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