drivers/char/drm/drm_memory.c

   1 /**
   2  * \file drm_memory.c
   3  * Memory management wrappers for DRM
   4  *
   5  * \author Rickard E. (Rik) Faith <faith@valinux.com>
   6  * \author Gareth Hughes <gareth@valinux.com>
   7  */
   8
   9 /*
  10  * Created: Thu Feb  4 14:00:34 1999 by faith@valinux.com
  11  *
  12  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
  13  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
  14  * All Rights Reserved.
  15  *
  16  * Permission is hereby granted, free of charge, to any person obtaining a
  17  * copy of this software and associated documentation files (the "Software"),
  18  * to deal in the Software without restriction, including without limitation
  19  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  20  * and/or sell copies of the Software, and to permit persons to whom the
  21  * Software is furnished to do so, subject to the following conditions:
  22  *
  23  * The above copyright notice and this permission notice (including the next
  24  * paragraph) shall be included in all copies or substantial portions of the
  25  * Software.
  26  *
  27  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  28  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  29  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  30  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  31  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  32  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  33  * OTHER DEALINGS IN THE SOFTWARE.
  34  */
  35
  36 #include <linux/config.h>
  37 #include <linux/highmem.h>
  38 #include "drmP.h"
  39
  40 #ifdef DEBUG_MEMORY
  41 #include "drm_memory_debug.h"
  42 #else
  43
  44 /** No-op. */
  45 void drm_mem_init(void)
  46 {
  47 }
  48
  49 /**
  50  * Called when "/proc/dri/%dev%/mem" is read.
  51  *
  52  * \param buf output buffer.
  53  * \param start start of output data.
  54  * \param offset requested start offset.
  55  * \param len requested number of bytes.
  56  * \param eof whether there is no more data to return.
  57  * \param data private data.
  58  * \return number of written bytes.
  59  *
  60  * No-op.
  61  */
  62 int drm_mem_info(char *buf, char **start, off_t offset,
  63                  int len, int *eof, void *data)
  64 {
  65         return 0;
  66 }
  67
  68 /** Wrapper around kmalloc() and kfree() */
  69 void *drm_realloc(void *oldpt, size_t oldsize, size_t size, int area)
  70 {
  71         void *pt;
  72
  73         if (!(pt = kmalloc(size, GFP_KERNEL)))
  74                 return NULL;
  75         if (oldpt && oldsize) {
  76                 memcpy(pt, oldpt, oldsize);
  77                 kfree(oldpt);
  78         }
  79         return pt;
  80 }
  81
  82 #if __OS_HAS_AGP
  83 /*
  84  * Find the drm_map that covers the range [offset, offset+size).
  85  */
  86 static drm_map_t *drm_lookup_map(unsigned long offset,
  87                                  unsigned long size, drm_device_t * dev)
  88 {
  89         struct list_head *list;
  90         drm_map_list_t *r_list;
  91         drm_map_t *map;
  92
  93         list_for_each(list, &dev->maplist->head) {
  94                 r_list = (drm_map_list_t *) list;
  95                 map = r_list->map;
  96                 if (!map)
  97                         continue;
  98                 if (map->offset <= offset
  99                     && (offset + size) <= (map->offset + map->size))
 100                         return map;
 101         }
 102         return NULL;
 103 }
 104
 105 static void *agp_remap(unsigned long offset, unsigned long size,
 106                        drm_device_t * dev)
 107 {
 108         unsigned long *phys_addr_map, i, num_pages =
 109             PAGE_ALIGN(size) / PAGE_SIZE;
 110         struct drm_agp_mem *agpmem;
 111         struct page **page_map;
 112         void *addr;
 113
 114         size = PAGE_ALIGN(size);
 115
 116 #ifdef __alpha__
 117         offset -= dev->hose->mem_space->start;
 118 #endif
 119
 120         for (agpmem = dev->agp->memory; agpmem; agpmem = agpmem->next)
 121                 if (agpmem->bound <= offset
 122                     && (agpmem->bound + (agpmem->pages << PAGE_SHIFT)) >=
 123                     (offset + size))
 124                         break;
 125         if (!agpmem)
 126                 return NULL;
 127
 128         /*
 129          * OK, we're mapping AGP space on a chipset/platform on which memory accesses by
 130          * the CPU do not get remapped by the GART.  We fix this by using the kernel's
 131          * page-table instead (that's probably faster anyhow...).
 132          */
 133         /* note: use vmalloc() because num_pages could be large... */
 134         page_map = vmalloc(num_pages * sizeof(struct page *));
 135         if (!page_map)
 136                 return NULL;
 137
 138         phys_addr_map =
 139             agpmem->memory->memory + (offset - agpmem->bound) / PAGE_SIZE;
 140         for (i = 0; i < num_pages; ++i)
 141                 page_map[i] = pfn_to_page(phys_addr_map[i] >> PAGE_SHIFT);
 142         addr = vmap(page_map, num_pages, VM_IOREMAP, PAGE_AGP);
 143         vfree(page_map);
 144
 145         return addr;
 146 }
 147
 148 /** Wrapper around agp_allocate_memory() */
 149 DRM_AGP_MEM *drm_alloc_agp(drm_device_t * dev, int pages, u32 type)
 150 {
 151         return drm_agp_allocate_memory(dev->agp->bridge, pages, type);
 152 }
 153
 154 /** Wrapper around agp_free_memory() */
 155 int drm_free_agp(DRM_AGP_MEM * handle, int pages)
 156 {
 157         return drm_agp_free_memory(handle) ? 0 : -EINVAL;
 158 }
 159
 160 /** Wrapper around agp_bind_memory() */
 161 int drm_bind_agp(DRM_AGP_MEM * handle, unsigned int start)
 162 {
 163         return drm_agp_bind_memory(handle, start);
 164 }
 165
 166 /** Wrapper around agp_unbind_memory() */
 167 int drm_unbind_agp(DRM_AGP_MEM * handle)
 168 {
 169         return drm_agp_unbind_memory(handle);
 170 }
 171
 172 #else  /*  __OS_HAS_AGP  */
 173
 174 static inline drm_map_t *drm_lookup_map(unsigned long offset,
 175                                         unsigned long size, drm_device_t * dev)
 176 {
 177         return NULL;
 178 }
 179
 180 static inline void *agp_remap(unsigned long offset, unsigned long size,
 181                               drm_device_t * dev)
 182 {
 183         return NULL;
 184 }
 185
 186 #endif                          /* agp */
 187
 188 void *drm_ioremap(unsigned long offset, unsigned long size,
 189                                 drm_device_t * dev)
 190 {
 191         if (drm_core_has_AGP(dev) && dev->agp && dev->agp->cant_use_aperture) {
 192                 drm_map_t *map = drm_lookup_map(offset, size, dev);
 193
 194                 if (map && map->type == _DRM_AGP)
 195                         return agp_remap(offset, size, dev);
 196         }
 197         return ioremap(offset, size);
 198 }
 199 EXPORT_SYMBOL(drm_ioremap);
 200
 201 #if 0
 202 void *drm_ioremap_nocache(unsigned long offset,
 203                                         unsigned long size, drm_device_t * dev)
 204 {
 205         if (drm_core_has_AGP(dev) && dev->agp && dev->agp->cant_use_aperture) {
 206                 drm_map_t *map = drm_lookup_map(offset, size, dev);
 207
 208                 if (map && map->type == _DRM_AGP)
 209                         return agp_remap(offset, size, dev);
 210         }
 211         return ioremap_nocache(offset, size);
 212 }
 213 #endif  /*  0  */
 214
 215 void drm_ioremapfree(void *pt, unsigned long size,
 216                                    drm_device_t * dev)
 217 {
 218         /*
 219          * This is a bit ugly.  It would be much cleaner if the DRM API would use separate
 220          * routines for handling mappings in the AGP space.  Hopefully this can be done in
 221          * a future revision of the interface...
 222          */
 223         if (drm_core_has_AGP(dev) && dev->agp && dev->agp->cant_use_aperture
 224             && ((unsigned long)pt >= VMALLOC_START
 225                 && (unsigned long)pt < VMALLOC_END)) {
 226                 unsigned long offset;
 227                 drm_map_t *map;
 228
 229                 offset = drm_follow_page(pt) | ((unsigned long)pt & ~PAGE_MASK);
 230                 map = drm_lookup_map(offset, size, dev);
 231                 if (map && map->type == _DRM_AGP) {
 232                         vunmap(pt);
 233                         return;
 234                 }
 235         }
 236
 237         iounmap(pt);
 238 }
 239 EXPORT_SYMBOL(drm_ioremapfree);
 240
 241 #endif                          /* debug_memory */