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 #include <drm/drmP.h>
  31
  32 #include "i915_drv.h"
  33
  34 static struct drm_i915_gem_object *dma_buf_to_obj(struct dma_buf *buf)
  35 {
  36         return to_intel_bo(buf->priv);
  37 }
  38
  39 static struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachment,
  40                                              enum dma_data_direction dir)
  41 {
  42         struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);
  43         struct sg_table *st;
  44         struct scatterlist *src, *dst;
  45         int ret, i;
  46
  47         ret = i915_mutex_lock_interruptible(obj->base.dev);
  48         if (ret)
  49                 goto err;
  50
  51         ret = i915_gem_object_get_pages(obj);
  52         if (ret)
  53                 goto err_unlock;
  54
  55         i915_gem_object_pin_pages(obj);
  56
  57         /* Copy sg so that we make an independent mapping */
  58         st = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
  59         if (st == NULL) {
  60                 ret = -ENOMEM;
  61                 goto err_unpin;
  62         }
  63
  64         ret = sg_alloc_table(st, obj->pages->nents, GFP_KERNEL);
  65         if (ret)
  66                 goto err_free;
  67
  68         src = obj->pages->sgl;
  69         dst = st->sgl;
  70         for (i = 0; i < obj->pages->nents; i++) {
  71                 sg_set_page(dst, sg_page(src), src->length, 0);
  72                 dst = sg_next(dst);
  73                 src = sg_next(src);
  74         }
  75
  76         if (!dma_map_sg(attachment->dev, st->sgl, st->nents, dir)) {
  77                 ret =-ENOMEM;
  78                 goto err_free_sg;
  79         }
  80
  81         mutex_unlock(&obj->base.dev->struct_mutex);
  82         return st;
  83
  84 err_free_sg:
  85         sg_free_table(st);
  86 err_free:
  87         kfree(st);
  88 err_unpin:
  89         i915_gem_object_unpin_pages(obj);
  90 err_unlock:
  91         mutex_unlock(&obj->base.dev->struct_mutex);
  92 err:
  93         return ERR_PTR(ret);
  94 }
  95
  96 static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
  97                                    struct sg_table *sg,
  98                                    enum dma_data_direction dir)
  99 {
 100         struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);
 101
 102         dma_unmap_sg(attachment->dev, sg->sgl, sg->nents, dir);
 103         sg_free_table(sg);
 104         kfree(sg);
 105
 106         mutex_lock(&obj->base.dev->struct_mutex);
 107         i915_gem_object_unpin_pages(obj);
 108         mutex_unlock(&obj->base.dev->struct_mutex);
 109 }
 110
 111 static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
 112 {
 113         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 114         struct drm_device *dev = obj->base.dev;
 115         void *addr;
 116         int ret;
 117
 118         ret = i915_mutex_lock_interruptible(dev);
 119         if (ret)
 120                 return ERR_PTR(ret);
 121
 122         addr = i915_gem_object_pin_map(obj, I915_MAP_WB);
 123         mutex_unlock(&dev->struct_mutex);
 124
 125         return addr;
 126 }
 127
 128 static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
 129 {
 130         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 131         struct drm_device *dev = obj->base.dev;
 132
 133         mutex_lock(&dev->struct_mutex);
 134         i915_gem_object_unpin_map(obj);
 135         mutex_unlock(&dev->struct_mutex);
 136 }
 137
 138 static void *i915_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf, unsigned long page_num)
 139 {
 140         return NULL;
 141 }
 142
 143 static void i915_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
 144 {
 145
 146 }
 147 static void *i915_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
 148 {
 149         return NULL;
 150 }
 151
 152 static void i915_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
 153 {
 154
 155 }
 156
 157 static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
 158 {
 159         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 160         int ret;
 161
 162         if (obj->base.size < vma->vm_end - vma->vm_start)
 163                 return -EINVAL;
 164
 165         if (!obj->base.filp)
 166                 return -ENODEV;
 167
 168         ret = obj->base.filp->f_op->mmap(obj->base.filp, vma);
 169         if (ret)
 170                 return ret;
 171
 172         fput(vma->vm_file);
 173         vma->vm_file = get_file(obj->base.filp);
 174
 175         return 0;
 176 }
 177
 178 static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
 179 {
 180         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 181         struct drm_device *dev = obj->base.dev;
 182         int ret;
 183         bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE);
 184
 185         ret = i915_mutex_lock_interruptible(dev);
 186         if (ret)
 187                 return ret;
 188
 189         ret = i915_gem_object_set_to_cpu_domain(obj, write);
 190         mutex_unlock(&dev->struct_mutex);
 191         return ret;
 192 }
 193
 194 static int i915_gem_end_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
 195 {
 196         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 197         struct drm_device *dev = obj->base.dev;
 198         int ret;
 199
 200         ret = i915_mutex_lock_interruptible(dev);
 201         if (ret)
 202                 return ret;
 203
 204         ret = i915_gem_object_set_to_gtt_domain(obj, false);
 205         mutex_unlock(&dev->struct_mutex);
 206
 207         return ret;
 208 }
 209
 210 static const struct dma_buf_ops i915_dmabuf_ops =  {
 211         .map_dma_buf = i915_gem_map_dma_buf,
 212         .unmap_dma_buf = i915_gem_unmap_dma_buf,
 213         .release = drm_gem_dmabuf_release,
 214         .kmap = i915_gem_dmabuf_kmap,
 215         .kmap_atomic = i915_gem_dmabuf_kmap_atomic,
 216         .kunmap = i915_gem_dmabuf_kunmap,
 217         .kunmap_atomic = i915_gem_dmabuf_kunmap_atomic,
 218         .mmap = i915_gem_dmabuf_mmap,
 219         .vmap = i915_gem_dmabuf_vmap,
 220         .vunmap = i915_gem_dmabuf_vunmap,
 221         .begin_cpu_access = i915_gem_begin_cpu_access,
 222         .end_cpu_access = i915_gem_end_cpu_access,
 223 };
 224
 225 static void export_fences(struct drm_i915_gem_object *obj,
 226                           struct dma_buf *dma_buf)
 227 {
 228         struct reservation_object *resv = dma_buf->resv;
 229         struct drm_i915_gem_request *req;
 230         unsigned long active;
 231         int idx;
 232
 233         active = __I915_BO_ACTIVE(obj);
 234         if (!active)
 235                 return;
 236
 237         /* Serialise with execbuf to prevent concurrent fence-loops */
 238         mutex_lock(&obj->base.dev->struct_mutex);
 239
 240         /* Mark the object for future fences before racily adding old fences */
 241         obj->base.dma_buf = dma_buf;
 242
 243         ww_mutex_lock(&resv->lock, NULL);
 244
 245         for_each_active(active, idx) {
 246                 req = i915_gem_active_get(&obj->last_read[idx],
 247                                           &obj->base.dev->struct_mutex);
 248                 if (!req)
 249                         continue;
 250
 251                 if (reservation_object_reserve_shared(resv) == 0)
 252                         reservation_object_add_shared_fence(resv, &req->fence);
 253
 254                 i915_gem_request_put(req);
 255         }
 256
 257         req = i915_gem_active_get(&obj->last_write,
 258                                   &obj->base.dev->struct_mutex);
 259         if (req) {
 260                 reservation_object_add_excl_fence(resv, &req->fence);
 261                 i915_gem_request_put(req);
 262         }
 263
 264         ww_mutex_unlock(&resv->lock);
 265         mutex_unlock(&obj->base.dev->struct_mutex);
 266 }
 267
 268 struct dma_buf *i915_gem_prime_export(struct drm_device *dev,
 269                                       struct drm_gem_object *gem_obj, int flags)
 270 {
 271         struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
 272         DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 273         struct dma_buf *dma_buf;
 274
 275         exp_info.ops = &i915_dmabuf_ops;
 276         exp_info.size = gem_obj->size;
 277         exp_info.flags = flags;
 278         exp_info.priv = gem_obj;
 279
 280         if (obj->ops->dmabuf_export) {
 281                 int ret = obj->ops->dmabuf_export(obj);
 282                 if (ret)
 283                         return ERR_PTR(ret);
 284         }
 285
 286         dma_buf = dma_buf_export(&exp_info);
 287         if (IS_ERR(dma_buf))
 288                 return dma_buf;
 289
 290         export_fences(obj, dma_buf);
 291         return dma_buf;
 292 }
 293
 294 static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
 295 {
 296         struct sg_table *sg;
 297
 298         sg = dma_buf_map_attachment(obj->base.import_attach, DMA_BIDIRECTIONAL);
 299         if (IS_ERR(sg))
 300                 return PTR_ERR(sg);
 301
 302         obj->pages = sg;
 303         return 0;
 304 }
 305
 306 static void i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object *obj)
 307 {
 308         dma_buf_unmap_attachment(obj->base.import_attach,
 309                                  obj->pages, DMA_BIDIRECTIONAL);
 310 }
 311
 312 static const struct drm_i915_gem_object_ops i915_gem_object_dmabuf_ops = {
 313         .get_pages = i915_gem_object_get_pages_dmabuf,
 314         .put_pages = i915_gem_object_put_pages_dmabuf,
 315 };
 316
 317 struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
 318                                              struct dma_buf *dma_buf)
 319 {
 320         struct dma_buf_attachment *attach;
 321         struct drm_i915_gem_object *obj;
 322         int ret;
 323
 324         /* is this one of own objects? */
 325         if (dma_buf->ops == &i915_dmabuf_ops) {
 326                 obj = dma_buf_to_obj(dma_buf);
 327                 /* is it from our device? */
 328                 if (obj->base.dev == dev) {
 329                         /*
 330                          * Importing dmabuf exported from out own gem increases
 331                          * refcount on gem itself instead of f_count of dmabuf.
 332                          */
 333                         return &i915_gem_object_get(obj)->base;
 334                 }
 335         }
 336
 337         /* need to attach */
 338         attach = dma_buf_attach(dma_buf, dev->dev);
 339         if (IS_ERR(attach))
 340                 return ERR_CAST(attach);
 341
 342         get_dma_buf(dma_buf);
 343
 344         obj = i915_gem_object_alloc(dev);
 345         if (obj == NULL) {
 346                 ret = -ENOMEM;
 347                 goto fail_detach;
 348         }
 349
 350         drm_gem_private_object_init(dev, &obj->base, dma_buf->size);
 351         i915_gem_object_init(obj, &i915_gem_object_dmabuf_ops);
 352         obj->base.import_attach = attach;
 353
 354         /* We use GTT as shorthand for a coherent domain, one that is
 355          * neither in the GPU cache nor in the CPU cache, where all
 356          * writes are immediately visible in memory. (That's not strictly
 357          * true, but it's close! There are internal buffers such as the
 358          * write-combined buffer or a delay through the chipset for GTT
 359          * writes that do require us to treat GTT as a separate cache domain.)
 360          */
 361         obj->base.read_domains = I915_GEM_DOMAIN_GTT;
 362         obj->base.write_domain = 0;
 363
 364         return &obj->base;
 365
 366 fail_detach:
 367         dma_buf_detach(dma_buf, attach);
 368         dma_buf_put(dma_buf);
 369
 370         return ERR_PTR(ret);
 371 }