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 static void *omap_gem_dmabuf_kmap(struct dma_buf *buffer,
  97                 unsigned long page_num)
  98 {
  99         struct drm_gem_object *obj = buffer->priv;
 100         struct page **pages;
 101         omap_gem_get_pages(obj, &pages, false);
 102         omap_gem_cpu_sync_page(obj, page_num);
 103         return kmap(pages[page_num]);
 104 }
 105
 106 static void omap_gem_dmabuf_kunmap(struct dma_buf *buffer,
 107                 unsigned long page_num, void *addr)
 108 {
 109         struct drm_gem_object *obj = buffer->priv;
 110         struct page **pages;
 111         omap_gem_get_pages(obj, &pages, false);
 112         kunmap(pages[page_num]);
 113 }
 114
 115 static int omap_gem_dmabuf_mmap(struct dma_buf *buffer,
 116                 struct vm_area_struct *vma)
 117 {
 118         struct drm_gem_object *obj = buffer->priv;
 119         int ret = 0;
 120
 121         ret = drm_gem_mmap_obj(obj, omap_gem_mmap_size(obj), vma);
 122         if (ret < 0)
 123                 return ret;
 124
 125         return omap_gem_mmap_obj(obj, vma);
 126 }
 127
 128 static const struct dma_buf_ops omap_dmabuf_ops = {
 129         .map_dma_buf = omap_gem_map_dma_buf,
 130         .unmap_dma_buf = omap_gem_unmap_dma_buf,
 131         .release = drm_gem_dmabuf_release,
 132         .begin_cpu_access = omap_gem_dmabuf_begin_cpu_access,
 133         .end_cpu_access = omap_gem_dmabuf_end_cpu_access,
 134         .map = omap_gem_dmabuf_kmap,
 135         .unmap = omap_gem_dmabuf_kunmap,
 136         .mmap = omap_gem_dmabuf_mmap,
 137 };
 138
 139 struct dma_buf *omap_gem_prime_export(struct drm_device *dev,
 140                 struct drm_gem_object *obj, int flags)
 141 {
 142         DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 143
 144         exp_info.ops = &omap_dmabuf_ops;
 145         exp_info.size = obj->size;
 146         exp_info.flags = flags;
 147         exp_info.priv = obj;
 148
 149         return drm_gem_dmabuf_export(dev, &exp_info);
 150 }
 151
 152 /* -----------------------------------------------------------------------------
 153  * DMABUF Import
 154  */
 155
 156 struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev,
 157                                              struct dma_buf *dma_buf)
 158 {
 159         struct dma_buf_attachment *attach;
 160         struct drm_gem_object *obj;
 161         struct sg_table *sgt;
 162         int ret;
 163
 164         if (dma_buf->ops == &omap_dmabuf_ops) {
 165                 obj = dma_buf->priv;
 166                 if (obj->dev == dev) {
 167                         /*
 168                          * Importing dmabuf exported from out own gem increases
 169                          * refcount on gem itself instead of f_count of dmabuf.
 170                          */
 171                         drm_gem_object_get(obj);
 172                         return obj;
 173                 }
 174         }
 175
 176         attach = dma_buf_attach(dma_buf, dev->dev);
 177         if (IS_ERR(attach))
 178                 return ERR_CAST(attach);
 179
 180         get_dma_buf(dma_buf);
 181
 182         sgt = dma_buf_map_attachment(attach, DMA_TO_DEVICE);
 183         if (IS_ERR(sgt)) {
 184                 ret = PTR_ERR(sgt);
 185                 goto fail_detach;
 186         }
 187
 188         obj = omap_gem_new_dmabuf(dev, dma_buf->size, sgt);
 189         if (IS_ERR(obj)) {
 190                 ret = PTR_ERR(obj);
 191                 goto fail_unmap;
 192         }
 193
 194         obj->import_attach = attach;
 195
 196         return obj;
 197
 198 fail_unmap:
 199         dma_buf_unmap_attachment(attach, sgt, DMA_TO_DEVICE);
 200 fail_detach:
 201         dma_buf_detach(dma_buf, attach);
 202         dma_buf_put(dma_buf);
 203
 204         return ERR_PTR(ret);
 205 }