drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c

   1 /*
   2  * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
   3  * Author: Rob Clark <[email protected]>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 as published by
   7  * the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <linux/dma-buf.h>
  19
  20 #include "omap_drv.h"
  21
  22 /* -----------------------------------------------------------------------------
  23  * DMABUF Export
  24  */
  25
  26 static struct sg_table *omap_gem_map_dma_buf(
  27                 struct dma_buf_attachment *attachment,
  28                 enum dma_data_direction dir)
  29 {
  30         struct drm_gem_object *obj = attachment->dmabuf->priv;
  31         struct sg_table *sg;
  32         dma_addr_t dma_addr;
  33         int ret;
  34
  35         sg = kzalloc(sizeof(*sg), GFP_KERNEL);
  36         if (!sg)
  37                 return ERR_PTR(-ENOMEM);
  38
  39         /* camera, etc, need physically contiguous.. but we need a
  40          * better way to know this..
  41          */
  42         ret = omap_gem_pin(obj, &dma_addr);
  43         if (ret)
  44                 goto out;
  45
  46         ret = sg_alloc_table(sg, 1, GFP_KERNEL);
  47         if (ret)
  48                 goto out;
  49
  50         sg_init_table(sg->sgl, 1);
  51         sg_dma_len(sg->sgl) = obj->size;
  52         sg_set_page(sg->sgl, pfn_to_page(PFN_DOWN(dma_addr)), obj->size, 0);
  53         sg_dma_address(sg->sgl) = dma_addr;
  54
  55         /* this must be after omap_gem_pin() to ensure we have pages attached */
  56         omap_gem_dma_sync_buffer(obj, dir);
  57
  58         return sg;
  59 out:
  60         kfree(sg);
  61         return ERR_PTR(ret);
  62 }
  63
  64 static void omap_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
  65                 struct sg_table *sg, enum dma_data_direction dir)
  66 {
  67         struct drm_gem_object *obj = attachment->dmabuf->priv;
  68         omap_gem_unpin(obj);
  69         sg_free_table(sg);
  70         kfree(sg);
  71 }
  72
  73 static int omap_gem_dmabuf_begin_cpu_access(struct dma_buf *buffer,
  74                 enum dma_data_direction dir)
  75 {
  76         struct drm_gem_object *obj = buffer->priv;
  77         struct page **pages;
  78         if (omap_gem_flags(obj) & OMAP_BO_TILED) {
  79                 /* TODO we would need to pin at least part of the buffer to
  80                  * get de-tiled view.  For now just reject it.
  81                  */
  82                 return -ENOMEM;
  83         }
  84         /* make sure we have the pages: */
  85         return omap_gem_get_pages(obj, &pages, true);
  86 }
  87
  88 static int omap_gem_dmabuf_end_cpu_access(struct dma_buf *buffer,
  89                                           enum dma_data_direction dir)
  90 {
  91         struct drm_gem_object *obj = buffer->priv;
  92         omap_gem_put_pages(obj);
  93         return 0;
  94 }
  95
  96
  97 static void *omap_gem_dmabuf_kmap_atomic(struct dma_buf *buffer,
  98                 unsigned long page_num)
  99 {
 100         struct drm_gem_object *obj = buffer->priv;
 101         struct page **pages;
 102         omap_gem_get_pages(obj, &pages, false);
 103         omap_gem_cpu_sync_page(obj, page_num);
 104         return kmap_atomic(pages[page_num]);
 105 }
 106
 107 static void omap_gem_dmabuf_kunmap_atomic(struct dma_buf *buffer,
 108                 unsigned long page_num, void *addr)
 109 {
 110         kunmap_atomic(addr);
 111 }
 112
 113 static void *omap_gem_dmabuf_kmap(struct dma_buf *buffer,
 114                 unsigned long page_num)
 115 {
 116         struct drm_gem_object *obj = buffer->priv;
 117         struct page **pages;
 118         omap_gem_get_pages(obj, &pages, false);
 119         omap_gem_cpu_sync_page(obj, page_num);
 120         return kmap(pages[page_num]);
 121 }
 122
 123 static void omap_gem_dmabuf_kunmap(struct dma_buf *buffer,
 124                 unsigned long page_num, void *addr)
 125 {
 126         struct drm_gem_object *obj = buffer->priv;
 127         struct page **pages;
 128         omap_gem_get_pages(obj, &pages, false);
 129         kunmap(pages[page_num]);
 130 }
 131
 132 static int omap_gem_dmabuf_mmap(struct dma_buf *buffer,
 133                 struct vm_area_struct *vma)
 134 {
 135         struct drm_gem_object *obj = buffer->priv;
 136         int ret = 0;
 137
 138         ret = drm_gem_mmap_obj(obj, omap_gem_mmap_size(obj), vma);
 139         if (ret < 0)
 140                 return ret;
 141
 142         return omap_gem_mmap_obj(obj, vma);
 143 }
 144
 145 static const struct dma_buf_ops omap_dmabuf_ops = {
 146         .map_dma_buf = omap_gem_map_dma_buf,
 147         .unmap_dma_buf = omap_gem_unmap_dma_buf,
 148         .release = drm_gem_dmabuf_release,
 149         .begin_cpu_access = omap_gem_dmabuf_begin_cpu_access,
 150         .end_cpu_access = omap_gem_dmabuf_end_cpu_access,
 151         .map = omap_gem_dmabuf_kmap,
 152         .unmap = omap_gem_dmabuf_kunmap,
 153         .mmap = omap_gem_dmabuf_mmap,
 154 };
 155
 156 struct dma_buf *omap_gem_prime_export(struct drm_device *dev,
 157                 struct drm_gem_object *obj, int flags)
 158 {
 159         DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 160
 161         exp_info.ops = &omap_dmabuf_ops;
 162         exp_info.size = obj->size;
 163         exp_info.flags = flags;
 164         exp_info.priv = obj;
 165
 166         return drm_gem_dmabuf_export(dev, &exp_info);
 167 }
 168
 169 /* -----------------------------------------------------------------------------
 170  * DMABUF Import
 171  */
 172
 173 struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev,
 174                                              struct dma_buf *dma_buf)
 175 {
 176         struct dma_buf_attachment *attach;
 177         struct drm_gem_object *obj;
 178         struct sg_table *sgt;
 179         int ret;
 180
 181         if (dma_buf->ops == &omap_dmabuf_ops) {
 182                 obj = dma_buf->priv;
 183                 if (obj->dev == dev) {
 184                         /*
 185                          * Importing dmabuf exported from out own gem increases
 186                          * refcount on gem itself instead of f_count of dmabuf.
 187                          */
 188                         drm_gem_object_reference(obj);
 189                         return obj;
 190                 }
 191         }
 192
 193         attach = dma_buf_attach(dma_buf, dev->dev);
 194         if (IS_ERR(attach))
 195                 return ERR_CAST(attach);
 196
 197         get_dma_buf(dma_buf);
 198
 199         sgt = dma_buf_map_attachment(attach, DMA_TO_DEVICE);
 200         if (IS_ERR(sgt)) {
 201                 ret = PTR_ERR(sgt);
 202                 goto fail_detach;
 203         }
 204
 205         obj = omap_gem_new_dmabuf(dev, dma_buf->size, sgt);
 206         if (IS_ERR(obj)) {
 207                 ret = PTR_ERR(obj);
 208                 goto fail_unmap;
 209         }
 210
 211         obj->import_attach = attach;
 212
 213         return obj;
 214
 215 fail_unmap:
 216         dma_buf_unmap_attachment(attach, sgt, DMA_TO_DEVICE);
 217 fail_detach:
 218         dma_buf_detach(dma_buf, attach);
 219         dma_buf_put(dma_buf);
 220
 221         return ERR_PTR(ret);
 222 }