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 drm_i915_gem_object *dma_buf_to_obj(struct dma_buf *buf)
  31 {
  32         return to_intel_bo(buf->priv);
  33 }
  34
  35 static struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachment,
  36                                              enum dma_data_direction dir)
  37 {
  38         struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);
  39         struct sg_table *st;
  40         struct scatterlist *src, *dst;
  41         int ret, i;
  42
  43         ret = i915_mutex_lock_interruptible(obj->base.dev);
  44         if (ret)
  45                 goto err;
  46
  47         ret = i915_gem_object_get_pages(obj);
  48         if (ret)
  49                 goto err_unlock;
  50
  51         i915_gem_object_pin_pages(obj);
  52
  53         /* Copy sg so that we make an independent mapping */
  54         st = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
  55         if (st == NULL) {
  56                 ret = -ENOMEM;
  57                 goto err_unpin;
  58         }
  59
  60         ret = sg_alloc_table(st, obj->pages->nents, GFP_KERNEL);
  61         if (ret)
  62                 goto err_free;
  63
  64         src = obj->pages->sgl;
  65         dst = st->sgl;
  66         for (i = 0; i < obj->pages->nents; i++) {
  67                 sg_set_page(dst, sg_page(src), src->length, 0);
  68                 dst = sg_next(dst);
  69                 src = sg_next(src);
  70         }
  71
  72         if (!dma_map_sg(attachment->dev, st->sgl, st->nents, dir)) {
  73                 ret =-ENOMEM;
  74                 goto err_free_sg;
  75         }
  76
  77         mutex_unlock(&obj->base.dev->struct_mutex);
  78         return st;
  79
  80 err_free_sg:
  81         sg_free_table(st);
  82 err_free:
  83         kfree(st);
  84 err_unpin:
  85         i915_gem_object_unpin_pages(obj);
  86 err_unlock:
  87         mutex_unlock(&obj->base.dev->struct_mutex);
  88 err:
  89         return ERR_PTR(ret);
  90 }
  91
  92 static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
  93                                    struct sg_table *sg,
  94                                    enum dma_data_direction dir)
  95 {
  96         struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);
  97
  98         mutex_lock(&obj->base.dev->struct_mutex);
  99
 100         dma_unmap_sg(attachment->dev, sg->sgl, sg->nents, dir);
 101         sg_free_table(sg);
 102         kfree(sg);
 103
 104         i915_gem_object_unpin_pages(obj);
 105
 106         mutex_unlock(&obj->base.dev->struct_mutex);
 107 }
 108
 109 static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
 110 {
 111         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 112         struct drm_device *dev = obj->base.dev;
 113         struct sg_page_iter sg_iter;
 114         struct page **pages;
 115         int ret, i;
 116
 117         ret = i915_mutex_lock_interruptible(dev);
 118         if (ret)
 119                 return ERR_PTR(ret);
 120
 121         if (obj->dma_buf_vmapping) {
 122                 obj->vmapping_count++;
 123                 goto out_unlock;
 124         }
 125
 126         ret = i915_gem_object_get_pages(obj);
 127         if (ret)
 128                 goto error;
 129
 130         ret = -ENOMEM;
 131
 132         pages = drm_malloc_ab(obj->base.size >> PAGE_SHIFT, sizeof(*pages));
 133         if (pages == NULL)
 134                 goto error;
 135
 136         i = 0;
 137         for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0)
 138                 pages[i++] = sg_page_iter_page(&sg_iter);
 139
 140         obj->dma_buf_vmapping = vmap(pages, i, 0, PAGE_KERNEL);
 141         drm_free_large(pages);
 142
 143         if (!obj->dma_buf_vmapping)
 144                 goto error;
 145
 146         obj->vmapping_count = 1;
 147         i915_gem_object_pin_pages(obj);
 148 out_unlock:
 149         mutex_unlock(&dev->struct_mutex);
 150         return obj->dma_buf_vmapping;
 151
 152 error:
 153         mutex_unlock(&dev->struct_mutex);
 154         return ERR_PTR(ret);
 155 }
 156
 157 static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
 158 {
 159         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 160         struct drm_device *dev = obj->base.dev;
 161         int ret;
 162
 163         ret = i915_mutex_lock_interruptible(dev);
 164         if (ret)
 165                 return;
 166
 167         if (--obj->vmapping_count == 0) {
 168                 vunmap(obj->dma_buf_vmapping);
 169                 obj->dma_buf_vmapping = NULL;
 170
 171                 i915_gem_object_unpin_pages(obj);
 172         }
 173         mutex_unlock(&dev->struct_mutex);
 174 }
 175
 176 static void *i915_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf, unsigned long page_num)
 177 {
 178         return NULL;
 179 }
 180
 181 static void i915_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
 182 {
 183
 184 }
 185 static void *i915_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
 186 {
 187         return NULL;
 188 }
 189
 190 static void i915_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
 191 {
 192
 193 }
 194
 195 static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
 196 {
 197         return -EINVAL;
 198 }
 199
 200 static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, size_t start, size_t length, enum dma_data_direction direction)
 201 {
 202         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 203         struct drm_device *dev = obj->base.dev;
 204         int ret;
 205         bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE);
 206
 207         ret = i915_mutex_lock_interruptible(dev);
 208         if (ret)
 209                 return ret;
 210
 211         ret = i915_gem_object_set_to_cpu_domain(obj, write);
 212         mutex_unlock(&dev->struct_mutex);
 213         return ret;
 214 }
 215
 216 static const struct dma_buf_ops i915_dmabuf_ops =  {
 217         .map_dma_buf = i915_gem_map_dma_buf,
 218         .unmap_dma_buf = i915_gem_unmap_dma_buf,
 219         .release = drm_gem_dmabuf_release,
 220         .kmap = i915_gem_dmabuf_kmap,
 221         .kmap_atomic = i915_gem_dmabuf_kmap_atomic,
 222         .kunmap = i915_gem_dmabuf_kunmap,
 223         .kunmap_atomic = i915_gem_dmabuf_kunmap_atomic,
 224         .mmap = i915_gem_dmabuf_mmap,
 225         .vmap = i915_gem_dmabuf_vmap,
 226         .vunmap = i915_gem_dmabuf_vunmap,
 227         .begin_cpu_access = i915_gem_begin_cpu_access,
 228 };
 229
 230 struct dma_buf *i915_gem_prime_export(struct drm_device *dev,
 231                                       struct drm_gem_object *gem_obj, int flags)
 232 {
 233         return dma_buf_export(gem_obj, &i915_dmabuf_ops, gem_obj->size, flags);
 234 }
 235
 236 static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
 237 {
 238         struct sg_table *sg;
 239
 240         sg = dma_buf_map_attachment(obj->base.import_attach, DMA_BIDIRECTIONAL);
 241         if (IS_ERR(sg))
 242                 return PTR_ERR(sg);
 243
 244         obj->pages = sg;
 245         obj->has_dma_mapping = true;
 246         return 0;
 247 }
 248
 249 static void i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object *obj)
 250 {
 251         dma_buf_unmap_attachment(obj->base.import_attach,
 252                                  obj->pages, DMA_BIDIRECTIONAL);
 253         obj->has_dma_mapping = false;
 254 }
 255
 256 static const struct drm_i915_gem_object_ops i915_gem_object_dmabuf_ops = {
 257         .get_pages = i915_gem_object_get_pages_dmabuf,
 258         .put_pages = i915_gem_object_put_pages_dmabuf,
 259 };
 260
 261 struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
 262                                              struct dma_buf *dma_buf)
 263 {
 264         struct dma_buf_attachment *attach;
 265         struct drm_i915_gem_object *obj;
 266         int ret;
 267
 268         /* is this one of own objects? */
 269         if (dma_buf->ops == &i915_dmabuf_ops) {
 270                 obj = dma_buf_to_obj(dma_buf);
 271                 /* is it from our device? */
 272                 if (obj->base.dev == dev) {
 273                         /*
 274                          * Importing dmabuf exported from out own gem increases
 275                          * refcount on gem itself instead of f_count of dmabuf.
 276                          */
 277                         drm_gem_object_reference(&obj->base);
 278                         return &obj->base;
 279                 }
 280         }
 281
 282         /* need to attach */
 283         attach = dma_buf_attach(dma_buf, dev->dev);
 284         if (IS_ERR(attach))
 285                 return ERR_CAST(attach);
 286
 287         get_dma_buf(dma_buf);
 288
 289         obj = i915_gem_object_alloc(dev);
 290         if (obj == NULL) {
 291                 ret = -ENOMEM;
 292                 goto fail_detach;
 293         }
 294
 295         drm_gem_private_object_init(dev, &obj->base, dma_buf->size);
 296         i915_gem_object_init(obj, &i915_gem_object_dmabuf_ops);
 297         obj->base.import_attach = attach;
 298
 299         return &obj->base;
 300
 301 fail_detach:
 302         dma_buf_detach(dma_buf, attach);
 303         dma_buf_put(dma_buf);
 304
 305         return ERR_PTR(ret);
 306 }