_first(list);
259: while (!queue_end(list, (queue_entry_t)pager)) {
260: if (pager->pg_handle == handle)
261: return(pager);
262: pager = (vm_pager_t) queue_next(&pager->pg_list);
263: }
264: return(NULL);
265: }
266:
267: /*
268: * This routine gains a reference to the object.
269: * Explicit deallocation is necessary.
270: */
271: pager_cache(object, should_cache)
272: vm_object_t object;
273: boolean_t should_cache;
274: {
275: if (object == NULL)
276: return(KERN_INVALID_ARGUMENT);
277:
278: vm_object_cache_lock();
279: vm_object_lock(object);
280: object->can_persist = should_cache;
281: vm_object_unlock(object);
282: vm_object_cache_unlock();
283:
284: vm_object_deallocate(object);
285:
286: return(KERN_SUCCESS);
287: }
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