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
  27 #include <linux/dma-buf.h>
  28 #include <linux/reservation.h>
  29
  30 #include <drm/drmP.h>
  31
  32 #include "i915_drv.h"
  33
  34 static struct drm_i915_gem_object *dma_buf_to_obj(struct dma_buf *buf)
  35 {
  36         return to_intel_bo(buf->priv);
  37 }
  38
  39 static struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachment,
  40                                              enum dma_data_direction dir)
  41 {
  42         struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);
  43         struct sg_table *st;
  44         struct scatterlist *src, *dst;
  45         int ret, i;
  46
  47         ret = i915_gem_object_pin_pages(obj);
  48         if (ret)
  49                 goto err;
  50
  51         /* Copy sg so that we make an independent mapping */
  52         st = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
  53         if (st == NULL) {
  54                 ret = -ENOMEM;
  55                 goto err_unpin_pages;
  56         }
  57
  58         ret = sg_alloc_table(st, obj->mm.pages->nents, GFP_KERNEL);
  59         if (ret)
  60                 goto err_free;
  61
  62         src = obj->mm.pages->sgl;
  63         dst = st->sgl;
  64         for (i = 0; i < obj->mm.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                 ret = -ENOMEM;
  72                 goto err_free_sg;
  73         }
  74
  75         return st;
  76
  77 err_free_sg:
  78         sg_free_table(st);
  79 err_free:
  80         kfree(st);
  81 err_unpin_pages:
  82         i915_gem_object_unpin_pages(obj);
  83 err:
  84         return ERR_PTR(ret);
  85 }
  86
  87 static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
  88                                    struct sg_table *sg,
  89                                    enum dma_data_direction dir)
  90 {
  91         struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);
  92
  93         dma_unmap_sg(attachment->dev, sg->sgl, sg->nents, dir);
  94         sg_free_table(sg);
  95         kfree(sg);
  96
  97         i915_gem_object_unpin_pages(obj);
  98 }
  99
 100 static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
 101 {
 102         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 103
 104         return i915_gem_object_pin_map(obj, I915_MAP_WB);
 105 }
 106
 107 static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
 108 {
 109         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 110
 111         i915_gem_object_unpin_map(obj);
 112 }
 113
 114 static void *i915_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf, unsigned long page_num)
 115 {
 116         return NULL;
 117 }
 118
 119 static void i915_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
 120 {
 121
 122 }
 123 static void *i915_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
 124 {
 125         return NULL;
 126 }
 127
 128 static void i915_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
 129 {
 130
 131 }
 132
 133 static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
 134 {
 135         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 136         int ret;
 137
 138         if (obj->base.size < vma->vm_end - vma->vm_start)
 139                 return -EINVAL;
 140
 141         if (!obj->base.filp)
 142                 return -ENODEV;
 143
 144         ret = obj->base.filp->f_op->mmap(obj->base.filp, vma);
 145         if (ret)
 146                 return ret;
 147
 148         fput(vma->vm_file);
 149         vma->vm_file = get_file(obj->base.filp);
 150
 151         return 0;
 152 }
 153
 154 static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
 155 {
 156         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 157         struct drm_device *dev = obj->base.dev;
 158         bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE);
 159         int err;
 160
 161         err = i915_gem_object_pin_pages(obj);
 162         if (err)
 163                 return err;
 164
 165         err = i915_mutex_lock_interruptible(dev);
 166         if (err)
 167                 goto out;
 168
 169         err = i915_gem_object_set_to_cpu_domain(obj, write);
 170         mutex_unlock(&dev->struct_mutex);
 171
 172 out:
 173         i915_gem_object_unpin_pages(obj);
 174         return err;
 175 }
 176
 177 static int i915_gem_end_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
 178 {
 179         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 180         struct drm_device *dev = obj->base.dev;
 181         int err;
 182
 183         err = i915_gem_object_pin_pages(obj);
 184         if (err)
 185                 return err;
 186
 187         err = i915_mutex_lock_interruptible(dev);
 188         if (err)
 189                 goto out;
 190
 191         err = i915_gem_object_set_to_gtt_domain(obj, false);
 192         mutex_unlock(&dev->struct_mutex);
 193
 194 out:
 195         i915_gem_object_unpin_pages(obj);
 196         return err;
 197 }
 198
 199 static const struct dma_buf_ops i915_dmabuf_ops =  {
 200         .map_dma_buf = i915_gem_map_dma_buf,
 201         .unmap_dma_buf = i915_gem_unmap_dma_buf,
 202         .release = drm_gem_dmabuf_release,
 203         .kmap = i915_gem_dmabuf_kmap,
 204         .kmap_atomic = i915_gem_dmabuf_kmap_atomic,
 205         .kunmap = i915_gem_dmabuf_kunmap,
 206         .kunmap_atomic = i915_gem_dmabuf_kunmap_atomic,
 207         .mmap = i915_gem_dmabuf_mmap,
 208         .vmap = i915_gem_dmabuf_vmap,
 209         .vunmap = i915_gem_dmabuf_vunmap,
 210         .begin_cpu_access = i915_gem_begin_cpu_access,
 211         .end_cpu_access = i915_gem_end_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         DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 219
 220         exp_info.ops = &i915_dmabuf_ops;
 221         exp_info.size = gem_obj->size;
 222         exp_info.flags = flags;
 223         exp_info.priv = gem_obj;
 224         exp_info.resv = obj->resv;
 225
 226         if (obj->ops->dmabuf_export) {
 227                 int ret = obj->ops->dmabuf_export(obj);
 228                 if (ret)
 229                         return ERR_PTR(ret);
 230         }
 231
 232         return drm_gem_dmabuf_export(dev, &exp_info);
 233 }
 234
 235 static struct sg_table *
 236 i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
 237 {
 238         return dma_buf_map_attachment(obj->base.import_attach,
 239                                       DMA_BIDIRECTIONAL);
 240 }
 241
 242 static void i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object *obj,
 243                                              struct sg_table *pages)
 244 {
 245         dma_buf_unmap_attachment(obj->base.import_attach, pages,
 246                                  DMA_BIDIRECTIONAL);
 247 }
 248
 249 static const struct drm_i915_gem_object_ops i915_gem_object_dmabuf_ops = {
 250         .get_pages = i915_gem_object_get_pages_dmabuf,
 251         .put_pages = i915_gem_object_put_pages_dmabuf,
 252 };
 253
 254 struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
 255                                              struct dma_buf *dma_buf)
 256 {
 257         struct dma_buf_attachment *attach;
 258         struct drm_i915_gem_object *obj;
 259         int ret;
 260
 261         /* is this one of own objects? */
 262         if (dma_buf->ops == &i915_dmabuf_ops) {
 263                 obj = dma_buf_to_obj(dma_buf);
 264                 /* is it from our device? */
 265                 if (obj->base.dev == dev) {
 266                         /*
 267                          * Importing dmabuf exported from out own gem increases
 268                          * refcount on gem itself instead of f_count of dmabuf.
 269                          */
 270                         return &i915_gem_object_get(obj)->base;
 271                 }
 272         }
 273
 274         /* need to attach */
 275         attach = dma_buf_attach(dma_buf, dev->dev);
 276         if (IS_ERR(attach))
 277                 return ERR_CAST(attach);
 278
 279         get_dma_buf(dma_buf);
 280
 281         obj = i915_gem_object_alloc(to_i915(dev));
 282         if (obj == NULL) {
 283                 ret = -ENOMEM;
 284                 goto fail_detach;
 285         }
 286
 287         drm_gem_private_object_init(dev, &obj->base, dma_buf->size);
 288         i915_gem_object_init(obj, &i915_gem_object_dmabuf_ops);
 289         obj->base.import_attach = attach;
 290         obj->resv = dma_buf->resv;
 291
 292         /* We use GTT as shorthand for a coherent domain, one that is
 293          * neither in the GPU cache nor in the CPU cache, where all
 294          * writes are immediately visible in memory. (That's not strictly
 295          * true, but it's close! There are internal buffers such as the
 296          * write-combined buffer or a delay through the chipset for GTT
 297          * writes that do require us to treat GTT as a separate cache domain.)
 298          */
 299         obj->base.read_domains = I915_GEM_DOMAIN_GTT;
 300         obj->base.write_domain = 0;
 301
 302         return &obj->base;
 303
 304 fail_detach:
 305         dma_buf_detach(dma_buf, attach);
 306         dma_buf_put(dma_buf);
 307
 308         return ERR_PTR(ret);
 309 }