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 #include <machine/cpu.h>
  58
  59 static void dev_pager_init(void);
  60 static vm_object_t dev_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
  61     vm_ooffset_t, struct ucred *);
  62 static void dev_pager_dealloc(vm_object_t);
  63 static int dev_pager_getpages(vm_object_t, vm_page_t *, int, int);
  64 static void dev_pager_putpages(vm_object_t, vm_page_t *, int,
  65                 boolean_t, int *);
  66 static boolean_t dev_pager_haspage(vm_object_t, vm_pindex_t, int *,
  67                 int *);
  68 static void dev_pager_free_page(vm_object_t object, vm_page_t m);
  69
  70 /* list of device pager objects */
  71 static struct pagerlst dev_pager_object_list;
  72 /* protect list manipulation */
  73 static struct mtx dev_pager_mtx;
  74
  75 struct pagerops devicepagerops = {
  76         .pgo_init =     dev_pager_init,
  77         .pgo_alloc =    dev_pager_alloc,
  78         .pgo_dealloc =  dev_pager_dealloc,
  79         .pgo_getpages = dev_pager_getpages,
  80         .pgo_putpages = dev_pager_putpages,
  81         .pgo_haspage =  dev_pager_haspage,
  82 };
  83
  84 struct pagerops mgtdevicepagerops = {
  85         .pgo_alloc =    dev_pager_alloc,
  86         .pgo_dealloc =  dev_pager_dealloc,
  87         .pgo_getpages = dev_pager_getpages,
  88         .pgo_putpages = dev_pager_putpages,
  89         .pgo_haspage =  dev_pager_haspage,
  90 };
  91
  92 static int old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
  93     vm_ooffset_t foff, struct ucred *cred, u_short *color);
  94 static void old_dev_pager_dtor(void *handle);
  95 static int old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset,
  96     int prot, vm_page_t *mres);
  97
  98 static struct cdev_pager_ops old_dev_pager_ops = {
  99         .cdev_pg_ctor = old_dev_pager_ctor,
 100         .cdev_pg_dtor = old_dev_pager_dtor,
 101         .cdev_pg_fault = old_dev_pager_fault
 102 };
 103
 104 static void
 105 dev_pager_init()
 106 {
 107         TAILQ_INIT(&dev_pager_object_list);
 108         mtx_init(&dev_pager_mtx, "dev_pager list", NULL, MTX_DEF);
 109 }
 110
 111 vm_object_t
 112 cdev_pager_lookup(void *handle)
 113 {
 114         vm_object_t object;
 115
 116         mtx_lock(&dev_pager_mtx);
 117         object = vm_pager_object_lookup(&dev_pager_object_list, handle);
 118         mtx_unlock(&dev_pager_mtx);
 119         return (object);
 120 }
 121
 122 vm_object_t
 123 cdev_pager_allocate(void *handle, enum obj_type tp, struct cdev_pager_ops *ops,
 124     vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff, struct ucred *cred)
 125 {
 126         vm_object_t object, object1;
 127         vm_pindex_t pindex;
 128         u_short color;
 129
 130         if (tp != OBJT_DEVICE && tp != OBJT_MGTDEVICE)
 131                 return (NULL);
 132
 133         /*
 134          * Offset should be page aligned.
 135          */
 136         if (foff & PAGE_MASK)
 137                 return (NULL);
 138
 139         size = round_page(size);
 140         pindex = OFF_TO_IDX(foff + size);
 141
 142         if (ops->cdev_pg_ctor(handle, size, prot, foff, cred, &color) != 0)
 143                 return (NULL);
 144         mtx_lock(&dev_pager_mtx);
 145
 146         /*
 147          * Look up pager, creating as necessary.
 148          */
 149         object1 = NULL;
 150         object = vm_pager_object_lookup(&dev_pager_object_list, handle);
 151         if (object == NULL) {
 152                 /*
 153                  * Allocate object and associate it with the pager.  Initialize
 154                  * the object's pg_color based upon the physical address of the
 155                  * device's memory.
 156                  */
 157                 mtx_unlock(&dev_pager_mtx);
 158                 object1 = vm_object_allocate(tp, pindex);
 159                 object1->flags |= OBJ_COLORED;
 160                 object1->pg_color = color;
 161                 object1->handle = handle;
 162                 object1->un_pager.devp.ops = ops;
 163                 object1->un_pager.devp.dev = handle;
 164                 TAILQ_INIT(&object1->un_pager.devp.devp_pglist);
 165                 mtx_lock(&dev_pager_mtx);
 166                 object = vm_pager_object_lookup(&dev_pager_object_list, handle);
 167                 if (object != NULL) {
 168                         /*
 169                          * We raced with other thread while allocating object.
 170                          */
 171                         if (pindex > object->size)
 172                                 object->size = pindex;
 173                 } else {
 174                         object = object1;
 175                         object1 = NULL;
 176                         object->handle = handle;
 177                         TAILQ_INSERT_TAIL(&dev_pager_object_list, object,
 178                             pager_object_list);
 179                         KASSERT(object->type == tp,
 180                 ("Inconsistent device pager type %p %d", object, tp));
 181                 }
 182         } else {
 183                 if (pindex > object->size)
 184                         object->size = pindex;
 185         }
 186         mtx_unlock(&dev_pager_mtx);
 187         if (object1 != NULL) {
 188                 object1->handle = object1;
 189                 mtx_lock(&dev_pager_mtx);
 190                 TAILQ_INSERT_TAIL(&dev_pager_object_list, object1,
 191                     pager_object_list);
 192                 mtx_unlock(&dev_pager_mtx);
 193                 vm_object_deallocate(object1);
 194         }
 195         return (object);
 196 }
 197
 198 static vm_object_t
 199 dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
 200     vm_ooffset_t foff, struct ucred *cred)
 201 {
 202
 203         return (cdev_pager_allocate(handle, OBJT_DEVICE, &old_dev_pager_ops,
 204             size, prot, foff, cred));
 205 }
 206
 207 void
 208 cdev_pager_free_page(vm_object_t object, vm_page_t m)
 209 {
 210
 211         VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
 212         if (object->type == OBJT_MGTDEVICE) {
 213                 KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("unmanaged %p", m));
 214                 pmap_remove_all(m);
 215                 vm_page_lock(m);
 216                 vm_page_remove(m);
 217                 vm_page_unlock(m);
 218         } else if (object->type == OBJT_DEVICE)
 219                 dev_pager_free_page(object, m);
 220 }
 221
 222 static void
 223 dev_pager_free_page(vm_object_t object, vm_page_t m)
 224 {
 225
 226         VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
 227         KASSERT((object->type == OBJT_DEVICE &&
 228             (m->oflags & VPO_UNMANAGED) != 0),
 229             ("Managed device or page obj %p m %p", object, m));
 230         TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq);
 231         vm_page_putfake(m);
 232 }
 233
 234 static void
 235 dev_pager_dealloc(object)
 236         vm_object_t object;
 237 {
 238         vm_page_t m;
 239
 240         VM_OBJECT_UNLOCK(object);
 241         object->un_pager.devp.ops->cdev_pg_dtor(object->un_pager.devp.dev);
 242
 243         mtx_lock(&dev_pager_mtx);
 244         TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list);
 245         mtx_unlock(&dev_pager_mtx);
 246         VM_OBJECT_LOCK(object);
 247
 248         if (object->type == OBJT_DEVICE) {
 249                 /*
 250                  * Free up our fake pages.
 251                  */
 252                 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist))
 253                     != NULL)
 254                         dev_pager_free_page(object, m);
 255         }
 256 }
 257
 258 static int
 259 dev_pager_getpages(vm_object_t object, vm_page_t *ma, int count, int reqpage)
 260 {
 261         int error, i;
 262
 263         VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
 264         error = object->un_pager.devp.ops->cdev_pg_fault(object,
 265             IDX_TO_OFF(ma[reqpage]->pindex), PROT_READ, &ma[reqpage]);
 266
 267         VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
 268
 269         for (i = 0; i < count; i++) {
 270                 if (i != reqpage) {
 271                         vm_page_lock(ma[i]);
 272                         vm_page_free(ma[i]);
 273                         vm_page_unlock(ma[i]);
 274                 }
 275         }
 276
 277         if (error == VM_PAGER_OK) {
 278                 KASSERT((object->type == OBJT_DEVICE &&
 279                      (ma[reqpage]->oflags & VPO_UNMANAGED) != 0) ||
 280                     (object->type == OBJT_MGTDEVICE &&
 281                      (ma[reqpage]->oflags & VPO_UNMANAGED) == 0),
 282                     ("Wrong page type %p %p", ma[reqpage], object));
 283                 if (object->type == OBJT_DEVICE) {
 284                         TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist,
 285                             ma[reqpage], pageq);
 286                 }
 287         }
 288
 289         return (error);
 290 }
 291
 292 static int
 293 old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, int prot,
 294     vm_page_t *mres)
 295 {
 296         vm_pindex_t pidx;
 297         vm_paddr_t paddr;
 298         vm_page_t m_paddr, page;
 299         struct cdev *dev;
 300         struct cdevsw *csw;
 301         struct file *fpop;
 302         struct thread *td;
 303         vm_memattr_t memattr;
 304         int i, ref, ret;
 305
 306         pidx = OFF_TO_IDX(offset);
 307         memattr = object->memattr;
 308
 309         VM_OBJECT_UNLOCK(object);
 310
 311         dev = object->handle;
 312         csw = dev_refthread(dev, &ref);
 313         if (csw == NULL) {
 314                 VM_OBJECT_LOCK(object);
 315                 return (VM_PAGER_FAIL);
 316         }
 317         td = curthread;
 318         fpop = td->td_fpop;
 319         td->td_fpop = NULL;
 320         ret = csw->d_mmap(dev, offset, &paddr, prot, &memattr);
 321         td->td_fpop = fpop;
 322         dev_relthread(dev, ref);
 323         if (ret != 0) {
 324                 printf(
 325             "WARNING: dev_pager_getpage: map function returns error %d", ret);
 326                 VM_OBJECT_LOCK(object);
 327                 return (VM_PAGER_FAIL);
 328         }
 329
 330         /* If "paddr" is a real page, perform a sanity check on "memattr". */
 331         if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL &&
 332             pmap_page_get_memattr(m_paddr) != memattr) {
 333                 memattr = pmap_page_get_memattr(m_paddr);
 334                 printf(
 335             "WARNING: A device driver has set \"memattr\" inconsistently.\n");
 336         }
 337         if (((*mres)->flags & PG_FICTITIOUS) != 0) {
 338                 /*
 339                  * If the passed in result page is a fake page, update it with
 340                  * the new physical address.
 341                  */
 342                 page = *mres;
 343                 VM_OBJECT_LOCK(object);
 344                 vm_page_updatefake(page, paddr, memattr);
 345         } else {
 346                 /*
 347                  * Replace the passed in reqpage page with our own fake page and
 348                  * free up the all of the original pages.
 349                  */
 350                 page = vm_page_getfake(paddr, memattr);
 351                 VM_OBJECT_LOCK(object);
 352                 vm_page_lock(*mres);
 353                 vm_page_free(*mres);
 354                 vm_page_unlock(*mres);
 355                 *mres = page;
 356                 while (vm_page_insert(page, object, pidx) != 0) {
 357                         for (i = 0; i < 10000000; i++)
 358                                 cpu_spinwait();
 359                 }
 360         }
 361         page->valid = VM_PAGE_BITS_ALL;
 362         return (VM_PAGER_OK);
 363 }
 364
 365 static void
 366 dev_pager_putpages(object, m, count, sync, rtvals)
 367         vm_object_t object;
 368         vm_page_t *m;
 369         int count;
 370         boolean_t sync;
 371         int *rtvals;
 372 {
 373
 374         panic("dev_pager_putpage called");
 375 }
 376
 377 static boolean_t
 378 dev_pager_haspage(object, pindex, before, after)
 379         vm_object_t object;
 380         vm_pindex_t pindex;
 381         int *before;
 382         int *after;
 383 {
 384         if (before != NULL)
 385                 *before = 0;
 386         if (after != NULL)
 387                 *after = 0;
 388         return (TRUE);
 389 }
 390
 391 static int
 392 old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
 393     vm_ooffset_t foff, struct ucred *cred, u_short *color)
 394 {
 395         struct cdev *dev;
 396         struct cdevsw *csw;
 397         vm_memattr_t dummy;
 398         vm_ooffset_t off;
 399         vm_paddr_t paddr;
 400         unsigned int npages;
 401         int ref;
 402
 403         /*
 404          * Make sure this device can be mapped.
 405          */
 406         dev = handle;
 407         csw = dev_refthread(dev, &ref);
 408         if (csw == NULL)
 409                 return (ENXIO);
 410
 411         /*
 412          * Check that the specified range of the device allows the desired
 413          * protection.
 414          *
 415          * XXX assumes VM_PROT_* == PROT_*
 416          */
 417         npages = OFF_TO_IDX(size);
 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 }