drivers/gpu/drm/vmwgfx/vmwgfx_gmr.c

   1 /**************************************************************************
   2  *
   3  * Copyright © 2009 VMware, Inc., Palo Alto, CA., USA
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  21  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
  22  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  23  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  24  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28 #include "vmwgfx_drv.h"
  29 #include "drmP.h"
  30 #include "ttm/ttm_bo_driver.h"
  31
  32 /**
  33  * FIXME: Adjust to the ttm lowmem / highmem storage to minimize
  34  * the number of used descriptors.
  35  */
  36
  37 static int vmw_gmr_build_descriptors(struct list_head *desc_pages,
  38                                      struct page *pages[],
  39                                      unsigned long num_pages)
  40 {
  41         struct page *page, *next;
  42         struct svga_guest_mem_descriptor *page_virtual = NULL;
  43         struct svga_guest_mem_descriptor *desc_virtual = NULL;
  44         unsigned int desc_per_page;
  45         unsigned long prev_pfn;
  46         unsigned long pfn;
  47         int ret;
  48
  49         desc_per_page = PAGE_SIZE /
  50             sizeof(struct svga_guest_mem_descriptor) - 1;
  51
  52         while (likely(num_pages != 0)) {
  53                 page = alloc_page(__GFP_HIGHMEM);
  54                 if (unlikely(page == NULL)) {
  55                         ret = -ENOMEM;
  56                         goto out_err;
  57                 }
  58
  59                 list_add_tail(&page->lru, desc_pages);
  60
  61                 /*
  62                  * Point previous page terminating descriptor to this
  63                  * page before unmapping it.
  64                  */
  65
  66                 if (likely(page_virtual != NULL)) {
  67                         desc_virtual->ppn = page_to_pfn(page);
  68                         kunmap_atomic(page_virtual, KM_USER0);
  69                 }
  70
  71                 page_virtual = kmap_atomic(page, KM_USER0);
  72                 desc_virtual = page_virtual - 1;
  73                 prev_pfn = ~(0UL);
  74
  75                 while (likely(num_pages != 0)) {
  76                         pfn = page_to_pfn(*pages);
  77
  78                         if (pfn != prev_pfn + 1) {
  79
  80                                 if (desc_virtual - page_virtual ==
  81                                     desc_per_page - 1)
  82                                         break;
  83
  84                                 (++desc_virtual)->ppn = cpu_to_le32(pfn);
  85                                 desc_virtual->num_pages = cpu_to_le32(1);
  86                         } else {
  87                                 uint32_t tmp =
  88                                     le32_to_cpu(desc_virtual->num_pages);
  89                                 desc_virtual->num_pages = cpu_to_le32(tmp + 1);
  90                         }
  91                         prev_pfn = pfn;
  92                         --num_pages;
  93                         ++pages;
  94                 }
  95
  96                 (++desc_virtual)->ppn = cpu_to_le32(0);
  97                 desc_virtual->num_pages = cpu_to_le32(0);
  98         }
  99
 100         if (likely(page_virtual != NULL))
 101                 kunmap_atomic(page_virtual, KM_USER0);
 102
 103         return 0;
 104 out_err:
 105         list_for_each_entry_safe(page, next, desc_pages, lru) {
 106                 list_del_init(&page->lru);
 107                 __free_page(page);
 108         }
 109         return ret;
 110 }
 111
 112 static inline void vmw_gmr_free_descriptors(struct list_head *desc_pages)
 113 {
 114         struct page *page, *next;
 115
 116         list_for_each_entry_safe(page, next, desc_pages, lru) {
 117                 list_del_init(&page->lru);
 118                 __free_page(page);
 119         }
 120 }
 121
 122 static void vmw_gmr_fire_descriptors(struct vmw_private *dev_priv,
 123                                      int gmr_id, struct list_head *desc_pages)
 124 {
 125         struct page *page;
 126
 127         if (unlikely(list_empty(desc_pages)))
 128                 return;
 129
 130         page = list_entry(desc_pages->next, struct page, lru);
 131
 132         mutex_lock(&dev_priv->hw_mutex);
 133
 134         vmw_write(dev_priv, SVGA_REG_GMR_ID, gmr_id);
 135         wmb();
 136         vmw_write(dev_priv, SVGA_REG_GMR_DESCRIPTOR, page_to_pfn(page));
 137         mb();
 138
 139         mutex_unlock(&dev_priv->hw_mutex);
 140
 141 }
 142
 143 /**
 144  * FIXME: Adjust to the ttm lowmem / highmem storage to minimize
 145  * the number of used descriptors.
 146  */
 147
 148 static unsigned long vmw_gmr_count_descriptors(struct page *pages[],
 149                                                unsigned long num_pages)
 150 {
 151         unsigned long prev_pfn = ~(0UL);
 152         unsigned long pfn;
 153         unsigned long descriptors = 0;
 154
 155         while (num_pages--) {
 156                 pfn = page_to_pfn(*pages++);
 157                 if (prev_pfn + 1 != pfn)
 158                         ++descriptors;
 159                 prev_pfn = pfn;
 160         }
 161
 162         return descriptors;
 163 }
 164
 165 int vmw_gmr_bind(struct vmw_private *dev_priv,
 166                  struct ttm_buffer_object *bo)
 167 {
 168         struct ttm_tt *ttm = bo->ttm;
 169         unsigned long descriptors;
 170         int ret;
 171         uint32_t id;
 172         struct list_head desc_pages;
 173
 174         if (!(dev_priv->capabilities & SVGA_CAP_GMR))
 175                 return -EINVAL;
 176
 177         ret = ttm_tt_populate(ttm);
 178         if (unlikely(ret != 0))
 179                 return ret;
 180
 181         descriptors = vmw_gmr_count_descriptors(ttm->pages, ttm->num_pages);
 182         if (unlikely(descriptors > dev_priv->max_gmr_descriptors))
 183                 return -EINVAL;
 184
 185         INIT_LIST_HEAD(&desc_pages);
 186         ret = vmw_gmr_build_descriptors(&desc_pages, ttm->pages,
 187                                         ttm->num_pages);
 188         if (unlikely(ret != 0))
 189                 return ret;
 190
 191         ret = vmw_gmr_id_alloc(dev_priv, &id);
 192         if (unlikely(ret != 0))
 193                 goto out_no_id;
 194
 195         vmw_gmr_fire_descriptors(dev_priv, id, &desc_pages);
 196         vmw_gmr_free_descriptors(&desc_pages);
 197         vmw_dmabuf_set_gmr(bo, id);
 198         return 0;
 199
 200 out_no_id:
 201         vmw_gmr_free_descriptors(&desc_pages);
 202         return ret;
 203 }
 204
 205 void vmw_gmr_unbind(struct vmw_private *dev_priv, int gmr_id)
 206 {
 207         mutex_lock(&dev_priv->hw_mutex);
 208         vmw_write(dev_priv, SVGA_REG_GMR_ID, gmr_id);
 209         wmb();
 210         vmw_write(dev_priv, SVGA_REG_GMR_DESCRIPTOR, 0);
 211         mb();
 212         mutex_unlock(&dev_priv->hw_mutex);
 213 }