drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c

   1 /*
   2  * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
   3  * Author: Rob Clark <rob.clark@linaro.org>
   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 #include <linux/highmem.h>
  20
  21 #include <drm/drm_prime.h>
  22
  23 #include "omap_drv.h"
  24
  25 /* -----------------------------------------------------------------------------
  26  * DMABUF Export
  27  */
  28
  29 static struct sg_table *omap_gem_map_dma_buf(
  30                 struct dma_buf_attachment *attachment,
  31                 enum dma_data_direction dir)
  32 {
  33         struct drm_gem_object *obj = attachment->dmabuf->priv;
  34         struct sg_table *sg;
  35         dma_addr_t dma_addr;
  36         int ret;
  37
  38         sg = kzalloc(sizeof(*sg), GFP_KERNEL);
  39         if (!sg)
  40                 return ERR_PTR(-ENOMEM);
  41
  42         /* camera, etc, need physically contiguous.. but we need a
  43          * better way to know this..
  44          */
  45         ret = omap_gem_pin(obj, &dma_addr);
  46         if (ret)
  47                 goto out;
  48
  49         ret = sg_alloc_table(sg, 1, GFP_KERNEL);
  50         if (ret)
  51                 goto out;
  52
  53         sg_init_table(sg->sgl, 1);
  54         sg_dma_len(sg->sgl) = obj->size;
  55         sg_set_page(sg->sgl, pfn_to_page(PFN_DOWN(dma_addr)), obj->size, 0);
  56         sg_dma_address(sg->sgl) = dma_addr;
  57
  58         /* this must be after omap_gem_pin() to ensure we have pages attached */
  59         omap_gem_dma_sync_buffer(obj, dir);
  60
  61         return sg;
  62 out:
  63         kfree(sg);
  64         return ERR_PTR(ret);
  65 }
  66
  67 static void omap_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
  68                 struct sg_table *sg, enum dma_data_direction dir)
  69 {
  70         struct drm_gem_object *obj = attachment->dmabuf->priv;
  71         omap_gem_unpin(obj);
  72         sg_free_table(sg);
  73         kfree(sg);
  74 }
  75
  76 static int omap_gem_dmabuf_begin_cpu_access(struct dma_buf *buffer,
  77                 enum dma_data_direction dir)
  78 {
  79         struct drm_gem_object *obj = buffer->priv;
  80         struct page **pages;
  81         if (omap_gem_flags(obj) & OMAP_BO_TILED) {
  82                 /* TODO we would need to pin at least part of the buffer to
  83                  * get de-tiled view.  For now just reject it.
  84                  */
  85                 return -ENOMEM;
  86         }
  87         /* make sure we have the pages: */
  88         return omap_gem_get_pages(obj, &pages, true);
  89 }
  90
  91 static int omap_gem_dmabuf_end_cpu_access(struct dma_buf *buffer,
  92                                           enum dma_data_direction dir)
  93 {
  94         struct drm_gem_object *obj = buffer->priv;
  95         omap_gem_put_pages(obj);
  96         return 0;
  97 }
  98
  99 static void *omap_gem_dmabuf_kmap(struct dma_buf *buffer,
 100                 unsigned long page_num)
 101 {
 102         struct drm_gem_object *obj = buffer->priv;
 103         struct page **pages;
 104         omap_gem_get_pages(obj, &pages, false);
 105         omap_gem_cpu_sync_page(obj, page_num);
 106         return kmap(pages[page_num]);
 107 }
 108
 109 static void omap_gem_dmabuf_kunmap(struct dma_buf *buffer,
 110                 unsigned long page_num, void *addr)
 111 {
 112         struct drm_gem_object *obj = buffer->priv;
 113         struct page **pages;
 114         omap_gem_get_pages(obj, &pages, false);
 115         kunmap(pages[page_num]);
 116 }
 117
 118 static int omap_gem_dmabuf_mmap(struct dma_buf *buffer,
 119                 struct vm_area_struct *vma)
 120 {
 121         struct drm_gem_object *obj = buffer->priv;
 122         int ret = 0;
 123
 124         ret = drm_gem_mmap_obj(obj, omap_gem_mmap_size(obj), vma);
 125         if (ret < 0)
 126                 return ret;
 127
 128         return omap_gem_mmap_obj(obj, vma);
 129 }
 130
 131 static const struct dma_buf_ops omap_dmabuf_ops = {
 132         .map_dma_buf = omap_gem_map_dma_buf,
 133         .unmap_dma_buf = omap_gem_unmap_dma_buf,
 134         .release = drm_gem_dmabuf_release,
 135         .begin_cpu_access = omap_gem_dmabuf_begin_cpu_access,
 136         .end_cpu_access = omap_gem_dmabuf_end_cpu_access,
 137         .map = omap_gem_dmabuf_kmap,
 138         .unmap = omap_gem_dmabuf_kunmap,
 139         .mmap = omap_gem_dmabuf_mmap,
 140 };
 141
 142 struct dma_buf *omap_gem_prime_export(struct drm_gem_object *obj, int flags)
 143 {
 144         DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 145
 146         exp_info.ops = &omap_dmabuf_ops;
 147         exp_info.size = obj->size;
 148         exp_info.flags = flags;
 149         exp_info.priv = obj;
 150
 151         return drm_gem_dmabuf_export(obj->dev, &exp_info);
 152 }
 153
 154 /* -----------------------------------------------------------------------------
 155  * DMABUF Import
 156  */
 157
 158 struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev,
 159                                              struct dma_buf *dma_buf)
 160 {
 161         struct dma_buf_attachment *attach;
 162         struct drm_gem_object *obj;
 163         struct sg_table *sgt;
 164         int ret;
 165
 166         if (dma_buf->ops == &omap_dmabuf_ops) {
 167                 obj = dma_buf->priv;
 168                 if (obj->dev == dev) {
 169                         /*
 170                          * Importing dmabuf exported from out own gem increases
 171                          * refcount on gem itself instead of f_count of dmabuf.
 172                          */
 173                         drm_gem_object_get(obj);
 174                         return obj;
 175                 }
 176         }
 177
 178         attach = dma_buf_attach(dma_buf, dev->dev);
 179         if (IS_ERR(attach))
 180                 return ERR_CAST(attach);
 181
 182         get_dma_buf(dma_buf);
 183
 184         sgt = dma_buf_map_attachment(attach, DMA_TO_DEVICE);
 185         if (IS_ERR(sgt)) {
 186                 ret = PTR_ERR(sgt);
 187                 goto fail_detach;
 188         }
 189
 190         obj = omap_gem_new_dmabuf(dev, dma_buf->size, sgt);
 191         if (IS_ERR(obj)) {
 192                 ret = PTR_ERR(obj);
 193                 goto fail_unmap;
 194         }
 195
 196         obj->import_attach = attach;
 197
 198         return obj;
 199
 200 fail_unmap:
 201         dma_buf_unmap_attachment(attach, sgt, DMA_TO_DEVICE);
 202 fail_detach:
 203         dma_buf_detach(dma_buf, attach);
 204         dma_buf_put(dma_buf);
 205
 206         return ERR_PTR(ret);
 207 }