1/*
2 * Copyright (c) 1990 University of Utah.
3 * Copyright (c) 1991, 1993
4 * The Regents of the University of California. 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.

--- 22 unchanged lines hidden (view full) ---

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 8.1 (Berkeley) 6/11/93
39 * $Id: device_pager.c,v 1.10 1995/05/18 02:59:18 davidg Exp $
40 */
41
42/*
43 * Page to/from special files.
44 */
45
46#include <sys/param.h>
47#include <sys/systm.h>
48#include <sys/conf.h>
49#include <sys/mman.h>
50#include <sys/malloc.h>
51#include <sys/proc.h>
52
53#include <vm/vm.h>
54#include <vm/vm_kern.h>
55#include <vm/vm_page.h>
56#include <vm/device_pager.h>
57
58struct pagerlst dev_pager_list; /* list of managed devices */
59struct pglist dev_pager_fakelist; /* list of available vm_page_t's */
60
61#ifdef DEBUG
62int dpagerdebug;
63
64#define DDB_FOLLOW 0x01
65#define DDB_INIT 0x02
66#define DDB_ALLOC 0x04
67#define DDB_FAIL 0x08
68#endif
69
70static vm_pager_t dev_pager_alloc __P((void *, vm_size_t, vm_prot_t, vm_offset_t));
71static void dev_pager_dealloc __P((vm_pager_t));
72static int dev_pager_getpage __P((vm_pager_t, vm_page_t, boolean_t));
73static boolean_t dev_pager_haspage __P((vm_pager_t, vm_offset_t));
74static void dev_pager_init __P((void));
75static int dev_pager_putpage __P((vm_pager_t, vm_page_t, boolean_t));
76static vm_page_t dev_pager_getfake __P((vm_offset_t));
77static void dev_pager_putfake __P((vm_page_t));
78
79struct pagerops devicepagerops = {
80 dev_pager_init,
81 dev_pager_alloc,
82 dev_pager_dealloc,
83 dev_pager_getpage,
84 0,
85 dev_pager_putpage,
86 0,
87 dev_pager_haspage
88};
89
90static void
91dev_pager_init()
92{
93#ifdef DEBUG
94 if (dpagerdebug & DDB_FOLLOW)
95 printf("dev_pager_init()\n");
96#endif
97 TAILQ_INIT(&dev_pager_list);
98 TAILQ_INIT(&dev_pager_fakelist);
99}
100
101static vm_pager_t
102dev_pager_alloc(handle, size, prot, foff)
103 void *handle;
104 vm_size_t size;
105 vm_prot_t prot;
106 vm_offset_t foff;
107{
108 dev_t dev;
109 vm_pager_t pager;
110 int (*mapfunc) ();
111 vm_object_t object;
112 dev_pager_t devp;
113 unsigned int npages, off;
114
115#ifdef DEBUG
116 if (dpagerdebug & DDB_FOLLOW)
117 printf("dev_pager_alloc(%x, %x, %x, %x)\n",
118 handle, size, prot, foff);
119#endif
120#ifdef DIAGNOSTIC
121 /*
122 * Pageout to device, should never happen.
123 */
124 if (handle == NULL)
125 panic("dev_pager_alloc called");
126#endif
127
128 /*
129 * Make sure this device can be mapped.
130 */
131 dev = (dev_t) (u_long) handle;
132 mapfunc = cdevsw[major(dev)].d_mmap;
133 if (mapfunc == NULL || mapfunc == enodev || mapfunc == nullop)
134 return (NULL);
135
136 /*

--- 9 unchanged lines hidden (view full) ---

146 * XXX assumes VM_PROT_* == PROT_*
147 */
148 npages = atop(round_page(size));
149 for (off = foff; npages--; off += PAGE_SIZE)
150 if ((*mapfunc) (dev, off, (int) prot) == -1)
151 return (NULL);
152
153 /*
154 * Look up pager, creating as necessary.
155 */
156top:
157 pager = vm_pager_lookup(&dev_pager_list, handle);
158 if (pager == NULL) {
159 /*
160 * Allocate and initialize pager structs
161 */
162 pager = (vm_pager_t) malloc(sizeof *pager, M_VMPAGER, M_WAITOK);
163 if (pager == NULL)
164 return (NULL);
165 devp = (dev_pager_t) malloc(sizeof *devp, M_VMPGDATA, M_WAITOK);
166 if (devp == NULL) {
167 free((caddr_t) pager, M_VMPAGER);
168 return (NULL);
169 }
170 pager->pg_handle = handle;
171 pager->pg_ops = &devicepagerops;
172 pager->pg_type = PG_DEVICE;
173 pager->pg_data = (caddr_t) devp;
174 TAILQ_INIT(&devp->devp_pglist);
175 /*
176 * Allocate object and associate it with the pager.
177 */
178 object = devp->devp_object = vm_object_allocate(foff + size);
179 object->flags &= ~OBJ_INTERNAL;
180 vm_object_enter(object, pager);
181 object->pager = pager;
182 /*
183 * Finally, put it on the managed list so other can find it.
184 * First we re-lookup in case someone else beat us to this
185 * point (due to blocking in the various mallocs). If so, we
186 * free everything and start over.
187 */
188 if (vm_pager_lookup(&dev_pager_list, handle)) {
189 free((caddr_t) devp, M_VMPGDATA);
190 free((caddr_t) pager, M_VMPAGER);
191 goto top;
192 }
193 TAILQ_INSERT_TAIL(&dev_pager_list, pager, pg_list);
194#ifdef DEBUG
195 if (dpagerdebug & DDB_ALLOC) {
196 printf("dev_pager_alloc: pager %x devp %x object %x\n",
197 pager, devp, object);
198 vm_object_print(object, FALSE);
199 }
200#endif
201 } else {
202 /*
203 * Gain a reference to the object.
204 */
205 object = vm_object_lookup(pager);
206 if (foff + size > object->size)
207 object->size = foff + size;
208#ifdef DIAGNOSTIC
209 devp = (dev_pager_t) pager->pg_data;
210 if (object != devp->devp_object)
211 panic("dev_pager_setup: bad object");
212#endif
213 }
214 return (pager);
215}
216
217static void
218dev_pager_dealloc(pager)
219 vm_pager_t pager;
220{
221 dev_pager_t devp;
222 vm_object_t object;
223 vm_page_t m;
224
225#ifdef DEBUG
226 if (dpagerdebug & DDB_FOLLOW)
227 printf("dev_pager_dealloc(%x)\n", pager);
228#endif
229 TAILQ_REMOVE(&dev_pager_list, pager, pg_list);
230 /*
231 * Get the object. Note: cannot use vm_object_lookup since object has
232 * already been removed from the hash chain.
233 */
234 devp = (dev_pager_t) pager->pg_data;
235 object = devp->devp_object;
236#ifdef DEBUG
237 if (dpagerdebug & DDB_ALLOC)
238 printf("dev_pager_dealloc: devp %x object %x\n", devp, object);
239#endif
240 /*
241 * Free up our fake pages.
242 */
243 while ((m = devp->devp_pglist.tqh_first) != 0) {
244 TAILQ_REMOVE(&devp->devp_pglist, m, pageq);
245 dev_pager_putfake(m);
246 }
247 free((caddr_t) devp, M_VMPGDATA);
248 free((caddr_t) pager, M_VMPAGER);
249}
250
251static int
252dev_pager_getpage(pager, m, sync)
253 vm_pager_t pager;
254 vm_page_t m;
255 boolean_t sync;
256{
257 register vm_object_t object;
258 vm_offset_t offset, paddr;
259 vm_page_t page;
260 dev_t dev;
261 int s;
262 int (*mapfunc) (), prot;
263
264#ifdef DEBUG
265 if (dpagerdebug & DDB_FOLLOW)
266 printf("dev_pager_getpage(%x, %x)\n", pager, m);
267#endif
268
269 object = m->object;
270 dev = (dev_t) (u_long) pager->pg_handle;
271 offset = m->offset + object->paging_offset;
272 prot = PROT_READ; /* XXX should pass in? */
273 mapfunc = cdevsw[major(dev)].d_mmap;
274
275 if (mapfunc == NULL || mapfunc == enodev || mapfunc == nullop)
276 panic("dev_pager_getpage: no map function");
277
278 paddr = pmap_phys_address((*mapfunc) ((dev_t) dev, (int) offset, prot));
279#ifdef DIAGNOSTIC
280 if (paddr == -1)
281 panic("dev_pager_getpage: map function returns error");
282#endif
283 /*
284 * Replace the passed in page with our own fake page and free up the
285 * original.
286 */
287 page = dev_pager_getfake(paddr);
288 TAILQ_INSERT_TAIL(&((dev_pager_t) pager->pg_data)->devp_pglist,
289 page, pageq);
290 vm_object_lock(object);
291 vm_page_lock_queues();
292 PAGE_WAKEUP(m);
293 vm_page_free(m);
294 vm_page_unlock_queues();
295 s = splhigh();
296 vm_page_insert(page, object, offset);
297 splx(s);
298 vm_object_unlock(object);
299
300 return (VM_PAGER_OK);
301}
302
303static int
304dev_pager_putpage(pager, m, sync)
305 vm_pager_t pager;
306 vm_page_t m;
307 boolean_t sync;
308{
309#ifdef DEBUG
310 if (dpagerdebug & DDB_FOLLOW)
311 printf("dev_pager_putpage(%x, %x)\n", pager, m);
312#endif
313 if (pager == NULL)
314 return 0;
315 panic("dev_pager_putpage called");
316}
317
318static boolean_t
319dev_pager_haspage(pager, offset)
320 vm_pager_t pager;
321 vm_offset_t offset;
322{
323#ifdef DEBUG
324 if (dpagerdebug & DDB_FOLLOW)
325 printf("dev_pager_haspage(%x, %x)\n", pager, offset);
326#endif
327 return (TRUE);
328}
329
330static vm_page_t
331dev_pager_getfake(paddr)
332 vm_offset_t paddr;
333{
334 vm_page_t m;

--- 5 unchanged lines hidden (view full) ---

340 TAILQ_INSERT_TAIL(&dev_pager_fakelist, m, pageq);
341 m++;
342 }
343 }
344 m = dev_pager_fakelist.tqh_first;
345 TAILQ_REMOVE(&dev_pager_fakelist, m, pageq);
346
347 m->flags = PG_BUSY | PG_FICTITIOUS;
348 m->dirty = 0;
349 m->valid = VM_PAGE_BITS_ALL;
350 m->busy = 0;
351 m->bmapped = 0;
352
353 m->wire_count = 1;
354 m->phys_addr = paddr;
355
356 return (m);
357}
358
359static void
360dev_pager_putfake(m)
361 vm_page_t m;
362{
363#ifdef DIAGNOSTIC
364 if (!(m->flags & PG_FICTITIOUS))
365 panic("dev_pager_putfake: bad page");
366#endif
367 TAILQ_INSERT_TAIL(&dev_pager_fakelist, m, pageq);
368}