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_gtt(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 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_vmap(struct dma_buf *dma_buf)
  78 {
  79         struct drm_i915_gem_object *obj = dma_buf->priv;
  80         struct drm_device *dev = obj->base.dev;
  81         int ret;
  82
  83         ret = i915_mutex_lock_interruptible(dev);
  84         if (ret)
  85                 return ERR_PTR(ret);
  86
  87         if (obj->dma_buf_vmapping) {
  88                 obj->vmapping_count++;
  89                 goto out_unlock;
  90         }
  91
  92         ret = i915_gem_object_get_pages_gtt(obj);
  93         if (ret) {
  94                 mutex_unlock(&dev->struct_mutex);
  95                 return ERR_PTR(ret);
  96         }
  97
  98         obj->dma_buf_vmapping = vmap(obj->pages, obj->base.size / PAGE_SIZE, 0, PAGE_KERNEL);
  99         if (!obj->dma_buf_vmapping) {
 100                 DRM_ERROR("failed to vmap object\n");
 101                 goto out_unlock;
 102         }
 103
 104         obj->vmapping_count = 1;
 105 out_unlock:
 106         mutex_unlock(&dev->struct_mutex);
 107         return obj->dma_buf_vmapping;
 108 }
 109
 110 static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
 111 {
 112         struct drm_i915_gem_object *obj = dma_buf->priv;
 113         struct drm_device *dev = obj->base.dev;
 114         int ret;
 115
 116         ret = i915_mutex_lock_interruptible(dev);
 117         if (ret)
 118                 return;
 119
 120         --obj->vmapping_count;
 121         if (obj->vmapping_count == 0) {
 122                 vunmap(obj->dma_buf_vmapping);
 123                 obj->dma_buf_vmapping = NULL;
 124         }
 125         mutex_unlock(&dev->struct_mutex);
 126 }
 127
 128 static void *i915_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf, unsigned long page_num)
 129 {
 130         return NULL;
 131 }
 132
 133 static void i915_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
 134 {
 135
 136 }
 137 static void *i915_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
 138 {
 139         return NULL;
 140 }
 141
 142 static void i915_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
 143 {
 144
 145 }
 146
 147 static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
 148 {
 149         return -EINVAL;
 150 }
 151
 152 static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, size_t start, size_t length, enum dma_data_direction direction)
 153 {
 154         struct drm_i915_gem_object *obj = dma_buf->priv;
 155         struct drm_device *dev = obj->base.dev;
 156         int ret;
 157         bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE);
 158
 159         ret = i915_mutex_lock_interruptible(dev);
 160         if (ret)
 161                 return ret;
 162
 163         ret = i915_gem_object_set_to_cpu_domain(obj, write);
 164         mutex_unlock(&dev->struct_mutex);
 165         return ret;
 166 }
 167
 168 static const struct dma_buf_ops i915_dmabuf_ops =  {
 169         .map_dma_buf = i915_gem_map_dma_buf,
 170         .unmap_dma_buf = i915_gem_unmap_dma_buf,
 171         .release = i915_gem_dmabuf_release,
 172         .kmap = i915_gem_dmabuf_kmap,
 173         .kmap_atomic = i915_gem_dmabuf_kmap_atomic,
 174         .kunmap = i915_gem_dmabuf_kunmap,
 175         .kunmap_atomic = i915_gem_dmabuf_kunmap_atomic,
 176         .mmap = i915_gem_dmabuf_mmap,
 177         .vmap = i915_gem_dmabuf_vmap,
 178         .vunmap = i915_gem_dmabuf_vunmap,
 179         .begin_cpu_access = i915_gem_begin_cpu_access,
 180 };
 181
 182 struct dma_buf *i915_gem_prime_export(struct drm_device *dev,
 183                                 struct drm_gem_object *gem_obj, int flags)
 184 {
 185         struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
 186
 187         return dma_buf_export(obj, &i915_dmabuf_ops,
 188                                                   obj->base.size, 0600);
 189 }
 190
 191 struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
 192                                 struct dma_buf *dma_buf)
 193 {
 194         struct dma_buf_attachment *attach;
 195         struct sg_table *sg;
 196         struct drm_i915_gem_object *obj;
 197         int npages;
 198         int size;
 199         int ret;
 200
 201         /* is this one of own objects? */
 202         if (dma_buf->ops == &i915_dmabuf_ops) {
 203                 obj = dma_buf->priv;
 204                 /* is it from our device? */
 205                 if (obj->base.dev == dev) {
 206                         drm_gem_object_reference(&obj->base);
 207                         return &obj->base;
 208                 }
 209         }
 210
 211         /* need to attach */
 212         attach = dma_buf_attach(dma_buf, dev->dev);
 213         if (IS_ERR(attach))
 214                 return ERR_CAST(attach);
 215
 216         sg = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
 217         if (IS_ERR(sg)) {
 218                 ret = PTR_ERR(sg);
 219                 goto fail_detach;
 220         }
 221
 222         size = dma_buf->size;
 223         npages = size / PAGE_SIZE;
 224
 225         obj = kzalloc(sizeof(*obj), GFP_KERNEL);
 226         if (obj == NULL) {
 227                 ret = -ENOMEM;
 228                 goto fail_unmap;
 229         }
 230
 231         ret = drm_gem_private_object_init(dev, &obj->base, size);
 232         if (ret) {
 233                 kfree(obj);
 234                 goto fail_unmap;
 235         }
 236
 237         obj->sg_table = sg;
 238         obj->base.import_attach = attach;
 239
 240         return &obj->base;
 241
 242 fail_unmap:
 243         dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
 244 fail_detach:
 245         dma_buf_detach(dma_buf, attach);
 246         return ERR_PTR(ret);
 247 }