drivers/gpu/drm/i915/i915_gem_dmabuf.c

   1 /*
   2  * Copyright 2012 Red Hat Inc
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *      Dave Airlie <airlied@redhat.com>
  25  */
  26 #include "drmP.h"
  27 #include "i915_drv.h"
  28 #include <linux/dma-buf.h>
  29
  30 static struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachment,
  31                                       enum dma_data_direction dir)
  32 {
  33         struct drm_i915_gem_object *obj = attachment->dmabuf->priv;
  34         struct drm_device *dev = obj->base.dev;
  35         int npages = obj->base.size / PAGE_SIZE;
  36         struct sg_table *sg = NULL;
  37         int ret;
  38         int nents;
  39
  40         ret = i915_mutex_lock_interruptible(dev);
  41         if (ret)
  42                 return ERR_PTR(ret);
  43
  44         if (!obj->pages) {
  45                 ret = i915_gem_object_get_pages_gtt(obj, __GFP_NORETRY | __GFP_NOWARN);
  46                 if (ret)
  47                         goto out;
  48         }
  49
  50         /* link the pages into an SG then map the sg */
  51         sg = drm_prime_pages_to_sg(obj->pages, npages);
  52         nents = dma_map_sg(attachment->dev, sg->sgl, sg->nents, dir);
  53 out:
  54         mutex_unlock(&dev->struct_mutex);
  55         return sg;
  56 }
  57
  58 static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
  59                             struct sg_table *sg, enum dma_data_direction dir)
  60 {
  61         dma_unmap_sg(attachment->dev, sg->sgl, sg->nents, dir);
  62         sg_free_table(sg);
  63         kfree(sg);
  64 }
  65
  66 static void i915_gem_dmabuf_release(struct dma_buf *dma_buf)
  67 {
  68         struct drm_i915_gem_object *obj = dma_buf->priv;
  69
  70         if (obj->base.export_dma_buf == dma_buf) {
  71                 /* drop the reference on the export fd holds */
  72                 obj->base.export_dma_buf = NULL;
  73                 drm_gem_object_unreference_unlocked(&obj->base);
  74         }
  75 }
  76
  77 static void *i915_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf, unsigned long page_num)
  78 {
  79         return NULL;
  80 }
  81
  82 static void i915_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
  83 {
  84
  85 }
  86 static void *i915_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
  87 {
  88         return NULL;
  89 }
  90
  91 static void i915_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
  92 {
  93
  94 }
  95
  96 static const struct dma_buf_ops i915_dmabuf_ops =  {
  97         .map_dma_buf = i915_gem_map_dma_buf,
  98         .unmap_dma_buf = i915_gem_unmap_dma_buf,
  99         .release = i915_gem_dmabuf_release,
 100         .kmap = i915_gem_dmabuf_kmap,
 101         .kmap_atomic = i915_gem_dmabuf_kmap_atomic,
 102         .kunmap = i915_gem_dmabuf_kunmap,
 103         .kunmap_atomic = i915_gem_dmabuf_kunmap_atomic,
 104 };
 105
 106 struct dma_buf *i915_gem_prime_export(struct drm_device *dev,
 107                                 struct drm_gem_object *gem_obj, int flags)
 108 {
 109         struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
 110
 111         return dma_buf_export(obj, &i915_dmabuf_ops,
 112                                                   obj->base.size, 0600);
 113 }
 114
 115 struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
 116                                 struct dma_buf *dma_buf)
 117 {
 118         struct dma_buf_attachment *attach;
 119         struct sg_table *sg;
 120         struct drm_i915_gem_object *obj;
 121         int npages;
 122         int size;
 123         int ret;
 124
 125         /* is this one of own objects? */
 126         if (dma_buf->ops == &i915_dmabuf_ops) {
 127                 obj = dma_buf->priv;
 128                 /* is it from our device? */
 129                 if (obj->base.dev == dev) {
 130                         drm_gem_object_reference(&obj->base);
 131                         return &obj->base;
 132                 }
 133         }
 134
 135         /* need to attach */
 136         attach = dma_buf_attach(dma_buf, dev->dev);
 137         if (IS_ERR(attach))
 138                 return ERR_CAST(attach);
 139
 140         sg = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
 141         if (IS_ERR(sg)) {
 142                 ret = PTR_ERR(sg);
 143                 goto fail_detach;
 144         }
 145
 146         size = dma_buf->size;
 147         npages = size / PAGE_SIZE;
 148
 149         obj = kzalloc(sizeof(*obj), GFP_KERNEL);
 150         if (obj == NULL) {
 151                 ret = -ENOMEM;
 152                 goto fail_unmap;
 153         }
 154
 155         ret = drm_gem_private_object_init(dev, &obj->base, size);
 156         if (ret) {
 157                 kfree(obj);
 158                 goto fail_unmap;
 159         }
 160
 161         obj->sg_table = sg;
 162         obj->base.import_attach = attach;
 163
 164         return &obj->base;
 165
 166 fail_unmap:
 167         dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
 168 fail_detach:
 169         dma_buf_detach(dma_buf, attach);
 170         return ERR_PTR(ret);
 171 }