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 void 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 }
 106
 107
 108 static void *omap_gem_dmabuf_kmap_atomic(struct dma_buf *buffer,
 109                 unsigned long page_num)
 110 {
 111         struct drm_gem_object *obj = buffer->priv;
 112         struct page **pages;
 113         omap_gem_get_pages(obj, &pages, false);
 114         omap_gem_cpu_sync(obj, page_num);
 115         return kmap_atomic(pages[page_num]);
 116 }
 117
 118 static void omap_gem_dmabuf_kunmap_atomic(struct dma_buf *buffer,
 119                 unsigned long page_num, void *addr)
 120 {
 121         kunmap_atomic(addr);
 122 }
 123
 124 static void *omap_gem_dmabuf_kmap(struct dma_buf *buffer,
 125                 unsigned long page_num)
 126 {
 127         struct drm_gem_object *obj = buffer->priv;
 128         struct page **pages;
 129         omap_gem_get_pages(obj, &pages, false);
 130         omap_gem_cpu_sync(obj, page_num);
 131         return kmap(pages[page_num]);
 132 }
 133
 134 static void omap_gem_dmabuf_kunmap(struct dma_buf *buffer,
 135                 unsigned long page_num, void *addr)
 136 {
 137         struct drm_gem_object *obj = buffer->priv;
 138         struct page **pages;
 139         omap_gem_get_pages(obj, &pages, false);
 140         kunmap(pages[page_num]);
 141 }
 142
 143 static int omap_gem_dmabuf_mmap(struct dma_buf *buffer,
 144                 struct vm_area_struct *vma)
 145 {
 146         struct drm_gem_object *obj = buffer->priv;
 147         int ret = 0;
 148
 149         if (WARN_ON(!obj->filp))
 150                 return -EINVAL;
 151
 152         ret = drm_gem_mmap_obj(obj, omap_gem_mmap_size(obj), vma);
 153         if (ret < 0)
 154                 return ret;
 155
 156         return omap_gem_mmap_obj(obj, vma);
 157 }
 158
 159 static struct dma_buf_ops omap_dmabuf_ops = {
 160         .map_dma_buf = omap_gem_map_dma_buf,
 161         .unmap_dma_buf = omap_gem_unmap_dma_buf,
 162         .release = omap_gem_dmabuf_release,
 163         .begin_cpu_access = omap_gem_dmabuf_begin_cpu_access,
 164         .end_cpu_access = omap_gem_dmabuf_end_cpu_access,
 165         .kmap_atomic = omap_gem_dmabuf_kmap_atomic,
 166         .kunmap_atomic = omap_gem_dmabuf_kunmap_atomic,
 167         .kmap = omap_gem_dmabuf_kmap,
 168         .kunmap = omap_gem_dmabuf_kunmap,
 169         .mmap = omap_gem_dmabuf_mmap,
 170 };
 171
 172 struct dma_buf *omap_gem_prime_export(struct drm_device *dev,
 173                 struct drm_gem_object *obj, int flags)
 174 {
 175         DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 176
 177         exp_info.ops = &omap_dmabuf_ops;
 178         exp_info.size = obj->size;
 179         exp_info.flags = flags;
 180         exp_info.priv = obj;
 181
 182         return dma_buf_export(&exp_info);
 183 }
 184
 185 /* -----------------------------------------------------------------------------
 186  * DMABUF Import
 187  */
 188
 189 struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev,
 190                                              struct dma_buf *dma_buf)
 191 {
 192         struct dma_buf_attachment *attach;
 193         struct drm_gem_object *obj;
 194         struct sg_table *sgt;
 195         int ret;
 196
 197         if (dma_buf->ops == &omap_dmabuf_ops) {
 198                 obj = dma_buf->priv;
 199                 if (obj->dev == dev) {
 200                         /*
 201                          * Importing dmabuf exported from out own gem increases
 202                          * refcount on gem itself instead of f_count of dmabuf.
 203                          */
 204                         drm_gem_object_reference(obj);
 205                         return obj;
 206                 }
 207         }
 208
 209         attach = dma_buf_attach(dma_buf, dev->dev);
 210         if (IS_ERR(attach))
 211                 return ERR_CAST(attach);
 212
 213         get_dma_buf(dma_buf);
 214
 215         sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
 216         if (IS_ERR(sgt)) {
 217                 ret = PTR_ERR(sgt);
 218                 goto fail_detach;
 219         }
 220
 221         obj = omap_gem_new_dmabuf(dev, dma_buf->size, sgt);
 222         if (IS_ERR(obj)) {
 223                 ret = PTR_ERR(obj);
 224                 goto fail_unmap;
 225         }
 226
 227         obj->import_attach = attach;
 228
 229         return obj;
 230
 231 fail_unmap:
 232         dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
 233 fail_detach:
 234         dma_buf_detach(dma_buf, attach);
 235         dma_buf_put(dma_buf);
 236
 237         return ERR_PTR(ret);
 238 }