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   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 "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 = kmalloc(sizeof(*entry), GFP_KERNEL);
  87         if (!entry)
  88                 return -ENOMEM;
  89
  90         memset(entry, 0, sizeof(*entry));
  91         pages = (request->size + PAGE_SIZE - 1) / PAGE_SIZE;
  92         DRM_DEBUG("size=%ld pages=%ld\n", request->size, pages);
  93
  94         entry->pages = pages;
  95         entry->pagelist = kmalloc(pages * sizeof(*entry->pagelist), GFP_KERNEL);
  96         if (!entry->pagelist) {
  97                 kfree(entry);
  98                 return -ENOMEM;
  99         }
 100
 101         memset(entry->pagelist, 0, pages * sizeof(*entry->pagelist));
 102
 103         entry->busaddr = kmalloc(pages * sizeof(*entry->busaddr), GFP_KERNEL);
 104         if (!entry->busaddr) {
 105                 kfree(entry->pagelist);
 106                 kfree(entry);
 107                 return -ENOMEM;
 108         }
 109         memset((void *)entry->busaddr, 0, pages * sizeof(*entry->busaddr));
 110
 111         entry->virtual = drm_vmalloc_dma(pages << PAGE_SHIFT);
 112         if (!entry->virtual) {
 113                 kfree(entry->busaddr);
 114                 kfree(entry->pagelist);
 115                 kfree(entry);
 116                 return -ENOMEM;
 117         }
 118
 119         /* This also forces the mapping of COW pages, so our page list
 120          * will be valid.  Please don't remove it...
 121          */
 122         memset(entry->virtual, 0, pages << PAGE_SHIFT);
 123
 124         entry->handle = ScatterHandle((unsigned long)entry->virtual);
 125
 126         DRM_DEBUG("handle  = %08lx\n", entry->handle);
 127         DRM_DEBUG("virtual = %p\n", entry->virtual);
 128
 129         for (i = (unsigned long)entry->virtual, j = 0; j < pages;
 130              i += PAGE_SIZE, j++) {
 131                 entry->pagelist[j] = vmalloc_to_page((void *)i);
 132                 if (!entry->pagelist[j])
 133                         goto failed;
 134                 SetPageReserved(entry->pagelist[j]);
 135         }
 136
 137         request->handle = entry->handle;
 138
 139         dev->sg = entry;
 140
 141 #if DEBUG_SCATTER
 142         /* Verify that each page points to its virtual address, and vice
 143          * versa.
 144          */
 145         {
 146                 int error = 0;
 147
 148                 for (i = 0; i < pages; i++) {
 149                         unsigned long *tmp;
 150
 151                         tmp = page_address(entry->pagelist[i]);
 152                         for (j = 0;
 153                              j < PAGE_SIZE / sizeof(unsigned long);
 154                              j++, tmp++) {
 155                                 *tmp = 0xcafebabe;
 156                         }
 157                         tmp = (unsigned long *)((u8 *) entry->virtual +
 158                                                 (PAGE_SIZE * i));
 159                         for (j = 0;
 160                              j < PAGE_SIZE / sizeof(unsigned long);
 161                              j++, tmp++) {
 162                                 if (*tmp != 0xcafebabe && error == 0) {
 163                                         error = 1;
 164                                         DRM_ERROR("Scatter allocation error, "
 165                                                   "pagelist does not match "
 166                                                   "virtual mapping\n");
 167                                 }
 168                         }
 169                         tmp = page_address(entry->pagelist[i]);
 170                         for (j = 0;
 171                              j < PAGE_SIZE / sizeof(unsigned long);
 172                              j++, tmp++) {
 173                                 *tmp = 0;
 174                         }
 175                 }
 176                 if (error == 0)
 177                         DRM_ERROR("Scatter allocation matches pagelist\n");
 178         }
 179 #endif
 180
 181         return 0;
 182
 183       failed:
 184         drm_sg_cleanup(entry);
 185         return -ENOMEM;
 186 }
 187 EXPORT_SYMBOL(drm_sg_alloc);
 188
 189
 190 int drm_sg_alloc_ioctl(struct drm_device *dev, void *data,
 191                        struct drm_file *file_priv)
 192 {
 193         struct drm_scatter_gather *request = data;
 194
 195         return drm_sg_alloc(dev, request);
 196
 197 }
 198
 199 int drm_sg_free(struct drm_device *dev, void *data,
 200                 struct drm_file *file_priv)
 201 {
 202         struct drm_scatter_gather *request = data;
 203         struct drm_sg_mem *entry;
 204
 205         if (!drm_core_check_feature(dev, DRIVER_SG))
 206                 return -EINVAL;
 207
 208         entry = dev->sg;
 209         dev->sg = NULL;
 210
 211         if (!entry || entry->handle != request->handle)
 212                 return -EINVAL;
 213
 214         DRM_DEBUG("virtual  = %p\n", entry->virtual);
 215
 216         drm_sg_cleanup(entry);
 217
 218         return 0;
 219 }