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_dma_ops = {
  48         nopage:  drm_vm_dma_nopage,
  49         open:    drm_vm_open,
  50         close:   drm_vm_close,
  51 };
  52
  53 #if LINUX_VERSION_CODE < 0x020317
  54 unsigned long drm_vm_nopage(struct vm_area_struct *vma,
  55                             unsigned long address,
  56                             int write_access)
  57 #else
  58                                 /* Return type changed in 2.3.23 */
  59 struct page *drm_vm_nopage(struct vm_area_struct *vma,
  60                            unsigned long address,
  61                            int write_access)
  62 #endif
  63 {
  64         DRM_DEBUG("0x%08lx, %d\n", address, write_access);
  65
  66         return NOPAGE_SIGBUS;           /* Disallow mremap */
  67 }
  68
  69 #if LINUX_VERSION_CODE < 0x020317
  70 unsigned long drm_vm_shm_nopage(struct vm_area_struct *vma,
  71                                 unsigned long address,
  72                                 int write_access)
  73 #else
  74                                 /* Return type changed in 2.3.23 */
  75 struct page *drm_vm_shm_nopage(struct vm_area_struct *vma,
  76                                unsigned long address,
  77                                int write_access)
  78 #endif
  79 {
  80         drm_file_t       *priv   = vma->vm_file->private_data;
  81         drm_device_t     *dev    = priv->dev;
  82         unsigned long    physical;
  83         unsigned long    offset;
  84         unsigned long    page;
  85
  86         if (address > vma->vm_end) return NOPAGE_SIGBUS; /* Disallow mremap */
  87         if (!dev->lock.hw_lock)    return NOPAGE_OOM;  /* Nothing allocated */
  88
  89         offset   = address - vma->vm_start;
  90         page     = offset >> PAGE_SHIFT;
  91         physical = (unsigned long)dev->lock.hw_lock + offset;
  92         atomic_inc(&virt_to_page(physical)->count);     /* Dec. by kernel */
  93
  94         DRM_DEBUG("0x%08lx (page %lu) => 0x%08lx\n", address, page, physical);
  95 #if LINUX_VERSION_CODE < 0x020317
  96         return physical;
  97 #else
  98         return (virt_to_page(physical));
  99 #endif
 100 }
 101
 102 #if LINUX_VERSION_CODE < 0x020317
 103 unsigned long drm_vm_dma_nopage(struct vm_area_struct *vma,
 104                                 unsigned long address,
 105                                 int write_access)
 106 #else
 107                                 /* Return type changed in 2.3.23 */
 108 struct page *drm_vm_dma_nopage(struct vm_area_struct *vma,
 109                                unsigned long address,
 110                                int write_access)
 111 #endif
 112 {
 113         drm_file_t       *priv   = vma->vm_file->private_data;
 114         drm_device_t     *dev    = priv->dev;
 115         drm_device_dma_t *dma    = dev->dma;
 116         unsigned long    physical;
 117         unsigned long    offset;
 118         unsigned long    page;
 119
 120         if (!dma)                  return NOPAGE_SIGBUS; /* Error */
 121         if (address > vma->vm_end) return NOPAGE_SIGBUS; /* Disallow mremap */
 122         if (!dma->pagelist)        return NOPAGE_OOM ; /* Nothing allocated */
 123
 124         offset   = address - vma->vm_start; /* vm_[pg]off[set] should be 0 */
 125         page     = offset >> PAGE_SHIFT;
 126         physical = dma->pagelist[page] + (offset & (~PAGE_MASK));
 127         atomic_inc(&virt_to_page(physical)->count); /* Dec. by kernel */
 128
 129         DRM_DEBUG("0x%08lx (page %lu) => 0x%08lx\n", address, page, physical);
 130 #if LINUX_VERSION_CODE < 0x020317
 131         return physical;
 132 #else
 133         return (virt_to_page(physical));
 134 #endif
 135 }
 136
 137 void drm_vm_open(struct vm_area_struct *vma)
 138 {
 139         drm_file_t      *priv   = vma->vm_file->private_data;
 140         drm_device_t    *dev    = priv->dev;
 141 #if DRM_DEBUG_CODE
 142         drm_vma_entry_t *vma_entry;
 143 #endif
 144
 145         DRM_DEBUG("0x%08lx,0x%08lx\n",
 146                   vma->vm_start, vma->vm_end - vma->vm_start);
 147         atomic_inc(&dev->vma_count);
 148 #if LINUX_VERSION_CODE < 0x020333
 149                                 /* The map can exist after the fd is closed. */
 150         MOD_INC_USE_COUNT; /* Needed before Linux 2.3.51 */
 151 #endif
 152
 153
 154 #if DRM_DEBUG_CODE
 155         vma_entry = drm_alloc(sizeof(*vma_entry), DRM_MEM_VMAS);
 156         if (vma_entry) {
 157                 down(&dev->struct_sem);
 158                 vma_entry->vma  = vma;
 159                 vma_entry->next = dev->vmalist;
 160                 vma_entry->pid  = current->pid;
 161                 dev->vmalist    = vma_entry;
 162                 up(&dev->struct_sem);
 163         }
 164 #endif
 165 }
 166
 167 void drm_vm_close(struct vm_area_struct *vma)
 168 {
 169         drm_file_t      *priv   = vma->vm_file->private_data;
 170         drm_device_t    *dev    = priv->dev;
 171 #if DRM_DEBUG_CODE
 172         drm_vma_entry_t *pt, *prev;
 173 #endif
 174
 175         DRM_DEBUG("0x%08lx,0x%08lx\n",
 176                   vma->vm_start, vma->vm_end - vma->vm_start);
 177 #if LINUX_VERSION_CODE < 0x020333
 178         MOD_DEC_USE_COUNT; /* Needed before Linux 2.3.51 */
 179 #endif
 180         atomic_dec(&dev->vma_count);
 181
 182 #if DRM_DEBUG_CODE
 183         down(&dev->struct_sem);
 184         for (pt = dev->vmalist, prev = NULL; pt; prev = pt, pt = pt->next) {
 185                 if (pt->vma == vma) {
 186                         if (prev) {
 187                                 prev->next = pt->next;
 188                         } else {
 189                                 dev->vmalist = pt->next;
 190                         }
 191                         drm_free(pt, sizeof(*pt), DRM_MEM_VMAS);
 192                         break;
 193                 }
 194         }
 195         up(&dev->struct_sem);
 196 #endif
 197 }
 198
 199 int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma)
 200 {
 201         drm_file_t       *priv   = filp->private_data;
 202         drm_device_t     *dev;
 203         drm_device_dma_t *dma;
 204         unsigned long    length  = vma->vm_end - vma->vm_start;
 205
 206         lock_kernel();
 207         dev      = priv->dev;
 208         dma      = dev->dma;
 209         DRM_DEBUG("start = 0x%lx, end = 0x%lx, offset = 0x%lx\n",
 210                   vma->vm_start, vma->vm_end, VM_OFFSET(vma));
 211
 212                                 /* Length must match exact page count */
 213         if ((length >> PAGE_SHIFT) != dma->page_count) {
 214                 unlock_kernel();
 215                 return -EINVAL;
 216         }
 217         unlock_kernel();
 218
 219         vma->vm_ops   = &drm_vm_dma_ops;
 220         vma->vm_flags |= VM_LOCKED | VM_SHM; /* Don't swap */
 221
 222 #if LINUX_VERSION_CODE < 0x020203 /* KERNEL_VERSION(2,2,3) */
 223                                 /* In Linux 2.2.3 and above, this is
 224                                    handled in do_mmap() in mm/mmap.c. */
 225         ++filp->f_count;
 226 #endif
 227         vma->vm_file  =  filp;  /* Needed for drm_vm_open() */
 228         drm_vm_open(vma);
 229         return 0;
 230 }
 231
 232 int drm_mmap(struct file *filp, struct vm_area_struct *vma)
 233 {
 234         drm_file_t      *priv   = filp->private_data;
 235         drm_device_t    *dev    = priv->dev;
 236         drm_map_t       *map    = NULL;
 237         int             i;
 238
 239         DRM_DEBUG("start = 0x%lx, end = 0x%lx, offset = 0x%lx\n",
 240                   vma->vm_start, vma->vm_end, VM_OFFSET(vma));
 241
 242         if (!VM_OFFSET(vma)) return drm_mmap_dma(filp, vma);
 243
 244                                 /* A sequential search of a linked list is
 245                                    fine here because: 1) there will only be
 246                                    about 5-10 entries in the list and, 2) a
 247                                    DRI client only has to do this mapping
 248                                    once, so it doesn't have to be optimized
 249                                    for performance, even if the list was a
 250                                    bit longer. */
 251         for (i = 0; i < dev->map_count; i++) {
 252                 map = dev->maplist[i];
 253                 if (map->offset == VM_OFFSET(vma)) break;
 254         }
 255
 256         if (i >= dev->map_count) return -EINVAL;
 257         if (!map || ((map->flags&_DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN)))
 258                 return -EPERM;
 259
 260                                 /* Check for valid size. */
 261         if (map->size != vma->vm_end - vma->vm_start) return -EINVAL;
 262
 263         if (!capable(CAP_SYS_ADMIN) && (map->flags & _DRM_READ_ONLY)) {
 264                 vma->vm_flags &= VM_MAYWRITE;
 265 #if defined(__i386__)
 266                 pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
 267 #else
 268                                 /* Ye gads this is ugly.  With more thought
 269                                    we could move this up higher and use
 270                                    `protection_map' instead.  */
 271                 vma->vm_page_prot = __pgprot(pte_val(pte_wrprotect(
 272                         __pte(pgprot_val(vma->vm_page_prot)))));
 273 #endif
 274         }
 275
 276         switch (map->type) {
 277         case _DRM_FRAME_BUFFER:
 278         case _DRM_REGISTERS:
 279         case _DRM_AGP:
 280                 if (VM_OFFSET(vma) >= __pa(high_memory)) {
 281 #if defined(__i386__)
 282                         if (boot_cpu_data.x86 > 3 && map->type != _DRM_AGP) {
 283                                 pgprot_val(vma->vm_page_prot) |= _PAGE_PCD;
 284                                 pgprot_val(vma->vm_page_prot) &= ~_PAGE_PWT;
 285                         }
 286 #endif
 287                         vma->vm_flags |= VM_IO; /* not in core dump */
 288                 }
 289                 if (remap_page_range(vma->vm_start,
 290                                      VM_OFFSET(vma),
 291                                      vma->vm_end - vma->vm_start,
 292                                      vma->vm_page_prot))
 293                                 return -EAGAIN;
 294                 DRM_DEBUG("   Type = %d; start = 0x%lx, end = 0x%lx,"
 295                           " offset = 0x%lx\n",
 296                           map->type,
 297                           vma->vm_start, vma->vm_end, VM_OFFSET(vma));
 298                 vma->vm_ops = &drm_vm_ops;
 299                 break;
 300         case _DRM_SHM:
 301                 vma->vm_ops = &drm_vm_shm_ops;
 302                                 /* Don't let this area swap.  Change when
 303                                    DRM_KERNEL advisory is supported. */
 304                 vma->vm_flags |= VM_LOCKED;
 305                 break;
 306         default:
 307                 return -EINVAL; /* This should never happen. */
 308         }
 309         vma->vm_flags |= VM_LOCKED | VM_SHM; /* Don't swap */
 310
 311 #if LINUX_VERSION_CODE < 0x020203 /* KERNEL_VERSION(2,2,3) */
 312                                 /* In Linux 2.2.3 and above, this is
 313                                    handled in do_mmap() in mm/mmap.c. */
 314         ++filp->f_count;
 315 #endif
 316         vma->vm_file  =  filp;  /* Needed for drm_vm_open() */
 317         drm_vm_open(vma);
 318         return 0;
 319 }