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 vm_fault_t 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         vm_fault_t ret = VM_FAULT_SIGBUS;
  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         mutex_lock(&obj->pages_lock);
  81         if (obj->pages) {
  82                 get_page(obj->pages[page_offset]);
  83                 vmf->page = obj->pages[page_offset];
  84                 ret = 0;
  85         }
  86         mutex_unlock(&obj->pages_lock);
  87         if (ret) {
  88                 struct page *page;
  89
  90                 page = shmem_read_mapping_page(
  91                                         file_inode(obj->base.filp)->i_mapping,
  92                                         page_offset);
  93                 if (!IS_ERR(page)) {
  94                         vmf->page = page;
  95                         ret = 0;
  96                 } else switch (PTR_ERR(page)) {
  97                         case -ENOSPC:
  98                         case -ENOMEM:
  99                                 ret = VM_FAULT_OOM;
 100                                 break;
 101                         case -EBUSY:
 102                                 ret = VM_FAULT_RETRY;
 103                                 break;
 104                         case -EFAULT:
 105                         case -EINVAL:
 106                                 ret = VM_FAULT_SIGBUS;
 107                                 break;
 108                         default:
 109                                 WARN_ON(PTR_ERR(page));
 110                                 ret = VM_FAULT_SIGBUS;
 111                                 break;
 112                 }
 113
 114         }
 115         return ret;
 116 }
 117
 118 static const struct vm_operations_struct vgem_gem_vm_ops = {
 119         .fault = vgem_gem_fault,
 120         .open = drm_gem_vm_open,
 121         .close = drm_gem_vm_close,
 122 };
 123
 124 static int vgem_open(struct drm_device *dev, struct drm_file *file)
 125 {
 126         struct vgem_file *vfile;
 127         int ret;
 128
 129         vfile = kzalloc(sizeof(*vfile), GFP_KERNEL);
 130         if (!vfile)
 131                 return -ENOMEM;
 132
 133         file->driver_priv = vfile;
 134
 135         ret = vgem_fence_open(vfile);
 136         if (ret) {
 137                 kfree(vfile);
 138                 return ret;
 139         }
 140
 141         return 0;
 142 }
 143
 144 static void vgem_postclose(struct drm_device *dev, struct drm_file *file)
 145 {
 146         struct vgem_file *vfile = file->driver_priv;
 147
 148         vgem_fence_close(vfile);
 149         kfree(vfile);
 150 }
 151
 152 static struct drm_vgem_gem_object *__vgem_gem_create(struct drm_device *dev,
 153                                                 unsigned long size)
 154 {
 155         struct drm_vgem_gem_object *obj;
 156         int ret;
 157
 158         obj = kzalloc(sizeof(*obj), GFP_KERNEL);
 159         if (!obj)
 160                 return ERR_PTR(-ENOMEM);
 161
 162         ret = drm_gem_object_init(dev, &obj->base, roundup(size, PAGE_SIZE));
 163         if (ret) {
 164                 kfree(obj);
 165                 return ERR_PTR(ret);
 166         }
 167
 168         mutex_init(&obj->pages_lock);
 169
 170         return obj;
 171 }
 172
 173 static void __vgem_gem_destroy(struct drm_vgem_gem_object *obj)
 174 {
 175         drm_gem_object_release(&obj->base);
 176         kfree(obj);
 177 }
 178
 179 static struct drm_gem_object *vgem_gem_create(struct drm_device *dev,
 180                                               struct drm_file *file,
 181                                               unsigned int *handle,
 182                                               unsigned long size)
 183 {
 184         struct drm_vgem_gem_object *obj;
 185         int ret;
 186
 187         obj = __vgem_gem_create(dev, size);
 188         if (IS_ERR(obj))
 189                 return ERR_CAST(obj);
 190
 191         ret = drm_gem_handle_create(file, &obj->base, handle);
 192         drm_gem_object_put_unlocked(&obj->base);
 193         if (ret)
 194                 return ERR_PTR(ret);
 195
 196         return &obj->base;
 197 }
 198
 199 static int vgem_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
 200                                 struct drm_mode_create_dumb *args)
 201 {
 202         struct drm_gem_object *gem_object;
 203         u64 pitch, size;
 204
 205         pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
 206         size = args->height * pitch;
 207         if (size == 0)
 208                 return -EINVAL;
 209
 210         gem_object = vgem_gem_create(dev, file, &args->handle, size);
 211         if (IS_ERR(gem_object))
 212                 return PTR_ERR(gem_object);
 213
 214         args->size = gem_object->size;
 215         args->pitch = pitch;
 216
 217         DRM_DEBUG_DRIVER("Created object of size %lld\n", size);
 218
 219         return 0;
 220 }
 221
 222 static struct drm_ioctl_desc vgem_ioctls[] = {
 223         DRM_IOCTL_DEF_DRV(VGEM_FENCE_ATTACH, vgem_fence_attach_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
 224         DRM_IOCTL_DEF_DRV(VGEM_FENCE_SIGNAL, vgem_fence_signal_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
 225 };
 226
 227 static int vgem_mmap(struct file *filp, struct vm_area_struct *vma)
 228 {
 229         unsigned long flags = vma->vm_flags;
 230         int ret;
 231
 232         ret = drm_gem_mmap(filp, vma);
 233         if (ret)
 234                 return ret;
 235
 236         /* Keep the WC mmaping set by drm_gem_mmap() but our pages
 237          * are ordinary and not special.
 238          */
 239         vma->vm_flags = flags | VM_DONTEXPAND | VM_DONTDUMP;
 240         return 0;
 241 }
 242
 243 static const struct file_operations vgem_driver_fops = {
 244         .owner          = THIS_MODULE,
 245         .open           = drm_open,
 246         .mmap           = vgem_mmap,
 247         .poll           = drm_poll,
 248         .read           = drm_read,
 249         .unlocked_ioctl = drm_ioctl,
 250         .compat_ioctl   = drm_compat_ioctl,
 251         .release        = drm_release,
 252 };
 253
 254 static struct page **vgem_pin_pages(struct drm_vgem_gem_object *bo)
 255 {
 256         mutex_lock(&bo->pages_lock);
 257         if (bo->pages_pin_count++ == 0) {
 258                 struct page **pages;
 259
 260                 pages = drm_gem_get_pages(&bo->base);
 261                 if (IS_ERR(pages)) {
 262                         bo->pages_pin_count--;
 263                         mutex_unlock(&bo->pages_lock);
 264                         return pages;
 265                 }
 266
 267                 bo->pages = pages;
 268         }
 269         mutex_unlock(&bo->pages_lock);
 270
 271         return bo->pages;
 272 }
 273
 274 static void vgem_unpin_pages(struct drm_vgem_gem_object *bo)
 275 {
 276         mutex_lock(&bo->pages_lock);
 277         if (--bo->pages_pin_count == 0) {
 278                 drm_gem_put_pages(&bo->base, bo->pages, true, true);
 279                 bo->pages = NULL;
 280         }
 281         mutex_unlock(&bo->pages_lock);
 282 }
 283
 284 static int vgem_prime_pin(struct drm_gem_object *obj)
 285 {
 286         struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 287         long n_pages = obj->size >> PAGE_SHIFT;
 288         struct page **pages;
 289
 290         pages = vgem_pin_pages(bo);
 291         if (IS_ERR(pages))
 292                 return PTR_ERR(pages);
 293
 294         /* Flush the object from the CPU cache so that importers can rely
 295          * on coherent indirect access via the exported dma-address.
 296          */
 297         drm_clflush_pages(pages, n_pages);
 298
 299         return 0;
 300 }
 301
 302 static void vgem_prime_unpin(struct drm_gem_object *obj)
 303 {
 304         struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 305
 306         vgem_unpin_pages(bo);
 307 }
 308
 309 static struct sg_table *vgem_prime_get_sg_table(struct drm_gem_object *obj)
 310 {
 311         struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 312
 313         return drm_prime_pages_to_sg(bo->pages, bo->base.size >> PAGE_SHIFT);
 314 }
 315
 316 static struct drm_gem_object* vgem_prime_import(struct drm_device *dev,
 317                                                 struct dma_buf *dma_buf)
 318 {
 319         struct vgem_device *vgem = container_of(dev, typeof(*vgem), drm);
 320
 321         return drm_gem_prime_import_dev(dev, dma_buf, &vgem->platform->dev);
 322 }
 323
 324 static struct drm_gem_object *vgem_prime_import_sg_table(struct drm_device *dev,
 325                         struct dma_buf_attachment *attach, struct sg_table *sg)
 326 {
 327         struct drm_vgem_gem_object *obj;
 328         int npages;
 329
 330         obj = __vgem_gem_create(dev, attach->dmabuf->size);
 331         if (IS_ERR(obj))
 332                 return ERR_CAST(obj);
 333
 334         npages = PAGE_ALIGN(attach->dmabuf->size) / PAGE_SIZE;
 335
 336         obj->table = sg;
 337         obj->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
 338         if (!obj->pages) {
 339                 __vgem_gem_destroy(obj);
 340                 return ERR_PTR(-ENOMEM);
 341         }
 342
 343         obj->pages_pin_count++; /* perma-pinned */
 344         drm_prime_sg_to_page_addr_arrays(obj->table, obj->pages, NULL,
 345                                         npages);
 346         return &obj->base;
 347 }
 348
 349 static void *vgem_prime_vmap(struct drm_gem_object *obj)
 350 {
 351         struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 352         long n_pages = obj->size >> PAGE_SHIFT;
 353         struct page **pages;
 354
 355         pages = vgem_pin_pages(bo);
 356         if (IS_ERR(pages))
 357                 return NULL;
 358
 359         return vmap(pages, n_pages, 0, pgprot_writecombine(PAGE_KERNEL));
 360 }
 361
 362 static void vgem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
 363 {
 364         struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 365
 366         vunmap(vaddr);
 367         vgem_unpin_pages(bo);
 368 }
 369
 370 static int vgem_prime_mmap(struct drm_gem_object *obj,
 371                            struct vm_area_struct *vma)
 372 {
 373         int ret;
 374
 375         if (obj->size < vma->vm_end - vma->vm_start)
 376                 return -EINVAL;
 377
 378         if (!obj->filp)
 379                 return -ENODEV;
 380
 381         ret = call_mmap(obj->filp, vma);
 382         if (ret)
 383                 return ret;
 384
 385         fput(vma->vm_file);
 386         vma->vm_file = get_file(obj->filp);
 387         vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
 388         vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
 389
 390         return 0;
 391 }
 392
 393 static void vgem_release(struct drm_device *dev)
 394 {
 395         struct vgem_device *vgem = container_of(dev, typeof(*vgem), drm);
 396
 397         platform_device_unregister(vgem->platform);
 398         drm_dev_fini(&vgem->drm);
 399
 400         kfree(vgem);
 401 }
 402
 403 static struct drm_driver vgem_driver = {
 404         .driver_features                = DRIVER_GEM | DRIVER_PRIME,
 405         .release                        = vgem_release,
 406         .open                           = vgem_open,
 407         .postclose                      = vgem_postclose,
 408         .gem_free_object_unlocked       = vgem_gem_free_object,
 409         .gem_vm_ops                     = &vgem_gem_vm_ops,
 410         .ioctls                         = vgem_ioctls,
 411         .num_ioctls                     = ARRAY_SIZE(vgem_ioctls),
 412         .fops                           = &vgem_driver_fops,
 413
 414         .dumb_create                    = vgem_gem_dumb_create,
 415
 416         .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
 417         .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
 418         .gem_prime_pin = vgem_prime_pin,
 419         .gem_prime_unpin = vgem_prime_unpin,
 420         .gem_prime_import = vgem_prime_import,
 421         .gem_prime_export = drm_gem_prime_export,
 422         .gem_prime_import_sg_table = vgem_prime_import_sg_table,
 423         .gem_prime_get_sg_table = vgem_prime_get_sg_table,
 424         .gem_prime_vmap = vgem_prime_vmap,
 425         .gem_prime_vunmap = vgem_prime_vunmap,
 426         .gem_prime_mmap = vgem_prime_mmap,
 427
 428         .name   = DRIVER_NAME,
 429         .desc   = DRIVER_DESC,
 430         .date   = DRIVER_DATE,
 431         .major  = DRIVER_MAJOR,
 432         .minor  = DRIVER_MINOR,
 433 };
 434
 435 static int __init vgem_init(void)
 436 {
 437         int ret;
 438
 439         vgem_device = kzalloc(sizeof(*vgem_device), GFP_KERNEL);
 440         if (!vgem_device)
 441                 return -ENOMEM;
 442
 443         vgem_device->platform =
 444                 platform_device_register_simple("vgem", -1, NULL, 0);
 445         if (IS_ERR(vgem_device->platform)) {
 446                 ret = PTR_ERR(vgem_device->platform);
 447                 goto out_free;
 448         }
 449
 450         dma_coerce_mask_and_coherent(&vgem_device->platform->dev,
 451                                      DMA_BIT_MASK(64));
 452         ret = drm_dev_init(&vgem_device->drm, &vgem_driver,
 453                            &vgem_device->platform->dev);
 454         if (ret)
 455                 goto out_unregister;
 456
 457         /* Final step: expose the device/driver to userspace */
 458         ret  = drm_dev_register(&vgem_device->drm, 0);
 459         if (ret)
 460                 goto out_fini;
 461
 462         return 0;
 463
 464 out_fini:
 465         drm_dev_fini(&vgem_device->drm);
 466 out_unregister:
 467         platform_device_unregister(vgem_device->platform);
 468 out_free:
 469         kfree(vgem_device);
 470         return ret;
 471 }
 472
 473 static void __exit vgem_exit(void)
 474 {
 475         drm_dev_unregister(&vgem_device->drm);
 476         drm_dev_unref(&vgem_device->drm);
 477 }
 478
 479 module_init(vgem_init);
 480 module_exit(vgem_exit);
 481
 482 MODULE_AUTHOR("Red Hat, Inc.");
 483 MODULE_AUTHOR("Intel Corporation");
 484 MODULE_DESCRIPTION(DRIVER_DESC);
 485 MODULE_LICENSE("GPL and additional rights");