drivers/char/drm/vm.c

   1 /* vm.c -- Memory mapping for DRM -*- linux-c -*-
   2  * Created: Mon Jan  4 08:58:31 1999 by faith@precisioninsight.com
   3  *
   4  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
   5  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
   6  * All Rights Reserved.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice (including the next
  16  * paragraph) shall be included in all copies or substantial portions of the
  17  * Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  22  * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  23  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  24  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  25  * DEALINGS IN THE SOFTWARE.
  26  *
  27  * Authors:
  28  *    Rickard E. (Rik) Faith <faith@valinux.com>
  29  *
  30  */
  31
  32 #define __NO_VERSION__
  33 #include "drmP.h"
  34
  35 struct vm_operations_struct   drm_vm_ops = {
  36         nopage:  drm_vm_nopage,
  37         open:    drm_vm_open,
  38         close:   drm_vm_close,
  39 };
  40
  41 struct vm_operations_struct   drm_vm_shm_ops = {
  42         nopage:  drm_vm_shm_nopage,
  43         open:    drm_vm_open,
  44         close:   drm_vm_close,
  45 };
  46
  47 struct vm_operations_struct   drm_vm_shm_lock_ops = {
  48         nopage:  drm_vm_shm_nopage_lock,
  49         open:    drm_vm_open,
  50         close:   drm_vm_close,
  51 };
  52
  53 struct vm_operations_struct   drm_vm_dma_ops = {
  54         nopage:  drm_vm_dma_nopage,
  55         open:    drm_vm_open,
  56         close:   drm_vm_close,
  57 };
  58
  59 #if LINUX_VERSION_CODE < 0x020317
  60 unsigned long drm_vm_nopage(struct vm_area_struct *vma,
  61                             unsigned long address,
  62                             int write_access)
  63 #else
  64                                 /* Return type changed in 2.3.23 */
  65 struct page *drm_vm_nopage(struct vm_area_struct *vma,
  66                            unsigned long address,
  67                            int write_access)
  68 #endif
  69 {
  70         return NOPAGE_SIGBUS;           /* Disallow mremap */
  71 }
  72
  73 #if LINUX_VERSION_CODE < 0x020317
  74 unsigned long drm_vm_shm_nopage(struct vm_area_struct *vma,
  75                                 unsigned long address,
  76                                 int write_access)
  77 #else
  78                                 /* Return type changed in 2.3.23 */
  79 struct page *drm_vm_shm_nopage(struct vm_area_struct *vma,
  80                                unsigned long address,
  81                                int write_access)
  82 #endif
  83 {
  84 #if LINUX_VERSION_CODE >= 0x020300
  85         drm_map_t        *map    = (drm_map_t *)vma->vm_private_data;
  86 #else
  87         drm_map_t        *map    = (drm_map_t *)vma->vm_pte;
  88 #endif
  89         unsigned long    physical;
  90         unsigned long    offset;
  91
  92         if (address > vma->vm_end) return NOPAGE_SIGBUS; /* Disallow mremap */
  93         if (!map)                  return NOPAGE_OOM;  /* Nothing allocated */
  94
  95         offset   = address - vma->vm_start;
  96         physical = (unsigned long)map->handle + offset;
  97         atomic_inc(&virt_to_page(physical)->count); /* Dec. by kernel */
  98
  99         DRM_DEBUG("0x%08lx => 0x%08lx\n", address, physical);
 100 #if LINUX_VERSION_CODE < 0x020317
 101         return physical;
 102 #else
 103         return virt_to_page(physical);
 104 #endif
 105 }
 106
 107 #if LINUX_VERSION_CODE < 0x020317
 108 unsigned long drm_vm_shm_nopage_lock(struct vm_area_struct *vma,
 109                                      unsigned long address,
 110                                      int write_access)
 111 #else
 112                                 /* Return type changed in 2.3.23 */
 113 struct page *drm_vm_shm_nopage_lock(struct vm_area_struct *vma,
 114                                     unsigned long address,
 115                                     int write_access)
 116 #endif
 117 {
 118         drm_file_t       *priv   = vma->vm_file->private_data;
 119         drm_device_t     *dev    = priv->dev;
 120         unsigned long    physical;
 121         unsigned long    offset;
 122         unsigned long    page;
 123
 124         if (address > vma->vm_end) return NOPAGE_SIGBUS; /* Disallow mremap */
 125         if (!dev->lock.hw_lock)    return NOPAGE_OOM;  /* Nothing allocated */
 126
 127         offset   = address - vma->vm_start;
 128         page     = offset >> PAGE_SHIFT;
 129         physical = (unsigned long)dev->lock.hw_lock + offset;
 130         atomic_inc(&virt_to_page(physical)->count); /* Dec. by kernel */
 131
 132         DRM_DEBUG("0x%08lx (page %lu) => 0x%08lx\n", address, page, physical);
 133 #if LINUX_VERSION_CODE < 0x020317
 134         return physical;
 135 #else
 136         return virt_to_page(physical);
 137 #endif
 138 }
 139
 140 #if LINUX_VERSION_CODE < 0x020317
 141 unsigned long drm_vm_dma_nopage(struct vm_area_struct *vma,
 142                                 unsigned long address,
 143                                 int write_access)
 144 #else
 145                                 /* Return type changed in 2.3.23 */
 146 struct page *drm_vm_dma_nopage(struct vm_area_struct *vma,
 147                                unsigned long address,
 148                                int write_access)
 149 #endif
 150 {
 151         drm_file_t       *priv   = vma->vm_file->private_data;
 152         drm_device_t     *dev    = priv->dev;
 153         drm_device_dma_t *dma    = dev->dma;
 154         unsigned long    physical;
 155         unsigned long    offset;
 156         unsigned long    page;
 157
 158         if (!dma)                  return NOPAGE_SIGBUS; /* Error */
 159         if (address > vma->vm_end) return NOPAGE_SIGBUS; /* Disallow mremap */
 160         if (!dma->pagelist)        return NOPAGE_OOM ; /* Nothing allocated */
 161
 162         offset   = address - vma->vm_start; /* vm_[pg]off[set] should be 0 */
 163         page     = offset >> PAGE_SHIFT;
 164         physical = dma->pagelist[page] + (offset & (~PAGE_MASK));
 165         atomic_inc(&virt_to_page(physical)->count); /* Dec. by kernel */
 166
 167         DRM_DEBUG("0x%08lx (page %lu) => 0x%08lx\n", address, page, physical);
 168 #if LINUX_VERSION_CODE < 0x020317
 169         return physical;
 170 #else
 171         return virt_to_page(physical);
 172 #endif
 173 }
 174
 175 void drm_vm_open(struct vm_area_struct *vma)
 176 {
 177         drm_file_t      *priv   = vma->vm_file->private_data;
 178         drm_device_t    *dev    = priv->dev;
 179 #if DRM_DEBUG_CODE
 180         drm_vma_entry_t *vma_entry;
 181 #endif
 182
 183         DRM_DEBUG("0x%08lx,0x%08lx\n",
 184                   vma->vm_start, vma->vm_end - vma->vm_start);
 185         atomic_inc(&dev->vma_count);
 186 #if LINUX_VERSION_CODE < 0x020333
 187                                 /* The map can exist after the fd is closed. */
 188         MOD_INC_USE_COUNT; /* Needed before Linux 2.3.51 */
 189 #endif
 190
 191
 192 #if DRM_DEBUG_CODE
 193         vma_entry = drm_alloc(sizeof(*vma_entry), DRM_MEM_VMAS);
 194         if (vma_entry) {
 195                 down(&dev->struct_sem);
 196                 vma_entry->vma  = vma;
 197                 vma_entry->next = dev->vmalist;
 198                 vma_entry->pid  = current->pid;
 199                 dev->vmalist    = vma_entry;
 200                 up(&dev->struct_sem);
 201         }
 202 #endif
 203 }
 204
 205 void drm_vm_close(struct vm_area_struct *vma)
 206 {
 207         drm_file_t      *priv   = vma->vm_file->private_data;
 208         drm_device_t    *dev    = priv->dev;
 209 #if DRM_DEBUG_CODE
 210         drm_vma_entry_t *pt, *prev;
 211 #endif
 212
 213         DRM_DEBUG("0x%08lx,0x%08lx\n",
 214                   vma->vm_start, vma->vm_end - vma->vm_start);
 215 #if LINUX_VERSION_CODE < 0x020333
 216         MOD_DEC_USE_COUNT; /* Needed before Linux 2.3.51 */
 217 #endif
 218         atomic_dec(&dev->vma_count);
 219
 220 #if DRM_DEBUG_CODE
 221         down(&dev->struct_sem);
 222         for (pt = dev->vmalist, prev = NULL; pt; prev = pt, pt = pt->next) {
 223                 if (pt->vma == vma) {
 224                         if (prev) {
 225                                 prev->next = pt->next;
 226                         } else {
 227                                 dev->vmalist = pt->next;
 228                         }
 229                         drm_free(pt, sizeof(*pt), DRM_MEM_VMAS);
 230                         break;
 231                 }
 232         }
 233         up(&dev->struct_sem);
 234 #endif
 235 }
 236
 237 int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma)
 238 {
 239         drm_file_t       *priv   = filp->private_data;
 240         drm_device_t     *dev;
 241         drm_device_dma_t *dma;
 242         unsigned long    length  = vma->vm_end - vma->vm_start;
 243
 244         lock_kernel();
 245         dev      = priv->dev;
 246         dma      = dev->dma;
 247         DRM_DEBUG("start = 0x%lx, end = 0x%lx, offset = 0x%lx\n",
 248                   vma->vm_start, vma->vm_end, VM_OFFSET(vma));
 249
 250                                 /* Length must match exact page count */
 251         if (!dma || (length >> PAGE_SHIFT) != dma->page_count) {
 252                 unlock_kernel();
 253                 return -EINVAL;
 254         }
 255         unlock_kernel();
 256
 257         vma->vm_ops   = &drm_vm_dma_ops;
 258         vma->vm_flags |= VM_LOCKED | VM_SHM; /* Don't swap */
 259
 260 #if LINUX_VERSION_CODE < 0x020203 /* KERNEL_VERSION(2,2,3) */
 261                                 /* In Linux 2.2.3 and above, this is
 262                                    handled in do_mmap() in mm/mmap.c. */
 263         ++filp->f_count;
 264 #endif
 265         vma->vm_file  =  filp;  /* Needed for drm_vm_open() */
 266         drm_vm_open(vma);
 267         return 0;
 268 }
 269
 270 int drm_mmap(struct file *filp, struct vm_area_struct *vma)
 271 {
 272         drm_file_t      *priv   = filp->private_data;
 273         drm_device_t    *dev    = priv->dev;
 274         drm_map_t       *map    = NULL;
 275         int             i;
 276
 277         DRM_DEBUG("start = 0x%lx, end = 0x%lx, offset = 0x%lx\n",
 278                   vma->vm_start, vma->vm_end, VM_OFFSET(vma));
 279
 280         if (!VM_OFFSET(vma)) return drm_mmap_dma(filp, vma);
 281
 282                                 /* A sequential search of a linked list is
 283                                    fine here because: 1) there will only be
 284                                    about 5-10 entries in the list and, 2) a
 285                                    DRI client only has to do this mapping
 286                                    once, so it doesn't have to be optimized
 287                                    for performance, even if the list was a
 288                                    bit longer. */
 289         for (i = 0; i < dev->map_count; i++) {
 290                 map = dev->maplist[i];
 291                 if (map->offset == VM_OFFSET(vma)) break;
 292         }
 293
 294         if (i >= dev->map_count) return -EINVAL;
 295         if (!map || ((map->flags&_DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN)))
 296                 return -EPERM;
 297
 298                                 /* Check for valid size. */
 299         if (map->size != vma->vm_end - vma->vm_start) return -EINVAL;
 300
 301         if (!capable(CAP_SYS_ADMIN) && (map->flags & _DRM_READ_ONLY)) {
 302                 vma->vm_flags &= VM_MAYWRITE;
 303 #if defined(__i386__)
 304                 pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
 305 #else
 306                                 /* Ye gads this is ugly.  With more thought
 307                                    we could move this up higher and use
 308                                    `protection_map' instead.  */
 309                 vma->vm_page_prot = __pgprot(pte_val(pte_wrprotect(
 310                         __pte(pgprot_val(vma->vm_page_prot)))));
 311 #endif
 312         }
 313
 314         switch (map->type) {
 315         case _DRM_FRAME_BUFFER:
 316         case _DRM_REGISTERS:
 317         case _DRM_AGP:
 318                 if (VM_OFFSET(vma) >= __pa(high_memory)) {
 319 #if defined(__i386__)
 320                         if (boot_cpu_data.x86 > 3 && map->type != _DRM_AGP) {
 321                                 pgprot_val(vma->vm_page_prot) |= _PAGE_PCD;
 322                                 pgprot_val(vma->vm_page_prot) &= ~_PAGE_PWT;
 323                         }
 324 #elif defined(__ia64__)
 325                         if (map->type != _DRM_AGP)
 326                                 vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
 327 #endif
 328                         vma->vm_flags |= VM_IO; /* not in core dump */
 329                 }
 330                 if (remap_page_range(vma->vm_start,
 331                                      VM_OFFSET(vma),
 332                                      vma->vm_end - vma->vm_start,
 333                                      vma->vm_page_prot))
 334                                 return -EAGAIN;
 335                 DRM_DEBUG("   Type = %d; start = 0x%lx, end = 0x%lx,"
 336                           " offset = 0x%lx\n",
 337                           map->type,
 338                           vma->vm_start, vma->vm_end, VM_OFFSET(vma));
 339                 vma->vm_ops = &drm_vm_ops;
 340                 break;
 341         case _DRM_SHM:
 342                 if (map->flags & _DRM_CONTAINS_LOCK)
 343                         vma->vm_ops = &drm_vm_shm_lock_ops;
 344                 else {
 345                         vma->vm_ops = &drm_vm_shm_ops;
 346 #if LINUX_VERSION_CODE >= 0x020300
 347                         vma->vm_private_data = (void *)map;
 348 #else
 349                         vma->vm_pte = (unsigned long)map;
 350 #endif
 351                 }
 352
 353                                 /* Don't let this area swap.  Change when
 354                                    DRM_KERNEL advisory is supported. */
 355                 vma->vm_flags |= VM_LOCKED;
 356                 break;
 357         default:
 358                 return -EINVAL; /* This should never happen. */
 359         }
 360         vma->vm_flags |= VM_LOCKED | VM_SHM; /* Don't swap */
 361
 362 #if LINUX_VERSION_CODE < 0x020203 /* KERNEL_VERSION(2,2,3) */
 363                                 /* In Linux 2.2.3 and above, this is
 364                                    handled in do_mmap() in mm/mmap.c. */
 365         ++filp->f_count;
 366 #endif
 367         vma->vm_file  =  filp;  /* Needed for drm_vm_open() */
 368         drm_vm_open(vma);
 369         return 0;
 370 }