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         struct drm_i915_gem_object *obj = attachment->dmabuf->priv;
  89
  90         mutex_lock(&obj->base.dev->struct_mutex);
  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         mutex_unlock(&obj->base.dev->struct_mutex);
  99 }
 100
 101 static void i915_gem_dmabuf_release(struct dma_buf *dma_buf)
 102 {
 103         struct drm_i915_gem_object *obj = dma_buf->priv;
 104
 105         if (obj->base.export_dma_buf == dma_buf) {
 106                 /* drop the reference on the export fd holds */
 107                 obj->base.export_dma_buf = NULL;
 108                 drm_gem_object_unreference_unlocked(&obj->base);
 109         }
 110 }
 111
 112 static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
 113 {
 114         struct drm_i915_gem_object *obj = dma_buf->priv;
 115         struct drm_device *dev = obj->base.dev;
 116         struct sg_page_iter sg_iter;
 117         struct page **pages;
 118         int ret, i;
 119
 120         ret = i915_mutex_lock_interruptible(dev);
 121         if (ret)
 122                 return ERR_PTR(ret);
 123
 124         if (obj->dma_buf_vmapping) {
 125                 obj->vmapping_count++;
 126                 goto out_unlock;
 127         }
 128
 129         ret = i915_gem_object_get_pages(obj);
 130         if (ret)
 131                 goto error;
 132
 133         ret = -ENOMEM;
 134
 135         pages = drm_malloc_ab(obj->base.size >> PAGE_SHIFT, sizeof(*pages));
 136         if (pages == NULL)
 137                 goto error;
 138
 139         i = 0;
 140         for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0)
 141                 pages[i++] = sg_page_iter_page(&sg_iter);
 142
 143         obj->dma_buf_vmapping = vmap(pages, i, 0, PAGE_KERNEL);
 144         drm_free_large(pages);
 145
 146         if (!obj->dma_buf_vmapping)
 147                 goto error;
 148
 149         obj->vmapping_count = 1;
 150         i915_gem_object_pin_pages(obj);
 151 out_unlock:
 152         mutex_unlock(&dev->struct_mutex);
 153         return obj->dma_buf_vmapping;
 154
 155 error:
 156         mutex_unlock(&dev->struct_mutex);
 157         return ERR_PTR(ret);
 158 }
 159
 160 static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
 161 {
 162         struct drm_i915_gem_object *obj = dma_buf->priv;
 163         struct drm_device *dev = obj->base.dev;
 164         int ret;
 165
 166         ret = i915_mutex_lock_interruptible(dev);
 167         if (ret)
 168                 return;
 169
 170         if (--obj->vmapping_count == 0) {
 171                 vunmap(obj->dma_buf_vmapping);
 172                 obj->dma_buf_vmapping = NULL;
 173
 174                 i915_gem_object_unpin_pages(obj);
 175         }
 176         mutex_unlock(&dev->struct_mutex);
 177 }
 178
 179 static void *i915_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf, unsigned long page_num)
 180 {
 181         return NULL;
 182 }
 183
 184 static void i915_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
 185 {
 186
 187 }
 188 static void *i915_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
 189 {
 190         return NULL;
 191 }
 192
 193 static void i915_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
 194 {
 195
 196 }
 197
 198 static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
 199 {
 200         return -EINVAL;
 201 }
 202
 203 static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, size_t start, size_t length, enum dma_data_direction direction)
 204 {
 205         struct drm_i915_gem_object *obj = dma_buf->priv;
 206         struct drm_device *dev = obj->base.dev;
 207         int ret;
 208         bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE);
 209
 210         ret = i915_mutex_lock_interruptible(dev);
 211         if (ret)
 212                 return ret;
 213
 214         ret = i915_gem_object_set_to_cpu_domain(obj, write);
 215         mutex_unlock(&dev->struct_mutex);
 216         return ret;
 217 }
 218
 219 static const struct dma_buf_ops i915_dmabuf_ops =  {
 220         .map_dma_buf = i915_gem_map_dma_buf,
 221         .unmap_dma_buf = i915_gem_unmap_dma_buf,
 222         .release = i915_gem_dmabuf_release,
 223         .kmap = i915_gem_dmabuf_kmap,
 224         .kmap_atomic = i915_gem_dmabuf_kmap_atomic,
 225         .kunmap = i915_gem_dmabuf_kunmap,
 226         .kunmap_atomic = i915_gem_dmabuf_kunmap_atomic,
 227         .mmap = i915_gem_dmabuf_mmap,
 228         .vmap = i915_gem_dmabuf_vmap,
 229         .vunmap = i915_gem_dmabuf_vunmap,
 230         .begin_cpu_access = i915_gem_begin_cpu_access,
 231 };
 232
 233 struct dma_buf *i915_gem_prime_export(struct drm_device *dev,
 234                                       struct drm_gem_object *gem_obj, int flags)
 235 {
 236         struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
 237
 238         return dma_buf_export(obj, &i915_dmabuf_ops, obj->base.size, flags);
 239 }
 240
 241 static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
 242 {
 243         struct sg_table *sg;
 244
 245         sg = dma_buf_map_attachment(obj->base.import_attach, DMA_BIDIRECTIONAL);
 246         if (IS_ERR(sg))
 247                 return PTR_ERR(sg);
 248
 249         obj->pages = sg;
 250         obj->has_dma_mapping = true;
 251         return 0;
 252 }
 253
 254 static void i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object *obj)
 255 {
 256         dma_buf_unmap_attachment(obj->base.import_attach,
 257                                  obj->pages, DMA_BIDIRECTIONAL);
 258         obj->has_dma_mapping = false;
 259 }
 260
 261 static const struct drm_i915_gem_object_ops i915_gem_object_dmabuf_ops = {
 262         .get_pages = i915_gem_object_get_pages_dmabuf,
 263         .put_pages = i915_gem_object_put_pages_dmabuf,
 264 };
 265
 266 struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
 267                                              struct dma_buf *dma_buf)
 268 {
 269         struct dma_buf_attachment *attach;
 270         struct drm_i915_gem_object *obj;
 271         int ret;
 272
 273         /* is this one of own objects? */
 274         if (dma_buf->ops == &i915_dmabuf_ops) {
 275                 obj = dma_buf->priv;
 276                 /* is it from our device? */
 277                 if (obj->base.dev == dev) {
 278                         /*
 279                          * Importing dmabuf exported from out own gem increases
 280                          * refcount on gem itself instead of f_count of dmabuf.
 281                          */
 282                         drm_gem_object_reference(&obj->base);
 283                         return &obj->base;
 284                 }
 285         }
 286
 287         /* need to attach */
 288         attach = dma_buf_attach(dma_buf, dev->dev);
 289         if (IS_ERR(attach))
 290                 return ERR_CAST(attach);
 291
 292         get_dma_buf(dma_buf);
 293
 294         obj = i915_gem_object_alloc(dev);
 295         if (obj == NULL) {
 296                 ret = -ENOMEM;
 297                 goto fail_detach;
 298         }
 299
 300         ret = drm_gem_private_object_init(dev, &obj->base, dma_buf->size);
 301         if (ret) {
 302                 i915_gem_object_free(obj);
 303                 goto fail_detach;
 304         }
 305
 306         i915_gem_object_init(obj, &i915_gem_object_dmabuf_ops);
 307         obj->base.import_attach = attach;
 308
 309         return &obj->base;
 310
 311 fail_detach:
 312         dma_buf_detach(dma_buf, attach);
 313         dma_buf_put(dma_buf);
 314
 315         return ERR_PTR(ret);
 316 }