drivers/char/drm/drm_scatter.c

   1 /**
   2  * \file drm_scatter.c
   3  * IOCTLs to manage scatter/gather memory
   4  *
   5  * \author Gareth Hughes <gareth@valinux.com>
   6  */
   7
   8 /*
   9  * Created: Mon Dec 18 23:20:54 2000 by gareth@valinux.com
  10  *
  11  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
  12  * All Rights Reserved.
  13  *
  14  * Permission is hereby granted, free of charge, to any person obtaining a
  15  * copy of this software and associated documentation files (the "Software"),
  16  * to deal in the Software without restriction, including without limitation
  17  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  18  * and/or sell copies of the Software, and to permit persons to whom the
  19  * Software is furnished to do so, subject to the following conditions:
  20  *
  21  * The above copyright notice and this permission notice (including the next
  22  * paragraph) shall be included in all copies or substantial portions of the
  23  * Software.
  24  *
  25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  26  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  27  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  28  * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  29  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  30  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  31  * DEALINGS IN THE SOFTWARE.
  32  */
  33
  34 #include <linux/vmalloc.h>
  35 #include "drmP.h"
  36
  37 #define DEBUG_SCATTER 0
  38
  39 void drm_sg_cleanup(struct drm_sg_mem * entry)
  40 {
  41         struct page *page;
  42         int i;
  43
  44         for (i = 0; i < entry->pages; i++) {
  45                 page = entry->pagelist[i];
  46                 if (page)
  47                         ClearPageReserved(page);
  48         }
  49
  50         vfree(entry->virtual);
  51
  52         drm_free(entry->busaddr,
  53                  entry->pages * sizeof(*entry->busaddr), DRM_MEM_PAGES);
  54         drm_free(entry->pagelist,
  55                  entry->pages * sizeof(*entry->pagelist), DRM_MEM_PAGES);
  56         drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
  57 }
  58
  59 #ifdef _LP64
  60 # define ScatterHandle(x) (unsigned int)((x >> 32) + (x & ((1L << 32) - 1)))
  61 #else
  62 # define ScatterHandle(x) (unsigned int)(x)
  63 #endif
  64
  65 int drm_sg_alloc(struct drm_device *dev, struct drm_scatter_gather * request)
  66 {
  67         struct drm_sg_mem *entry;
  68         unsigned long pages, i, j;
  69
  70         DRM_DEBUG("%s\n", __FUNCTION__);
  71
  72         if (!drm_core_check_feature(dev, DRIVER_SG))
  73                 return -EINVAL;
  74
  75         if (dev->sg)
  76                 return -EINVAL;
  77
  78         entry = drm_alloc(sizeof(*entry), DRM_MEM_SGLISTS);
  79         if (!entry)
  80                 return -ENOMEM;
  81
  82         memset(entry, 0, sizeof(*entry));
  83         pages = (request->size + PAGE_SIZE - 1) / PAGE_SIZE;
  84         DRM_DEBUG("sg size=%ld pages=%ld\n", request->size, pages);
  85
  86         entry->pages = pages;
  87         entry->pagelist = drm_alloc(pages * sizeof(*entry->pagelist),
  88                                     DRM_MEM_PAGES);
  89         if (!entry->pagelist) {
  90                 drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
  91                 return -ENOMEM;
  92         }
  93
  94         memset(entry->pagelist, 0, pages * sizeof(*entry->pagelist));
  95
  96         entry->busaddr = drm_alloc(pages * sizeof(*entry->busaddr),
  97                                    DRM_MEM_PAGES);
  98         if (!entry->busaddr) {
  99                 drm_free(entry->pagelist,
 100                          entry->pages * sizeof(*entry->pagelist),
 101                          DRM_MEM_PAGES);
 102                 drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
 103                 return -ENOMEM;
 104         }
 105         memset((void *)entry->busaddr, 0, pages * sizeof(*entry->busaddr));
 106
 107         entry->virtual = vmalloc_32(pages << PAGE_SHIFT);
 108         if (!entry->virtual) {
 109                 drm_free(entry->busaddr,
 110                          entry->pages * sizeof(*entry->busaddr), DRM_MEM_PAGES);
 111                 drm_free(entry->pagelist,
 112                          entry->pages * sizeof(*entry->pagelist),
 113                          DRM_MEM_PAGES);
 114                 drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
 115                 return -ENOMEM;
 116         }
 117
 118         /* This also forces the mapping of COW pages, so our page list
 119          * will be valid.  Please don't remove it...
 120          */
 121         memset(entry->virtual, 0, pages << PAGE_SHIFT);
 122
 123         entry->handle = ScatterHandle((unsigned long)entry->virtual);
 124
 125         DRM_DEBUG("sg alloc handle  = %08lx\n", entry->handle);
 126         DRM_DEBUG("sg alloc virtual = %p\n", entry->virtual);
 127
 128         for (i = (unsigned long)entry->virtual, j = 0; j < pages;
 129              i += PAGE_SIZE, j++) {
 130                 entry->pagelist[j] = vmalloc_to_page((void *)i);
 131                 if (!entry->pagelist[j])
 132                         goto failed;
 133                 SetPageReserved(entry->pagelist[j]);
 134         }
 135
 136         request->handle = entry->handle;
 137
 138         dev->sg = entry;
 139
 140 #if DEBUG_SCATTER
 141         /* Verify that each page points to its virtual address, and vice
 142          * versa.
 143          */
 144         {
 145                 int error = 0;
 146
 147                 for (i = 0; i < pages; i++) {
 148                         unsigned long *tmp;
 149
 150                         tmp = page_address(entry->pagelist[i]);
 151                         for (j = 0;
 152                              j < PAGE_SIZE / sizeof(unsigned long);
 153                              j++, tmp++) {
 154                                 *tmp = 0xcafebabe;
 155                         }
 156                         tmp = (unsigned long *)((u8 *) entry->virtual +
 157                                                 (PAGE_SIZE * i));
 158                         for (j = 0;
 159                              j < PAGE_SIZE / sizeof(unsigned long);
 160                              j++, tmp++) {
 161                                 if (*tmp != 0xcafebabe && error == 0) {
 162                                         error = 1;
 163                                         DRM_ERROR("Scatter allocation error, "
 164                                                   "pagelist does not match "
 165                                                   "virtual mapping\n");
 166                                 }
 167                         }
 168                         tmp = page_address(entry->pagelist[i]);
 169                         for (j = 0;
 170                              j < PAGE_SIZE / sizeof(unsigned long);
 171                              j++, tmp++) {
 172                                 *tmp = 0;
 173                         }
 174                 }
 175                 if (error == 0)
 176                         DRM_ERROR("Scatter allocation matches pagelist\n");
 177         }
 178 #endif
 179
 180         return 0;
 181
 182       failed:
 183         drm_sg_cleanup(entry);
 184         return -ENOMEM;
 185 }
 186 EXPORT_SYMBOL(drm_sg_alloc);
 187
 188
 189 int drm_sg_alloc_ioctl(struct drm_device *dev, void *data,
 190                        struct drm_file *file_priv)
 191 {
 192         struct drm_scatter_gather *request = data;
 193
 194         return drm_sg_alloc(dev, request);
 195
 196 }
 197
 198 int drm_sg_free(struct drm_device *dev, void *data,
 199                 struct drm_file *file_priv)
 200 {
 201         struct drm_scatter_gather *request = data;
 202         struct drm_sg_mem *entry;
 203
 204         if (!drm_core_check_feature(dev, DRIVER_SG))
 205                 return -EINVAL;
 206
 207         entry = dev->sg;
 208         dev->sg = NULL;
 209
 210         if (!entry || entry->handle != request->handle)
 211                 return -EINVAL;
 212
 213         DRM_DEBUG("sg free virtual  = %p\n", entry->virtual);
 214
 215         drm_sg_cleanup(entry);
 216
 217         return 0;
 218 }