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