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 <drm/drmP.h>
  27 #include <drm/exynos_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         if (!sgt) {
  90                 DRM_DEBUG_PRIME("exynos_pages_to_sg returned NULL!\n");
  91                 goto err_unlock;
  92         }
  93         nents = dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir);
  94
  95         DRM_DEBUG_PRIME("npages = %d buffer size = 0x%lx page_size = 0x%lx\n",
  96                         npages, buf->size, buf->page_size);
  97
  98 err_unlock:
  99         mutex_unlock(&dev->struct_mutex);
 100         return sgt;
 101 }
 102
 103 static void exynos_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
 104                                                 struct sg_table *sgt,
 105                                                 enum dma_data_direction dir)
 106 {
 107         dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
 108         sg_free_table(sgt);
 109         kfree(sgt);
 110         sgt = NULL;
 111 }
 112
 113 static void exynos_dmabuf_release(struct dma_buf *dmabuf)
 114 {
 115         struct exynos_drm_gem_obj *exynos_gem_obj = dmabuf->priv;
 116
 117         DRM_DEBUG_PRIME("%s\n", __FILE__);
 118
 119         /*
 120          * exynos_dmabuf_release() call means that file object's
 121          * f_count is 0 and it calls drm_gem_object_handle_unreference()
 122          * to drop the references that these values had been increased
 123          * at drm_prime_handle_to_fd()
 124          */
 125         if (exynos_gem_obj->base.export_dma_buf == dmabuf) {
 126                 exynos_gem_obj->base.export_dma_buf = NULL;
 127
 128                 /*
 129                  * drop this gem object refcount to release allocated buffer
 130                  * and resources.
 131                  */
 132                 drm_gem_object_unreference_unlocked(&exynos_gem_obj->base);
 133         }
 134 }
 135
 136 static void *exynos_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
 137                                                 unsigned long page_num)
 138 {
 139         /* TODO */
 140
 141         return NULL;
 142 }
 143
 144 static void exynos_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
 145                                                 unsigned long page_num,
 146                                                 void *addr)
 147 {
 148         /* TODO */
 149 }
 150
 151 static void *exynos_gem_dmabuf_kmap(struct dma_buf *dma_buf,
 152                                         unsigned long page_num)
 153 {
 154         /* TODO */
 155
 156         return NULL;
 157 }
 158
 159 static void exynos_gem_dmabuf_kunmap(struct dma_buf *dma_buf,
 160                                         unsigned long page_num, void *addr)
 161 {
 162         /* TODO */
 163 }
 164
 165 static int exynos_gem_dmabuf_mmap(struct dma_buf *dma_buf,
 166         struct vm_area_struct *vma)
 167 {
 168         return -ENOTTY;
 169 }
 170
 171 static struct dma_buf_ops exynos_dmabuf_ops = {
 172         .map_dma_buf            = exynos_gem_map_dma_buf,
 173         .unmap_dma_buf          = exynos_gem_unmap_dma_buf,
 174         .kmap                   = exynos_gem_dmabuf_kmap,
 175         .kmap_atomic            = exynos_gem_dmabuf_kmap_atomic,
 176         .kunmap                 = exynos_gem_dmabuf_kunmap,
 177         .kunmap_atomic          = exynos_gem_dmabuf_kunmap_atomic,
 178         .mmap                   = exynos_gem_dmabuf_mmap,
 179         .release                = exynos_dmabuf_release,
 180 };
 181
 182 struct dma_buf *exynos_dmabuf_prime_export(struct drm_device *drm_dev,
 183                                 struct drm_gem_object *obj, int flags)
 184 {
 185         struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
 186
 187         return dma_buf_export(exynos_gem_obj, &exynos_dmabuf_ops,
 188                                 exynos_gem_obj->base.size, 0600);
 189 }
 190
 191 struct drm_gem_object *exynos_dmabuf_prime_import(struct drm_device *drm_dev,
 192                                 struct dma_buf *dma_buf)
 193 {
 194         struct dma_buf_attachment *attach;
 195         struct sg_table *sgt;
 196         struct scatterlist *sgl;
 197         struct exynos_drm_gem_obj *exynos_gem_obj;
 198         struct exynos_drm_gem_buf *buffer;
 199         struct page *page;
 200         int ret;
 201
 202         DRM_DEBUG_PRIME("%s\n", __FILE__);
 203
 204         /* is this one of own objects? */
 205         if (dma_buf->ops == &exynos_dmabuf_ops) {
 206                 struct drm_gem_object *obj;
 207
 208                 exynos_gem_obj = dma_buf->priv;
 209                 obj = &exynos_gem_obj->base;
 210
 211                 /* is it from our device? */
 212                 if (obj->dev == drm_dev) {
 213                         drm_gem_object_reference(obj);
 214                         return obj;
 215                 }
 216         }
 217
 218         attach = dma_buf_attach(dma_buf, drm_dev->dev);
 219         if (IS_ERR(attach))
 220                 return ERR_PTR(-EINVAL);
 221
 222
 223         sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
 224         if (IS_ERR_OR_NULL(sgt)) {
 225                 ret = PTR_ERR(sgt);
 226                 goto err_buf_detach;
 227         }
 228
 229         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 230         if (!buffer) {
 231                 DRM_ERROR("failed to allocate exynos_drm_gem_buf.\n");
 232                 ret = -ENOMEM;
 233                 goto err_unmap_attach;
 234         }
 235
 236         buffer->pages = kzalloc(sizeof(*page) * sgt->nents, GFP_KERNEL);
 237         if (!buffer->pages) {
 238                 DRM_ERROR("failed to allocate pages.\n");
 239                 ret = -ENOMEM;
 240                 goto err_free_buffer;
 241         }
 242
 243         exynos_gem_obj = exynos_drm_gem_init(drm_dev, dma_buf->size);
 244         if (!exynos_gem_obj) {
 245                 ret = -ENOMEM;
 246                 goto err_free_pages;
 247         }
 248
 249         sgl = sgt->sgl;
 250
 251         if (sgt->nents == 1) {
 252                 buffer->dma_addr = sg_dma_address(sgt->sgl);
 253                 buffer->size = sg_dma_len(sgt->sgl);
 254
 255                 /* always physically continuous memory if sgt->nents is 1. */
 256                 exynos_gem_obj->flags |= EXYNOS_BO_CONTIG;
 257         } else {
 258                 unsigned int i = 0;
 259
 260                 buffer->dma_addr = sg_dma_address(sgl);
 261                 while (i < sgt->nents) {
 262                         buffer->pages[i] = sg_page(sgl);
 263                         buffer->size += sg_dma_len(sgl);
 264                         sgl = sg_next(sgl);
 265                         i++;
 266                 }
 267
 268                 exynos_gem_obj->flags |= EXYNOS_BO_NONCONTIG;
 269         }
 270
 271         exynos_gem_obj->buffer = buffer;
 272         buffer->sgt = sgt;
 273         exynos_gem_obj->base.import_attach = attach;
 274
 275         DRM_DEBUG_PRIME("dma_addr = 0x%x, size = 0x%lx\n", buffer->dma_addr,
 276                                                                 buffer->size);
 277
 278         return &exynos_gem_obj->base;
 279
 280 err_free_pages:
 281         kfree(buffer->pages);
 282         buffer->pages = NULL;
 283 err_free_buffer:
 284         kfree(buffer);
 285         buffer = NULL;
 286 err_unmap_attach:
 287         dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
 288 err_buf_detach:
 289         dma_buf_detach(dma_buf, attach);
 290         return ERR_PTR(ret);
 291 }
 292
 293 MODULE_AUTHOR("Inki Dae <inki.dae@samsung.com>");
 294 MODULE_DESCRIPTION("Samsung SoC DRM DMABUF Module");
 295 MODULE_LICENSE("GPL");