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 <drm/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 sg_table *st;
  35         struct scatterlist *src, *dst;
  36         int ret, i;
  37
  38         ret = i915_mutex_lock_interruptible(obj->base.dev);
  39         if (ret)
  40                 return ERR_PTR(ret);
  41
  42         ret = i915_gem_object_get_pages(obj);
  43         if (ret) {
  44                 st = ERR_PTR(ret);
  45                 goto out;
  46         }
  47
  48         /* Copy sg so that we make an independent mapping */
  49         st = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
  50         if (st == NULL) {
  51                 st = ERR_PTR(-ENOMEM);
  52                 goto out;
  53         }
  54
  55         ret = sg_alloc_table(st, obj->pages->nents, GFP_KERNEL);
  56         if (ret) {
  57                 kfree(st);
  58                 st = ERR_PTR(ret);
  59                 goto out;
  60         }
  61
  62         src = obj->pages->sgl;
  63         dst = st->sgl;
  64         for (i = 0; i < obj->pages->nents; i++) {
  65                 sg_set_page(dst, sg_page(src), src->length, 0);
  66                 dst = sg_next(dst);
  67                 src = sg_next(src);
  68         }
  69
  70         if (!dma_map_sg(attachment->dev, st->sgl, st->nents, dir)) {
  71                 sg_free_table(st);
  72                 kfree(st);
  73                 st = ERR_PTR(-ENOMEM);
  74                 goto out;
  75         }
  76
  77         i915_gem_object_pin_pages(obj);
  78
  79 out:
  80         mutex_unlock(&obj->base.dev->struct_mutex);
  81         return st;
  82 }
  83
  84 static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
  85                                    struct sg_table *sg,
  86                                    enum dma_data_direction dir)
  87 {
  88         dma_unmap_sg(attachment->dev, sg->sgl, sg->nents, dir);
  89         sg_free_table(sg);
  90         kfree(sg);
  91 }
  92
  93 static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
  94 {
  95         struct drm_i915_gem_object *obj = dma_buf->priv;
  96         struct drm_device *dev = obj->base.dev;
  97         struct sg_page_iter sg_iter;
  98         struct page **pages;
  99         int ret, i;
 100
 101         ret = i915_mutex_lock_interruptible(dev);
 102         if (ret)
 103                 return ERR_PTR(ret);
 104
 105         if (obj->dma_buf_vmapping) {
 106                 obj->vmapping_count++;
 107                 goto out_unlock;
 108         }
 109
 110         ret = i915_gem_object_get_pages(obj);
 111         if (ret)
 112                 goto error;
 113
 114         ret = -ENOMEM;
 115
 116         pages = drm_malloc_ab(obj->base.size >> PAGE_SHIFT, sizeof(*pages));
 117         if (pages == NULL)
 118                 goto error;
 119
 120         i = 0;
 121         for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0)
 122                 pages[i++] = sg_page_iter_page(&sg_iter);
 123
 124         obj->dma_buf_vmapping = vmap(pages, i, 0, PAGE_KERNEL);
 125         drm_free_large(pages);
 126
 127         if (!obj->dma_buf_vmapping)
 128                 goto error;
 129
 130         obj->vmapping_count = 1;
 131         i915_gem_object_pin_pages(obj);
 132 out_unlock:
 133         mutex_unlock(&dev->struct_mutex);
 134         return obj->dma_buf_vmapping;
 135
 136 error:
 137         mutex_unlock(&dev->struct_mutex);
 138         return ERR_PTR(ret);
 139 }
 140
 141 static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
 142 {
 143         struct drm_i915_gem_object *obj = dma_buf->priv;
 144         struct drm_device *dev = obj->base.dev;
 145         int ret;
 146
 147         ret = i915_mutex_lock_interruptible(dev);
 148         if (ret)
 149                 return;
 150
 151         if (--obj->vmapping_count == 0) {
 152                 vunmap(obj->dma_buf_vmapping);
 153                 obj->dma_buf_vmapping = NULL;
 154
 155                 i915_gem_object_unpin_pages(obj);
 156         }
 157         mutex_unlock(&dev->struct_mutex);
 158 }
 159
 160 static void *i915_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf, unsigned long page_num)
 161 {
 162         return NULL;
 163 }
 164
 165 static void i915_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
 166 {
 167
 168 }
 169 static void *i915_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
 170 {
 171         return NULL;
 172 }
 173
 174 static void i915_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
 175 {
 176
 177 }
 178
 179 static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
 180 {
 181         return -EINVAL;
 182 }
 183
 184 static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, size_t start, size_t length, enum dma_data_direction direction)
 185 {
 186         struct drm_i915_gem_object *obj = dma_buf->priv;
 187         struct drm_device *dev = obj->base.dev;
 188         int ret;
 189         bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE);
 190
 191         ret = i915_mutex_lock_interruptible(dev);
 192         if (ret)
 193                 return ret;
 194
 195         ret = i915_gem_object_set_to_cpu_domain(obj, write);
 196         mutex_unlock(&dev->struct_mutex);
 197         return ret;
 198 }
 199
 200 static const struct dma_buf_ops i915_dmabuf_ops =  {
 201         .map_dma_buf = i915_gem_map_dma_buf,
 202         .unmap_dma_buf = i915_gem_unmap_dma_buf,
 203         .release = drm_gem_dmabuf_release,
 204         .kmap = i915_gem_dmabuf_kmap,
 205         .kmap_atomic = i915_gem_dmabuf_kmap_atomic,
 206         .kunmap = i915_gem_dmabuf_kunmap,
 207         .kunmap_atomic = i915_gem_dmabuf_kunmap_atomic,
 208         .mmap = i915_gem_dmabuf_mmap,
 209         .vmap = i915_gem_dmabuf_vmap,
 210         .vunmap = i915_gem_dmabuf_vunmap,
 211         .begin_cpu_access = i915_gem_begin_cpu_access,
 212 };
 213
 214 struct dma_buf *i915_gem_prime_export(struct drm_device *dev,
 215                                       struct drm_gem_object *gem_obj, int flags)
 216 {
 217         struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
 218
 219         return dma_buf_export(obj, &i915_dmabuf_ops, obj->base.size, flags);
 220 }
 221
 222 static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
 223 {
 224         struct sg_table *sg;
 225
 226         sg = dma_buf_map_attachment(obj->base.import_attach, DMA_BIDIRECTIONAL);
 227         if (IS_ERR(sg))
 228                 return PTR_ERR(sg);
 229
 230         obj->pages = sg;
 231         obj->has_dma_mapping = true;
 232         return 0;
 233 }
 234
 235 static void i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object *obj)
 236 {
 237         dma_buf_unmap_attachment(obj->base.import_attach,
 238                                  obj->pages, DMA_BIDIRECTIONAL);
 239         obj->has_dma_mapping = false;
 240 }
 241
 242 static const struct drm_i915_gem_object_ops i915_gem_object_dmabuf_ops = {
 243         .get_pages = i915_gem_object_get_pages_dmabuf,
 244         .put_pages = i915_gem_object_put_pages_dmabuf,
 245 };
 246
 247 struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
 248                                              struct dma_buf *dma_buf)
 249 {
 250         struct dma_buf_attachment *attach;
 251         struct drm_i915_gem_object *obj;
 252         int ret;
 253
 254         /* is this one of own objects? */
 255         if (dma_buf->ops == &i915_dmabuf_ops) {
 256                 obj = dma_buf->priv;
 257                 /* is it from our device? */
 258                 if (obj->base.dev == dev) {
 259                         /*
 260                          * Importing dmabuf exported from out own gem increases
 261                          * refcount on gem itself instead of f_count of dmabuf.
 262                          */
 263                         drm_gem_object_reference(&obj->base);
 264                         return &obj->base;
 265                 }
 266         }
 267
 268         /* need to attach */
 269         attach = dma_buf_attach(dma_buf, dev->dev);
 270         if (IS_ERR(attach))
 271                 return ERR_CAST(attach);
 272
 273         get_dma_buf(dma_buf);
 274
 275         obj = i915_gem_object_alloc(dev);
 276         if (obj == NULL) {
 277                 ret = -ENOMEM;
 278                 goto fail_detach;
 279         }
 280
 281         drm_gem_private_object_init(dev, &obj->base, dma_buf->size);
 282         i915_gem_object_init(obj, &i915_gem_object_dmabuf_ops);
 283         obj->base.import_attach = attach;
 284
 285         return &obj->base;
 286
 287 fail_detach:
 288         dma_buf_detach(dma_buf, attach);
 289         dma_buf_put(dma_buf);
 290
 291         return ERR_PTR(ret);
 292 }