drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c

   1 /*
   2  * drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c
   3  *
   4  * Copyright (C) 2011 Texas Instruments
   5  * Author: Rob Clark <rob.clark@linaro.org>
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License version 2 as published by
   9  * the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14  * more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along with
  17  * this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <linux/dma-buf.h>
  21
  22 #include "omap_drv.h"
  23
  24 /* -----------------------------------------------------------------------------
  25  * DMABUF Export
  26  */
  27
  28 static struct sg_table *omap_gem_map_dma_buf(
  29                 struct dma_buf_attachment *attachment,
  30                 enum dma_data_direction dir)
  31 {
  32         struct drm_gem_object *obj = attachment->dmabuf->priv;
  33         struct sg_table *sg;
  34         dma_addr_t dma_addr;
  35         int ret;
  36
  37         sg = kzalloc(sizeof(*sg), GFP_KERNEL);
  38         if (!sg)
  39                 return ERR_PTR(-ENOMEM);
  40
  41         /* camera, etc, need physically contiguous.. but we need a
  42          * better way to know this..
  43          */
  44         ret = omap_gem_pin(obj, &dma_addr);
  45         if (ret)
  46                 goto out;
  47
  48         ret = sg_alloc_table(sg, 1, GFP_KERNEL);
  49         if (ret)
  50                 goto out;
  51
  52         sg_init_table(sg->sgl, 1);
  53         sg_dma_len(sg->sgl) = obj->size;
  54         sg_set_page(sg->sgl, pfn_to_page(PFN_DOWN(dma_addr)), obj->size, 0);
  55         sg_dma_address(sg->sgl) = dma_addr;
  56
  57         /* this must be after omap_gem_pin() to ensure we have pages attached */
  58         omap_gem_dma_sync_buffer(obj, dir);
  59
  60         return sg;
  61 out:
  62         kfree(sg);
  63         return ERR_PTR(ret);
  64 }
  65
  66 static void omap_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
  67                 struct sg_table *sg, enum dma_data_direction dir)
  68 {
  69         struct drm_gem_object *obj = attachment->dmabuf->priv;
  70         omap_gem_unpin(obj);
  71         sg_free_table(sg);
  72         kfree(sg);
  73 }
  74
  75 static int omap_gem_dmabuf_begin_cpu_access(struct dma_buf *buffer,
  76                 enum dma_data_direction dir)
  77 {
  78         struct drm_gem_object *obj = buffer->priv;
  79         struct page **pages;
  80         if (omap_gem_flags(obj) & OMAP_BO_TILED) {
  81                 /* TODO we would need to pin at least part of the buffer to
  82                  * get de-tiled view.  For now just reject it.
  83                  */
  84                 return -ENOMEM;
  85         }
  86         /* make sure we have the pages: */
  87         return omap_gem_get_pages(obj, &pages, true);
  88 }
  89
  90 static int omap_gem_dmabuf_end_cpu_access(struct dma_buf *buffer,
  91                                           enum dma_data_direction dir)
  92 {
  93         struct drm_gem_object *obj = buffer->priv;
  94         omap_gem_put_pages(obj);
  95         return 0;
  96 }
  97
  98
  99 static void *omap_gem_dmabuf_kmap_atomic(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_atomic(pages[page_num]);
 107 }
 108
 109 static void omap_gem_dmabuf_kunmap_atomic(struct dma_buf *buffer,
 110                 unsigned long page_num, void *addr)
 111 {
 112         kunmap_atomic(addr);
 113 }
 114
 115 static void *omap_gem_dmabuf_kmap(struct dma_buf *buffer,
 116                 unsigned long page_num)
 117 {
 118         struct drm_gem_object *obj = buffer->priv;
 119         struct page **pages;
 120         omap_gem_get_pages(obj, &pages, false);
 121         omap_gem_cpu_sync_page(obj, page_num);
 122         return kmap(pages[page_num]);
 123 }
 124
 125 static void omap_gem_dmabuf_kunmap(struct dma_buf *buffer,
 126                 unsigned long page_num, void *addr)
 127 {
 128         struct drm_gem_object *obj = buffer->priv;
 129         struct page **pages;
 130         omap_gem_get_pages(obj, &pages, false);
 131         kunmap(pages[page_num]);
 132 }
 133
 134 static int omap_gem_dmabuf_mmap(struct dma_buf *buffer,
 135                 struct vm_area_struct *vma)
 136 {
 137         struct drm_gem_object *obj = buffer->priv;
 138         int ret = 0;
 139
 140         ret = drm_gem_mmap_obj(obj, omap_gem_mmap_size(obj), vma);
 141         if (ret < 0)
 142                 return ret;
 143
 144         return omap_gem_mmap_obj(obj, vma);
 145 }
 146
 147 static struct dma_buf_ops omap_dmabuf_ops = {
 148         .map_dma_buf = omap_gem_map_dma_buf,
 149         .unmap_dma_buf = omap_gem_unmap_dma_buf,
 150         .release = drm_gem_dmabuf_release,
 151         .begin_cpu_access = omap_gem_dmabuf_begin_cpu_access,
 152         .end_cpu_access = omap_gem_dmabuf_end_cpu_access,
 153         .map_atomic = omap_gem_dmabuf_kmap_atomic,
 154         .unmap_atomic = omap_gem_dmabuf_kunmap_atomic,
 155         .map = omap_gem_dmabuf_kmap,
 156         .unmap = omap_gem_dmabuf_kunmap,
 157         .mmap = omap_gem_dmabuf_mmap,
 158 };
 159
 160 struct dma_buf *omap_gem_prime_export(struct drm_device *dev,
 161                 struct drm_gem_object *obj, int flags)
 162 {
 163         DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 164
 165         exp_info.ops = &omap_dmabuf_ops;
 166         exp_info.size = obj->size;
 167         exp_info.flags = flags;
 168         exp_info.priv = obj;
 169
 170         return drm_gem_dmabuf_export(dev, &exp_info);
 171 }
 172
 173 /* -----------------------------------------------------------------------------
 174  * DMABUF Import
 175  */
 176
 177 struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev,
 178                                              struct dma_buf *dma_buf)
 179 {
 180         struct dma_buf_attachment *attach;
 181         struct drm_gem_object *obj;
 182         struct sg_table *sgt;
 183         int ret;
 184
 185         if (dma_buf->ops == &omap_dmabuf_ops) {
 186                 obj = dma_buf->priv;
 187                 if (obj->dev == dev) {
 188                         /*
 189                          * Importing dmabuf exported from out own gem increases
 190                          * refcount on gem itself instead of f_count of dmabuf.
 191                          */
 192                         drm_gem_object_reference(obj);
 193                         return obj;
 194                 }
 195         }
 196
 197         attach = dma_buf_attach(dma_buf, dev->dev);
 198         if (IS_ERR(attach))
 199                 return ERR_CAST(attach);
 200
 201         get_dma_buf(dma_buf);
 202
 203         sgt = dma_buf_map_attachment(attach, DMA_TO_DEVICE);
 204         if (IS_ERR(sgt)) {
 205                 ret = PTR_ERR(sgt);
 206                 goto fail_detach;
 207         }
 208
 209         obj = omap_gem_new_dmabuf(dev, dma_buf->size, sgt);
 210         if (IS_ERR(obj)) {
 211                 ret = PTR_ERR(obj);
 212                 goto fail_unmap;
 213         }
 214
 215         obj->import_attach = attach;
 216
 217         return obj;
 218
 219 fail_unmap:
 220         dma_buf_unmap_attachment(attach, sgt, DMA_TO_DEVICE);
 221 fail_detach:
 222         dma_buf_detach(dma_buf, attach);
 223         dma_buf_put(dma_buf);
 224
 225         return ERR_PTR(ret);
 226 }