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 paddr;
  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_get_paddr(obj, &paddr, true);
  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(paddr)), obj->size, 0);
  55         sg_dma_address(sg->sgl) = paddr;
  56
  57         /* this should be after _get_paddr() to ensure we have pages attached */
  58         omap_gem_dma_sync(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_put_paddr(obj);
  71         sg_free_table(sg);
  72         kfree(sg);
  73 }
  74
  75 static void omap_gem_dmabuf_release(struct dma_buf *buffer)
  76 {
  77         struct drm_gem_object *obj = buffer->priv;
  78         /* release reference that was taken when dmabuf was exported
  79          * in omap_gem_prime_set()..
  80          */
  81         drm_gem_object_unreference_unlocked(obj);
  82 }
  83
  84
  85 static int omap_gem_dmabuf_begin_cpu_access(struct dma_buf *buffer,
  86                 enum dma_data_direction dir)
  87 {
  88         struct drm_gem_object *obj = buffer->priv;
  89         struct page **pages;
  90         if (omap_gem_flags(obj) & OMAP_BO_TILED) {
  91                 /* TODO we would need to pin at least part of the buffer to
  92                  * get de-tiled view.  For now just reject it.
  93                  */
  94                 return -ENOMEM;
  95         }
  96         /* make sure we have the pages: */
  97         return omap_gem_get_pages(obj, &pages, true);
  98 }
  99
 100 static int omap_gem_dmabuf_end_cpu_access(struct dma_buf *buffer,
 101                                           enum dma_data_direction dir)
 102 {
 103         struct drm_gem_object *obj = buffer->priv;
 104         omap_gem_put_pages(obj);
 105         return 0;
 106 }
 107
 108
 109 static void *omap_gem_dmabuf_kmap_atomic(struct dma_buf *buffer,
 110                 unsigned long page_num)
 111 {
 112         struct drm_gem_object *obj = buffer->priv;
 113         struct page **pages;
 114         omap_gem_get_pages(obj, &pages, false);
 115         omap_gem_cpu_sync(obj, page_num);
 116         return kmap_atomic(pages[page_num]);
 117 }
 118
 119 static void omap_gem_dmabuf_kunmap_atomic(struct dma_buf *buffer,
 120                 unsigned long page_num, void *addr)
 121 {
 122         kunmap_atomic(addr);
 123 }
 124
 125 static void *omap_gem_dmabuf_kmap(struct dma_buf *buffer,
 126                 unsigned long page_num)
 127 {
 128         struct drm_gem_object *obj = buffer->priv;
 129         struct page **pages;
 130         omap_gem_get_pages(obj, &pages, false);
 131         omap_gem_cpu_sync(obj, page_num);
 132         return kmap(pages[page_num]);
 133 }
 134
 135 static void omap_gem_dmabuf_kunmap(struct dma_buf *buffer,
 136                 unsigned long page_num, void *addr)
 137 {
 138         struct drm_gem_object *obj = buffer->priv;
 139         struct page **pages;
 140         omap_gem_get_pages(obj, &pages, false);
 141         kunmap(pages[page_num]);
 142 }
 143
 144 static int omap_gem_dmabuf_mmap(struct dma_buf *buffer,
 145                 struct vm_area_struct *vma)
 146 {
 147         struct drm_gem_object *obj = buffer->priv;
 148         int ret = 0;
 149
 150         if (WARN_ON(!obj->filp))
 151                 return -EINVAL;
 152
 153         ret = drm_gem_mmap_obj(obj, omap_gem_mmap_size(obj), vma);
 154         if (ret < 0)
 155                 return ret;
 156
 157         return omap_gem_mmap_obj(obj, vma);
 158 }
 159
 160 static struct dma_buf_ops omap_dmabuf_ops = {
 161         .map_dma_buf = omap_gem_map_dma_buf,
 162         .unmap_dma_buf = omap_gem_unmap_dma_buf,
 163         .release = omap_gem_dmabuf_release,
 164         .begin_cpu_access = omap_gem_dmabuf_begin_cpu_access,
 165         .end_cpu_access = omap_gem_dmabuf_end_cpu_access,
 166         .kmap_atomic = omap_gem_dmabuf_kmap_atomic,
 167         .kunmap_atomic = omap_gem_dmabuf_kunmap_atomic,
 168         .kmap = omap_gem_dmabuf_kmap,
 169         .kunmap = omap_gem_dmabuf_kunmap,
 170         .mmap = omap_gem_dmabuf_mmap,
 171 };
 172
 173 struct dma_buf *omap_gem_prime_export(struct drm_device *dev,
 174                 struct drm_gem_object *obj, int flags)
 175 {
 176         DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 177
 178         exp_info.ops = &omap_dmabuf_ops;
 179         exp_info.size = obj->size;
 180         exp_info.flags = flags;
 181         exp_info.priv = obj;
 182
 183         return dma_buf_export(&exp_info);
 184 }
 185
 186 /* -----------------------------------------------------------------------------
 187  * DMABUF Import
 188  */
 189
 190 struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev,
 191                                              struct dma_buf *dma_buf)
 192 {
 193         struct dma_buf_attachment *attach;
 194         struct drm_gem_object *obj;
 195         struct sg_table *sgt;
 196         int ret;
 197
 198         if (dma_buf->ops == &omap_dmabuf_ops) {
 199                 obj = dma_buf->priv;
 200                 if (obj->dev == dev) {
 201                         /*
 202                          * Importing dmabuf exported from out own gem increases
 203                          * refcount on gem itself instead of f_count of dmabuf.
 204                          */
 205                         drm_gem_object_reference(obj);
 206                         return obj;
 207                 }
 208         }
 209
 210         attach = dma_buf_attach(dma_buf, dev->dev);
 211         if (IS_ERR(attach))
 212                 return ERR_CAST(attach);
 213
 214         get_dma_buf(dma_buf);
 215
 216         sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
 217         if (IS_ERR(sgt)) {
 218                 ret = PTR_ERR(sgt);
 219                 goto fail_detach;
 220         }
 221
 222         obj = omap_gem_new_dmabuf(dev, dma_buf->size, sgt);
 223         if (IS_ERR(obj)) {
 224                 ret = PTR_ERR(obj);
 225                 goto fail_unmap;
 226         }
 227
 228         obj->import_attach = attach;
 229
 230         return obj;
 231
 232 fail_unmap:
 233         dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
 234 fail_detach:
 235         dma_buf_detach(dma_buf, attach);
 236         dma_buf_put(dma_buf);
 237
 238         return ERR_PTR(ret);
 239 }