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         drm_gem_object_put_unlocked(&obj->base);
 194         if (ret)
 195                 goto err;
 196
 197         return &obj->base;
 198
 199 err:
 200         __vgem_gem_destroy(obj);
 201         return ERR_PTR(ret);
 202 }
 203
 204 static int vgem_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
 205                                 struct drm_mode_create_dumb *args)
 206 {
 207         struct drm_gem_object *gem_object;
 208         u64 pitch, size;
 209
 210         pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
 211         size = args->height * pitch;
 212         if (size == 0)
 213                 return -EINVAL;
 214
 215         gem_object = vgem_gem_create(dev, file, &args->handle, size);
 216         if (IS_ERR(gem_object))
 217                 return PTR_ERR(gem_object);
 218
 219         args->size = gem_object->size;
 220         args->pitch = pitch;
 221
 222         DRM_DEBUG_DRIVER("Created object of size %lld\n", size);
 223
 224         return 0;
 225 }
 226
 227 static int vgem_gem_dumb_map(struct drm_file *file, struct drm_device *dev,
 228                              uint32_t handle, uint64_t *offset)
 229 {
 230         struct drm_gem_object *obj;
 231         int ret;
 232
 233         obj = drm_gem_object_lookup(file, handle);
 234         if (!obj)
 235                 return -ENOENT;
 236
 237         if (!obj->filp) {
 238                 ret = -EINVAL;
 239                 goto unref;
 240         }
 241
 242         ret = drm_gem_create_mmap_offset(obj);
 243         if (ret)
 244                 goto unref;
 245
 246         *offset = drm_vma_node_offset_addr(&obj->vma_node);
 247 unref:
 248         drm_gem_object_put_unlocked(obj);
 249
 250         return ret;
 251 }
 252
 253 static struct drm_ioctl_desc vgem_ioctls[] = {
 254         DRM_IOCTL_DEF_DRV(VGEM_FENCE_ATTACH, vgem_fence_attach_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
 255         DRM_IOCTL_DEF_DRV(VGEM_FENCE_SIGNAL, vgem_fence_signal_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
 256 };
 257
 258 static int vgem_mmap(struct file *filp, struct vm_area_struct *vma)
 259 {
 260         unsigned long flags = vma->vm_flags;
 261         int ret;
 262
 263         ret = drm_gem_mmap(filp, vma);
 264         if (ret)
 265                 return ret;
 266
 267         /* Keep the WC mmaping set by drm_gem_mmap() but our pages
 268          * are ordinary and not special.
 269          */
 270         vma->vm_flags = flags | VM_DONTEXPAND | VM_DONTDUMP;
 271         return 0;
 272 }
 273
 274 static const struct file_operations vgem_driver_fops = {
 275         .owner          = THIS_MODULE,
 276         .open           = drm_open,
 277         .mmap           = vgem_mmap,
 278         .poll           = drm_poll,
 279         .read           = drm_read,
 280         .unlocked_ioctl = drm_ioctl,
 281         .compat_ioctl   = drm_compat_ioctl,
 282         .release        = drm_release,
 283 };
 284
 285 static struct page **vgem_pin_pages(struct drm_vgem_gem_object *bo)
 286 {
 287         mutex_lock(&bo->pages_lock);
 288         if (bo->pages_pin_count++ == 0) {
 289                 struct page **pages;
 290
 291                 pages = drm_gem_get_pages(&bo->base);
 292                 if (IS_ERR(pages)) {
 293                         bo->pages_pin_count--;
 294                         mutex_unlock(&bo->pages_lock);
 295                         return pages;
 296                 }
 297
 298                 bo->pages = pages;
 299         }
 300         mutex_unlock(&bo->pages_lock);
 301
 302         return bo->pages;
 303 }
 304
 305 static void vgem_unpin_pages(struct drm_vgem_gem_object *bo)
 306 {
 307         mutex_lock(&bo->pages_lock);
 308         if (--bo->pages_pin_count == 0) {
 309                 drm_gem_put_pages(&bo->base, bo->pages, true, true);
 310                 bo->pages = NULL;
 311         }
 312         mutex_unlock(&bo->pages_lock);
 313 }
 314
 315 static int vgem_prime_pin(struct drm_gem_object *obj)
 316 {
 317         struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 318         long n_pages = obj->size >> PAGE_SHIFT;
 319         struct page **pages;
 320
 321         pages = vgem_pin_pages(bo);
 322         if (IS_ERR(pages))
 323                 return PTR_ERR(pages);
 324
 325         /* Flush the object from the CPU cache so that importers can rely
 326          * on coherent indirect access via the exported dma-address.
 327          */
 328         drm_clflush_pages(pages, n_pages);
 329
 330         return 0;
 331 }
 332
 333 static void vgem_prime_unpin(struct drm_gem_object *obj)
 334 {
 335         struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 336
 337         vgem_unpin_pages(bo);
 338 }
 339
 340 static struct sg_table *vgem_prime_get_sg_table(struct drm_gem_object *obj)
 341 {
 342         struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 343
 344         return drm_prime_pages_to_sg(bo->pages, bo->base.size >> PAGE_SHIFT);
 345 }
 346
 347 static struct drm_gem_object* vgem_prime_import(struct drm_device *dev,
 348                                                 struct dma_buf *dma_buf)
 349 {
 350         struct vgem_device *vgem = container_of(dev, typeof(*vgem), drm);
 351
 352         return drm_gem_prime_import_dev(dev, dma_buf, &vgem->platform->dev);
 353 }
 354
 355 static struct drm_gem_object *vgem_prime_import_sg_table(struct drm_device *dev,
 356                         struct dma_buf_attachment *attach, struct sg_table *sg)
 357 {
 358         struct drm_vgem_gem_object *obj;
 359         int npages;
 360
 361         obj = __vgem_gem_create(dev, attach->dmabuf->size);
 362         if (IS_ERR(obj))
 363                 return ERR_CAST(obj);
 364
 365         npages = PAGE_ALIGN(attach->dmabuf->size) / PAGE_SIZE;
 366
 367         obj->table = sg;
 368         obj->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
 369         if (!obj->pages) {
 370                 __vgem_gem_destroy(obj);
 371                 return ERR_PTR(-ENOMEM);
 372         }
 373
 374         obj->pages_pin_count++; /* perma-pinned */
 375         drm_prime_sg_to_page_addr_arrays(obj->table, obj->pages, NULL,
 376                                         npages);
 377         return &obj->base;
 378 }
 379
 380 static void *vgem_prime_vmap(struct drm_gem_object *obj)
 381 {
 382         struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 383         long n_pages = obj->size >> PAGE_SHIFT;
 384         struct page **pages;
 385
 386         pages = vgem_pin_pages(bo);
 387         if (IS_ERR(pages))
 388                 return NULL;
 389
 390         return vmap(pages, n_pages, 0, pgprot_writecombine(PAGE_KERNEL));
 391 }
 392
 393 static void vgem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
 394 {
 395         struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 396
 397         vunmap(vaddr);
 398         vgem_unpin_pages(bo);
 399 }
 400
 401 static int vgem_prime_mmap(struct drm_gem_object *obj,
 402                            struct vm_area_struct *vma)
 403 {
 404         int ret;
 405
 406         if (obj->size < vma->vm_end - vma->vm_start)
 407                 return -EINVAL;
 408
 409         if (!obj->filp)
 410                 return -ENODEV;
 411
 412         ret = call_mmap(obj->filp, vma);
 413         if (ret)
 414                 return ret;
 415
 416         fput(vma->vm_file);
 417         vma->vm_file = get_file(obj->filp);
 418         vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
 419         vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
 420
 421         return 0;
 422 }
 423
 424 static void vgem_release(struct drm_device *dev)
 425 {
 426         struct vgem_device *vgem = container_of(dev, typeof(*vgem), drm);
 427
 428         platform_device_unregister(vgem->platform);
 429         drm_dev_fini(&vgem->drm);
 430
 431         kfree(vgem);
 432 }
 433
 434 static struct drm_driver vgem_driver = {
 435         .driver_features                = DRIVER_GEM | DRIVER_PRIME,
 436         .release                        = vgem_release,
 437         .open                           = vgem_open,
 438         .postclose                      = vgem_postclose,
 439         .gem_free_object_unlocked       = vgem_gem_free_object,
 440         .gem_vm_ops                     = &vgem_gem_vm_ops,
 441         .ioctls                         = vgem_ioctls,
 442         .num_ioctls                     = ARRAY_SIZE(vgem_ioctls),
 443         .fops                           = &vgem_driver_fops,
 444
 445         .dumb_create                    = vgem_gem_dumb_create,
 446         .dumb_map_offset                = vgem_gem_dumb_map,
 447
 448         .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
 449         .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
 450         .gem_prime_pin = vgem_prime_pin,
 451         .gem_prime_unpin = vgem_prime_unpin,
 452         .gem_prime_import = vgem_prime_import,
 453         .gem_prime_export = drm_gem_prime_export,
 454         .gem_prime_import_sg_table = vgem_prime_import_sg_table,
 455         .gem_prime_get_sg_table = vgem_prime_get_sg_table,
 456         .gem_prime_vmap = vgem_prime_vmap,
 457         .gem_prime_vunmap = vgem_prime_vunmap,
 458         .gem_prime_mmap = vgem_prime_mmap,
 459
 460         .name   = DRIVER_NAME,
 461         .desc   = DRIVER_DESC,
 462         .date   = DRIVER_DATE,
 463         .major  = DRIVER_MAJOR,
 464         .minor  = DRIVER_MINOR,
 465 };
 466
 467 static int __init vgem_init(void)
 468 {
 469         int ret;
 470
 471         vgem_device = kzalloc(sizeof(*vgem_device), GFP_KERNEL);
 472         if (!vgem_device)
 473                 return -ENOMEM;
 474
 475         ret = drm_dev_init(&vgem_device->drm, &vgem_driver, NULL);
 476         if (ret)
 477                 goto out_free;
 478
 479         vgem_device->platform =
 480                 platform_device_register_simple("vgem", -1, NULL, 0);
 481         if (IS_ERR(vgem_device->platform)) {
 482                 ret = PTR_ERR(vgem_device->platform);
 483                 goto out_fini;
 484         }
 485
 486         dma_coerce_mask_and_coherent(&vgem_device->platform->dev,
 487                                      DMA_BIT_MASK(64));
 488
 489         /* Final step: expose the device/driver to userspace */
 490         ret  = drm_dev_register(&vgem_device->drm, 0);
 491         if (ret)
 492                 goto out_unregister;
 493
 494         return 0;
 495
 496 out_unregister:
 497         platform_device_unregister(vgem_device->platform);
 498 out_fini:
 499         drm_dev_fini(&vgem_device->drm);
 500 out_free:
 501         kfree(vgem_device);
 502         return ret;
 503 }
 504
 505 static void __exit vgem_exit(void)
 506 {
 507         drm_dev_unregister(&vgem_device->drm);
 508         drm_dev_unref(&vgem_device->drm);
 509 }
 510
 511 module_init(vgem_init);
 512 module_exit(vgem_exit);
 513
 514 MODULE_AUTHOR("Red Hat, Inc.");
 515 MODULE_AUTHOR("Intel Corporation");
 516 MODULE_DESCRIPTION(DRIVER_DESC);
 517 MODULE_LICENSE("GPL and additional rights");