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.h"
  29 #include "exynos_drm_drv.h"
  30 #include "exynos_drm_gem.h"
  31
  32 #include <linux/dma-buf.h>
  33
  34 static struct sg_table *exynos_pages_to_sg(struct page **pages, int nr_pages,
  35                 unsigned int page_size)
  36 {
  37         struct sg_table *sgt = NULL;
  38         struct scatterlist *sgl;
  39         int i, ret;
  40
  41         sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
  42         if (!sgt)
  43                 goto out;
  44
  45         ret = sg_alloc_table(sgt, nr_pages, GFP_KERNEL);
  46         if (ret)
  47                 goto err_free_sgt;
  48
  49         if (page_size < PAGE_SIZE)
  50                 page_size = PAGE_SIZE;
  51
  52         for_each_sg(sgt->sgl, sgl, nr_pages, i)
  53                 sg_set_page(sgl, pages[i], page_size, 0);
  54
  55         return sgt;
  56
  57 err_free_sgt:
  58         kfree(sgt);
  59         sgt = NULL;
  60 out:
  61         return NULL;
  62 }
  63
  64 static struct sg_table *
  65                 exynos_gem_map_dma_buf(struct dma_buf_attachment *attach,
  66                                         enum dma_data_direction dir)
  67 {
  68         struct exynos_drm_gem_obj *gem_obj = attach->dmabuf->priv;
  69         struct drm_device *dev = gem_obj->base.dev;
  70         struct exynos_drm_gem_buf *buf;
  71         struct sg_table *sgt = NULL;
  72         unsigned int npages;
  73         int nents;
  74
  75         DRM_DEBUG_PRIME("%s\n", __FILE__);
  76
  77         mutex_lock(&dev->struct_mutex);
  78
  79         buf = gem_obj->buffer;
  80
  81         /* there should always be pages allocated. */
  82         if (!buf->pages) {
  83                 DRM_ERROR("pages is null.\n");
  84                 goto err_unlock;
  85         }
  86
  87         npages = buf->size / buf->page_size;
  88
  89         sgt = exynos_pages_to_sg(buf->pages, npages, buf->page_size);
  90         if (!sgt) {
  91                 DRM_DEBUG_PRIME("exynos_pages_to_sg returned NULL!\n");
  92                 goto err_unlock;
  93         }
  94         nents = dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir);
  95
  96         DRM_DEBUG_PRIME("npages = %d buffer size = 0x%lx page_size = 0x%lx\n",
  97                         npages, buf->size, buf->page_size);
  98
  99 err_unlock:
 100         mutex_unlock(&dev->struct_mutex);
 101         return sgt;
 102 }
 103
 104 static void exynos_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
 105                                                 struct sg_table *sgt,
 106                                                 enum dma_data_direction dir)
 107 {
 108         dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
 109         sg_free_table(sgt);
 110         kfree(sgt);
 111         sgt = NULL;
 112 }
 113
 114 static void exynos_dmabuf_release(struct dma_buf *dmabuf)
 115 {
 116         struct exynos_drm_gem_obj *exynos_gem_obj = dmabuf->priv;
 117
 118         DRM_DEBUG_PRIME("%s\n", __FILE__);
 119
 120         /*
 121          * exynos_dmabuf_release() call means that file object's
 122          * f_count is 0 and it calls drm_gem_object_handle_unreference()
 123          * to drop the references that these values had been increased
 124          * at drm_prime_handle_to_fd()
 125          */
 126         if (exynos_gem_obj->base.export_dma_buf == dmabuf) {
 127                 exynos_gem_obj->base.export_dma_buf = NULL;
 128
 129                 /*
 130                  * drop this gem object refcount to release allocated buffer
 131                  * and resources.
 132                  */
 133                 drm_gem_object_unreference_unlocked(&exynos_gem_obj->base);
 134         }
 135 }
 136
 137 static void *exynos_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
 138                                                 unsigned long page_num)
 139 {
 140         /* TODO */
 141
 142         return NULL;
 143 }
 144
 145 static void exynos_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
 146                                                 unsigned long page_num,
 147                                                 void *addr)
 148 {
 149         /* TODO */
 150 }
 151
 152 static void *exynos_gem_dmabuf_kmap(struct dma_buf *dma_buf,
 153                                         unsigned long page_num)
 154 {
 155         /* TODO */
 156
 157         return NULL;
 158 }
 159
 160 static void exynos_gem_dmabuf_kunmap(struct dma_buf *dma_buf,
 161                                         unsigned long page_num, void *addr)
 162 {
 163         /* TODO */
 164 }
 165
 166 static struct dma_buf_ops exynos_dmabuf_ops = {
 167         .map_dma_buf            = exynos_gem_map_dma_buf,
 168         .unmap_dma_buf          = exynos_gem_unmap_dma_buf,
 169         .kmap                   = exynos_gem_dmabuf_kmap,
 170         .kmap_atomic            = exynos_gem_dmabuf_kmap_atomic,
 171         .kunmap                 = exynos_gem_dmabuf_kunmap,
 172         .kunmap_atomic          = exynos_gem_dmabuf_kunmap_atomic,
 173         .release                = exynos_dmabuf_release,
 174 };
 175
 176 struct dma_buf *exynos_dmabuf_prime_export(struct drm_device *drm_dev,
 177                                 struct drm_gem_object *obj, int flags)
 178 {
 179         struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
 180
 181         return dma_buf_export(exynos_gem_obj, &exynos_dmabuf_ops,
 182                                 exynos_gem_obj->base.size, 0600);
 183 }
 184
 185 struct drm_gem_object *exynos_dmabuf_prime_import(struct drm_device *drm_dev,
 186                                 struct dma_buf *dma_buf)
 187 {
 188         struct dma_buf_attachment *attach;
 189         struct sg_table *sgt;
 190         struct scatterlist *sgl;
 191         struct exynos_drm_gem_obj *exynos_gem_obj;
 192         struct exynos_drm_gem_buf *buffer;
 193         struct page *page;
 194         int ret;
 195
 196         DRM_DEBUG_PRIME("%s\n", __FILE__);
 197
 198         /* is this one of own objects? */
 199         if (dma_buf->ops == &exynos_dmabuf_ops) {
 200                 struct drm_gem_object *obj;
 201
 202                 exynos_gem_obj = dma_buf->priv;
 203                 obj = &exynos_gem_obj->base;
 204
 205                 /* is it from our device? */
 206                 if (obj->dev == drm_dev) {
 207                         drm_gem_object_reference(obj);
 208                         return obj;
 209                 }
 210         }
 211
 212         attach = dma_buf_attach(dma_buf, drm_dev->dev);
 213         if (IS_ERR(attach))
 214                 return ERR_PTR(-EINVAL);
 215
 216
 217         sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
 218         if (IS_ERR_OR_NULL(sgt)) {
 219                 ret = PTR_ERR(sgt);
 220                 goto err_buf_detach;
 221         }
 222
 223         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 224         if (!buffer) {
 225                 DRM_ERROR("failed to allocate exynos_drm_gem_buf.\n");
 226                 ret = -ENOMEM;
 227                 goto err_unmap_attach;
 228         }
 229
 230         buffer->pages = kzalloc(sizeof(*page) * sgt->nents, GFP_KERNEL);
 231         if (!buffer->pages) {
 232                 DRM_ERROR("failed to allocate pages.\n");
 233                 ret = -ENOMEM;
 234                 goto err_free_buffer;
 235         }
 236
 237         exynos_gem_obj = exynos_drm_gem_init(drm_dev, dma_buf->size);
 238         if (!exynos_gem_obj) {
 239                 ret = -ENOMEM;
 240                 goto err_free_pages;
 241         }
 242
 243         sgl = sgt->sgl;
 244
 245         if (sgt->nents == 1) {
 246                 buffer->dma_addr = sg_dma_address(sgt->sgl);
 247                 buffer->size = sg_dma_len(sgt->sgl);
 248
 249                 /* always physically continuous memory if sgt->nents is 1. */
 250                 exynos_gem_obj->flags |= EXYNOS_BO_CONTIG;
 251         } else {
 252                 unsigned int i = 0;
 253
 254                 buffer->dma_addr = sg_dma_address(sgl);
 255                 while (i < sgt->nents) {
 256                         buffer->pages[i] = sg_page(sgl);
 257                         buffer->size += sg_dma_len(sgl);
 258                         sgl = sg_next(sgl);
 259                         i++;
 260                 }
 261
 262                 exynos_gem_obj->flags |= EXYNOS_BO_NONCONTIG;
 263         }
 264
 265         exynos_gem_obj->buffer = buffer;
 266         buffer->sgt = sgt;
 267         exynos_gem_obj->base.import_attach = attach;
 268
 269         DRM_DEBUG_PRIME("dma_addr = 0x%x, size = 0x%lx\n", buffer->dma_addr,
 270                                                                 buffer->size);
 271
 272         return &exynos_gem_obj->base;
 273
 274 err_free_pages:
 275         kfree(buffer->pages);
 276         buffer->pages = NULL;
 277 err_free_buffer:
 278         kfree(buffer);
 279         buffer = NULL;
 280 err_unmap_attach:
 281         dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
 282 err_buf_detach:
 283         dma_buf_detach(dma_buf, attach);
 284         return ERR_PTR(ret);
 285 }
 286
 287 MODULE_AUTHOR("Inki Dae <inki.dae@samsung.com>");
 288 MODULE_DESCRIPTION("Samsung SoC DRM DMABUF Module");
 289 MODULE_LICENSE("GPL");