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/highmem.h>
  37 #include "drmP.h"
  38
  39 #ifdef DEBUG_MEMORY
  40 #include "drm_memory_debug.h"
  41 #else
  42
  43 /** No-op. */
  44 void drm_mem_init(void)
  45 {
  46 }
  47
  48 /**
  49  * Called when "/proc/dri/%dev%/mem" is read.
  50  *
  51  * \param buf output buffer.
  52  * \param start start of output data.
  53  * \param offset requested start offset.
  54  * \param len requested number of bytes.
  55  * \param eof whether there is no more data to return.
  56  * \param data private data.
  57  * \return number of written bytes.
  58  *
  59  * No-op.
  60  */
  61 int drm_mem_info(char *buf, char **start, off_t offset,
  62                  int len, int *eof, void *data)
  63 {
  64         return 0;
  65 }
  66
  67 /** Wrapper around kmalloc() and kfree() */
  68 void *drm_realloc(void *oldpt, size_t oldsize, size_t size, int area)
  69 {
  70         void *pt;
  71
  72         if (!(pt = kmalloc(size, GFP_KERNEL)))
  73                 return NULL;
  74         if (oldpt && oldsize) {
  75                 memcpy(pt, oldpt, oldsize);
  76                 kfree(oldpt);
  77         }
  78         return pt;
  79 }
  80
  81 #if __OS_HAS_AGP
  82 /*
  83  * Find the drm_map that covers the range [offset, offset+size).
  84  */
  85 static drm_map_t *drm_lookup_map(unsigned long offset,
  86                                  unsigned long size, drm_device_t * dev)
  87 {
  88         struct list_head *list;
  89         drm_map_list_t *r_list;
  90         drm_map_t *map;
  91
  92         list_for_each(list, &dev->maplist->head) {
  93                 r_list = (drm_map_list_t *) list;
  94                 map = r_list->map;
  95                 if (!map)
  96                         continue;
  97                 if (map->offset <= offset
  98                     && (offset + size) <= (map->offset + map->size))
  99                         return map;
 100         }
 101         return NULL;
 102 }
 103
 104 static void *agp_remap(unsigned long offset, unsigned long size,
 105                        drm_device_t * dev)
 106 {
 107         unsigned long *phys_addr_map, i, num_pages =
 108             PAGE_ALIGN(size) / PAGE_SIZE;
 109         struct drm_agp_mem *agpmem;
 110         struct page **page_map;
 111         void *addr;
 112
 113         size = PAGE_ALIGN(size);
 114
 115 #ifdef __alpha__
 116         offset -= dev->hose->mem_space->start;
 117 #endif
 118
 119         for (agpmem = dev->agp->memory; agpmem; agpmem = agpmem->next)
 120                 if (agpmem->bound <= offset
 121                     && (agpmem->bound + (agpmem->pages << PAGE_SHIFT)) >=
 122                     (offset + size))
 123                         break;
 124         if (!agpmem)
 125                 return NULL;
 126
 127         /*
 128          * OK, we're mapping AGP space on a chipset/platform on which memory accesses by
 129          * the CPU do not get remapped by the GART.  We fix this by using the kernel's
 130          * page-table instead (that's probably faster anyhow...).
 131          */
 132         /* note: use vmalloc() because num_pages could be large... */
 133         page_map = vmalloc(num_pages * sizeof(struct page *));
 134         if (!page_map)
 135                 return NULL;
 136
 137         phys_addr_map =
 138             agpmem->memory->memory + (offset - agpmem->bound) / PAGE_SIZE;
 139         for (i = 0; i < num_pages; ++i)
 140                 page_map[i] = pfn_to_page(phys_addr_map[i] >> PAGE_SHIFT);
 141         addr = vmap(page_map, num_pages, VM_IOREMAP, PAGE_AGP);
 142         vfree(page_map);
 143
 144         return addr;
 145 }
 146
 147 /** Wrapper around agp_allocate_memory() */
 148 DRM_AGP_MEM *drm_alloc_agp(drm_device_t * dev, int pages, u32 type)
 149 {
 150         return drm_agp_allocate_memory(dev->agp->bridge, pages, type);
 151 }
 152
 153 /** Wrapper around agp_free_memory() */
 154 int drm_free_agp(DRM_AGP_MEM * handle, int pages)
 155 {
 156         return drm_agp_free_memory(handle) ? 0 : -EINVAL;
 157 }
 158
 159 /** Wrapper around agp_bind_memory() */
 160 int drm_bind_agp(DRM_AGP_MEM * handle, unsigned int start)
 161 {
 162         return drm_agp_bind_memory(handle, start);
 163 }
 164
 165 /** Wrapper around agp_unbind_memory() */
 166 int drm_unbind_agp(DRM_AGP_MEM * handle)
 167 {
 168         return drm_agp_unbind_memory(handle);
 169 }
 170
 171 #else  /*  __OS_HAS_AGP  */
 172
 173 static inline drm_map_t *drm_lookup_map(unsigned long offset,
 174                                         unsigned long size, drm_device_t * dev)
 175 {
 176         return NULL;
 177 }
 178
 179 static inline void *agp_remap(unsigned long offset, unsigned long size,
 180                               drm_device_t * dev)
 181 {
 182         return NULL;
 183 }
 184
 185 #endif                          /* agp */
 186
 187 void *drm_ioremap(unsigned long offset, unsigned long size,
 188                                 drm_device_t * dev)
 189 {
 190         if (drm_core_has_AGP(dev) && dev->agp && dev->agp->cant_use_aperture) {
 191                 drm_map_t *map = drm_lookup_map(offset, size, dev);
 192
 193                 if (map && map->type == _DRM_AGP)
 194                         return agp_remap(offset, size, dev);
 195         }
 196         return ioremap(offset, size);
 197 }
 198 EXPORT_SYMBOL(drm_ioremap);
 199
 200 #if 0
 201 void *drm_ioremap_nocache(unsigned long offset,
 202                                         unsigned long size, drm_device_t * dev)
 203 {
 204         if (drm_core_has_AGP(dev) && dev->agp && dev->agp->cant_use_aperture) {
 205                 drm_map_t *map = drm_lookup_map(offset, size, dev);
 206
 207                 if (map && map->type == _DRM_AGP)
 208                         return agp_remap(offset, size, dev);
 209         }
 210         return ioremap_nocache(offset, size);
 211 }
 212 #endif  /*  0  */
 213
 214 void drm_ioremapfree(void *pt, unsigned long size,
 215                                    drm_device_t * dev)
 216 {
 217         /*
 218          * This is a bit ugly.  It would be much cleaner if the DRM API would use separate
 219          * routines for handling mappings in the AGP space.  Hopefully this can be done in
 220          * a future revision of the interface...
 221          */
 222         if (drm_core_has_AGP(dev) && dev->agp && dev->agp->cant_use_aperture
 223             && ((unsigned long)pt >= VMALLOC_START
 224                 && (unsigned long)pt < VMALLOC_END)) {
 225                 unsigned long offset;
 226                 drm_map_t *map;
 227
 228                 offset = drm_follow_page(pt) | ((unsigned long)pt & ~PAGE_MASK);
 229                 map = drm_lookup_map(offset, size, dev);
 230                 if (map && map->type == _DRM_AGP) {
 231                         vunmap(pt);
 232                         return;
 233                 }
 234         }
 235
 236         iounmap(pt);
 237 }
 238 EXPORT_SYMBOL(drm_ioremapfree);
 239
 240 #endif                          /* debug_memory */