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