drivers/gpu/drm/exynos/exynos_drm_dmabuf.c

   1 /* exynos_drm_dmabuf.c
   2  *
   3  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
   4  * Author: Inki Dae <inki.dae@samsung.com>
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice (including the next
  14  * paragraph) shall be included in all copies or substantial portions of the
  15  * Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  21  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  22  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  23  * OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26 #include "drmP.h"
  27 #include "drm.h"
  28 #include "exynos_drm_drv.h"
  29 #include "exynos_drm_gem.h"
  30
  31 #include <linux/dma-buf.h>
  32
  33 static struct sg_table *exynos_pages_to_sg(struct page **pages, int nr_pages,
  34                 unsigned int page_size)
  35 {
  36         struct sg_table *sgt = NULL;
  37         struct scatterlist *sgl;
  38         int i, ret;
  39
  40         sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
  41         if (!sgt)
  42                 goto out;
  43
  44         ret = sg_alloc_table(sgt, nr_pages, GFP_KERNEL);
  45         if (ret)
  46                 goto err_free_sgt;
  47
  48         if (page_size < PAGE_SIZE)
  49                 page_size = PAGE_SIZE;
  50
  51         for_each_sg(sgt->sgl, sgl, nr_pages, i)
  52                 sg_set_page(sgl, pages[i], page_size, 0);
  53
  54         return sgt;
  55
  56 err_free_sgt:
  57         kfree(sgt);
  58         sgt = NULL;
  59 out:
  60         return NULL;
  61 }
  62
  63 static struct sg_table *
  64                 exynos_gem_map_dma_buf(struct dma_buf_attachment *attach,
  65                                         enum dma_data_direction dir)
  66 {
  67         struct exynos_drm_gem_obj *gem_obj = attach->dmabuf->priv;
  68         struct drm_device *dev = gem_obj->base.dev;
  69         struct exynos_drm_gem_buf *buf;
  70         struct sg_table *sgt = NULL;
  71         unsigned int npages;
  72         int nents;
  73
  74         DRM_DEBUG_PRIME("%s\n", __FILE__);
  75
  76         mutex_lock(&dev->struct_mutex);
  77
  78         buf = gem_obj->buffer;
  79
  80         /* there should always be pages allocated. */
  81         if (!buf->pages) {
  82                 DRM_ERROR("pages is null.\n");
  83                 goto err_unlock;
  84         }
  85
  86         npages = buf->size / buf->page_size;
  87
  88         sgt = exynos_pages_to_sg(buf->pages, npages, buf->page_size);
  89         nents = dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir);
  90
  91         DRM_DEBUG_PRIME("npages = %d buffer size = 0x%lx page_size = 0x%lx\n",
  92                         npages, buf->size, buf->page_size);
  93
  94 err_unlock:
  95         mutex_unlock(&dev->struct_mutex);
  96         return sgt;
  97 }
  98
  99 static void exynos_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
 100                                                 struct sg_table *sgt,
 101                                                 enum dma_data_direction dir)
 102 {
 103         dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
 104         sg_free_table(sgt);
 105         kfree(sgt);
 106         sgt = NULL;
 107 }
 108
 109 static void exynos_dmabuf_release(struct dma_buf *dmabuf)
 110 {
 111         struct exynos_drm_gem_obj *exynos_gem_obj = dmabuf->priv;
 112
 113         DRM_DEBUG_PRIME("%s\n", __FILE__);
 114
 115         /*
 116          * exynos_dmabuf_release() call means that file object's
 117          * f_count is 0 and it calls drm_gem_object_handle_unreference()
 118          * to drop the references that these values had been increased
 119          * at drm_prime_handle_to_fd()
 120          */
 121         if (exynos_gem_obj->base.export_dma_buf == dmabuf) {
 122                 exynos_gem_obj->base.export_dma_buf = NULL;
 123
 124                 /*
 125                  * drop this gem object refcount to release allocated buffer
 126                  * and resources.
 127                  */
 128                 drm_gem_object_unreference_unlocked(&exynos_gem_obj->base);
 129         }
 130 }
 131
 132 static void *exynos_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
 133                                                 unsigned long page_num)
 134 {
 135         /* TODO */
 136
 137         return NULL;
 138 }
 139
 140 static void exynos_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
 141                                                 unsigned long page_num,
 142                                                 void *addr)
 143 {
 144         /* TODO */
 145 }
 146
 147 static void *exynos_gem_dmabuf_kmap(struct dma_buf *dma_buf,
 148                                         unsigned long page_num)
 149 {
 150         /* TODO */
 151
 152         return NULL;
 153 }
 154
 155 static void exynos_gem_dmabuf_kunmap(struct dma_buf *dma_buf,
 156                                         unsigned long page_num, void *addr)
 157 {
 158         /* TODO */
 159 }
 160
 161 static struct dma_buf_ops exynos_dmabuf_ops = {
 162         .map_dma_buf            = exynos_gem_map_dma_buf,
 163         .unmap_dma_buf          = exynos_gem_unmap_dma_buf,
 164         .kmap                   = exynos_gem_dmabuf_kmap,
 165         .kmap_atomic            = exynos_gem_dmabuf_kmap_atomic,
 166         .kunmap                 = exynos_gem_dmabuf_kunmap,
 167         .kunmap_atomic          = exynos_gem_dmabuf_kunmap_atomic,
 168         .release                = exynos_dmabuf_release,
 169 };
 170
 171 struct dma_buf *exynos_dmabuf_prime_export(struct drm_device *drm_dev,
 172                                 struct drm_gem_object *obj, int flags)
 173 {
 174         struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
 175
 176         return dma_buf_export(exynos_gem_obj, &exynos_dmabuf_ops,
 177                                 exynos_gem_obj->base.size, 0600);
 178 }
 179
 180 struct drm_gem_object *exynos_dmabuf_prime_import(struct drm_device *drm_dev,
 181                                 struct dma_buf *dma_buf)
 182 {
 183         struct dma_buf_attachment *attach;
 184         struct sg_table *sgt;
 185         struct scatterlist *sgl;
 186         struct exynos_drm_gem_obj *exynos_gem_obj;
 187         struct exynos_drm_gem_buf *buffer;
 188         struct page *page;
 189         int ret, i = 0;
 190
 191         DRM_DEBUG_PRIME("%s\n", __FILE__);
 192
 193         /* is this one of own objects? */
 194         if (dma_buf->ops == &exynos_dmabuf_ops) {
 195                 struct drm_gem_object *obj;
 196
 197                 exynos_gem_obj = dma_buf->priv;
 198                 obj = &exynos_gem_obj->base;
 199
 200                 /* is it from our device? */
 201                 if (obj->dev == drm_dev) {
 202                         drm_gem_object_reference(obj);
 203                         return obj;
 204                 }
 205         }
 206
 207         attach = dma_buf_attach(dma_buf, drm_dev->dev);
 208         if (IS_ERR(attach))
 209                 return ERR_PTR(-EINVAL);
 210
 211
 212         sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
 213         if (IS_ERR(sgt)) {
 214                 ret = PTR_ERR(sgt);
 215                 goto err_buf_detach;
 216         }
 217
 218         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 219         if (!buffer) {
 220                 DRM_ERROR("failed to allocate exynos_drm_gem_buf.\n");
 221                 ret = -ENOMEM;
 222                 goto err_unmap_attach;
 223         }
 224
 225         buffer->pages = kzalloc(sizeof(*page) * sgt->nents, GFP_KERNEL);
 226         if (!buffer->pages) {
 227                 DRM_ERROR("failed to allocate pages.\n");
 228                 ret = -ENOMEM;
 229                 goto err_free_buffer;
 230         }
 231
 232         exynos_gem_obj = exynos_drm_gem_init(drm_dev, dma_buf->size);
 233         if (!exynos_gem_obj) {
 234                 ret = -ENOMEM;
 235                 goto err_free_pages;
 236         }
 237
 238         sgl = sgt->sgl;
 239         buffer->dma_addr = sg_dma_address(sgl);
 240
 241         while (i < sgt->nents) {
 242                 buffer->pages[i] = sg_page(sgl);
 243                 buffer->size += sg_dma_len(sgl);
 244                 sgl = sg_next(sgl);
 245                 i++;
 246         }
 247
 248         exynos_gem_obj->buffer = buffer;
 249         buffer->sgt = sgt;
 250         exynos_gem_obj->base.import_attach = attach;
 251
 252         DRM_DEBUG_PRIME("dma_addr = 0x%x, size = 0x%lx\n", buffer->dma_addr,
 253                                                                 buffer->size);
 254
 255         return &exynos_gem_obj->base;
 256
 257 err_free_pages:
 258         kfree(buffer->pages);
 259         buffer->pages = NULL;
 260 err_free_buffer:
 261         kfree(buffer);
 262         buffer = NULL;
 263 err_unmap_attach:
 264         dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
 265 err_buf_detach:
 266         dma_buf_detach(dma_buf, attach);
 267         return ERR_PTR(ret);
 268 }
 269
 270 MODULE_AUTHOR("Inki Dae <inki.dae@samsung.com>");
 271 MODULE_DESCRIPTION("Samsung SoC DRM DMABUF Module");
 272 MODULE_LICENSE("GPL");