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