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