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 static inline void *drm_vmalloc_dma(unsigned long size)
  40 {
  41 #if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE)
  42         return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL | _PAGE_NO_CACHE);
  43 #else
  44         return vmalloc_32(size);
  45 #endif
  46 }
  47
  48 void drm_sg_cleanup(struct drm_sg_mem * entry)
  49 {
  50         struct page *page;
  51         int i;
  52
  53         for (i = 0; i < entry->pages; i++) {
  54                 page = entry->pagelist[i];
  55                 if (page)
  56                         ClearPageReserved(page);
  57         }
  58
  59         vfree(entry->virtual);
  60
  61         drm_free(entry->busaddr,
  62                  entry->pages * sizeof(*entry->busaddr), DRM_MEM_PAGES);
  63         drm_free(entry->pagelist,
  64                  entry->pages * sizeof(*entry->pagelist), DRM_MEM_PAGES);
  65         drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
  66 }
  67
  68 #ifdef _LP64
  69 # define ScatterHandle(x) (unsigned int)((x >> 32) + (x & ((1L << 32) - 1)))
  70 #else
  71 # define ScatterHandle(x) (unsigned int)(x)
  72 #endif
  73
  74 int drm_sg_alloc(struct drm_device *dev, struct drm_scatter_gather * request)
  75 {
  76         struct drm_sg_mem *entry;
  77         unsigned long pages, i, j;
  78
  79         DRM_DEBUG("\n");
  80
  81         if (!drm_core_check_feature(dev, DRIVER_SG))
  82                 return -EINVAL;
  83
  84         if (dev->sg)
  85                 return -EINVAL;
  86
  87         entry = drm_alloc(sizeof(*entry), DRM_MEM_SGLISTS);
  88         if (!entry)
  89                 return -ENOMEM;
  90
  91         memset(entry, 0, sizeof(*entry));
  92         pages = (request->size + PAGE_SIZE - 1) / PAGE_SIZE;
  93         DRM_DEBUG("size=%ld pages=%ld\n", request->size, pages);
  94
  95         entry->pages = pages;
  96         entry->pagelist = drm_alloc(pages * sizeof(*entry->pagelist),
  97                                     DRM_MEM_PAGES);
  98         if (!entry->pagelist) {
  99                 drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
 100                 return -ENOMEM;
 101         }
 102
 103         memset(entry->pagelist, 0, pages * sizeof(*entry->pagelist));
 104
 105         entry->busaddr = drm_alloc(pages * sizeof(*entry->busaddr),
 106                                    DRM_MEM_PAGES);
 107         if (!entry->busaddr) {
 108                 drm_free(entry->pagelist,
 109                          entry->pages * sizeof(*entry->pagelist),
 110                          DRM_MEM_PAGES);
 111                 drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
 112                 return -ENOMEM;
 113         }
 114         memset((void *)entry->busaddr, 0, pages * sizeof(*entry->busaddr));
 115
 116         entry->virtual = drm_vmalloc_dma(pages << PAGE_SHIFT);
 117         if (!entry->virtual) {
 118                 drm_free(entry->busaddr,
 119                          entry->pages * sizeof(*entry->busaddr), DRM_MEM_PAGES);
 120                 drm_free(entry->pagelist,
 121                          entry->pages * sizeof(*entry->pagelist),
 122                          DRM_MEM_PAGES);
 123                 drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
 124                 return -ENOMEM;
 125         }
 126
 127         /* This also forces the mapping of COW pages, so our page list
 128          * will be valid.  Please don't remove it...
 129          */
 130         memset(entry->virtual, 0, pages << PAGE_SHIFT);
 131
 132         entry->handle = ScatterHandle((unsigned long)entry->virtual);
 133
 134         DRM_DEBUG("handle  = %08lx\n", entry->handle);
 135         DRM_DEBUG("virtual = %p\n", entry->virtual);
 136
 137         for (i = (unsigned long)entry->virtual, j = 0; j < pages;
 138              i += PAGE_SIZE, j++) {
 139                 entry->pagelist[j] = vmalloc_to_page((void *)i);
 140                 if (!entry->pagelist[j])
 141                         goto failed;
 142                 SetPageReserved(entry->pagelist[j]);
 143         }
 144
 145         request->handle = entry->handle;
 146
 147         dev->sg = entry;
 148
 149 #if DEBUG_SCATTER
 150         /* Verify that each page points to its virtual address, and vice
 151          * versa.
 152          */
 153         {
 154                 int error = 0;
 155
 156                 for (i = 0; i < pages; i++) {
 157                         unsigned long *tmp;
 158
 159                         tmp = page_address(entry->pagelist[i]);
 160                         for (j = 0;
 161                              j < PAGE_SIZE / sizeof(unsigned long);
 162                              j++, tmp++) {
 163                                 *tmp = 0xcafebabe;
 164                         }
 165                         tmp = (unsigned long *)((u8 *) entry->virtual +
 166                                                 (PAGE_SIZE * i));
 167                         for (j = 0;
 168                              j < PAGE_SIZE / sizeof(unsigned long);
 169                              j++, tmp++) {
 170                                 if (*tmp != 0xcafebabe && error == 0) {
 171                                         error = 1;
 172                                         DRM_ERROR("Scatter allocation error, "
 173                                                   "pagelist does not match "
 174                                                   "virtual mapping\n");
 175                                 }
 176                         }
 177                         tmp = page_address(entry->pagelist[i]);
 178                         for (j = 0;
 179                              j < PAGE_SIZE / sizeof(unsigned long);
 180                              j++, tmp++) {
 181                                 *tmp = 0;
 182                         }
 183                 }
 184                 if (error == 0)
 185                         DRM_ERROR("Scatter allocation matches pagelist\n");
 186         }
 187 #endif
 188
 189         return 0;
 190
 191       failed:
 192         drm_sg_cleanup(entry);
 193         return -ENOMEM;
 194 }
 195 EXPORT_SYMBOL(drm_sg_alloc);
 196
 197
 198 int drm_sg_alloc_ioctl(struct drm_device *dev, void *data,
 199                        struct drm_file *file_priv)
 200 {
 201         struct drm_scatter_gather *request = data;
 202
 203         return drm_sg_alloc(dev, request);
 204
 205 }
 206
 207 int drm_sg_free(struct drm_device *dev, void *data,
 208                 struct drm_file *file_priv)
 209 {
 210         struct drm_scatter_gather *request = data;
 211         struct drm_sg_mem *entry;
 212
 213         if (!drm_core_check_feature(dev, DRIVER_SG))
 214                 return -EINVAL;
 215
 216         entry = dev->sg;
 217         dev->sg = NULL;
 218
 219         if (!entry || entry->handle != request->handle)
 220                 return -EINVAL;
 221
 222         DRM_DEBUG("virtual  = %p\n", entry->virtual);
 223
 224         drm_sg_cleanup(entry);
 225
 226         return 0;
 227 }