root/drivers/gpu/drm/vgem/vgem_drv.c

DEFINITIONS

1. vgem_gem_free_object
2. vgem_gem_fault
3. vgem_open
4. vgem_postclose
5. __vgem_gem_create
6. __vgem_gem_destroy
7. vgem_gem_create
8. vgem_gem_dumb_create
9. vgem_gem_dumb_map
10. vgem_mmap
11. vgem_pin_pages
12. vgem_unpin_pages
13. vgem_prime_pin
14. vgem_prime_unpin
15. vgem_prime_get_sg_table
16. vgem_prime_import
17. vgem_prime_import_sg_table
18. vgem_prime_vmap
19. vgem_prime_vunmap
20. vgem_prime_mmap
21. vgem_release
22. vgem_init
23. vgem_exit

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