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         DRM_DEBUG("0x%08lx, %d\n", address, write_access);
  71
  72         return NOPAGE_SIGBUS;           /* Disallow mremap */
  73 }
  74
  75 #if LINUX_VERSION_CODE < 0x020317
  76 unsigned long drm_vm_shm_nopage(struct vm_area_struct *vma,
  77                                 unsigned long address,
  78                                 int write_access)
  79 #else
  80                                 /* Return type changed in 2.3.23 */
  81 struct page *drm_vm_shm_nopage(struct vm_area_struct *vma,
  82                                unsigned long address,
  83                                int write_access)
  84 #endif
  85 {
  86 #if LINUX_VERSION_CODE >= 0x020300
  87         drm_map_t        *map    = (drm_map_t *)vma->vm_private_data;
  88 #else
  89         drm_map_t        *map    = (drm_map_t *)vma->vm_pte;
  90 #endif
  91         unsigned long    physical;
  92         unsigned long    offset;
  93
  94         if (address > vma->vm_end) return NOPAGE_SIGBUS; /* Disallow mremap */
  95         if (!map)                  return NOPAGE_OOM;  /* Nothing allocated */
  96
  97         offset   = address - vma->vm_start;
  98         physical = (unsigned long)map->handle + offset;
  99         atomic_inc(&virt_to_page(physical)->count); /* Dec. by kernel */
 100
 101         DRM_DEBUG("0x%08lx => 0x%08lx\n", address, physical);
 102 #if LINUX_VERSION_CODE < 0x020317
 103         return physical;
 104 #else
 105         return virt_to_page(physical);
 106 #endif
 107 }
 108
 109 #if LINUX_VERSION_CODE < 0x020317
 110 unsigned long drm_vm_shm_nopage_lock(struct vm_area_struct *vma,
 111                                      unsigned long address,
 112                                      int write_access)
 113 #else
 114                                 /* Return type changed in 2.3.23 */
 115 struct page *drm_vm_shm_nopage_lock(struct vm_area_struct *vma,
 116                                     unsigned long address,
 117                                     int write_access)
 118 #endif
 119 {
 120         drm_file_t       *priv   = vma->vm_file->private_data;
 121         drm_device_t     *dev    = priv->dev;
 122         unsigned long    physical;
 123         unsigned long    offset;
 124         unsigned long    page;
 125
 126         if (address > vma->vm_end) return NOPAGE_SIGBUS; /* Disallow mremap */
 127         if (!dev->lock.hw_lock)    return NOPAGE_OOM;  /* Nothing allocated */
 128
 129         offset   = address - vma->vm_start;
 130         page     = offset >> PAGE_SHIFT;
 131         physical = (unsigned long)dev->lock.hw_lock + offset;
 132         atomic_inc(&virt_to_page(physical)->count); /* Dec. by kernel */
 133
 134         DRM_DEBUG("0x%08lx (page %lu) => 0x%08lx\n", address, page, physical);
 135 #if LINUX_VERSION_CODE < 0x020317
 136         return physical;
 137 #else
 138         return virt_to_page(physical);
 139 #endif
 140 }
 141
 142 #if LINUX_VERSION_CODE < 0x020317
 143 unsigned long drm_vm_dma_nopage(struct vm_area_struct *vma,
 144                                 unsigned long address,
 145                                 int write_access)
 146 #else
 147                                 /* Return type changed in 2.3.23 */
 148 struct page *drm_vm_dma_nopage(struct vm_area_struct *vma,
 149                                unsigned long address,
 150                                int write_access)
 151 #endif
 152 {
 153         drm_file_t       *priv   = vma->vm_file->private_data;
 154         drm_device_t     *dev    = priv->dev;
 155         drm_device_dma_t *dma    = dev->dma;
 156         unsigned long    physical;
 157         unsigned long    offset;
 158         unsigned long    page;
 159
 160         if (!dma)                  return NOPAGE_SIGBUS; /* Error */
 161         if (address > vma->vm_end) return NOPAGE_SIGBUS; /* Disallow mremap */
 162         if (!dma->pagelist)        return NOPAGE_OOM ; /* Nothing allocated */
 163
 164         offset   = address - vma->vm_start; /* vm_[pg]off[set] should be 0 */
 165         page     = offset >> PAGE_SHIFT;
 166         physical = dma->pagelist[page] + (offset & (~PAGE_MASK));
 167         atomic_inc(&virt_to_page(physical)->count); /* Dec. by kernel */
 168
 169         DRM_DEBUG("0x%08lx (page %lu) => 0x%08lx\n", address, page, physical);
 170 #if LINUX_VERSION_CODE < 0x020317
 171         return physical;
 172 #else
 173         return virt_to_page(physical);
 174 #endif
 175 }
 176
 177 void drm_vm_open(struct vm_area_struct *vma)
 178 {
 179         drm_file_t      *priv   = vma->vm_file->private_data;
 180         drm_device_t    *dev    = priv->dev;
 181 #if DRM_DEBUG_CODE
 182         drm_vma_entry_t *vma_entry;
 183 #endif
 184
 185         DRM_DEBUG("0x%08lx,0x%08lx\n",
 186                   vma->vm_start, vma->vm_end - vma->vm_start);
 187         atomic_inc(&dev->vma_count);
 188 #if LINUX_VERSION_CODE < 0x020333
 189                                 /* The map can exist after the fd is closed. */
 190         MOD_INC_USE_COUNT; /* Needed before Linux 2.3.51 */
 191 #endif
 192
 193
 194 #if DRM_DEBUG_CODE
 195         vma_entry = drm_alloc(sizeof(*vma_entry), DRM_MEM_VMAS);
 196         if (vma_entry) {
 197                 down(&dev->struct_sem);
 198                 vma_entry->vma  = vma;
 199                 vma_entry->next = dev->vmalist;
 200                 vma_entry->pid  = current->pid;
 201                 dev->vmalist    = vma_entry;
 202                 up(&dev->struct_sem);
 203         }
 204 #endif
 205 }
 206
 207 void drm_vm_close(struct vm_area_struct *vma)
 208 {
 209         drm_file_t      *priv   = vma->vm_file->private_data;
 210         drm_device_t    *dev    = priv->dev;
 211 #if DRM_DEBUG_CODE
 212         drm_vma_entry_t *pt, *prev;
 213 #endif
 214
 215         DRM_DEBUG("0x%08lx,0x%08lx\n",
 216                   vma->vm_start, vma->vm_end - vma->vm_start);
 217 #if LINUX_VERSION_CODE < 0x020333
 218         MOD_DEC_USE_COUNT; /* Needed before Linux 2.3.51 */
 219 #endif
 220         atomic_dec(&dev->vma_count);
 221
 222 #if DRM_DEBUG_CODE
 223         down(&dev->struct_sem);
 224         for (pt = dev->vmalist, prev = NULL; pt; prev = pt, pt = pt->next) {
 225                 if (pt->vma == vma) {
 226                         if (prev) {
 227                                 prev->next = pt->next;
 228                         } else {
 229                                 dev->vmalist = pt->next;
 230                         }
 231                         drm_free(pt, sizeof(*pt), DRM_MEM_VMAS);
 232                         break;
 233                 }
 234         }
 235         up(&dev->struct_sem);
 236 #endif
 237 }
 238
 239 int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma)
 240 {
 241         drm_file_t       *priv   = filp->private_data;
 242         drm_device_t     *dev;
 243         drm_device_dma_t *dma;
 244         unsigned long    length  = vma->vm_end - vma->vm_start;
 245
 246         lock_kernel();
 247         dev      = priv->dev;
 248         dma      = dev->dma;
 249         DRM_DEBUG("start = 0x%lx, end = 0x%lx, offset = 0x%lx\n",
 250                   vma->vm_start, vma->vm_end, VM_OFFSET(vma));
 251
 252                                 /* Length must match exact page count */
 253         if ((length >> PAGE_SHIFT) != dma->page_count) {
 254                 unlock_kernel();
 255                 return -EINVAL;
 256         }
 257         unlock_kernel();
 258
 259         vma->vm_ops   = &drm_vm_dma_ops;
 260         vma->vm_flags |= VM_LOCKED | VM_SHM; /* Don't swap */
 261
 262 #if LINUX_VERSION_CODE < 0x020203 /* KERNEL_VERSION(2,2,3) */
 263                                 /* In Linux 2.2.3 and above, this is
 264                                    handled in do_mmap() in mm/mmap.c. */
 265         ++filp->f_count;
 266 #endif
 267         vma->vm_file  =  filp;  /* Needed for drm_vm_open() */
 268         drm_vm_open(vma);
 269         return 0;
 270 }
 271
 272 int drm_mmap(struct file *filp, struct vm_area_struct *vma)
 273 {
 274         drm_file_t      *priv   = filp->private_data;
 275         drm_device_t    *dev    = priv->dev;
 276         drm_map_t       *map    = NULL;
 277         int             i;
 278
 279         DRM_DEBUG("start = 0x%lx, end = 0x%lx, offset = 0x%lx\n",
 280                   vma->vm_start, vma->vm_end, VM_OFFSET(vma));
 281
 282         if (!VM_OFFSET(vma)) return drm_mmap_dma(filp, vma);
 283
 284                                 /* A sequential search of a linked list is
 285                                    fine here because: 1) there will only be
 286                                    about 5-10 entries in the list and, 2) a
 287                                    DRI client only has to do this mapping
 288                                    once, so it doesn't have to be optimized
 289                                    for performance, even if the list was a
 290                                    bit longer. */
 291         for (i = 0; i < dev->map_count; i++) {
 292                 map = dev->maplist[i];
 293                 if (map->offset == VM_OFFSET(vma)) break;
 294         }
 295
 296         if (i >= dev->map_count) return -EINVAL;
 297         if (!map || ((map->flags&_DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN)))
 298                 return -EPERM;
 299
 300                                 /* Check for valid size. */
 301         if (map->size != vma->vm_end - vma->vm_start) return -EINVAL;
 302
 303         if (!capable(CAP_SYS_ADMIN) && (map->flags & _DRM_READ_ONLY)) {
 304                 vma->vm_flags &= VM_MAYWRITE;
 305 #if defined(__i386__)
 306                 pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
 307 #else
 308                                 /* Ye gads this is ugly.  With more thought
 309                                    we could move this up higher and use
 310                                    `protection_map' instead.  */
 311                 vma->vm_page_prot = __pgprot(pte_val(pte_wrprotect(
 312                         __pte(pgprot_val(vma->vm_page_prot)))));
 313 #endif
 314         }
 315
 316         switch (map->type) {
 317         case _DRM_FRAME_BUFFER:
 318         case _DRM_REGISTERS:
 319         case _DRM_AGP:
 320                 if (VM_OFFSET(vma) >= __pa(high_memory)) {
 321 #if defined(__i386__)
 322                         if (boot_cpu_data.x86 > 3 && map->type != _DRM_AGP) {
 323                                 pgprot_val(vma->vm_page_prot) |= _PAGE_PCD;
 324                                 pgprot_val(vma->vm_page_prot) &= ~_PAGE_PWT;
 325                         }
 326 #endif
 327                         vma->vm_flags |= VM_IO; /* not in core dump */
 328                 }
 329                 if (remap_page_range(vma->vm_start,
 330                                      VM_OFFSET(vma),
 331                                      vma->vm_end - vma->vm_start,
 332                                      vma->vm_page_prot))
 333                                 return -EAGAIN;
 334                 DRM_DEBUG("   Type = %d; start = 0x%lx, end = 0x%lx,"
 335                           " offset = 0x%lx\n",
 336                           map->type,
 337                           vma->vm_start, vma->vm_end, VM_OFFSET(vma));
 338                 vma->vm_ops = &drm_vm_ops;
 339                 break;
 340         case _DRM_SHM:
 341                 if (map->flags & _DRM_CONTAINS_LOCK)
 342                         vma->vm_ops = &drm_vm_shm_lock_ops;
 343                 else {
 344                         vma->vm_ops = &drm_vm_shm_ops;
 345 #if LINUX_VERSION_CODE >= 0x020300
 346                         vma->vm_private_data = (void *)map;
 347 #else
 348                         vma->vm_pte = (unsigned long)map;
 349 #endif
 350                 }
 351
 352                                 /* Don't let this area swap.  Change when
 353                                    DRM_KERNEL advisory is supported. */
 354                 vma->vm_flags |= VM_LOCKED;
 355                 break;
 356         default:
 357                 return -EINVAL; /* This should never happen. */
 358         }
 359         vma->vm_flags |= VM_LOCKED | VM_SHM; /* Don't swap */
 360
 361 #if LINUX_VERSION_CODE < 0x020203 /* KERNEL_VERSION(2,2,3) */
 362                                 /* In Linux 2.2.3 and above, this is
 363                                    handled in do_mmap() in mm/mmap.c. */
 364         ++filp->f_count;
 365 #endif
 366         vma->vm_file  =  filp;  /* Needed for drm_vm_open() */
 367         drm_vm_open(vma);
 368         return 0;
 369 }