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 void drm_sg_cleanup(struct drm_sg_mem * entry)
  47 {
  48         struct page *page;
  49         int i;
  50
  51         for (i = 0; i < entry->pages; i++) {
  52                 page = entry->pagelist[i];
  53                 if (page)
  54                         ClearPageReserved(page);
  55         }
  56
  57         vfree(entry->virtual);
  58
  59         kfree(entry->busaddr);
  60         kfree(entry->pagelist);
  61         kfree(entry);
  62 }
  63
  64 void drm_legacy_sg_cleanup(struct drm_device *dev)
  65 {
  66         if (drm_core_check_feature(dev, DRIVER_SG) && dev->sg &&
  67             drm_core_check_feature(dev, DRIVER_LEGACY)) {
  68                 drm_sg_cleanup(dev->sg);
  69                 dev->sg = NULL;
  70         }
  71 }
  72 #ifdef _LP64
  73 # define ScatterHandle(x) (unsigned int)((x >> 32) + (x & ((1L << 32) - 1)))
  74 #else
  75 # define ScatterHandle(x) (unsigned int)(x)
  76 #endif
  77
  78 int drm_legacy_sg_alloc(struct drm_device *dev, void *data,
  79                         struct drm_file *file_priv)
  80 {
  81         struct drm_scatter_gather *request = data;
  82         struct drm_sg_mem *entry;
  83         unsigned long pages, i, j;
  84
  85         DRM_DEBUG("\n");
  86
  87         if (!drm_core_check_feature(dev, DRIVER_LEGACY))
  88                 return -EOPNOTSUPP;
  89
  90         if (!drm_core_check_feature(dev, DRIVER_SG))
  91                 return -EOPNOTSUPP;
  92
  93         if (request->size > SIZE_MAX - PAGE_SIZE)
  94                 return -EINVAL;
  95
  96         if (dev->sg)
  97                 return -EINVAL;
  98
  99         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 100         if (!entry)
 101                 return -ENOMEM;
 102
 103         pages = (request->size + PAGE_SIZE - 1) / PAGE_SIZE;
 104         DRM_DEBUG("size=%ld pages=%ld\n", request->size, pages);
 105
 106         entry->pages = pages;
 107         entry->pagelist = kcalloc(pages, sizeof(*entry->pagelist), GFP_KERNEL);
 108         if (!entry->pagelist) {
 109                 kfree(entry);
 110                 return -ENOMEM;
 111         }
 112
 113         entry->busaddr = kcalloc(pages, sizeof(*entry->busaddr), GFP_KERNEL);
 114         if (!entry->busaddr) {
 115                 kfree(entry->pagelist);
 116                 kfree(entry);
 117                 return -ENOMEM;
 118         }
 119
 120         entry->virtual = vmalloc_32(pages << PAGE_SHIFT);
 121         if (!entry->virtual) {
 122                 kfree(entry->busaddr);
 123                 kfree(entry->pagelist);
 124                 kfree(entry);
 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("handle  = %08lx\n", entry->handle);
 136         DRM_DEBUG("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         dev->sg = entry;
 149
 150 #if DEBUG_SCATTER
 151         /* Verify that each page points to its virtual address, and vice
 152          * versa.
 153          */
 154         {
 155                 int error = 0;
 156
 157                 for (i = 0; i < pages; i++) {
 158                         unsigned long *tmp;
 159
 160                         tmp = page_address(entry->pagelist[i]);
 161                         for (j = 0;
 162                              j < PAGE_SIZE / sizeof(unsigned long);
 163                              j++, tmp++) {
 164                                 *tmp = 0xcafebabe;
 165                         }
 166                         tmp = (unsigned long *)((u8 *) entry->virtual +
 167                                                 (PAGE_SIZE * i));
 168                         for (j = 0;
 169                              j < PAGE_SIZE / sizeof(unsigned long);
 170                              j++, tmp++) {
 171                                 if (*tmp != 0xcafebabe && error == 0) {
 172                                         error = 1;
 173                                         DRM_ERROR("Scatter allocation error, "
 174                                                   "pagelist does not match "
 175                                                   "virtual mapping\n");
 176                                 }
 177                         }
 178                         tmp = page_address(entry->pagelist[i]);
 179                         for (j = 0;
 180                              j < PAGE_SIZE / sizeof(unsigned long);
 181                              j++, tmp++) {
 182                                 *tmp = 0;
 183                         }
 184                 }
 185                 if (error == 0)
 186                         DRM_ERROR("Scatter allocation matches pagelist\n");
 187         }
 188 #endif
 189
 190         return 0;
 191
 192       failed:
 193         drm_sg_cleanup(entry);
 194         return -ENOMEM;
 195 }
 196
 197 int drm_legacy_sg_free(struct drm_device *dev, void *data,
 198                        struct drm_file *file_priv)
 199 {
 200         struct drm_scatter_gather *request = data;
 201         struct drm_sg_mem *entry;
 202
 203         if (!drm_core_check_feature(dev, DRIVER_LEGACY))
 204                 return -EOPNOTSUPP;
 205
 206         if (!drm_core_check_feature(dev, DRIVER_SG))
 207                 return -EOPNOTSUPP;
 208
 209         entry = dev->sg;
 210         dev->sg = NULL;
 211
 212         if (!entry || entry->handle != request->handle)
 213                 return -EINVAL;
 214
 215         DRM_DEBUG("virtual  = %p\n", entry->virtual);
 216
 217         drm_sg_cleanup(entry);
 218
 219         return 0;
 220 }