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/dma-buf.h>
  34 #include <linux/module.h>
  35 #include <linux/platform_device.h>
  36 #include <linux/shmem_fs.h>
  37 #include <linux/vmalloc.h>
  38
  39 #include <drm/drm_drv.h>
  40 #include <drm/drm_file.h>
  41 #include <drm/drm_ioctl.h>
  42 #include <drm/drm_prime.h>
  43
  44 #include "vgem_drv.h"
  45
  46 #define DRIVER_NAME     "vgem"
  47 #define DRIVER_DESC     "Virtual GEM provider"
  48 #define DRIVER_DATE     "20120112"
  49 #define DRIVER_MAJOR    1
  50 #define DRIVER_MINOR    0
  51
  52 static struct vgem_device {
  53         struct drm_device drm;
  54         struct platform_device *platform;
  55 } *vgem_device;
  56
  57 static void vgem_gem_free_object(struct drm_gem_object *obj)
  58 {
  59         struct drm_vgem_gem_object *vgem_obj = to_vgem_bo(obj);
  60
  61         kvfree(vgem_obj->pages);
  62         mutex_destroy(&vgem_obj->pages_lock);
  63
  64         if (obj->import_attach)
  65                 drm_prime_gem_destroy(obj, vgem_obj->table);
  66
  67         drm_gem_object_release(obj);
  68         kfree(vgem_obj);
  69 }
  70
  71 static vm_fault_t vgem_gem_fault(struct vm_fault *vmf)
  72 {
  73         struct vm_area_struct *vma = vmf->vma;
  74         struct drm_vgem_gem_object *obj = vma->vm_private_data;
  75         /* We don't use vmf->pgoff since that has the fake offset */
  76         unsigned long vaddr = vmf->address;
  77         vm_fault_t ret = VM_FAULT_SIGBUS;
  78         loff_t num_pages;
  79         pgoff_t page_offset;
  80         page_offset = (vaddr - vma->vm_start) >> PAGE_SHIFT;
  81
  82         num_pages = DIV_ROUND_UP(obj->base.size, PAGE_SIZE);
  83
  84         if (page_offset >= num_pages)
  85                 return VM_FAULT_SIGBUS;
  86
  87         mutex_lock(&obj->pages_lock);
  88         if (obj->pages) {
  89                 get_page(obj->pages[page_offset]);
  90                 vmf->page = obj->pages[page_offset];
  91                 ret = 0;
  92         }
  93         mutex_unlock(&obj->pages_lock);
  94         if (ret) {
  95                 struct page *page;
  96
  97                 page = shmem_read_mapping_page(
  98                                         file_inode(obj->base.filp)->i_mapping,
  99                                         page_offset);
 100                 if (!IS_ERR(page)) {
 101                         vmf->page = page;
 102                         ret = 0;
 103                 } else switch (PTR_ERR(page)) {
 104                         case -ENOSPC:
 105                         case -ENOMEM:
 106                                 ret = VM_FAULT_OOM;
 107                                 break;
 108                         case -EBUSY:
 109                                 ret = VM_FAULT_RETRY;
 110                                 break;
 111                         case -EFAULT:
 112                         case -EINVAL:
 113                                 ret = VM_FAULT_SIGBUS;
 114                                 break;
 115                         default:
 116                                 WARN_ON(PTR_ERR(page));
 117                                 ret = VM_FAULT_SIGBUS;
 118                                 break;
 119                 }
 120
 121         }
 122         return ret;
 123 }
 124
 125 static const struct vm_operations_struct vgem_gem_vm_ops = {
 126         .fault = vgem_gem_fault,
 127         .open = drm_gem_vm_open,
 128         .close = drm_gem_vm_close,
 129 };
 130
 131 static int vgem_open(struct drm_device *dev, struct drm_file *file)
 132 {
 133         struct vgem_file *vfile;
 134         int ret;
 135
 136         vfile = kzalloc(sizeof(*vfile), GFP_KERNEL);
 137         if (!vfile)
 138                 return -ENOMEM;
 139
 140         file->driver_priv = vfile;
 141
 142         ret = vgem_fence_open(vfile);
 143         if (ret) {
 144                 kfree(vfile);
 145                 return ret;
 146         }
 147
 148         return 0;
 149 }
 150
 151 static void vgem_postclose(struct drm_device *dev, struct drm_file *file)
 152 {
 153         struct vgem_file *vfile = file->driver_priv;
 154
 155         vgem_fence_close(vfile);
 156         kfree(vfile);
 157 }
 158
 159 static struct drm_vgem_gem_object *__vgem_gem_create(struct drm_device *dev,
 160                                                 unsigned long size)
 161 {
 162         struct drm_vgem_gem_object *obj;
 163         int ret;
 164
 165         obj = kzalloc(sizeof(*obj), GFP_KERNEL);
 166         if (!obj)
 167                 return ERR_PTR(-ENOMEM);
 168
 169         ret = drm_gem_object_init(dev, &obj->base, roundup(size, PAGE_SIZE));
 170         if (ret) {
 171                 kfree(obj);
 172                 return ERR_PTR(ret);
 173         }
 174
 175         mutex_init(&obj->pages_lock);
 176
 177         return obj;
 178 }
 179
 180 static void __vgem_gem_destroy(struct drm_vgem_gem_object *obj)
 181 {
 182         drm_gem_object_release(&obj->base);
 183         kfree(obj);
 184 }
 185
 186 static struct drm_gem_object *vgem_gem_create(struct drm_device *dev,
 187                                               struct drm_file *file,
 188                                               unsigned int *handle,
 189                                               unsigned long size)
 190 {
 191         struct drm_vgem_gem_object *obj;
 192         int ret;
 193
 194         obj = __vgem_gem_create(dev, size);
 195         if (IS_ERR(obj))
 196                 return ERR_CAST(obj);
 197
 198         ret = drm_gem_handle_create(file, &obj->base, handle);
 199         drm_gem_object_put_unlocked(&obj->base);
 200         if (ret)
 201                 return ERR_PTR(ret);
 202
 203         return &obj->base;
 204 }
 205
 206 static int vgem_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
 207                                 struct drm_mode_create_dumb *args)
 208 {
 209         struct drm_gem_object *gem_object;
 210         u64 pitch, size;
 211
 212         pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
 213         size = args->height * pitch;
 214         if (size == 0)
 215                 return -EINVAL;
 216
 217         gem_object = vgem_gem_create(dev, file, &args->handle, size);
 218         if (IS_ERR(gem_object))
 219                 return PTR_ERR(gem_object);
 220
 221         args->size = gem_object->size;
 222         args->pitch = pitch;
 223
 224         DRM_DEBUG("Created object of size %lld\n", size);
 225
 226         return 0;
 227 }
 228
 229 static int vgem_gem_dumb_map(struct drm_file *file, struct drm_device *dev,
 230                              uint32_t handle, uint64_t *offset)
 231 {
 232         struct drm_gem_object *obj;
 233         int ret;
 234
 235         obj = drm_gem_object_lookup(file, handle);
 236         if (!obj)
 237                 return -ENOENT;
 238
 239         if (!obj->filp) {
 240                 ret = -EINVAL;
 241                 goto unref;
 242         }
 243
 244         ret = drm_gem_create_mmap_offset(obj);
 245         if (ret)
 246                 goto unref;
 247
 248         *offset = drm_vma_node_offset_addr(&obj->vma_node);
 249 unref:
 250         drm_gem_object_put_unlocked(obj);
 251
 252         return ret;
 253 }
 254
 255 static struct drm_ioctl_desc vgem_ioctls[] = {
 256         DRM_IOCTL_DEF_DRV(VGEM_FENCE_ATTACH, vgem_fence_attach_ioctl, DRM_RENDER_ALLOW),
 257         DRM_IOCTL_DEF_DRV(VGEM_FENCE_SIGNAL, vgem_fence_signal_ioctl, DRM_RENDER_ALLOW),
 258 };
 259
 260 static int vgem_mmap(struct file *filp, struct vm_area_struct *vma)
 261 {
 262         unsigned long flags = vma->vm_flags;
 263         int ret;
 264
 265         ret = drm_gem_mmap(filp, vma);
 266         if (ret)
 267                 return ret;
 268
 269         /* Keep the WC mmaping set by drm_gem_mmap() but our pages
 270          * are ordinary and not special.
 271          */
 272         vma->vm_flags = flags | VM_DONTEXPAND | VM_DONTDUMP;
 273         return 0;
 274 }
 275
 276 static const struct file_operations vgem_driver_fops = {
 277         .owner          = THIS_MODULE,
 278         .open           = drm_open,
 279         .mmap           = vgem_mmap,
 280         .poll           = drm_poll,
 281         .read           = drm_read,
 282         .unlocked_ioctl = drm_ioctl,
 283         .compat_ioctl   = drm_compat_ioctl,
 284         .release        = drm_release,
 285 };
 286
 287 static struct page **vgem_pin_pages(struct drm_vgem_gem_object *bo)
 288 {
 289         mutex_lock(&bo->pages_lock);
 290         if (bo->pages_pin_count++ == 0) {
 291                 struct page **pages;
 292
 293                 pages = drm_gem_get_pages(&bo->base);
 294                 if (IS_ERR(pages)) {
 295                         bo->pages_pin_count--;
 296                         mutex_unlock(&bo->pages_lock);
 297                         return pages;
 298                 }
 299
 300                 bo->pages = pages;
 301         }
 302         mutex_unlock(&bo->pages_lock);
 303
 304         return bo->pages;
 305 }
 306
 307 static void vgem_unpin_pages(struct drm_vgem_gem_object *bo)
 308 {
 309         mutex_lock(&bo->pages_lock);
 310         if (--bo->pages_pin_count == 0) {
 311                 drm_gem_put_pages(&bo->base, bo->pages, true, true);
 312                 bo->pages = NULL;
 313         }
 314         mutex_unlock(&bo->pages_lock);
 315 }
 316
 317 static int vgem_prime_pin(struct drm_gem_object *obj)
 318 {
 319         struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 320         long n_pages = obj->size >> PAGE_SHIFT;
 321         struct page **pages;
 322
 323         pages = vgem_pin_pages(bo);
 324         if (IS_ERR(pages))
 325                 return PTR_ERR(pages);
 326
 327         /* Flush the object from the CPU cache so that importers can rely
 328          * on coherent indirect access via the exported dma-address.
 329          */
 330         drm_clflush_pages(pages, n_pages);
 331
 332         return 0;
 333 }
 334
 335 static void vgem_prime_unpin(struct drm_gem_object *obj)
 336 {
 337         struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 338
 339         vgem_unpin_pages(bo);
 340 }
 341
 342 static struct sg_table *vgem_prime_get_sg_table(struct drm_gem_object *obj)
 343 {
 344         struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 345
 346         return drm_prime_pages_to_sg(bo->pages, bo->base.size >> PAGE_SHIFT);
 347 }
 348
 349 static struct drm_gem_object* vgem_prime_import(struct drm_device *dev,
 350                                                 struct dma_buf *dma_buf)
 351 {
 352         struct vgem_device *vgem = container_of(dev, typeof(*vgem), drm);
 353
 354         return drm_gem_prime_import_dev(dev, dma_buf, &vgem->platform->dev);
 355 }
 356
 357 static struct drm_gem_object *vgem_prime_import_sg_table(struct drm_device *dev,
 358                         struct dma_buf_attachment *attach, struct sg_table *sg)
 359 {
 360         struct drm_vgem_gem_object *obj;
 361         int npages;
 362
 363         obj = __vgem_gem_create(dev, attach->dmabuf->size);
 364         if (IS_ERR(obj))
 365                 return ERR_CAST(obj);
 366
 367         npages = PAGE_ALIGN(attach->dmabuf->size) / PAGE_SIZE;
 368
 369         obj->table = sg;
 370         obj->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
 371         if (!obj->pages) {
 372                 __vgem_gem_destroy(obj);
 373                 return ERR_PTR(-ENOMEM);
 374         }
 375
 376         obj->pages_pin_count++; /* perma-pinned */
 377         drm_prime_sg_to_page_addr_arrays(obj->table, obj->pages, NULL,
 378                                         npages);
 379         return &obj->base;
 380 }
 381
 382 static void *vgem_prime_vmap(struct drm_gem_object *obj)
 383 {
 384         struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 385         long n_pages = obj->size >> PAGE_SHIFT;
 386         struct page **pages;
 387
 388         pages = vgem_pin_pages(bo);
 389         if (IS_ERR(pages))
 390                 return NULL;
 391
 392         return vmap(pages, n_pages, 0, pgprot_writecombine(PAGE_KERNEL));
 393 }
 394
 395 static void vgem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
 396 {
 397         struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 398
 399         vunmap(vaddr);
 400         vgem_unpin_pages(bo);
 401 }
 402
 403 static int vgem_prime_mmap(struct drm_gem_object *obj,
 404                            struct vm_area_struct *vma)
 405 {
 406         int ret;
 407
 408         if (obj->size < vma->vm_end - vma->vm_start)
 409                 return -EINVAL;
 410
 411         if (!obj->filp)
 412                 return -ENODEV;
 413
 414         ret = call_mmap(obj->filp, vma);
 415         if (ret)
 416                 return ret;
 417
 418         fput(vma->vm_file);
 419         vma->vm_file = get_file(obj->filp);
 420         vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
 421         vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
 422
 423         return 0;
 424 }
 425
 426 static void vgem_release(struct drm_device *dev)
 427 {
 428         struct vgem_device *vgem = container_of(dev, typeof(*vgem), drm);
 429
 430         platform_device_unregister(vgem->platform);
 431         drm_dev_fini(&vgem->drm);
 432
 433         kfree(vgem);
 434 }
 435
 436 static struct drm_driver vgem_driver = {
 437         .driver_features                = DRIVER_GEM | DRIVER_RENDER,
 438         .release                        = vgem_release,
 439         .open                           = vgem_open,
 440         .postclose                      = vgem_postclose,
 441         .gem_free_object_unlocked       = vgem_gem_free_object,
 442         .gem_vm_ops                     = &vgem_gem_vm_ops,
 443         .ioctls                         = vgem_ioctls,
 444         .num_ioctls                     = ARRAY_SIZE(vgem_ioctls),
 445         .fops                           = &vgem_driver_fops,
 446
 447         .dumb_create                    = vgem_gem_dumb_create,
 448         .dumb_map_offset                = vgem_gem_dumb_map,
 449
 450         .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
 451         .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
 452         .gem_prime_pin = vgem_prime_pin,
 453         .gem_prime_unpin = vgem_prime_unpin,
 454         .gem_prime_import = vgem_prime_import,
 455         .gem_prime_import_sg_table = vgem_prime_import_sg_table,
 456         .gem_prime_get_sg_table = vgem_prime_get_sg_table,
 457         .gem_prime_vmap = vgem_prime_vmap,
 458         .gem_prime_vunmap = vgem_prime_vunmap,
 459         .gem_prime_mmap = vgem_prime_mmap,
 460
 461         .name   = DRIVER_NAME,
 462         .desc   = DRIVER_DESC,
 463         .date   = DRIVER_DATE,
 464         .major  = DRIVER_MAJOR,
 465         .minor  = DRIVER_MINOR,
 466 };
 467
 468 static int __init vgem_init(void)
 469 {
 470         int ret;
 471
 472         vgem_device = kzalloc(sizeof(*vgem_device), GFP_KERNEL);
 473         if (!vgem_device)
 474                 return -ENOMEM;
 475
 476         vgem_device->platform =
 477                 platform_device_register_simple("vgem", -1, NULL, 0);
 478         if (IS_ERR(vgem_device->platform)) {
 479                 ret = PTR_ERR(vgem_device->platform);
 480                 goto out_free;
 481         }
 482
 483         dma_coerce_mask_and_coherent(&vgem_device->platform->dev,
 484                                      DMA_BIT_MASK(64));
 485         ret = drm_dev_init(&vgem_device->drm, &vgem_driver,
 486                            &vgem_device->platform->dev);
 487         if (ret)
 488                 goto out_unregister;
 489
 490         /* Final step: expose the device/driver to userspace */
 491         ret  = drm_dev_register(&vgem_device->drm, 0);
 492         if (ret)
 493                 goto out_fini;
 494
 495         return 0;
 496
 497 out_fini:
 498         drm_dev_fini(&vgem_device->drm);
 499 out_unregister:
 500         platform_device_unregister(vgem_device->platform);
 501 out_free:
 502         kfree(vgem_device);
 503         return ret;
 504 }
 505
 506 static void __exit vgem_exit(void)
 507 {
 508         drm_dev_unregister(&vgem_device->drm);
 509         drm_dev_put(&vgem_device->drm);
 510 }
 511
 512 module_init(vgem_init);
 513 module_exit(vgem_exit);
 514
 515 MODULE_AUTHOR("Red Hat, Inc.");
 516 MODULE_AUTHOR("Intel Corporation");
 517 MODULE_DESCRIPTION(DRIVER_DESC);
 518 MODULE_LICENSE("GPL and additional rights");