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/config.h>
  35 #include <linux/vmalloc.h>
  36 #include "drmP.h"
  37
  38 #define DEBUG_SCATTER 0
  39
  40 void drm_sg_cleanup(drm_sg_mem_t * entry)
  41 {
  42         struct page *page;
  43         int i;
  44
  45         for (i = 0; i < entry->pages; i++) {
  46                 page = entry->pagelist[i];
  47                 if (page)
  48                         ClearPageReserved(page);
  49         }
  50
  51         vfree(entry->virtual);
  52
  53         drm_free(entry->busaddr,
  54                  entry->pages * sizeof(*entry->busaddr), DRM_MEM_PAGES);
  55         drm_free(entry->pagelist,
  56                  entry->pages * sizeof(*entry->pagelist), DRM_MEM_PAGES);
  57         drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
  58 }
  59
  60 #ifdef _LP64
  61 # define ScatterHandle(x) (unsigned int)((x >> 32) + (x & ((1L << 32) - 1)))
  62 #else
  63 # define ScatterHandle(x) (unsigned int)(x)
  64 #endif
  65
  66 int drm_sg_alloc(struct inode *inode, struct file *filp,
  67                  unsigned int cmd, unsigned long arg)
  68 {
  69         drm_file_t *priv = filp->private_data;
  70         drm_device_t *dev = priv->head->dev;
  71         drm_scatter_gather_t __user *argp = (void __user *)arg;
  72         drm_scatter_gather_t request;
  73         drm_sg_mem_t *entry;
  74         unsigned long pages, i, j;
  75
  76         DRM_DEBUG("%s\n", __FUNCTION__);
  77
  78         if (!drm_core_check_feature(dev, DRIVER_SG))
  79                 return -EINVAL;
  80
  81         if (dev->sg)
  82                 return -EINVAL;
  83
  84         if (copy_from_user(&request, argp, sizeof(request)))
  85                 return -EFAULT;
  86
  87         entry = drm_alloc(sizeof(*entry), DRM_MEM_SGLISTS);
  88         if (!entry)
  89                 return -ENOMEM;
  90
  91         memset(entry, 0, sizeof(*entry));
  92
  93         pages = (request.size + PAGE_SIZE - 1) / PAGE_SIZE;
  94         DRM_DEBUG("sg size=%ld pages=%ld\n", request.size, pages);
  95
  96         entry->pages = pages;
  97         entry->pagelist = drm_alloc(pages * sizeof(*entry->pagelist),
  98                                     DRM_MEM_PAGES);
  99         if (!entry->pagelist) {
 100                 drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
 101                 return -ENOMEM;
 102         }
 103
 104         memset(entry->pagelist, 0, pages * sizeof(*entry->pagelist));
 105
 106         entry->busaddr = drm_alloc(pages * sizeof(*entry->busaddr),
 107                                    DRM_MEM_PAGES);
 108         if (!entry->busaddr) {
 109                 drm_free(entry->pagelist,
 110                          entry->pages * sizeof(*entry->pagelist),
 111                          DRM_MEM_PAGES);
 112                 drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
 113                 return -ENOMEM;
 114         }
 115         memset((void *)entry->busaddr, 0, pages * sizeof(*entry->busaddr));
 116
 117         entry->virtual = vmalloc_32(pages << PAGE_SHIFT);
 118         if (!entry->virtual) {
 119                 drm_free(entry->busaddr,
 120                          entry->pages * sizeof(*entry->busaddr), DRM_MEM_PAGES);
 121                 drm_free(entry->pagelist,
 122                          entry->pages * sizeof(*entry->pagelist),
 123                          DRM_MEM_PAGES);
 124                 drm_free(entry, sizeof(*entry), DRM_MEM_SGLISTS);
 125                 return -ENOMEM;
 126         }
 127
 128         /* This also forces the mapping of COW pages, so our page list
 129          * will be valid.  Please don't remove it...
 130          */
 131         memset(entry->virtual, 0, pages << PAGE_SHIFT);
 132
 133         entry->handle = ScatterHandle((unsigned long)entry->virtual);
 134
 135         DRM_DEBUG("sg alloc handle  = %08lx\n", entry->handle);
 136         DRM_DEBUG("sg alloc virtual = %p\n", entry->virtual);
 137
 138         for (i = (unsigned long)entry->virtual, j = 0; j < pages;
 139              i += PAGE_SIZE, j++) {
 140                 entry->pagelist[j] = vmalloc_to_page((void *)i);
 141                 if (!entry->pagelist[j])
 142                         goto failed;
 143                 SetPageReserved(entry->pagelist[j]);
 144         }
 145
 146         request.handle = entry->handle;
 147
 148         if (copy_to_user(argp, &request, sizeof(request))) {
 149                 drm_sg_cleanup(entry);
 150                 return -EFAULT;
 151         }
 152
 153         dev->sg = entry;
 154
 155 #if DEBUG_SCATTER
 156         /* Verify that each page points to its virtual address, and vice
 157          * versa.
 158          */
 159         {
 160                 int error = 0;
 161
 162                 for (i = 0; i < pages; i++) {
 163                         unsigned long *tmp;
 164
 165                         tmp = page_address(entry->pagelist[i]);
 166                         for (j = 0;
 167                              j < PAGE_SIZE / sizeof(unsigned long);
 168                              j++, tmp++) {
 169                                 *tmp = 0xcafebabe;
 170                         }
 171                         tmp = (unsigned long *)((u8 *) entry->virtual +
 172                                                 (PAGE_SIZE * i));
 173                         for (j = 0;
 174                              j < PAGE_SIZE / sizeof(unsigned long);
 175                              j++, tmp++) {
 176                                 if (*tmp != 0xcafebabe && error == 0) {
 177                                         error = 1;
 178                                         DRM_ERROR("Scatter allocation error, "
 179                                                   "pagelist does not match "
 180                                                   "virtual mapping\n");
 181                                 }
 182                         }
 183                         tmp = page_address(entry->pagelist[i]);
 184                         for (j = 0;
 185                              j < PAGE_SIZE / sizeof(unsigned long);
 186                              j++, tmp++) {
 187                                 *tmp = 0;
 188                         }
 189                 }
 190                 if (error == 0)
 191                         DRM_ERROR("Scatter allocation matches pagelist\n");
 192         }
 193 #endif
 194
 195         return 0;
 196
 197       failed:
 198         drm_sg_cleanup(entry);
 199         return -ENOMEM;
 200 }
 201
 202 int drm_sg_free(struct inode *inode, struct file *filp,
 203                 unsigned int cmd, unsigned long arg)
 204 {
 205         drm_file_t *priv = filp->private_data;
 206         drm_device_t *dev = priv->head->dev;
 207         drm_scatter_gather_t request;
 208         drm_sg_mem_t *entry;
 209
 210         if (!drm_core_check_feature(dev, DRIVER_SG))
 211                 return -EINVAL;
 212
 213         if (copy_from_user(&request,
 214                            (drm_scatter_gather_t __user *) arg,
 215                            sizeof(request)))
 216                 return -EFAULT;
 217
 218         entry = dev->sg;
 219         dev->sg = NULL;
 220
 221         if (!entry || entry->handle != request.handle)
 222                 return -EINVAL;
 223
 224         DRM_DEBUG("sg free virtual  = %p\n", entry->virtual);
 225
 226         drm_sg_cleanup(entry);
 227
 228         return 0;
 229 }