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