2 * Copyright 2011 Red Hat, Inc.
3 * Copyright © 2014 The Chromium OS Authors
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:
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
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.
24 * Adam Jackson <ajax@redhat.com>
25 * Ben Widawsky <ben@bwidawsk.net>
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.
33 #include <linux/module.h>
34 #include <linux/ramfs.h>
35 #include <linux/shmem_fs.h>
36 #include <linux/dma-buf.h>
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
45 static struct vgem_device {
46 struct drm_device drm;
47 struct platform_device *platform;
50 static void vgem_gem_free_object(struct drm_gem_object *obj)
52 struct drm_vgem_gem_object *vgem_obj = to_vgem_bo(obj);
54 kvfree(vgem_obj->pages);
55 mutex_destroy(&vgem_obj->pages_lock);
57 if (obj->import_attach)
58 drm_prime_gem_destroy(obj, vgem_obj->table);
60 drm_gem_object_release(obj);
64 static vm_fault_t vgem_gem_fault(struct vm_fault *vmf)
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;
73 page_offset = (vaddr - vma->vm_start) >> PAGE_SHIFT;
75 num_pages = DIV_ROUND_UP(obj->base.size, PAGE_SIZE);
77 if (page_offset >= num_pages)
78 return VM_FAULT_SIGBUS;
80 mutex_lock(&obj->pages_lock);
82 get_page(obj->pages[page_offset]);
83 vmf->page = obj->pages[page_offset];
86 mutex_unlock(&obj->pages_lock);
90 page = shmem_read_mapping_page(
91 file_inode(obj->base.filp)->i_mapping,
96 } else switch (PTR_ERR(page)) {
102 ret = VM_FAULT_RETRY;
106 ret = VM_FAULT_SIGBUS;
109 WARN_ON(PTR_ERR(page));
110 ret = VM_FAULT_SIGBUS;
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,
124 static int vgem_open(struct drm_device *dev, struct drm_file *file)
126 struct vgem_file *vfile;
129 vfile = kzalloc(sizeof(*vfile), GFP_KERNEL);
133 file->driver_priv = vfile;
135 ret = vgem_fence_open(vfile);
144 static void vgem_postclose(struct drm_device *dev, struct drm_file *file)
146 struct vgem_file *vfile = file->driver_priv;
148 vgem_fence_close(vfile);
152 static struct drm_vgem_gem_object *__vgem_gem_create(struct drm_device *dev,
155 struct drm_vgem_gem_object *obj;
158 obj = kzalloc(sizeof(*obj), GFP_KERNEL);
160 return ERR_PTR(-ENOMEM);
162 ret = drm_gem_object_init(dev, &obj->base, roundup(size, PAGE_SIZE));
168 mutex_init(&obj->pages_lock);
173 static void __vgem_gem_destroy(struct drm_vgem_gem_object *obj)
175 drm_gem_object_release(&obj->base);
179 static struct drm_gem_object *vgem_gem_create(struct drm_device *dev,
180 struct drm_file *file,
181 unsigned int *handle,
184 struct drm_vgem_gem_object *obj;
187 obj = __vgem_gem_create(dev, size);
189 return ERR_CAST(obj);
191 ret = drm_gem_handle_create(file, &obj->base, handle);
192 drm_gem_object_put_unlocked(&obj->base);
199 static int vgem_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
200 struct drm_mode_create_dumb *args)
202 struct drm_gem_object *gem_object;
205 pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
206 size = args->height * pitch;
210 gem_object = vgem_gem_create(dev, file, &args->handle, size);
211 if (IS_ERR(gem_object))
212 return PTR_ERR(gem_object);
214 args->size = gem_object->size;
217 DRM_DEBUG_DRIVER("Created object of size %lld\n", size);
222 static int vgem_gem_dumb_map(struct drm_file *file, struct drm_device *dev,
223 uint32_t handle, uint64_t *offset)
225 struct drm_gem_object *obj;
228 obj = drm_gem_object_lookup(file, handle);
237 ret = drm_gem_create_mmap_offset(obj);
241 *offset = drm_vma_node_offset_addr(&obj->vma_node);
243 drm_gem_object_put_unlocked(obj);
248 static struct drm_ioctl_desc vgem_ioctls[] = {
249 DRM_IOCTL_DEF_DRV(VGEM_FENCE_ATTACH, vgem_fence_attach_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
250 DRM_IOCTL_DEF_DRV(VGEM_FENCE_SIGNAL, vgem_fence_signal_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
253 static int vgem_mmap(struct file *filp, struct vm_area_struct *vma)
255 unsigned long flags = vma->vm_flags;
258 ret = drm_gem_mmap(filp, vma);
262 /* Keep the WC mmaping set by drm_gem_mmap() but our pages
263 * are ordinary and not special.
265 vma->vm_flags = flags | VM_DONTEXPAND | VM_DONTDUMP;
269 static const struct file_operations vgem_driver_fops = {
270 .owner = THIS_MODULE,
275 .unlocked_ioctl = drm_ioctl,
276 .compat_ioctl = drm_compat_ioctl,
277 .release = drm_release,
280 static struct page **vgem_pin_pages(struct drm_vgem_gem_object *bo)
282 mutex_lock(&bo->pages_lock);
283 if (bo->pages_pin_count++ == 0) {
286 pages = drm_gem_get_pages(&bo->base);
288 bo->pages_pin_count--;
289 mutex_unlock(&bo->pages_lock);
295 mutex_unlock(&bo->pages_lock);
300 static void vgem_unpin_pages(struct drm_vgem_gem_object *bo)
302 mutex_lock(&bo->pages_lock);
303 if (--bo->pages_pin_count == 0) {
304 drm_gem_put_pages(&bo->base, bo->pages, true, true);
307 mutex_unlock(&bo->pages_lock);
310 static int vgem_prime_pin(struct drm_gem_object *obj)
312 struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
313 long n_pages = obj->size >> PAGE_SHIFT;
316 pages = vgem_pin_pages(bo);
318 return PTR_ERR(pages);
320 /* Flush the object from the CPU cache so that importers can rely
321 * on coherent indirect access via the exported dma-address.
323 drm_clflush_pages(pages, n_pages);
328 static void vgem_prime_unpin(struct drm_gem_object *obj)
330 struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
332 vgem_unpin_pages(bo);
335 static struct sg_table *vgem_prime_get_sg_table(struct drm_gem_object *obj)
337 struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
339 return drm_prime_pages_to_sg(bo->pages, bo->base.size >> PAGE_SHIFT);
342 static struct drm_gem_object* vgem_prime_import(struct drm_device *dev,
343 struct dma_buf *dma_buf)
345 struct vgem_device *vgem = container_of(dev, typeof(*vgem), drm);
347 return drm_gem_prime_import_dev(dev, dma_buf, &vgem->platform->dev);
350 static struct drm_gem_object *vgem_prime_import_sg_table(struct drm_device *dev,
351 struct dma_buf_attachment *attach, struct sg_table *sg)
353 struct drm_vgem_gem_object *obj;
356 obj = __vgem_gem_create(dev, attach->dmabuf->size);
358 return ERR_CAST(obj);
360 npages = PAGE_ALIGN(attach->dmabuf->size) / PAGE_SIZE;
363 obj->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
365 __vgem_gem_destroy(obj);
366 return ERR_PTR(-ENOMEM);
369 obj->pages_pin_count++; /* perma-pinned */
370 drm_prime_sg_to_page_addr_arrays(obj->table, obj->pages, NULL,
375 static void *vgem_prime_vmap(struct drm_gem_object *obj)
377 struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
378 long n_pages = obj->size >> PAGE_SHIFT;
381 pages = vgem_pin_pages(bo);
385 return vmap(pages, n_pages, 0, pgprot_writecombine(PAGE_KERNEL));
388 static void vgem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
390 struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
393 vgem_unpin_pages(bo);
396 static int vgem_prime_mmap(struct drm_gem_object *obj,
397 struct vm_area_struct *vma)
401 if (obj->size < vma->vm_end - vma->vm_start)
407 ret = call_mmap(obj->filp, vma);
412 vma->vm_file = get_file(obj->filp);
413 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
414 vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
419 static void vgem_release(struct drm_device *dev)
421 struct vgem_device *vgem = container_of(dev, typeof(*vgem), drm);
423 platform_device_unregister(vgem->platform);
424 drm_dev_fini(&vgem->drm);
429 static struct drm_driver vgem_driver = {
430 .driver_features = DRIVER_GEM | DRIVER_PRIME |
432 .release = vgem_release,
434 .postclose = vgem_postclose,
435 .gem_free_object_unlocked = vgem_gem_free_object,
436 .gem_vm_ops = &vgem_gem_vm_ops,
437 .ioctls = vgem_ioctls,
438 .num_ioctls = ARRAY_SIZE(vgem_ioctls),
439 .fops = &vgem_driver_fops,
441 .dumb_create = vgem_gem_dumb_create,
442 .dumb_map_offset = vgem_gem_dumb_map,
444 .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
445 .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
446 .gem_prime_pin = vgem_prime_pin,
447 .gem_prime_unpin = vgem_prime_unpin,
448 .gem_prime_import = vgem_prime_import,
449 .gem_prime_export = drm_gem_prime_export,
450 .gem_prime_import_sg_table = vgem_prime_import_sg_table,
451 .gem_prime_get_sg_table = vgem_prime_get_sg_table,
452 .gem_prime_vmap = vgem_prime_vmap,
453 .gem_prime_vunmap = vgem_prime_vunmap,
454 .gem_prime_mmap = vgem_prime_mmap,
459 .major = DRIVER_MAJOR,
460 .minor = DRIVER_MINOR,
463 static int __init vgem_init(void)
467 vgem_device = kzalloc(sizeof(*vgem_device), GFP_KERNEL);
471 vgem_device->platform =
472 platform_device_register_simple("vgem", -1, NULL, 0);
473 if (IS_ERR(vgem_device->platform)) {
474 ret = PTR_ERR(vgem_device->platform);
478 dma_coerce_mask_and_coherent(&vgem_device->platform->dev,
480 ret = drm_dev_init(&vgem_device->drm, &vgem_driver,
481 &vgem_device->platform->dev);
485 /* Final step: expose the device/driver to userspace */
486 ret = drm_dev_register(&vgem_device->drm, 0);
493 drm_dev_fini(&vgem_device->drm);
495 platform_device_unregister(vgem_device->platform);
501 static void __exit vgem_exit(void)
503 drm_dev_unregister(&vgem_device->drm);
504 drm_dev_put(&vgem_device->drm);
507 module_init(vgem_init);
508 module_exit(vgem_exit);
510 MODULE_AUTHOR("Red Hat, Inc.");
511 MODULE_AUTHOR("Intel Corporation");
512 MODULE_DESCRIPTION(DRIVER_DESC);
513 MODULE_LICENSE("GPL and additional rights");