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