sys/vm/device_pager.c

   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.
   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  * 4. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  *      @(#)device_pager.c      8.1 (Berkeley) 6/11/93
  35  */
  36
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD$");
  39
  40 #include <sys/param.h>
  41 #include <sys/systm.h>
  42 #include <sys/conf.h>
  43 #include <sys/lock.h>
  44 #include <sys/proc.h>
  45 #include <sys/mutex.h>
  46 #include <sys/mman.h>
  47 #include <sys/rwlock.h>
  48 #include <sys/sx.h>
  49
  50 #include <vm/vm.h>
  51 #include <vm/vm_param.h>
  52 #include <vm/vm_object.h>
  53 #include <vm/vm_page.h>
  54 #include <vm/vm_pager.h>
  55 #include <vm/vm_phys.h>
  56 #include <vm/uma.h>
  57
  58 static void dev_pager_init(void);
  59 static vm_object_t dev_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
  60     vm_ooffset_t, struct ucred *);
  61 static void dev_pager_dealloc(vm_object_t);
  62 static int dev_pager_getpages(vm_object_t, vm_page_t *, int, int);
  63 static void dev_pager_putpages(vm_object_t, vm_page_t *, int,
  64                 boolean_t, int *);
  65 static boolean_t dev_pager_haspage(vm_object_t, vm_pindex_t, int *,
  66                 int *);
  67 static void dev_pager_free_page(vm_object_t object, vm_page_t m);
  68
  69 /* list of device pager objects */
  70 static struct pagerlst dev_pager_object_list;
  71 /* protect list manipulation */
  72 static struct mtx dev_pager_mtx;
  73
  74 struct pagerops devicepagerops = {
  75         .pgo_init =     dev_pager_init,
  76         .pgo_alloc =    dev_pager_alloc,
  77         .pgo_dealloc =  dev_pager_dealloc,
  78         .pgo_getpages = dev_pager_getpages,
  79         .pgo_putpages = dev_pager_putpages,
  80         .pgo_haspage =  dev_pager_haspage,
  81 };
  82
  83 struct pagerops mgtdevicepagerops = {
  84         .pgo_alloc =    dev_pager_alloc,
  85         .pgo_dealloc =  dev_pager_dealloc,
  86         .pgo_getpages = dev_pager_getpages,
  87         .pgo_putpages = dev_pager_putpages,
  88         .pgo_haspage =  dev_pager_haspage,
  89 };
  90
  91 static int old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
  92     vm_ooffset_t foff, struct ucred *cred, u_short *color);
  93 static void old_dev_pager_dtor(void *handle);
  94 static int old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset,
  95     int prot, vm_page_t *mres);
  96
  97 static struct cdev_pager_ops old_dev_pager_ops = {
  98         .cdev_pg_ctor = old_dev_pager_ctor,
  99         .cdev_pg_dtor = old_dev_pager_dtor,
 100         .cdev_pg_fault = old_dev_pager_fault
 101 };
 102
 103 static void
 104 dev_pager_init()
 105 {
 106         TAILQ_INIT(&dev_pager_object_list);
 107         mtx_init(&dev_pager_mtx, "dev_pager list", NULL, MTX_DEF);
 108 }
 109
 110 vm_object_t
 111 cdev_pager_lookup(void *handle)
 112 {
 113         vm_object_t object;
 114
 115         mtx_lock(&dev_pager_mtx);
 116         object = vm_pager_object_lookup(&dev_pager_object_list, handle);
 117         mtx_unlock(&dev_pager_mtx);
 118         return (object);
 119 }
 120
 121 vm_object_t
 122 cdev_pager_allocate(void *handle, enum obj_type tp, struct cdev_pager_ops *ops,
 123     vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff, struct ucred *cred)
 124 {
 125         vm_object_t object, object1;
 126         vm_pindex_t pindex;
 127         u_short color;
 128
 129         if (tp != OBJT_DEVICE && tp != OBJT_MGTDEVICE)
 130                 return (NULL);
 131
 132         /*
 133          * Offset should be page aligned.
 134          */
 135         if (foff & PAGE_MASK)
 136                 return (NULL);
 137
 138         size = round_page(size);
 139         pindex = OFF_TO_IDX(foff + size);
 140
 141         if (ops->cdev_pg_ctor(handle, size, prot, foff, cred, &color) != 0)
 142                 return (NULL);
 143         mtx_lock(&dev_pager_mtx);
 144
 145         /*
 146          * Look up pager, creating as necessary.
 147          */
 148         object1 = NULL;
 149         object = vm_pager_object_lookup(&dev_pager_object_list, handle);
 150         if (object == NULL) {
 151                 /*
 152                  * Allocate object and associate it with the pager.  Initialize
 153                  * the object's pg_color based upon the physical address of the
 154                  * device's memory.
 155                  */
 156                 mtx_unlock(&dev_pager_mtx);
 157                 object1 = vm_object_allocate(tp, pindex);
 158                 object1->flags |= OBJ_COLORED;
 159                 object1->pg_color = color;
 160                 object1->handle = handle;
 161                 object1->un_pager.devp.ops = ops;
 162                 object1->un_pager.devp.dev = handle;
 163                 TAILQ_INIT(&object1->un_pager.devp.devp_pglist);
 164                 mtx_lock(&dev_pager_mtx);
 165                 object = vm_pager_object_lookup(&dev_pager_object_list, handle);
 166                 if (object != NULL) {
 167                         /*
 168                          * We raced with other thread while allocating object.
 169                          */
 170                         if (pindex > object->size)
 171                                 object->size = pindex;
 172                 } else {
 173                         object = object1;
 174                         object1 = NULL;
 175                         object->handle = handle;
 176                         TAILQ_INSERT_TAIL(&dev_pager_object_list, object,
 177                             pager_object_list);
 178                         KASSERT(object->type == tp,
 179                 ("Inconsistent device pager type %p %d", object, tp));
 180                 }
 181         } else {
 182                 if (pindex > object->size)
 183                         object->size = pindex;
 184         }
 185         mtx_unlock(&dev_pager_mtx);
 186         if (object1 != NULL) {
 187                 object1->handle = object1;
 188                 mtx_lock(&dev_pager_mtx);
 189                 TAILQ_INSERT_TAIL(&dev_pager_object_list, object1,
 190                     pager_object_list);
 191                 mtx_unlock(&dev_pager_mtx);
 192                 vm_object_deallocate(object1);
 193         }
 194         return (object);
 195 }
 196
 197 static vm_object_t
 198 dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
 199     vm_ooffset_t foff, struct ucred *cred)
 200 {
 201
 202         return (cdev_pager_allocate(handle, OBJT_DEVICE, &old_dev_pager_ops,
 203             size, prot, foff, cred));
 204 }
 205
 206 void
 207 cdev_pager_free_page(vm_object_t object, vm_page_t m)
 208 {
 209
 210         VM_OBJECT_ASSERT_WLOCKED(object);
 211         if (object->type == OBJT_MGTDEVICE) {
 212                 KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("unmanaged %p", m));
 213                 pmap_remove_all(m);
 214                 vm_page_lock(m);
 215                 vm_page_remove(m);
 216                 vm_page_unlock(m);
 217         } else if (object->type == OBJT_DEVICE)
 218                 dev_pager_free_page(object, m);
 219 }
 220
 221 static void
 222 dev_pager_free_page(vm_object_t object, vm_page_t m)
 223 {
 224
 225         VM_OBJECT_ASSERT_WLOCKED(object);
 226         KASSERT((object->type == OBJT_DEVICE &&
 227             (m->oflags & VPO_UNMANAGED) != 0),
 228             ("Managed device or page obj %p m %p", object, m));
 229         TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, plinks.q);
 230         vm_page_putfake(m);
 231 }
 232
 233 static void
 234 dev_pager_dealloc(object)
 235         vm_object_t object;
 236 {
 237         vm_page_t m;
 238
 239         VM_OBJECT_WUNLOCK(object);
 240         object->un_pager.devp.ops->cdev_pg_dtor(object->un_pager.devp.dev);
 241
 242         mtx_lock(&dev_pager_mtx);
 243         TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list);
 244         mtx_unlock(&dev_pager_mtx);
 245         VM_OBJECT_WLOCK(object);
 246
 247         if (object->type == OBJT_DEVICE) {
 248                 /*
 249                  * Free up our fake pages.
 250                  */
 251                 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist))
 252                     != NULL)
 253                         dev_pager_free_page(object, m);
 254         }
 255         object->handle = NULL;
 256         object->type = OBJT_DEAD;
 257 }
 258
 259 static int
 260 dev_pager_getpages(vm_object_t object, vm_page_t *ma, int count, int reqpage)
 261 {
 262         int error, i;
 263
 264         VM_OBJECT_ASSERT_WLOCKED(object);
 265         error = object->un_pager.devp.ops->cdev_pg_fault(object,
 266             IDX_TO_OFF(ma[reqpage]->pindex), PROT_READ, &ma[reqpage]);
 267
 268         VM_OBJECT_ASSERT_WLOCKED(object);
 269
 270         for (i = 0; i < count; i++) {
 271                 if (i != reqpage) {
 272                         vm_page_lock(ma[i]);
 273                         vm_page_free(ma[i]);
 274                         vm_page_unlock(ma[i]);
 275                 }
 276         }
 277
 278         if (error == VM_PAGER_OK) {
 279                 KASSERT((object->type == OBJT_DEVICE &&
 280                      (ma[reqpage]->oflags & VPO_UNMANAGED) != 0) ||
 281                     (object->type == OBJT_MGTDEVICE &&
 282                      (ma[reqpage]->oflags & VPO_UNMANAGED) == 0),
 283                     ("Wrong page type %p %p", ma[reqpage], object));
 284                 if (object->type == OBJT_DEVICE) {
 285                         TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist,
 286                             ma[reqpage], plinks.q);
 287                 }
 288         }
 289
 290         return (error);
 291 }
 292
 293 static int
 294 old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, int prot,
 295     vm_page_t *mres)
 296 {
 297         vm_pindex_t pidx;
 298         vm_paddr_t paddr;
 299         vm_page_t m_paddr, page;
 300         struct cdev *dev;
 301         struct cdevsw *csw;
 302         struct file *fpop;
 303         struct thread *td;
 304         vm_memattr_t memattr;
 305         int ref, ret;
 306
 307         pidx = OFF_TO_IDX(offset);
 308         memattr = object->memattr;
 309
 310         VM_OBJECT_WUNLOCK(object);
 311
 312         dev = object->handle;
 313         csw = dev_refthread(dev, &ref);
 314         if (csw == NULL) {
 315                 VM_OBJECT_WLOCK(object);
 316                 return (VM_PAGER_FAIL);
 317         }
 318         td = curthread;
 319         fpop = td->td_fpop;
 320         td->td_fpop = NULL;
 321         ret = csw->d_mmap(dev, offset, &paddr, prot, &memattr);
 322         td->td_fpop = fpop;
 323         dev_relthread(dev, ref);
 324         if (ret != 0) {
 325                 printf(
 326             "WARNING: dev_pager_getpage: map function returns error %d", ret);
 327                 VM_OBJECT_WLOCK(object);
 328                 return (VM_PAGER_FAIL);
 329         }
 330
 331         /* If "paddr" is a real page, perform a sanity check on "memattr". */
 332         if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL &&
 333             pmap_page_get_memattr(m_paddr) != memattr) {
 334                 memattr = pmap_page_get_memattr(m_paddr);
 335                 printf(
 336             "WARNING: A device driver has set \"memattr\" inconsistently.\n");
 337         }
 338         if (((*mres)->flags & PG_FICTITIOUS) != 0) {
 339                 /*
 340                  * If the passed in result page is a fake page, update it with
 341                  * the new physical address.
 342                  */
 343                 page = *mres;
 344                 VM_OBJECT_WLOCK(object);
 345                 vm_page_updatefake(page, paddr, memattr);
 346         } else {
 347                 /*
 348                  * Replace the passed in reqpage page with our own fake page and
 349                  * free up the all of the original pages.
 350                  */
 351                 page = vm_page_getfake(paddr, memattr);
 352                 VM_OBJECT_WLOCK(object);
 353                 if (vm_page_replace(page, object, (*mres)->pindex) != *mres)
 354                         panic("old_dev_pager_fault: invalid page replacement");
 355                 vm_page_lock(*mres);
 356                 vm_page_free(*mres);
 357                 vm_page_unlock(*mres);
 358                 *mres = page;
 359         }
 360         page->valid = VM_PAGE_BITS_ALL;
 361         return (VM_PAGER_OK);
 362 }
 363
 364 static void
 365 dev_pager_putpages(object, m, count, sync, rtvals)
 366         vm_object_t object;
 367         vm_page_t *m;
 368         int count;
 369         boolean_t sync;
 370         int *rtvals;
 371 {
 372
 373         panic("dev_pager_putpage called");
 374 }
 375
 376 static boolean_t
 377 dev_pager_haspage(object, pindex, before, after)
 378         vm_object_t object;
 379         vm_pindex_t pindex;
 380         int *before;
 381         int *after;
 382 {
 383         if (before != NULL)
 384                 *before = 0;
 385         if (after != NULL)
 386                 *after = 0;
 387         return (TRUE);
 388 }
 389
 390 static int
 391 old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
 392     vm_ooffset_t foff, struct ucred *cred, u_short *color)
 393 {
 394         struct cdev *dev;
 395         struct cdevsw *csw;
 396         vm_memattr_t dummy;
 397         vm_ooffset_t off;
 398         vm_paddr_t paddr;
 399         unsigned int npages;
 400         int ref;
 401
 402         /*
 403          * Make sure this device can be mapped.
 404          */
 405         dev = handle;
 406         csw = dev_refthread(dev, &ref);
 407         if (csw == NULL)
 408                 return (ENXIO);
 409
 410         /*
 411          * Check that the specified range of the device allows the desired
 412          * protection.
 413          *
 414          * XXX assumes VM_PROT_* == PROT_*
 415          */
 416         npages = OFF_TO_IDX(size);
 417         paddr = 0; /* Make paddr initialized for the case of size == 0. */
 418         for (off = foff; npages--; off += PAGE_SIZE) {
 419                 if (csw->d_mmap(dev, off, &paddr, (int)prot, &dummy) != 0) {
 420                         dev_relthread(dev, ref);
 421                         return (EINVAL);
 422                 }
 423         }
 424
 425         dev_ref(dev);
 426         dev_relthread(dev, ref);
 427         *color = atop(paddr) - OFF_TO_IDX(off - PAGE_SIZE);
 428         return (0);
 429 }
 430
 431 static void
 432 old_dev_pager_dtor(void *handle)
 433 {
 434
 435         dev_rel(handle);
 436 }