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  * Revised: Fri Aug 20 22:48:11 1999 by faith@precisioninsight.com
   4  *
   5  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
   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  * $PI: xc/programs/Xserver/hw/xfree86/os-support/linux/drm/generic/vm.c,v 1.7 1999/08/21 02:48:34 faith Exp $
  28  * $XFree86$
  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 unsigned long drm_vm_nopage(struct vm_area_struct *vma,
  54                             unsigned long address,
  55                             int write_access)
  56 {
  57         DRM_DEBUG("0x%08lx, %d\n", address, write_access);
  58
  59         return 0;               /* Disallow mremap */
  60 }
  61
  62 unsigned long drm_vm_shm_nopage(struct vm_area_struct *vma,
  63                                 unsigned long address,
  64                                 int write_access)
  65 {
  66         drm_file_t       *priv   = vma->vm_file->private_data;
  67         drm_device_t     *dev    = priv->dev;
  68         unsigned long    physical;
  69         unsigned long    offset;
  70         unsigned long    page;
  71
  72         if (address > vma->vm_end) return 0; /* Disallow mremap */
  73         if (!dev->lock.hw_lock)    return 0; /* Nothing allocated */
  74
  75         offset   = address - vma->vm_start;
  76         page     = offset >> PAGE_SHIFT;
  77         physical = (unsigned long)dev->lock.hw_lock + (offset & (~PAGE_MASK));
  78         atomic_inc(&mem_map[MAP_NR(physical)].count); /* Dec. by kernel */
  79
  80         DRM_DEBUG("0x%08lx (page %lu) => 0x%08lx\n", address, page, physical);
  81         return physical;
  82 }
  83
  84 unsigned long drm_vm_dma_nopage(struct vm_area_struct *vma,
  85                                 unsigned long address,
  86                                 int write_access)
  87 {
  88         drm_file_t       *priv   = vma->vm_file->private_data;
  89         drm_device_t     *dev    = priv->dev;
  90         drm_device_dma_t *dma    = dev->dma;
  91         unsigned long    physical;
  92         unsigned long    offset;
  93         unsigned long    page;
  94
  95         if (!dma)                  return 0; /* Error */
  96         if (address > vma->vm_end) return 0; /* Disallow mremap */
  97         if (!dma->pagelist)        return 0; /* Nothing allocated */
  98
  99         offset   = address - vma->vm_start; /* vm_offset should be 0 */
 100         page     = offset >> PAGE_SHIFT;
 101         physical = dma->pagelist[page] + (offset & (~PAGE_MASK));
 102         atomic_inc(&mem_map[MAP_NR(physical)].count); /* Dec. by kernel */
 103
 104         DRM_DEBUG("0x%08lx (page %lu) => 0x%08lx\n", address, page, physical);
 105         return physical;
 106 }
 107
 108 void drm_vm_open(struct vm_area_struct *vma)
 109 {
 110         drm_file_t      *priv   = vma->vm_file->private_data;
 111         drm_device_t    *dev    = priv->dev;
 112 #if DRM_DEBUG_CODE
 113         drm_vma_entry_t *vma_entry;
 114 #endif
 115
 116         DRM_DEBUG("0x%08lx,0x%08lx\n",
 117                   vma->vm_start, vma->vm_end - vma->vm_start);
 118         atomic_inc(&dev->vma_count);
 119         MOD_INC_USE_COUNT;
 120
 121 #if DRM_DEBUG_CODE
 122         vma_entry = drm_alloc(sizeof(*vma_entry), DRM_MEM_VMAS);
 123         if (vma_entry) {
 124                 down(&dev->struct_sem);
 125                 vma_entry->vma  = vma;
 126                 vma_entry->next = dev->vmalist;
 127                 vma_entry->pid  = current->pid;
 128                 dev->vmalist    = vma_entry;
 129                 up(&dev->struct_sem);
 130         }
 131 #endif
 132 }
 133
 134 void drm_vm_close(struct vm_area_struct *vma)
 135 {
 136         drm_file_t      *priv   = vma->vm_file->private_data;
 137         drm_device_t    *dev    = priv->dev;
 138 #if DRM_DEBUG_CODE
 139         drm_vma_entry_t *pt, *prev;
 140 #endif
 141
 142         DRM_DEBUG("0x%08lx,0x%08lx\n",
 143                   vma->vm_start, vma->vm_end - vma->vm_start);
 144         MOD_DEC_USE_COUNT;
 145         atomic_dec(&dev->vma_count);
 146
 147 #if DRM_DEBUG_CODE
 148         down(&dev->struct_sem);
 149         for (pt = dev->vmalist, prev = NULL; pt; prev = pt, pt = pt->next) {
 150                 if (pt->vma == vma) {
 151                         if (prev) {
 152                                 prev->next = pt->next;
 153                         } else {
 154                                 dev->vmalist = pt->next;
 155                         }
 156                         drm_free(pt, sizeof(*pt), DRM_MEM_VMAS);
 157                         break;
 158                 }
 159         }
 160         up(&dev->struct_sem);
 161 #endif
 162 }
 163
 164 int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma)
 165 {
 166         drm_file_t       *priv   = filp->private_data;
 167         drm_device_t     *dev    = priv->dev;
 168         drm_device_dma_t *dma    = dev->dma;
 169         unsigned long    length  = vma->vm_end - vma->vm_start;
 170
 171         DRM_DEBUG("start = 0x%lx, end = 0x%lx, offset = 0x%lx\n",
 172                   vma->vm_start, vma->vm_end, vma->vm_offset);
 173
 174                                 /* Length must match exact page count */
 175         if ((length >> PAGE_SHIFT) != dma->page_count) return -EINVAL;
 176
 177         vma->vm_ops   = &drm_vm_dma_ops;
 178         vma->vm_flags |= VM_LOCKED | VM_SHM; /* Don't swap */
 179
 180 #if LINUX_VERSION_CODE < 0x020203 /* KERNEL_VERSION(2,2,3) */
 181                                 /* In Linux 2.2.3 and above, this is
 182                                    handled in do_mmap() in mm/mmap.c. */
 183         ++filp->f_count;
 184 #endif
 185         vma->vm_file  =  filp;  /* Needed for drm_vm_open() */
 186         drm_vm_open(vma);
 187         return 0;
 188 }
 189
 190 int drm_mmap(struct file *filp, struct vm_area_struct *vma)
 191 {
 192         drm_file_t      *priv   = filp->private_data;
 193         drm_device_t    *dev    = priv->dev;
 194         drm_map_t       *map    = NULL;
 195         int             i;
 196
 197         DRM_DEBUG("start = 0x%lx, end = 0x%lx, offset = 0x%lx\n",
 198                   vma->vm_start, vma->vm_end, vma->vm_offset);
 199
 200         if (!vma->vm_offset) return drm_mmap_dma(filp, vma);
 201
 202                                 /* A sequential search of a linked list is
 203                                    fine here because: 1) there will only be
 204                                    about 5-10 entries in the list and, 2) a
 205                                    DRI client only has to do this mapping
 206                                    once, so it doesn't have to be optimized
 207                                    for performance, even if the list was a
 208                                    bit longer. */
 209         for (i = 0; i < dev->map_count; i++) {
 210                 map = dev->maplist[i];
 211                 if (map->offset == vma->vm_offset) break;
 212         }
 213
 214         if (i >= dev->map_count) return -EINVAL;
 215         if (!map || ((map->flags&_DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN)))
 216                 return -EPERM;
 217
 218                                 /* Check for valid size. */
 219         if (map->size != vma->vm_end - vma->vm_start) return -EINVAL;
 220
 221
 222         switch (map->type) {
 223         case _DRM_FRAME_BUFFER:
 224         case _DRM_REGISTERS:
 225                 if (vma->vm_offset >= __pa(high_memory)) {
 226 #if defined(__i386__)
 227                         if (boot_cpu_data.x86 > 3) {
 228                                 pgprot_val(vma->vm_page_prot) |= _PAGE_PCD;
 229                                 pgprot_val(vma->vm_page_prot) &= ~_PAGE_PWT;
 230                         }
 231 #endif
 232                         vma->vm_flags |= VM_IO; /* not in core dump */
 233                 }
 234                 if (remap_page_range(vma->vm_start,
 235                                      vma->vm_offset,
 236                                      vma->vm_end - vma->vm_start,
 237                                      vma->vm_page_prot))
 238                                 return -EAGAIN;
 239                 vma->vm_ops = &drm_vm_ops;
 240                 break;
 241         case _DRM_SHM:
 242                 vma->vm_ops = &drm_vm_shm_ops;
 243                                 /* Don't let this area swap.  Change when
 244                                    DRM_KERNEL advisory is supported. */
 245                 vma->vm_flags |= VM_LOCKED;
 246                 break;
 247         default:
 248                 return -EINVAL; /* This should never happen. */
 249         }
 250         vma->vm_flags |= VM_LOCKED | VM_SHM; /* Don't swap */
 251         if (map->flags & _DRM_READ_ONLY) {
 252                 pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
 253         }
 254
 255
 256 #if LINUX_VERSION_CODE < 0x020203 /* KERNEL_VERSION(2,2,3) */
 257                                 /* In Linux 2.2.3 and above, this is
 258                                    handled in do_mmap() in mm/mmap.c. */
 259         ++filp->f_count;
 260 #endif
 261         vma->vm_file  =  filp;  /* Needed for drm_vm_open() */
 262         drm_vm_open(vma);
 263         return 0;
 264 }