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1.1 root 1: /*
2: * Copyright (c) 1990 University of Utah.
3: * Copyright (c) 1991 The Regents of the University of California.
4: * All rights reserved.
5: *
6: * This code is derived from software contributed to Berkeley by
7: * the Systems Programming Group of the University of Utah Computer
8: * Science Department.
9: *
10: * Redistribution and use in source and binary forms, with or without
11: * modification, are permitted provided that the following conditions
12: * are met:
13: * 1. Redistributions of source code must retain the above copyright
14: * notice, this list of conditions and the following disclaimer.
15: * 2. Redistributions in binary form must reproduce the above copyright
16: * notice, this list of conditions and the following disclaimer in the
17: * documentation and/or other materials provided with the distribution.
18: * 3. All advertising materials mentioning features or use of this software
19: * must display the following acknowledgement:
20: * This product includes software developed by the University of
21: * California, Berkeley and its contributors.
22: * 4. Neither the name of the University nor the names of its contributors
23: * may be used to endorse or promote products derived from this software
24: * without specific prior written permission.
25: *
26: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36: * SUCH DAMAGE.
37: *
38: * @(#)device_pager.c 7.2 (Berkeley) 4/20/91
39: */
40:
41: /*
42: * Page to/from special files.
43: */
44:
45: #include "devpager.h"
46: #if NDEVPAGER > 0
47:
48: #include "param.h"
49: #include "conf.h"
50: #include "mman.h"
51: #include "malloc.h"
52:
53: #include "vm.h"
54: #include "vm_page.h"
55: #include "vm_kern.h"
56: #include "device_pager.h"
57:
58: queue_head_t dev_pager_list; /* list of managed devices */
59:
60: #ifdef DEBUG
61: int dpagerdebug = 0;
62: #define DDB_FOLLOW 0x01
63: #define DDB_INIT 0x02
64: #define DDB_ALLOC 0x04
65: #define DDB_FAIL 0x08
66: #endif
67:
68: void
69: dev_pager_init()
70: {
71: #ifdef DEBUG
72: if (dpagerdebug & DDB_FOLLOW)
73: printf("dev_pager_init()\n");
74: #endif
75: queue_init(&dev_pager_list);
76: }
77:
78: vm_pager_t
79: dev_pager_alloc(handle, size, prot)
80: caddr_t handle;
81: vm_size_t size;
82: vm_prot_t prot;
83: {
84: dev_t dev;
85: vm_pager_t pager;
86: int (*mapfunc)(), nprot;
87: register vm_object_t object;
88: register vm_page_t page;
89: register dev_pager_t devp;
90: register int npages, off;
91: extern int nullop(), enodev();
92:
93:
94: #ifdef DEBUG
95: if (dpagerdebug & DDB_FOLLOW)
96: printf("dev_pager_alloc(%x, %x, %x)\n", handle, size, prot);
97: #endif
98: /*
99: * Pageout to device, should never happen.
100: */
101: if (handle == NULL)
102: panic("dev_pager_alloc called");
103:
104: /*
105: * Look it up, creating as necessary
106: */
107: pager = vm_pager_lookup(&dev_pager_list, handle);
108: if (pager == NULL) {
109: /*
110: * Validation. Make sure this device can be mapped
111: * and that range to map is acceptible to device.
112: */
113: dev = (dev_t)handle;
114: mapfunc = cdevsw[major(dev)].d_mmap;
115: if (!mapfunc || mapfunc == enodev || mapfunc == nullop)
116: return(NULL);
117: nprot = 0;
118: if (prot & VM_PROT_READ)
119: nprot |= PROT_READ;
120: if (prot & VM_PROT_WRITE)
121: nprot |= PROT_WRITE;
122: if (prot & VM_PROT_EXECUTE)
123: nprot |= PROT_EXEC;
124: npages = atop(round_page(size));
125: for (off = 0; npages--; off += PAGE_SIZE)
126: if ((*mapfunc)(dev, off, nprot) == -1)
127: return(NULL);
128: /*
129: * Allocate and initialize pager structs
130: */
131: pager = (vm_pager_t)malloc(sizeof *pager, M_VMPAGER, M_WAITOK);
132: if (pager == NULL)
133: return(NULL);
134: devp = (dev_pager_t)malloc(sizeof *devp, M_VMPGDATA, M_WAITOK);
135: if (devp == NULL) {
136: free((caddr_t)pager, M_VMPAGER);
137: return(NULL);
138: }
139: devp->devp_dev = dev;
140: devp->devp_npages = atop(round_page(size));
141: pager->pg_handle = handle;
142: pager->pg_ops = &devicepagerops;
143: pager->pg_type = PG_DEVICE;
144: pager->pg_data = (caddr_t)devp;
145: /*
146: * Allocate object and vm_page structures to describe memory
147: */
148: npages = devp->devp_npages;
149: object = devp->devp_object = vm_object_allocate(ptoa(npages));
150: vm_object_enter(object, pager);
151: vm_object_setpager(object, pager, (vm_offset_t)0, FALSE);
152: devp->devp_pages = (vm_page_t)
153: kmem_alloc(kernel_map, npages*sizeof(struct vm_page));
154: off = 0;
155: for (page = devp->devp_pages;
156: page < &devp->devp_pages[npages]; page++) {
157: vm_object_lock(object);
158: vm_page_init(page, object, off);
159: page->phys_addr =
160: pmap_phys_address((*mapfunc)(dev, off, nprot));
161: page->wire_count = 1;
162: page->fictitious = TRUE;
163: PAGE_WAKEUP(page);
164: vm_object_unlock(object);
165: off += PAGE_SIZE;
166: }
167: /*
168: * Finally, put it on the managed list so other can find it.
169: */
1.1.1.2 ! root 170: queue_enter(&dev_pager_list, pager, vm_pager_t, pg_list);
1.1 root 171: #ifdef DEBUG
172: if (dpagerdebug & DDB_ALLOC)
173: printf("dev_pager_alloc: pages %d@%x\n",
174: devp->devp_npages, devp->devp_pages);
175: #endif
176: } else {
177: /*
178: * vm_object_lookup() gains a reference and also
179: * removes the object from the cache.
180: */
181: devp = (dev_pager_t)pager->pg_data;
182: if (vm_object_lookup(pager) != devp->devp_object)
183: panic("dev_pager_setup: bad object");
184: }
185: #ifdef DEBUG
186: if (dpagerdebug & DDB_ALLOC) {
187: printf("dev_pager_alloc: pager %x devp %x object %x\n",
188: pager, devp, object);
189: vm_object_print(object, FALSE);
190: }
191: #endif
192: return(pager);
193:
194: }
195:
196: void
197: dev_pager_dealloc(pager)
198: vm_pager_t pager;
199: {
200: dev_pager_t devp = (dev_pager_t)pager->pg_data;
201: register vm_object_t object;
202:
203: #ifdef DEBUG
204: if (dpagerdebug & DDB_FOLLOW)
205: printf("dev_pager_dealloc(%x)\n", pager);
206: #endif
1.1.1.2 ! root 207: queue_remove(&dev_pager_list, pager, vm_pager_t, pg_list);
1.1 root 208: object = devp->devp_object;
209: #ifdef DEBUG
210: if (dpagerdebug & DDB_ALLOC)
211: printf("dev_pager_dealloc: devp %x object %x pages %d@%x\n",
212: devp, object, devp->devp_npages, devp->devp_pages);
213: #endif
214: while (!queue_empty(&object->memq))
215: vm_page_remove((vm_page_t)queue_first(&object->memq));
216: kmem_free(kernel_map, devp->devp_pages,
217: devp->devp_npages * sizeof(struct vm_page));
218: free((caddr_t)devp, M_VMPGDATA);
1.1.1.2 ! root 219: free((caddr_t)pager, M_VMPAGER);
1.1 root 220: pager->pg_data = 0;
221: }
222:
223: dev_pager_getpage(pager, m, sync)
224: vm_pager_t pager;
225: vm_page_t m;
226: boolean_t sync;
227: {
228: #ifdef DEBUG
229: if (dpagerdebug & DDB_FOLLOW)
230: printf("dev_pager_getpage(%x, %x)\n", pager, m);
231: #endif
232: return(VM_PAGER_BAD);
233: }
234:
235: dev_pager_putpage(pager, m, sync)
236: vm_pager_t pager;
237: vm_page_t m;
238: boolean_t sync;
239: {
240: #ifdef DEBUG
241: if (dpagerdebug & DDB_FOLLOW)
242: printf("dev_pager_putpage(%x, %x)\n", pager, m);
243: #endif
244: if (pager == NULL)
245: return;
246: panic("dev_pager_putpage called");
247: }
248:
249: boolean_t
250: dev_pager_haspage(pager, offset)
251: vm_pager_t pager;
252: vm_offset_t offset;
253: {
254: #ifdef DEBUG
255: if (dpagerdebug & DDB_FOLLOW)
256: printf("dev_pager_haspage(%x, %x)\n", pager, offset);
257: #endif
258: return(TRUE);
259: }
260: #endif
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