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 struct exynos_drm_dmabuf_attachment {
  34         struct sg_table sgt;
  35         enum dma_data_direction dir;
  36 };
  37
  38 static int exynos_gem_attach_dma_buf(struct dma_buf *dmabuf,
  39                                         struct device *dev,
  40                                         struct dma_buf_attachment *attach)
  41 {
  42         struct exynos_drm_dmabuf_attachment *exynos_attach;
  43
  44         exynos_attach = kzalloc(sizeof(*exynos_attach), GFP_KERNEL);
  45         if (!exynos_attach)
  46                 return -ENOMEM;
  47
  48         exynos_attach->dir = DMA_NONE;
  49         attach->priv = exynos_attach;
  50
  51         return 0;
  52 }
  53
  54 static void exynos_gem_detach_dma_buf(struct dma_buf *dmabuf,
  55                                         struct dma_buf_attachment *attach)
  56 {
  57         struct exynos_drm_dmabuf_attachment *exynos_attach = attach->priv;
  58         struct sg_table *sgt;
  59
  60         if (!exynos_attach)
  61                 return;
  62
  63         sgt = &exynos_attach->sgt;
  64
  65         if (exynos_attach->dir != DMA_NONE)
  66                 dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents,
  67                                 exynos_attach->dir);
  68
  69         sg_free_table(sgt);
  70         kfree(exynos_attach);
  71         attach->priv = NULL;
  72 }
  73
  74 static struct sg_table *
  75                 exynos_gem_map_dma_buf(struct dma_buf_attachment *attach,
  76                                         enum dma_data_direction dir)
  77 {
  78         struct exynos_drm_dmabuf_attachment *exynos_attach = attach->priv;
  79         struct exynos_drm_gem_obj *gem_obj = attach->dmabuf->priv;
  80         struct drm_device *dev = gem_obj->base.dev;
  81         struct exynos_drm_gem_buf *buf;
  82         struct scatterlist *rd, *wr;
  83         struct sg_table *sgt = NULL;
  84         unsigned int i;
  85         int nents, ret;
  86
  87         DRM_DEBUG_PRIME("%s\n", __FILE__);
  88
  89         if (WARN_ON(dir == DMA_NONE))
  90                 return ERR_PTR(-EINVAL);
  91
  92         /* just return current sgt if already requested. */
  93         if (exynos_attach->dir == dir)
  94                 return &exynos_attach->sgt;
  95
  96         /* reattaching is not allowed. */
  97         if (WARN_ON(exynos_attach->dir != DMA_NONE))
  98                 return ERR_PTR(-EBUSY);
  99
 100         buf = gem_obj->buffer;
 101         if (!buf) {
 102                 DRM_ERROR("buffer is null.\n");
 103                 return ERR_PTR(-ENOMEM);
 104         }
 105
 106         sgt = &exynos_attach->sgt;
 107
 108         ret = sg_alloc_table(sgt, buf->sgt->orig_nents, GFP_KERNEL);
 109         if (ret) {
 110                 DRM_ERROR("failed to alloc sgt.\n");
 111                 return ERR_PTR(-ENOMEM);
 112         }
 113
 114         mutex_lock(&dev->struct_mutex);
 115
 116         rd = buf->sgt->sgl;
 117         wr = sgt->sgl;
 118         for (i = 0; i < sgt->orig_nents; ++i) {
 119                 sg_set_page(wr, sg_page(rd), rd->length, rd->offset);
 120                 rd = sg_next(rd);
 121                 wr = sg_next(wr);
 122         }
 123
 124         nents = dma_map_sg(attach->dev, sgt->sgl, sgt->orig_nents, dir);
 125         if (!nents) {
 126                 DRM_ERROR("failed to map sgl with iommu.\n");
 127                 sgt = ERR_PTR(-EIO);
 128                 goto err_unlock;
 129         }
 130
 131         exynos_attach->dir = dir;
 132         attach->priv = exynos_attach;
 133
 134         DRM_DEBUG_PRIME("buffer size = 0x%lx\n", buf->size);
 135
 136 err_unlock:
 137         mutex_unlock(&dev->struct_mutex);
 138         return sgt;
 139 }
 140
 141 static void exynos_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
 142                                                 struct sg_table *sgt,
 143                                                 enum dma_data_direction dir)
 144 {
 145         /* Nothing to do. */
 146 }
 147
 148 static void exynos_dmabuf_release(struct dma_buf *dmabuf)
 149 {
 150         struct exynos_drm_gem_obj *exynos_gem_obj = dmabuf->priv;
 151
 152         DRM_DEBUG_PRIME("%s\n", __FILE__);
 153
 154         /*
 155          * exynos_dmabuf_release() call means that file object's
 156          * f_count is 0 and it calls drm_gem_object_handle_unreference()
 157          * to drop the references that these values had been increased
 158          * at drm_prime_handle_to_fd()
 159          */
 160         if (exynos_gem_obj->base.export_dma_buf == dmabuf) {
 161                 exynos_gem_obj->base.export_dma_buf = NULL;
 162
 163                 /*
 164                  * drop this gem object refcount to release allocated buffer
 165                  * and resources.
 166                  */
 167                 drm_gem_object_unreference_unlocked(&exynos_gem_obj->base);
 168         }
 169 }
 170
 171 static void *exynos_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
 172                                                 unsigned long page_num)
 173 {
 174         /* TODO */
 175
 176         return NULL;
 177 }
 178
 179 static void exynos_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
 180                                                 unsigned long page_num,
 181                                                 void *addr)
 182 {
 183         /* TODO */
 184 }
 185
 186 static void *exynos_gem_dmabuf_kmap(struct dma_buf *dma_buf,
 187                                         unsigned long page_num)
 188 {
 189         /* TODO */
 190
 191         return NULL;
 192 }
 193
 194 static void exynos_gem_dmabuf_kunmap(struct dma_buf *dma_buf,
 195                                         unsigned long page_num, void *addr)
 196 {
 197         /* TODO */
 198 }
 199
 200 static int exynos_gem_dmabuf_mmap(struct dma_buf *dma_buf,
 201         struct vm_area_struct *vma)
 202 {
 203         return -ENOTTY;
 204 }
 205
 206 static struct dma_buf_ops exynos_dmabuf_ops = {
 207         .attach                 = exynos_gem_attach_dma_buf,
 208         .detach                 = exynos_gem_detach_dma_buf,
 209         .map_dma_buf            = exynos_gem_map_dma_buf,
 210         .unmap_dma_buf          = exynos_gem_unmap_dma_buf,
 211         .kmap                   = exynos_gem_dmabuf_kmap,
 212         .kmap_atomic            = exynos_gem_dmabuf_kmap_atomic,
 213         .kunmap                 = exynos_gem_dmabuf_kunmap,
 214         .kunmap_atomic          = exynos_gem_dmabuf_kunmap_atomic,
 215         .mmap                   = exynos_gem_dmabuf_mmap,
 216         .release                = exynos_dmabuf_release,
 217 };
 218
 219 struct dma_buf *exynos_dmabuf_prime_export(struct drm_device *drm_dev,
 220                                 struct drm_gem_object *obj, int flags)
 221 {
 222         struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
 223
 224         return dma_buf_export(exynos_gem_obj, &exynos_dmabuf_ops,
 225                                 exynos_gem_obj->base.size, 0600);
 226 }
 227
 228 struct drm_gem_object *exynos_dmabuf_prime_import(struct drm_device *drm_dev,
 229                                 struct dma_buf *dma_buf)
 230 {
 231         struct dma_buf_attachment *attach;
 232         struct sg_table *sgt;
 233         struct scatterlist *sgl;
 234         struct exynos_drm_gem_obj *exynos_gem_obj;
 235         struct exynos_drm_gem_buf *buffer;
 236         int ret;
 237
 238         DRM_DEBUG_PRIME("%s\n", __FILE__);
 239
 240         /* is this one of own objects? */
 241         if (dma_buf->ops == &exynos_dmabuf_ops) {
 242                 struct drm_gem_object *obj;
 243
 244                 exynos_gem_obj = dma_buf->priv;
 245                 obj = &exynos_gem_obj->base;
 246
 247                 /* is it from our device? */
 248                 if (obj->dev == drm_dev) {
 249                         drm_gem_object_reference(obj);
 250                         return obj;
 251                 }
 252         }
 253
 254         attach = dma_buf_attach(dma_buf, drm_dev->dev);
 255         if (IS_ERR(attach))
 256                 return ERR_PTR(-EINVAL);
 257
 258
 259         sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
 260         if (IS_ERR_OR_NULL(sgt)) {
 261                 ret = PTR_ERR(sgt);
 262                 goto err_buf_detach;
 263         }
 264
 265         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 266         if (!buffer) {
 267                 DRM_ERROR("failed to allocate exynos_drm_gem_buf.\n");
 268                 ret = -ENOMEM;
 269                 goto err_unmap_attach;
 270         }
 271
 272         exynos_gem_obj = exynos_drm_gem_init(drm_dev, dma_buf->size);
 273         if (!exynos_gem_obj) {
 274                 ret = -ENOMEM;
 275                 goto err_free_buffer;
 276         }
 277
 278         sgl = sgt->sgl;
 279
 280         buffer->size = dma_buf->size;
 281         buffer->dma_addr = sg_dma_address(sgl);
 282
 283         if (sgt->nents == 1) {
 284                 /* always physically continuous memory if sgt->nents is 1. */
 285                 exynos_gem_obj->flags |= EXYNOS_BO_CONTIG;
 286         } else {
 287                 /*
 288                  * this case could be CONTIG or NONCONTIG type but for now
 289                  * sets NONCONTIG.
 290                  * TODO. we have to find a way that exporter can notify
 291                  * the type of its own buffer to importer.
 292                  */
 293                 exynos_gem_obj->flags |= EXYNOS_BO_NONCONTIG;
 294         }
 295
 296         exynos_gem_obj->buffer = buffer;
 297         buffer->sgt = sgt;
 298         exynos_gem_obj->base.import_attach = attach;
 299
 300         DRM_DEBUG_PRIME("dma_addr = 0x%x, size = 0x%lx\n", buffer->dma_addr,
 301                                                                 buffer->size);
 302
 303         return &exynos_gem_obj->base;
 304
 305 err_free_buffer:
 306         kfree(buffer);
 307         buffer = NULL;
 308 err_unmap_attach:
 309         dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
 310 err_buf_detach:
 311         dma_buf_detach(dma_buf, attach);
 312         return ERR_PTR(ret);
 313 }
 314
 315 MODULE_AUTHOR("Inki Dae <inki.dae@samsung.com>");
 316 MODULE_DESCRIPTION("Samsung SoC DRM DMABUF Module");
 317 MODULE_LICENSE("GPL");