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;
  37         int ret;
  38         int nents;
  39
  40         ret = i915_mutex_lock_interruptible(dev);
  41         if (ret)
  42                 return ERR_PTR(ret);
  43
  44         ret = i915_gem_object_get_pages(obj);
  45         if (ret) {
  46                 sg = ERR_PTR(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         i915_gem_object_pin_pages(obj);
  54
  55 out:
  56         mutex_unlock(&dev->struct_mutex);
  57         return sg;
  58 }
  59
  60 static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
  61                             struct sg_table *sg, enum dma_data_direction dir)
  62 {
  63         dma_unmap_sg(attachment->dev, sg->sgl, sg->nents, dir);
  64         sg_free_table(sg);
  65         kfree(sg);
  66 }
  67
  68 static void i915_gem_dmabuf_release(struct dma_buf *dma_buf)
  69 {
  70         struct drm_i915_gem_object *obj = dma_buf->priv;
  71
  72         if (obj->base.export_dma_buf == dma_buf) {
  73                 /* drop the reference on the export fd holds */
  74                 obj->base.export_dma_buf = NULL;
  75                 drm_gem_object_unreference_unlocked(&obj->base);
  76         }
  77 }
  78
  79 static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
  80 {
  81         struct drm_i915_gem_object *obj = dma_buf->priv;
  82         struct drm_device *dev = obj->base.dev;
  83         int ret;
  84
  85         ret = i915_mutex_lock_interruptible(dev);
  86         if (ret)
  87                 return ERR_PTR(ret);
  88
  89         if (obj->dma_buf_vmapping) {
  90                 obj->vmapping_count++;
  91                 goto out_unlock;
  92         }
  93
  94         ret = i915_gem_object_get_pages(obj);
  95         if (ret) {
  96                 mutex_unlock(&dev->struct_mutex);
  97                 return ERR_PTR(ret);
  98         }
  99
 100         obj->dma_buf_vmapping = vmap(obj->pages, obj->base.size / PAGE_SIZE, 0, PAGE_KERNEL);
 101         if (!obj->dma_buf_vmapping) {
 102                 DRM_ERROR("failed to vmap object\n");
 103                 goto out_unlock;
 104         }
 105
 106         obj->vmapping_count = 1;
 107         i915_gem_object_pin_pages(obj);
 108 out_unlock:
 109         mutex_unlock(&dev->struct_mutex);
 110         return obj->dma_buf_vmapping;
 111 }
 112
 113 static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
 114 {
 115         struct drm_i915_gem_object *obj = dma_buf->priv;
 116         struct drm_device *dev = obj->base.dev;
 117         int ret;
 118
 119         ret = i915_mutex_lock_interruptible(dev);
 120         if (ret)
 121                 return;
 122
 123         if (--obj->vmapping_count == 0) {
 124                 vunmap(obj->dma_buf_vmapping);
 125                 obj->dma_buf_vmapping = NULL;
 126
 127                 i915_gem_object_unpin_pages(obj);
 128         }
 129         mutex_unlock(&dev->struct_mutex);
 130 }
 131
 132 static void *i915_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf, unsigned long page_num)
 133 {
 134         return NULL;
 135 }
 136
 137 static void i915_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
 138 {
 139
 140 }
 141 static void *i915_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
 142 {
 143         return NULL;
 144 }
 145
 146 static void i915_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
 147 {
 148
 149 }
 150
 151 static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
 152 {
 153         return -EINVAL;
 154 }
 155
 156 static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, size_t start, size_t length, enum dma_data_direction direction)
 157 {
 158         struct drm_i915_gem_object *obj = dma_buf->priv;
 159         struct drm_device *dev = obj->base.dev;
 160         int ret;
 161         bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE);
 162
 163         ret = i915_mutex_lock_interruptible(dev);
 164         if (ret)
 165                 return ret;
 166
 167         ret = i915_gem_object_set_to_cpu_domain(obj, write);
 168         mutex_unlock(&dev->struct_mutex);
 169         return ret;
 170 }
 171
 172 static const struct dma_buf_ops i915_dmabuf_ops =  {
 173         .map_dma_buf = i915_gem_map_dma_buf,
 174         .unmap_dma_buf = i915_gem_unmap_dma_buf,
 175         .release = i915_gem_dmabuf_release,
 176         .kmap = i915_gem_dmabuf_kmap,
 177         .kmap_atomic = i915_gem_dmabuf_kmap_atomic,
 178         .kunmap = i915_gem_dmabuf_kunmap,
 179         .kunmap_atomic = i915_gem_dmabuf_kunmap_atomic,
 180         .mmap = i915_gem_dmabuf_mmap,
 181         .vmap = i915_gem_dmabuf_vmap,
 182         .vunmap = i915_gem_dmabuf_vunmap,
 183         .begin_cpu_access = i915_gem_begin_cpu_access,
 184 };
 185
 186 struct dma_buf *i915_gem_prime_export(struct drm_device *dev,
 187                                 struct drm_gem_object *gem_obj, int flags)
 188 {
 189         struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
 190
 191         return dma_buf_export(obj, &i915_dmabuf_ops,
 192                                                   obj->base.size, 0600);
 193 }
 194
 195 struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
 196                                 struct dma_buf *dma_buf)
 197 {
 198         struct dma_buf_attachment *attach;
 199         struct sg_table *sg;
 200         struct drm_i915_gem_object *obj;
 201         int npages;
 202         int size;
 203         int ret;
 204
 205         /* is this one of own objects? */
 206         if (dma_buf->ops == &i915_dmabuf_ops) {
 207                 obj = dma_buf->priv;
 208                 /* is it from our device? */
 209                 if (obj->base.dev == dev) {
 210                         drm_gem_object_reference(&obj->base);
 211                         return &obj->base;
 212                 }
 213         }
 214
 215         /* need to attach */
 216         attach = dma_buf_attach(dma_buf, dev->dev);
 217         if (IS_ERR(attach))
 218                 return ERR_CAST(attach);
 219
 220         sg = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
 221         if (IS_ERR(sg)) {
 222                 ret = PTR_ERR(sg);
 223                 goto fail_detach;
 224         }
 225
 226         size = dma_buf->size;
 227         npages = size / PAGE_SIZE;
 228
 229         obj = kzalloc(sizeof(*obj), GFP_KERNEL);
 230         if (obj == NULL) {
 231                 ret = -ENOMEM;
 232                 goto fail_unmap;
 233         }
 234
 235         ret = drm_gem_private_object_init(dev, &obj->base, size);
 236         if (ret) {
 237                 kfree(obj);
 238                 goto fail_unmap;
 239         }
 240
 241         obj->sg_table = sg;
 242         obj->base.import_attach = attach;
 243
 244         return &obj->base;
 245
 246 fail_unmap:
 247         dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
 248 fail_detach:
 249         dma_buf_detach(dma_buf, attach);
 250         return ERR_PTR(ret);
 251 }