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_release(struct dma_buf *dma_buf)
  94 {
  95         struct drm_i915_gem_object *obj = dma_buf->priv;
  96
  97         if (obj->base.export_dma_buf == dma_buf) {
  98                 /* drop the reference on the export fd holds */
  99                 obj->base.export_dma_buf = NULL;
 100                 drm_gem_object_unreference_unlocked(&obj->base);
 101         }
 102 }
 103
 104 static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
 105 {
 106         struct drm_i915_gem_object *obj = dma_buf->priv;
 107         struct drm_device *dev = obj->base.dev;
 108         struct sg_page_iter sg_iter;
 109         struct page **pages;
 110         int ret, i;
 111
 112         ret = i915_mutex_lock_interruptible(dev);
 113         if (ret)
 114                 return ERR_PTR(ret);
 115
 116         if (obj->dma_buf_vmapping) {
 117                 obj->vmapping_count++;
 118                 goto out_unlock;
 119         }
 120
 121         ret = i915_gem_object_get_pages(obj);
 122         if (ret)
 123                 goto error;
 124
 125         ret = -ENOMEM;
 126
 127         pages = drm_malloc_ab(obj->base.size >> PAGE_SHIFT, sizeof(*pages));
 128         if (pages == NULL)
 129                 goto error;
 130
 131         i = 0;
 132         for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0)
 133                 pages[i++] = sg_page_iter_page(&sg_iter);
 134
 135         obj->dma_buf_vmapping = vmap(pages, i, 0, PAGE_KERNEL);
 136         drm_free_large(pages);
 137
 138         if (!obj->dma_buf_vmapping)
 139                 goto error;
 140
 141         obj->vmapping_count = 1;
 142         i915_gem_object_pin_pages(obj);
 143 out_unlock:
 144         mutex_unlock(&dev->struct_mutex);
 145         return obj->dma_buf_vmapping;
 146
 147 error:
 148         mutex_unlock(&dev->struct_mutex);
 149         return ERR_PTR(ret);
 150 }
 151
 152 static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
 153 {
 154         struct drm_i915_gem_object *obj = dma_buf->priv;
 155         struct drm_device *dev = obj->base.dev;
 156         int ret;
 157
 158         ret = i915_mutex_lock_interruptible(dev);
 159         if (ret)
 160                 return;
 161
 162         if (--obj->vmapping_count == 0) {
 163                 vunmap(obj->dma_buf_vmapping);
 164                 obj->dma_buf_vmapping = NULL;
 165
 166                 i915_gem_object_unpin_pages(obj);
 167         }
 168         mutex_unlock(&dev->struct_mutex);
 169 }
 170
 171 static void *i915_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf, unsigned long page_num)
 172 {
 173         return NULL;
 174 }
 175
 176 static void i915_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
 177 {
 178
 179 }
 180 static void *i915_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
 181 {
 182         return NULL;
 183 }
 184
 185 static void i915_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
 186 {
 187
 188 }
 189
 190 static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
 191 {
 192         return -EINVAL;
 193 }
 194
 195 static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, size_t start, size_t length, enum dma_data_direction direction)
 196 {
 197         struct drm_i915_gem_object *obj = dma_buf->priv;
 198         struct drm_device *dev = obj->base.dev;
 199         int ret;
 200         bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE);
 201
 202         ret = i915_mutex_lock_interruptible(dev);
 203         if (ret)
 204                 return ret;
 205
 206         ret = i915_gem_object_set_to_cpu_domain(obj, write);
 207         mutex_unlock(&dev->struct_mutex);
 208         return ret;
 209 }
 210
 211 static const struct dma_buf_ops i915_dmabuf_ops =  {
 212         .map_dma_buf = i915_gem_map_dma_buf,
 213         .unmap_dma_buf = i915_gem_unmap_dma_buf,
 214         .release = i915_gem_dmabuf_release,
 215         .kmap = i915_gem_dmabuf_kmap,
 216         .kmap_atomic = i915_gem_dmabuf_kmap_atomic,
 217         .kunmap = i915_gem_dmabuf_kunmap,
 218         .kunmap_atomic = i915_gem_dmabuf_kunmap_atomic,
 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 };
 224
 225 struct dma_buf *i915_gem_prime_export(struct drm_device *dev,
 226                                       struct drm_gem_object *gem_obj, int flags)
 227 {
 228         struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
 229
 230         return dma_buf_export(obj, &i915_dmabuf_ops, obj->base.size, flags);
 231 }
 232
 233 static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
 234 {
 235         struct sg_table *sg;
 236
 237         sg = dma_buf_map_attachment(obj->base.import_attach, DMA_BIDIRECTIONAL);
 238         if (IS_ERR(sg))
 239                 return PTR_ERR(sg);
 240
 241         obj->pages = sg;
 242         obj->has_dma_mapping = true;
 243         return 0;
 244 }
 245
 246 static void i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object *obj)
 247 {
 248         dma_buf_unmap_attachment(obj->base.import_attach,
 249                                  obj->pages, DMA_BIDIRECTIONAL);
 250         obj->has_dma_mapping = false;
 251 }
 252
 253 static const struct drm_i915_gem_object_ops i915_gem_object_dmabuf_ops = {
 254         .get_pages = i915_gem_object_get_pages_dmabuf,
 255         .put_pages = i915_gem_object_put_pages_dmabuf,
 256 };
 257
 258 struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
 259                                              struct dma_buf *dma_buf)
 260 {
 261         struct dma_buf_attachment *attach;
 262         struct drm_i915_gem_object *obj;
 263         int ret;
 264
 265         /* is this one of own objects? */
 266         if (dma_buf->ops == &i915_dmabuf_ops) {
 267                 obj = dma_buf->priv;
 268                 /* is it from our device? */
 269                 if (obj->base.dev == dev) {
 270                         /*
 271                          * Importing dmabuf exported from out own gem increases
 272                          * refcount on gem itself instead of f_count of dmabuf.
 273                          */
 274                         drm_gem_object_reference(&obj->base);
 275                         return &obj->base;
 276                 }
 277         }
 278
 279         /* need to attach */
 280         attach = dma_buf_attach(dma_buf, dev->dev);
 281         if (IS_ERR(attach))
 282                 return ERR_CAST(attach);
 283
 284         get_dma_buf(dma_buf);
 285
 286         obj = i915_gem_object_alloc(dev);
 287         if (obj == NULL) {
 288                 ret = -ENOMEM;
 289                 goto fail_detach;
 290         }
 291
 292         ret = drm_gem_private_object_init(dev, &obj->base, dma_buf->size);
 293         if (ret) {
 294                 i915_gem_object_free(obj);
 295                 goto fail_detach;
 296         }
 297
 298         i915_gem_object_init(obj, &i915_gem_object_dmabuf_ops);
 299         obj->base.import_attach = attach;
 300
 301         return &obj->base;
 302
 303 fail_detach:
 304         dma_buf_detach(dma_buf, attach);
 305         dma_buf_put(dma_buf);
 306
 307         return ERR_PTR(ret);
 308 }