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