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
  31 #include "i915_drv.h"
  32
  33 static struct drm_i915_gem_object *dma_buf_to_obj(struct dma_buf *buf)
  34 {
  35         return to_intel_bo(buf->priv);
  36 }
  37
  38 static struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachment,
  39                                              enum dma_data_direction dir)
  40 {
  41         struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);
  42         struct sg_table *st;
  43         struct scatterlist *src, *dst;
  44         int ret, i;
  45
  46         ret = i915_gem_object_pin_pages(obj);
  47         if (ret)
  48                 goto err;
  49
  50         /* Copy sg so that we make an independent mapping */
  51         st = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
  52         if (st == NULL) {
  53                 ret = -ENOMEM;
  54                 goto err_unpin_pages;
  55         }
  56
  57         ret = sg_alloc_table(st, obj->mm.pages->nents, GFP_KERNEL);
  58         if (ret)
  59                 goto err_free;
  60
  61         src = obj->mm.pages->sgl;
  62         dst = st->sgl;
  63         for (i = 0; i < obj->mm.pages->nents; i++) {
  64                 sg_set_page(dst, sg_page(src), src->length, 0);
  65                 dst = sg_next(dst);
  66                 src = sg_next(src);
  67         }
  68
  69         if (!dma_map_sg(attachment->dev, st->sgl, st->nents, dir)) {
  70                 ret = -ENOMEM;
  71                 goto err_free_sg;
  72         }
  73
  74         return st;
  75
  76 err_free_sg:
  77         sg_free_table(st);
  78 err_free:
  79         kfree(st);
  80 err_unpin_pages:
  81         i915_gem_object_unpin_pages(obj);
  82 err:
  83         return ERR_PTR(ret);
  84 }
  85
  86 static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
  87                                    struct sg_table *sg,
  88                                    enum dma_data_direction dir)
  89 {
  90         struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);
  91
  92         dma_unmap_sg(attachment->dev, sg->sgl, sg->nents, dir);
  93         sg_free_table(sg);
  94         kfree(sg);
  95
  96         i915_gem_object_unpin_pages(obj);
  97 }
  98
  99 static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
 100 {
 101         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 102
 103         return i915_gem_object_pin_map(obj, I915_MAP_WB);
 104 }
 105
 106 static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
 107 {
 108         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 109
 110         i915_gem_object_flush_map(obj);
 111         i915_gem_object_unpin_map(obj);
 112 }
 113
 114 static void *i915_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
 115 {
 116         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 117         struct page *page;
 118
 119         if (page_num >= obj->base.size >> PAGE_SHIFT)
 120                 return NULL;
 121
 122         if (!i915_gem_object_has_struct_page(obj))
 123                 return NULL;
 124
 125         if (i915_gem_object_pin_pages(obj))
 126                 return NULL;
 127
 128         /* Synchronisation is left to the caller (via .begin_cpu_access()) */
 129         page = i915_gem_object_get_page(obj, page_num);
 130         if (IS_ERR(page))
 131                 goto err_unpin;
 132
 133         return kmap(page);
 134
 135 err_unpin:
 136         i915_gem_object_unpin_pages(obj);
 137         return NULL;
 138 }
 139
 140 static void i915_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
 141 {
 142         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 143
 144         kunmap(virt_to_page(addr));
 145         i915_gem_object_unpin_pages(obj);
 146 }
 147
 148 static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
 149 {
 150         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 151         int ret;
 152
 153         if (obj->base.size < vma->vm_end - vma->vm_start)
 154                 return -EINVAL;
 155
 156         if (!obj->base.filp)
 157                 return -ENODEV;
 158
 159         ret = call_mmap(obj->base.filp, vma);
 160         if (ret)
 161                 return ret;
 162
 163         fput(vma->vm_file);
 164         vma->vm_file = get_file(obj->base.filp);
 165
 166         return 0;
 167 }
 168
 169 static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
 170 {
 171         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 172         struct drm_device *dev = obj->base.dev;
 173         bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE);
 174         int err;
 175
 176         err = i915_gem_object_pin_pages(obj);
 177         if (err)
 178                 return err;
 179
 180         err = i915_mutex_lock_interruptible(dev);
 181         if (err)
 182                 goto out;
 183
 184         err = i915_gem_object_set_to_cpu_domain(obj, write);
 185         mutex_unlock(&dev->struct_mutex);
 186
 187 out:
 188         i915_gem_object_unpin_pages(obj);
 189         return err;
 190 }
 191
 192 static int i915_gem_end_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
 193 {
 194         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 195         struct drm_device *dev = obj->base.dev;
 196         int err;
 197
 198         err = i915_gem_object_pin_pages(obj);
 199         if (err)
 200                 return err;
 201
 202         err = i915_mutex_lock_interruptible(dev);
 203         if (err)
 204                 goto out;
 205
 206         err = i915_gem_object_set_to_gtt_domain(obj, false);
 207         mutex_unlock(&dev->struct_mutex);
 208
 209 out:
 210         i915_gem_object_unpin_pages(obj);
 211         return err;
 212 }
 213
 214 static const struct dma_buf_ops i915_dmabuf_ops =  {
 215         .map_dma_buf = i915_gem_map_dma_buf,
 216         .unmap_dma_buf = i915_gem_unmap_dma_buf,
 217         .release = drm_gem_dmabuf_release,
 218         .map = i915_gem_dmabuf_kmap,
 219         .unmap = i915_gem_dmabuf_kunmap,
 220         .mmap = i915_gem_dmabuf_mmap,
 221         .vmap = i915_gem_dmabuf_vmap,
 222         .vunmap = i915_gem_dmabuf_vunmap,
 223         .begin_cpu_access = i915_gem_begin_cpu_access,
 224         .end_cpu_access = i915_gem_end_cpu_access,
 225 };
 226
 227 struct dma_buf *i915_gem_prime_export(struct drm_device *dev,
 228                                       struct drm_gem_object *gem_obj, int flags)
 229 {
 230         struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
 231         DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 232
 233         exp_info.ops = &i915_dmabuf_ops;
 234         exp_info.size = gem_obj->size;
 235         exp_info.flags = flags;
 236         exp_info.priv = gem_obj;
 237         exp_info.resv = obj->resv;
 238
 239         if (obj->ops->dmabuf_export) {
 240                 int ret = obj->ops->dmabuf_export(obj);
 241                 if (ret)
 242                         return ERR_PTR(ret);
 243         }
 244
 245         return drm_gem_dmabuf_export(dev, &exp_info);
 246 }
 247
 248 static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
 249 {
 250         struct sg_table *pages;
 251         unsigned int sg_page_sizes;
 252
 253         pages = dma_buf_map_attachment(obj->base.import_attach,
 254                                        DMA_BIDIRECTIONAL);
 255         if (IS_ERR(pages))
 256                 return PTR_ERR(pages);
 257
 258         sg_page_sizes = i915_sg_page_sizes(pages->sgl);
 259
 260         __i915_gem_object_set_pages(obj, pages, sg_page_sizes);
 261
 262         return 0;
 263 }
 264
 265 static void i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object *obj,
 266                                              struct sg_table *pages)
 267 {
 268         dma_buf_unmap_attachment(obj->base.import_attach, pages,
 269                                  DMA_BIDIRECTIONAL);
 270 }
 271
 272 static const struct drm_i915_gem_object_ops i915_gem_object_dmabuf_ops = {
 273         .get_pages = i915_gem_object_get_pages_dmabuf,
 274         .put_pages = i915_gem_object_put_pages_dmabuf,
 275 };
 276
 277 struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
 278                                              struct dma_buf *dma_buf)
 279 {
 280         struct dma_buf_attachment *attach;
 281         struct drm_i915_gem_object *obj;
 282         int ret;
 283
 284         /* is this one of own objects? */
 285         if (dma_buf->ops == &i915_dmabuf_ops) {
 286                 obj = dma_buf_to_obj(dma_buf);
 287                 /* is it from our device? */
 288                 if (obj->base.dev == dev) {
 289                         /*
 290                          * Importing dmabuf exported from out own gem increases
 291                          * refcount on gem itself instead of f_count of dmabuf.
 292                          */
 293                         return &i915_gem_object_get(obj)->base;
 294                 }
 295         }
 296
 297         /* need to attach */
 298         attach = dma_buf_attach(dma_buf, dev->dev);
 299         if (IS_ERR(attach))
 300                 return ERR_CAST(attach);
 301
 302         get_dma_buf(dma_buf);
 303
 304         obj = i915_gem_object_alloc();
 305         if (obj == NULL) {
 306                 ret = -ENOMEM;
 307                 goto fail_detach;
 308         }
 309
 310         drm_gem_private_object_init(dev, &obj->base, dma_buf->size);
 311         i915_gem_object_init(obj, &i915_gem_object_dmabuf_ops);
 312         obj->base.import_attach = attach;
 313         obj->resv = dma_buf->resv;
 314
 315         /* We use GTT as shorthand for a coherent domain, one that is
 316          * neither in the GPU cache nor in the CPU cache, where all
 317          * writes are immediately visible in memory. (That's not strictly
 318          * true, but it's close! There are internal buffers such as the
 319          * write-combined buffer or a delay through the chipset for GTT
 320          * writes that do require us to treat GTT as a separate cache domain.)
 321          */
 322         obj->read_domains = I915_GEM_DOMAIN_GTT;
 323         obj->write_domain = 0;
 324
 325         return &obj->base;
 326
 327 fail_detach:
 328         dma_buf_detach(dma_buf, attach);
 329         dma_buf_put(dma_buf);
 330
 331         return ERR_PTR(ret);
 332 }
 333
 334 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
 335 #include "selftests/mock_dmabuf.c"
 336 #include "selftests/i915_gem_dmabuf.c"
 337 #endif