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 int exynos_gem_dmabuf_mmap(struct dma_buf *dma_buf,
 167         struct vm_area_struct *vma)
 168 {
 169         return -ENOTTY;
 170 }
 171
 172 static struct dma_buf_ops exynos_dmabuf_ops = {
 173         .map_dma_buf            = exynos_gem_map_dma_buf,
 174         .unmap_dma_buf          = exynos_gem_unmap_dma_buf,
 175         .kmap                   = exynos_gem_dmabuf_kmap,
 176         .kmap_atomic            = exynos_gem_dmabuf_kmap_atomic,
 177         .kunmap                 = exynos_gem_dmabuf_kunmap,
 178         .kunmap_atomic          = exynos_gem_dmabuf_kunmap_atomic,
 179         .mmap                   = exynos_gem_dmabuf_mmap,
 180         .release                = exynos_dmabuf_release,
 181 };
 182
 183 struct dma_buf *exynos_dmabuf_prime_export(struct drm_device *drm_dev,
 184                                 struct drm_gem_object *obj, int flags)
 185 {
 186         struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
 187
 188         return dma_buf_export(exynos_gem_obj, &exynos_dmabuf_ops,
 189                                 exynos_gem_obj->base.size, 0600);
 190 }
 191
 192 struct drm_gem_object *exynos_dmabuf_prime_import(struct drm_device *drm_dev,
 193                                 struct dma_buf *dma_buf)
 194 {
 195         struct dma_buf_attachment *attach;
 196         struct sg_table *sgt;
 197         struct scatterlist *sgl;
 198         struct exynos_drm_gem_obj *exynos_gem_obj;
 199         struct exynos_drm_gem_buf *buffer;
 200         struct page *page;
 201         int ret;
 202
 203         DRM_DEBUG_PRIME("%s\n", __FILE__);
 204
 205         /* is this one of own objects? */
 206         if (dma_buf->ops == &exynos_dmabuf_ops) {
 207                 struct drm_gem_object *obj;
 208
 209                 exynos_gem_obj = dma_buf->priv;
 210                 obj = &exynos_gem_obj->base;
 211
 212                 /* is it from our device? */
 213                 if (obj->dev == drm_dev) {
 214                         drm_gem_object_reference(obj);
 215                         return obj;
 216                 }
 217         }
 218
 219         attach = dma_buf_attach(dma_buf, drm_dev->dev);
 220         if (IS_ERR(attach))
 221                 return ERR_PTR(-EINVAL);
 222
 223
 224         sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
 225         if (IS_ERR_OR_NULL(sgt)) {
 226                 ret = PTR_ERR(sgt);
 227                 goto err_buf_detach;
 228         }
 229
 230         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 231         if (!buffer) {
 232                 DRM_ERROR("failed to allocate exynos_drm_gem_buf.\n");
 233                 ret = -ENOMEM;
 234                 goto err_unmap_attach;
 235         }
 236
 237         buffer->pages = kzalloc(sizeof(*page) * sgt->nents, GFP_KERNEL);
 238         if (!buffer->pages) {
 239                 DRM_ERROR("failed to allocate pages.\n");
 240                 ret = -ENOMEM;
 241                 goto err_free_buffer;
 242         }
 243
 244         exynos_gem_obj = exynos_drm_gem_init(drm_dev, dma_buf->size);
 245         if (!exynos_gem_obj) {
 246                 ret = -ENOMEM;
 247                 goto err_free_pages;
 248         }
 249
 250         sgl = sgt->sgl;
 251
 252         if (sgt->nents == 1) {
 253                 buffer->dma_addr = sg_dma_address(sgt->sgl);
 254                 buffer->size = sg_dma_len(sgt->sgl);
 255
 256                 /* always physically continuous memory if sgt->nents is 1. */
 257                 exynos_gem_obj->flags |= EXYNOS_BO_CONTIG;
 258         } else {
 259                 unsigned int i = 0;
 260
 261                 buffer->dma_addr = sg_dma_address(sgl);
 262                 while (i < sgt->nents) {
 263                         buffer->pages[i] = sg_page(sgl);
 264                         buffer->size += sg_dma_len(sgl);
 265                         sgl = sg_next(sgl);
 266                         i++;
 267                 }
 268
 269                 exynos_gem_obj->flags |= EXYNOS_BO_NONCONTIG;
 270         }
 271
 272         exynos_gem_obj->buffer = buffer;
 273         buffer->sgt = sgt;
 274         exynos_gem_obj->base.import_attach = attach;
 275
 276         DRM_DEBUG_PRIME("dma_addr = 0x%x, size = 0x%lx\n", buffer->dma_addr,
 277                                                                 buffer->size);
 278
 279         return &exynos_gem_obj->base;
 280
 281 err_free_pages:
 282         kfree(buffer->pages);
 283         buffer->pages = NULL;
 284 err_free_buffer:
 285         kfree(buffer);
 286         buffer = NULL;
 287 err_unmap_attach:
 288         dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
 289 err_buf_detach:
 290         dma_buf_detach(dma_buf, attach);
 291         return ERR_PTR(ret);
 292 }
 293
 294 MODULE_AUTHOR("Inki Dae <inki.dae@samsung.com>");
 295 MODULE_DESCRIPTION("Samsung SoC DRM DMABUF Module");
 296 MODULE_LICENSE("GPL");