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_unpin_map(obj);
 111 }
 112
 113 static void *i915_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
 114 {
 115         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 116         struct page *page;
 117
 118         if (page_num >= obj->base.size >> PAGE_SHIFT)
 119                 return NULL;
 120
 121         if (!i915_gem_object_has_struct_page(obj))
 122                 return NULL;
 123
 124         if (i915_gem_object_pin_pages(obj))
 125                 return NULL;
 126
 127         /* Synchronisation is left to the caller (via .begin_cpu_access()) */
 128         page = i915_gem_object_get_page(obj, page_num);
 129         if (IS_ERR(page))
 130                 goto err_unpin;
 131
 132         return kmap(page);
 133
 134 err_unpin:
 135         i915_gem_object_unpin_pages(obj);
 136         return NULL;
 137 }
 138
 139 static void i915_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
 140 {
 141         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 142
 143         kunmap(virt_to_page(addr));
 144         i915_gem_object_unpin_pages(obj);
 145 }
 146
 147 static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
 148 {
 149         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 150         int ret;
 151
 152         if (obj->base.size < vma->vm_end - vma->vm_start)
 153                 return -EINVAL;
 154
 155         if (!obj->base.filp)
 156                 return -ENODEV;
 157
 158         ret = call_mmap(obj->base.filp, vma);
 159         if (ret)
 160                 return ret;
 161
 162         fput(vma->vm_file);
 163         vma->vm_file = get_file(obj->base.filp);
 164
 165         return 0;
 166 }
 167
 168 static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
 169 {
 170         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 171         struct drm_device *dev = obj->base.dev;
 172         bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE);
 173         int err;
 174
 175         err = i915_gem_object_pin_pages(obj);
 176         if (err)
 177                 return err;
 178
 179         err = i915_mutex_lock_interruptible(dev);
 180         if (err)
 181                 goto out;
 182
 183         err = i915_gem_object_set_to_cpu_domain(obj, write);
 184         mutex_unlock(&dev->struct_mutex);
 185
 186 out:
 187         i915_gem_object_unpin_pages(obj);
 188         return err;
 189 }
 190
 191 static int i915_gem_end_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
 192 {
 193         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 194         struct drm_device *dev = obj->base.dev;
 195         int err;
 196
 197         err = i915_gem_object_pin_pages(obj);
 198         if (err)
 199                 return err;
 200
 201         err = i915_mutex_lock_interruptible(dev);
 202         if (err)
 203                 goto out;
 204
 205         err = i915_gem_object_set_to_gtt_domain(obj, false);
 206         mutex_unlock(&dev->struct_mutex);
 207
 208 out:
 209         i915_gem_object_unpin_pages(obj);
 210         return err;
 211 }
 212
 213 static const struct dma_buf_ops i915_dmabuf_ops =  {
 214         .map_dma_buf = i915_gem_map_dma_buf,
 215         .unmap_dma_buf = i915_gem_unmap_dma_buf,
 216         .release = drm_gem_dmabuf_release,
 217         .map = i915_gem_dmabuf_kmap,
 218         .unmap = i915_gem_dmabuf_kunmap,
 219         .mmap = i915_gem_dmabuf_mmap,
 220         .vmap = i915_gem_dmabuf_vmap,
 221         .vunmap = i915_gem_dmabuf_vunmap,
 222         .begin_cpu_access = i915_gem_begin_cpu_access,
 223         .end_cpu_access = i915_gem_end_cpu_access,
 224 };
 225
 226 struct dma_buf *i915_gem_prime_export(struct drm_device *dev,
 227                                       struct drm_gem_object *gem_obj, int flags)
 228 {
 229         struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
 230         DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 231
 232         exp_info.ops = &i915_dmabuf_ops;
 233         exp_info.size = gem_obj->size;
 234         exp_info.flags = flags;
 235         exp_info.priv = gem_obj;
 236         exp_info.resv = obj->resv;
 237
 238         if (obj->ops->dmabuf_export) {
 239                 int ret = obj->ops->dmabuf_export(obj);
 240                 if (ret)
 241                         return ERR_PTR(ret);
 242         }
 243
 244         return drm_gem_dmabuf_export(dev, &exp_info);
 245 }
 246
 247 static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
 248 {
 249         struct sg_table *pages;
 250         unsigned int sg_page_sizes;
 251
 252         pages = dma_buf_map_attachment(obj->base.import_attach,
 253                                        DMA_BIDIRECTIONAL);
 254         if (IS_ERR(pages))
 255                 return PTR_ERR(pages);
 256
 257         sg_page_sizes = i915_sg_page_sizes(pages->sgl);
 258
 259         __i915_gem_object_set_pages(obj, pages, sg_page_sizes);
 260
 261         return 0;
 262 }
 263
 264 static void i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object *obj,
 265                                              struct sg_table *pages)
 266 {
 267         dma_buf_unmap_attachment(obj->base.import_attach, pages,
 268                                  DMA_BIDIRECTIONAL);
 269 }
 270
 271 static const struct drm_i915_gem_object_ops i915_gem_object_dmabuf_ops = {
 272         .get_pages = i915_gem_object_get_pages_dmabuf,
 273         .put_pages = i915_gem_object_put_pages_dmabuf,
 274 };
 275
 276 struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
 277                                              struct dma_buf *dma_buf)
 278 {
 279         struct dma_buf_attachment *attach;
 280         struct drm_i915_gem_object *obj;
 281         int ret;
 282
 283         /* is this one of own objects? */
 284         if (dma_buf->ops == &i915_dmabuf_ops) {
 285                 obj = dma_buf_to_obj(dma_buf);
 286                 /* is it from our device? */
 287                 if (obj->base.dev == dev) {
 288                         /*
 289                          * Importing dmabuf exported from out own gem increases
 290                          * refcount on gem itself instead of f_count of dmabuf.
 291                          */
 292                         return &i915_gem_object_get(obj)->base;
 293                 }
 294         }
 295
 296         /* need to attach */
 297         attach = dma_buf_attach(dma_buf, dev->dev);
 298         if (IS_ERR(attach))
 299                 return ERR_CAST(attach);
 300
 301         get_dma_buf(dma_buf);
 302
 303         obj = i915_gem_object_alloc(to_i915(dev));
 304         if (obj == NULL) {
 305                 ret = -ENOMEM;
 306                 goto fail_detach;
 307         }
 308
 309         drm_gem_private_object_init(dev, &obj->base, dma_buf->size);
 310         i915_gem_object_init(obj, &i915_gem_object_dmabuf_ops);
 311         obj->base.import_attach = attach;
 312         obj->resv = dma_buf->resv;
 313
 314         /* We use GTT as shorthand for a coherent domain, one that is
 315          * neither in the GPU cache nor in the CPU cache, where all
 316          * writes are immediately visible in memory. (That's not strictly
 317          * true, but it's close! There are internal buffers such as the
 318          * write-combined buffer or a delay through the chipset for GTT
 319          * writes that do require us to treat GTT as a separate cache domain.)
 320          */
 321         obj->read_domains = I915_GEM_DOMAIN_GTT;
 322         obj->write_domain = 0;
 323
 324         return &obj->base;
 325
 326 fail_detach:
 327         dma_buf_detach(dma_buf, attach);
 328         dma_buf_put(dma_buf);
 329
 330         return ERR_PTR(ret);
 331 }
 332
 333 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
 334 #include "selftests/mock_dmabuf.c"
 335 #include "selftests/i915_gem_dmabuf.c"
 336 #endif