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(drm_sg_mem_t * 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 inode *inode, struct file *filp,
  66                  unsigned int cmd, unsigned long arg)
  67 {
  68         drm_file_t *priv = filp->private_data;
  69         drm_device_t *dev = priv->head->dev;
  70         drm_scatter_gather_t __user *argp = (void __user *)arg;
  71         drm_scatter_gather_t request;
  72         drm_sg_mem_t *entry;
  73         unsigned long pages, i, j;
  74
  75         DRM_DEBUG("%s\n", __FUNCTION__);
  76
  77         if (!drm_core_check_feature(dev, DRIVER_SG))
  78                 return -EINVAL;
  79
  80         if (dev->sg)
  81                 return -EINVAL;
  82
  83         if (copy_from_user(&request, argp, sizeof(request)))
  84                 return -EFAULT;
  85
  86         entry = drm_alloc(sizeof(*entry), DRM_MEM_SGLISTS);
  87         if (!entry)
  88                 return -ENOMEM;
  89
  90         memset(entry, 0, sizeof(*entry));
  91
  92         pages = (request.size + PAGE_SIZE - 1) / PAGE_SIZE;
  93         DRM_DEBUG("sg 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 = vmalloc_32(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("sg alloc handle  = %08lx\n", entry->handle);
 135         DRM_DEBUG("sg alloc 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         if (copy_to_user(argp, &request, sizeof(request))) {
 148                 drm_sg_cleanup(entry);
 149                 return -EFAULT;
 150         }
 151
 152         dev->sg = entry;
 153
 154 #if DEBUG_SCATTER
 155         /* Verify that each page points to its virtual address, and vice
 156          * versa.
 157          */
 158         {
 159                 int error = 0;
 160
 161                 for (i = 0; i < pages; i++) {
 162                         unsigned long *tmp;
 163
 164                         tmp = page_address(entry->pagelist[i]);
 165                         for (j = 0;
 166                              j < PAGE_SIZE / sizeof(unsigned long);
 167                              j++, tmp++) {
 168                                 *tmp = 0xcafebabe;
 169                         }
 170                         tmp = (unsigned long *)((u8 *) entry->virtual +
 171                                                 (PAGE_SIZE * i));
 172                         for (j = 0;
 173                              j < PAGE_SIZE / sizeof(unsigned long);
 174                              j++, tmp++) {
 175                                 if (*tmp != 0xcafebabe && error == 0) {
 176                                         error = 1;
 177                                         DRM_ERROR("Scatter allocation error, "
 178                                                   "pagelist does not match "
 179                                                   "virtual mapping\n");
 180                                 }
 181                         }
 182                         tmp = page_address(entry->pagelist[i]);
 183                         for (j = 0;
 184                              j < PAGE_SIZE / sizeof(unsigned long);
 185                              j++, tmp++) {
 186                                 *tmp = 0;
 187                         }
 188                 }
 189                 if (error == 0)
 190                         DRM_ERROR("Scatter allocation matches pagelist\n");
 191         }
 192 #endif
 193
 194         return 0;
 195
 196       failed:
 197         drm_sg_cleanup(entry);
 198         return -ENOMEM;
 199 }
 200
 201 int drm_sg_free(struct inode *inode, struct file *filp,
 202                 unsigned int cmd, unsigned long arg)
 203 {
 204         drm_file_t *priv = filp->private_data;
 205         drm_device_t *dev = priv->head->dev;
 206         drm_scatter_gather_t request;
 207         drm_sg_mem_t *entry;
 208
 209         if (!drm_core_check_feature(dev, DRIVER_SG))
 210                 return -EINVAL;
 211
 212         if (copy_from_user(&request,
 213                            (drm_scatter_gather_t __user *) arg,
 214                            sizeof(request)))
 215                 return -EFAULT;
 216
 217         entry = dev->sg;
 218         dev->sg = NULL;
 219
 220         if (!entry || entry->handle != request.handle)
 221                 return -EINVAL;
 222
 223         DRM_DEBUG("sg free virtual  = %p\n", entry->virtual);
 224
 225         drm_sg_cleanup(entry);
 226
 227         return 0;
 228 }