drivers/gpu/drm/vgem/vgem_drv.c

   1 /*
   2  * Copyright 2011 Red Hat, Inc.
   3  * Copyright © 2014 The Chromium OS Authors
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software")
   7  * to deal in the software without restriction, including without limitation
   8  * on the rights to use, copy, modify, merge, publish, distribute, sub
   9  * license, and/or sell copies of the Software, and to permit persons to whom
  10  * them Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice (including the next
  13  * paragraph) shall be included in all copies or substantial portions of the
  14  * Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTIBILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES, OR OTHER LIABILITY, WHETHER
  20  * IN AN ACTION OF CONTRACT, TORT, OR OTHERWISE, ARISING FROM, OUT OF OR IN
  21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *      Adam Jackson <ajax@redhat.com>
  25  *      Ben Widawsky <ben@bwidawsk.net>
  26  */
  27
  28 /**
  29  * This is vgem, a (non-hardware-backed) GEM service.  This is used by Mesa's
  30  * software renderer and the X server for efficient buffer sharing.
  31  */
  32
  33 #include <linux/module.h>
  34 #include <linux/ramfs.h>
  35 #include <linux/shmem_fs.h>
  36 #include <linux/dma-buf.h>
  37 #include "vgem_drv.h"
  38
  39 #define DRIVER_NAME     "vgem"
  40 #define DRIVER_DESC     "Virtual GEM provider"
  41 #define DRIVER_DATE     "20120112"
  42 #define DRIVER_MAJOR    1
  43 #define DRIVER_MINOR    0
  44
  45 static struct vgem_device {
  46         struct drm_device drm;
  47         struct platform_device *platform;
  48 } *vgem_device;
  49
  50 static void vgem_gem_free_object(struct drm_gem_object *obj)
  51 {
  52         struct drm_vgem_gem_object *vgem_obj = to_vgem_bo(obj);
  53
  54         kvfree(vgem_obj->pages);
  55         mutex_destroy(&vgem_obj->pages_lock);
  56
  57         if (obj->import_attach)
  58                 drm_prime_gem_destroy(obj, vgem_obj->table);
  59
  60         drm_gem_object_release(obj);
  61         kfree(vgem_obj);
  62 }
  63
  64 static int vgem_gem_fault(struct vm_fault *vmf)
  65 {
  66         struct vm_area_struct *vma = vmf->vma;
  67         struct drm_vgem_gem_object *obj = vma->vm_private_data;
  68         /* We don't use vmf->pgoff since that has the fake offset */
  69         unsigned long vaddr = vmf->address;
  70         int ret;
  71         loff_t num_pages;
  72         pgoff_t page_offset;
  73         page_offset = (vaddr - vma->vm_start) >> PAGE_SHIFT;
  74
  75         num_pages = DIV_ROUND_UP(obj->base.size, PAGE_SIZE);
  76
  77         if (page_offset > num_pages)
  78                 return VM_FAULT_SIGBUS;
  79
  80         ret = -ENOENT;
  81         mutex_lock(&obj->pages_lock);
  82         if (obj->pages) {
  83                 get_page(obj->pages[page_offset]);
  84                 vmf->page = obj->pages[page_offset];
  85                 ret = 0;
  86         }
  87         mutex_unlock(&obj->pages_lock);
  88         if (ret) {
  89                 struct page *page;
  90
  91                 page = shmem_read_mapping_page(
  92                                         file_inode(obj->base.filp)->i_mapping,
  93                                         page_offset);
  94                 if (!IS_ERR(page)) {
  95                         vmf->page = page;
  96                         ret = 0;
  97                 } else switch (PTR_ERR(page)) {
  98                         case -ENOSPC:
  99                         case -ENOMEM:
 100                                 ret = VM_FAULT_OOM;
 101                                 break;
 102                         case -EBUSY:
 103                                 ret = VM_FAULT_RETRY;
 104                                 break;
 105                         case -EFAULT:
 106                         case -EINVAL:
 107                                 ret = VM_FAULT_SIGBUS;
 108                                 break;
 109                         default:
 110                                 WARN_ON(PTR_ERR(page));
 111                                 ret = VM_FAULT_SIGBUS;
 112                                 break;
 113                 }
 114
 115         }
 116         return ret;
 117 }
 118
 119 static const struct vm_operations_struct vgem_gem_vm_ops = {
 120         .fault = vgem_gem_fault,
 121         .open = drm_gem_vm_open,
 122         .close = drm_gem_vm_close,
 123 };
 124
 125 static int vgem_open(struct drm_device *dev, struct drm_file *file)
 126 {
 127         struct vgem_file *vfile;
 128         int ret;
 129
 130         vfile = kzalloc(sizeof(*vfile), GFP_KERNEL);
 131         if (!vfile)
 132                 return -ENOMEM;
 133
 134         file->driver_priv = vfile;
 135
 136         ret = vgem_fence_open(vfile);
 137         if (ret) {
 138                 kfree(vfile);
 139                 return ret;
 140         }
 141
 142         return 0;
 143 }
 144
 145 static void vgem_postclose(struct drm_device *dev, struct drm_file *file)
 146 {
 147         struct vgem_file *vfile = file->driver_priv;
 148
 149         vgem_fence_close(vfile);
 150         kfree(vfile);
 151 }
 152
 153 static struct drm_vgem_gem_object *__vgem_gem_create(struct drm_device *dev,
 154                                                 unsigned long size)
 155 {
 156         struct drm_vgem_gem_object *obj;
 157         int ret;
 158
 159         obj = kzalloc(sizeof(*obj), GFP_KERNEL);
 160         if (!obj)
 161                 return ERR_PTR(-ENOMEM);
 162
 163         ret = drm_gem_object_init(dev, &obj->base, roundup(size, PAGE_SIZE));
 164         if (ret) {
 165                 kfree(obj);
 166                 return ERR_PTR(ret);
 167         }
 168
 169         mutex_init(&obj->pages_lock);
 170
 171         return obj;
 172 }
 173
 174 static void __vgem_gem_destroy(struct drm_vgem_gem_object *obj)
 175 {
 176         drm_gem_object_release(&obj->base);
 177         kfree(obj);
 178 }
 179
 180 static struct drm_gem_object *vgem_gem_create(struct drm_device *dev,
 181                                               struct drm_file *file,
 182                                               unsigned int *handle,
 183                                               unsigned long size)
 184 {
 185         struct drm_vgem_gem_object *obj;
 186         int ret;
 187
 188         obj = __vgem_gem_create(dev, size);
 189         if (IS_ERR(obj))
 190                 return ERR_CAST(obj);
 191
 192         ret = drm_gem_handle_create(file, &obj->base, handle);
 193         if (ret) {
 194                 drm_gem_object_put_unlocked(&obj->base);
 195                 return ERR_PTR(ret);
 196         }
 197
 198         return &obj->base;
 199 }
 200
 201 static int vgem_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
 202                                 struct drm_mode_create_dumb *args)
 203 {
 204         struct drm_gem_object *gem_object;
 205         u64 pitch, size;
 206
 207         pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
 208         size = args->height * pitch;
 209         if (size == 0)
 210                 return -EINVAL;
 211
 212         gem_object = vgem_gem_create(dev, file, &args->handle, size);
 213         if (IS_ERR(gem_object))
 214                 return PTR_ERR(gem_object);
 215
 216         args->size = gem_object->size;
 217         args->pitch = pitch;
 218
 219         drm_gem_object_put_unlocked(gem_object);
 220
 221         DRM_DEBUG_DRIVER("Created object of size %llu\n", args->size);
 222
 223         return 0;
 224 }
 225
 226 static struct drm_ioctl_desc vgem_ioctls[] = {
 227         DRM_IOCTL_DEF_DRV(VGEM_FENCE_ATTACH, vgem_fence_attach_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
 228         DRM_IOCTL_DEF_DRV(VGEM_FENCE_SIGNAL, vgem_fence_signal_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
 229 };
 230
 231 static int vgem_mmap(struct file *filp, struct vm_area_struct *vma)
 232 {
 233         unsigned long flags = vma->vm_flags;
 234         int ret;
 235
 236         ret = drm_gem_mmap(filp, vma);
 237         if (ret)
 238                 return ret;
 239
 240         /* Keep the WC mmaping set by drm_gem_mmap() but our pages
 241          * are ordinary and not special.
 242          */
 243         vma->vm_flags = flags | VM_DONTEXPAND | VM_DONTDUMP;
 244         return 0;
 245 }
 246
 247 static const struct file_operations vgem_driver_fops = {
 248         .owner          = THIS_MODULE,
 249         .open           = drm_open,
 250         .mmap           = vgem_mmap,
 251         .poll           = drm_poll,
 252         .read           = drm_read,
 253         .unlocked_ioctl = drm_ioctl,
 254         .compat_ioctl   = drm_compat_ioctl,
 255         .release        = drm_release,
 256 };
 257
 258 static struct page **vgem_pin_pages(struct drm_vgem_gem_object *bo)
 259 {
 260         mutex_lock(&bo->pages_lock);
 261         if (bo->pages_pin_count++ == 0) {
 262                 struct page **pages;
 263
 264                 pages = drm_gem_get_pages(&bo->base);
 265                 if (IS_ERR(pages)) {
 266                         bo->pages_pin_count--;
 267                         mutex_unlock(&bo->pages_lock);
 268                         return pages;
 269                 }
 270
 271                 bo->pages = pages;
 272         }
 273         mutex_unlock(&bo->pages_lock);
 274
 275         return bo->pages;
 276 }
 277
 278 static void vgem_unpin_pages(struct drm_vgem_gem_object *bo)
 279 {
 280         mutex_lock(&bo->pages_lock);
 281         if (--bo->pages_pin_count == 0) {
 282                 drm_gem_put_pages(&bo->base, bo->pages, true, true);
 283                 bo->pages = NULL;
 284         }
 285         mutex_unlock(&bo->pages_lock);
 286 }
 287
 288 static int vgem_prime_pin(struct drm_gem_object *obj)
 289 {
 290         struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 291         long n_pages = obj->size >> PAGE_SHIFT;
 292         struct page **pages;
 293
 294         pages = vgem_pin_pages(bo);
 295         if (IS_ERR(pages))
 296                 return PTR_ERR(pages);
 297
 298         /* Flush the object from the CPU cache so that importers can rely
 299          * on coherent indirect access via the exported dma-address.
 300          */
 301         drm_clflush_pages(pages, n_pages);
 302
 303         return 0;
 304 }
 305
 306 static void vgem_prime_unpin(struct drm_gem_object *obj)
 307 {
 308         struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 309
 310         vgem_unpin_pages(bo);
 311 }
 312
 313 static struct sg_table *vgem_prime_get_sg_table(struct drm_gem_object *obj)
 314 {
 315         struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 316
 317         return drm_prime_pages_to_sg(bo->pages, bo->base.size >> PAGE_SHIFT);
 318 }
 319
 320 static struct drm_gem_object* vgem_prime_import(struct drm_device *dev,
 321                                                 struct dma_buf *dma_buf)
 322 {
 323         struct vgem_device *vgem = container_of(dev, typeof(*vgem), drm);
 324
 325         return drm_gem_prime_import_dev(dev, dma_buf, &vgem->platform->dev);
 326 }
 327
 328 static struct drm_gem_object *vgem_prime_import_sg_table(struct drm_device *dev,
 329                         struct dma_buf_attachment *attach, struct sg_table *sg)
 330 {
 331         struct drm_vgem_gem_object *obj;
 332         int npages;
 333
 334         obj = __vgem_gem_create(dev, attach->dmabuf->size);
 335         if (IS_ERR(obj))
 336                 return ERR_CAST(obj);
 337
 338         npages = PAGE_ALIGN(attach->dmabuf->size) / PAGE_SIZE;
 339
 340         obj->table = sg;
 341         obj->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
 342         if (!obj->pages) {
 343                 __vgem_gem_destroy(obj);
 344                 return ERR_PTR(-ENOMEM);
 345         }
 346
 347         obj->pages_pin_count++; /* perma-pinned */
 348         drm_prime_sg_to_page_addr_arrays(obj->table, obj->pages, NULL,
 349                                         npages);
 350         return &obj->base;
 351 }
 352
 353 static void *vgem_prime_vmap(struct drm_gem_object *obj)
 354 {
 355         struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 356         long n_pages = obj->size >> PAGE_SHIFT;
 357         struct page **pages;
 358
 359         pages = vgem_pin_pages(bo);
 360         if (IS_ERR(pages))
 361                 return NULL;
 362
 363         return vmap(pages, n_pages, 0, pgprot_writecombine(PAGE_KERNEL));
 364 }
 365
 366 static void vgem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
 367 {
 368         struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 369
 370         vunmap(vaddr);
 371         vgem_unpin_pages(bo);
 372 }
 373
 374 static int vgem_prime_mmap(struct drm_gem_object *obj,
 375                            struct vm_area_struct *vma)
 376 {
 377         int ret;
 378
 379         if (obj->size < vma->vm_end - vma->vm_start)
 380                 return -EINVAL;
 381
 382         if (!obj->filp)
 383                 return -ENODEV;
 384
 385         ret = call_mmap(obj->filp, vma);
 386         if (ret)
 387                 return ret;
 388
 389         fput(vma->vm_file);
 390         vma->vm_file = get_file(obj->filp);
 391         vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
 392         vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
 393
 394         return 0;
 395 }
 396
 397 static void vgem_release(struct drm_device *dev)
 398 {
 399         struct vgem_device *vgem = container_of(dev, typeof(*vgem), drm);
 400
 401         platform_device_unregister(vgem->platform);
 402         drm_dev_fini(&vgem->drm);
 403
 404         kfree(vgem);
 405 }
 406
 407 static struct drm_driver vgem_driver = {
 408         .driver_features                = DRIVER_GEM | DRIVER_PRIME,
 409         .release                        = vgem_release,
 410         .open                           = vgem_open,
 411         .postclose                      = vgem_postclose,
 412         .gem_free_object_unlocked       = vgem_gem_free_object,
 413         .gem_vm_ops                     = &vgem_gem_vm_ops,
 414         .ioctls                         = vgem_ioctls,
 415         .num_ioctls                     = ARRAY_SIZE(vgem_ioctls),
 416         .fops                           = &vgem_driver_fops,
 417
 418         .dumb_create                    = vgem_gem_dumb_create,
 419
 420         .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
 421         .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
 422         .gem_prime_pin = vgem_prime_pin,
 423         .gem_prime_unpin = vgem_prime_unpin,
 424         .gem_prime_import = vgem_prime_import,
 425         .gem_prime_export = drm_gem_prime_export,
 426         .gem_prime_import_sg_table = vgem_prime_import_sg_table,
 427         .gem_prime_get_sg_table = vgem_prime_get_sg_table,
 428         .gem_prime_vmap = vgem_prime_vmap,
 429         .gem_prime_vunmap = vgem_prime_vunmap,
 430         .gem_prime_mmap = vgem_prime_mmap,
 431
 432         .name   = DRIVER_NAME,
 433         .desc   = DRIVER_DESC,
 434         .date   = DRIVER_DATE,
 435         .major  = DRIVER_MAJOR,
 436         .minor  = DRIVER_MINOR,
 437 };
 438
 439 static int __init vgem_init(void)
 440 {
 441         int ret;
 442
 443         vgem_device = kzalloc(sizeof(*vgem_device), GFP_KERNEL);
 444         if (!vgem_device)
 445                 return -ENOMEM;
 446
 447         vgem_device->platform =
 448                 platform_device_register_simple("vgem", -1, NULL, 0);
 449         if (IS_ERR(vgem_device->platform)) {
 450                 ret = PTR_ERR(vgem_device->platform);
 451                 goto out_free;
 452         }
 453
 454         dma_coerce_mask_and_coherent(&vgem_device->platform->dev,
 455                                      DMA_BIT_MASK(64));
 456         ret = drm_dev_init(&vgem_device->drm, &vgem_driver,
 457                            &vgem_device->platform->dev);
 458         if (ret)
 459                 goto out_unregister;
 460
 461         /* Final step: expose the device/driver to userspace */
 462         ret  = drm_dev_register(&vgem_device->drm, 0);
 463         if (ret)
 464                 goto out_fini;
 465
 466         return 0;
 467
 468 out_fini:
 469         drm_dev_fini(&vgem_device->drm);
 470 out_unregister:
 471         platform_device_unregister(vgem_device->platform);
 472 out_free:
 473         kfree(vgem_device);
 474         return ret;
 475 }
 476
 477 static void __exit vgem_exit(void)
 478 {
 479         drm_dev_unregister(&vgem_device->drm);
 480         drm_dev_unref(&vgem_device->drm);
 481 }
 482
 483 module_init(vgem_init);
 484 module_exit(vgem_exit);
 485
 486 MODULE_AUTHOR("Red Hat, Inc.");
 487 MODULE_AUTHOR("Intel Corporation");
 488 MODULE_DESCRIPTION(DRIVER_DESC);
 489 MODULE_LICENSE("GPL and additional rights");