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 int 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;
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;
81 mutex_lock(&obj->pages_lock);
83 get_page(obj->pages[page_offset]);
84 vmf->page = obj->pages[page_offset];
87 mutex_unlock(&obj->pages_lock);
91 page = shmem_read_mapping_page(
92 file_inode(obj->base.filp)->i_mapping,
97 } else switch (PTR_ERR(page)) {
103 ret = VM_FAULT_RETRY;
107 ret = VM_FAULT_SIGBUS;
110 WARN_ON(PTR_ERR(page));
111 ret = VM_FAULT_SIGBUS;
119 static const struct vm_operations_struct vgem_gem_vm_ops = {
120 .fault = vgem_gem_fault,
121 .open = drm_gem_vm_open,
122 .close = drm_gem_vm_close,
125 static int vgem_open(struct drm_device *dev, struct drm_file *file)
127 struct vgem_file *vfile;
130 vfile = kzalloc(sizeof(*vfile), GFP_KERNEL);
134 file->driver_priv = vfile;
136 ret = vgem_fence_open(vfile);
145 static void vgem_postclose(struct drm_device *dev, struct drm_file *file)
147 struct vgem_file *vfile = file->driver_priv;
149 vgem_fence_close(vfile);
153 static struct drm_vgem_gem_object *__vgem_gem_create(struct drm_device *dev,
156 struct drm_vgem_gem_object *obj;
159 obj = kzalloc(sizeof(*obj), GFP_KERNEL);
161 return ERR_PTR(-ENOMEM);
163 ret = drm_gem_object_init(dev, &obj->base, roundup(size, PAGE_SIZE));
169 mutex_init(&obj->pages_lock);
174 static void __vgem_gem_destroy(struct drm_vgem_gem_object *obj)
176 drm_gem_object_release(&obj->base);
180 static struct drm_gem_object *vgem_gem_create(struct drm_device *dev,
181 struct drm_file *file,
182 unsigned int *handle,
185 struct drm_vgem_gem_object *obj;
188 obj = __vgem_gem_create(dev, size);
190 return ERR_CAST(obj);
192 ret = drm_gem_handle_create(file, &obj->base, handle);
194 drm_gem_object_put_unlocked(&obj->base);
201 static int vgem_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
202 struct drm_mode_create_dumb *args)
204 struct drm_gem_object *gem_object;
207 pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
208 size = args->height * pitch;
212 gem_object = vgem_gem_create(dev, file, &args->handle, size);
213 if (IS_ERR(gem_object))
214 return PTR_ERR(gem_object);
216 args->size = gem_object->size;
219 drm_gem_object_put_unlocked(gem_object);
221 DRM_DEBUG_DRIVER("Created object of size %llu\n", args->size);
226 static struct drm_ioctl_desc vgem_ioctls[] = {
227 DRM_IOCTL_DEF_DRV(VGEM_FENCE_ATTACH, vgem_fence_attach_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
228 DRM_IOCTL_DEF_DRV(VGEM_FENCE_SIGNAL, vgem_fence_signal_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
231 static int vgem_mmap(struct file *filp, struct vm_area_struct *vma)
233 unsigned long flags = vma->vm_flags;
236 ret = drm_gem_mmap(filp, vma);
240 /* Keep the WC mmaping set by drm_gem_mmap() but our pages
241 * are ordinary and not special.
243 vma->vm_flags = flags | VM_DONTEXPAND | VM_DONTDUMP;
247 static const struct file_operations vgem_driver_fops = {
248 .owner = THIS_MODULE,
253 .unlocked_ioctl = drm_ioctl,
254 .compat_ioctl = drm_compat_ioctl,
255 .release = drm_release,
258 static struct page **vgem_pin_pages(struct drm_vgem_gem_object *bo)
260 mutex_lock(&bo->pages_lock);
261 if (bo->pages_pin_count++ == 0) {
264 pages = drm_gem_get_pages(&bo->base);
266 bo->pages_pin_count--;
267 mutex_unlock(&bo->pages_lock);
273 mutex_unlock(&bo->pages_lock);
278 static void vgem_unpin_pages(struct drm_vgem_gem_object *bo)
280 mutex_lock(&bo->pages_lock);
281 if (--bo->pages_pin_count == 0) {
282 drm_gem_put_pages(&bo->base, bo->pages, true, true);
285 mutex_unlock(&bo->pages_lock);
288 static int vgem_prime_pin(struct drm_gem_object *obj)
290 struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
291 long n_pages = obj->size >> PAGE_SHIFT;
294 pages = vgem_pin_pages(bo);
296 return PTR_ERR(pages);
298 /* Flush the object from the CPU cache so that importers can rely
299 * on coherent indirect access via the exported dma-address.
301 drm_clflush_pages(pages, n_pages);
306 static void vgem_prime_unpin(struct drm_gem_object *obj)
308 struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
310 vgem_unpin_pages(bo);
313 static struct sg_table *vgem_prime_get_sg_table(struct drm_gem_object *obj)
315 struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
317 return drm_prime_pages_to_sg(bo->pages, bo->base.size >> PAGE_SHIFT);
320 static struct drm_gem_object* vgem_prime_import(struct drm_device *dev,
321 struct dma_buf *dma_buf)
323 struct vgem_device *vgem = container_of(dev, typeof(*vgem), drm);
325 return drm_gem_prime_import_dev(dev, dma_buf, &vgem->platform->dev);
328 static struct drm_gem_object *vgem_prime_import_sg_table(struct drm_device *dev,
329 struct dma_buf_attachment *attach, struct sg_table *sg)
331 struct drm_vgem_gem_object *obj;
334 obj = __vgem_gem_create(dev, attach->dmabuf->size);
336 return ERR_CAST(obj);
338 npages = PAGE_ALIGN(attach->dmabuf->size) / PAGE_SIZE;
341 obj->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
343 __vgem_gem_destroy(obj);
344 return ERR_PTR(-ENOMEM);
347 obj->pages_pin_count++; /* perma-pinned */
348 drm_prime_sg_to_page_addr_arrays(obj->table, obj->pages, NULL,
353 static void *vgem_prime_vmap(struct drm_gem_object *obj)
355 struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
356 long n_pages = obj->size >> PAGE_SHIFT;
359 pages = vgem_pin_pages(bo);
363 return vmap(pages, n_pages, 0, pgprot_writecombine(PAGE_KERNEL));
366 static void vgem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
368 struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
371 vgem_unpin_pages(bo);
374 static int vgem_prime_mmap(struct drm_gem_object *obj,
375 struct vm_area_struct *vma)
379 if (obj->size < vma->vm_end - vma->vm_start)
385 ret = call_mmap(obj->filp, vma);
390 vma->vm_file = get_file(obj->filp);
391 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
392 vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
397 static void vgem_release(struct drm_device *dev)
399 struct vgem_device *vgem = container_of(dev, typeof(*vgem), drm);
401 platform_device_unregister(vgem->platform);
402 drm_dev_fini(&vgem->drm);
407 static struct drm_driver vgem_driver = {
408 .driver_features = DRIVER_GEM | DRIVER_PRIME,
409 .release = vgem_release,
411 .postclose = vgem_postclose,
412 .gem_free_object_unlocked = vgem_gem_free_object,
413 .gem_vm_ops = &vgem_gem_vm_ops,
414 .ioctls = vgem_ioctls,
415 .num_ioctls = ARRAY_SIZE(vgem_ioctls),
416 .fops = &vgem_driver_fops,
418 .dumb_create = vgem_gem_dumb_create,
420 .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
421 .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
422 .gem_prime_pin = vgem_prime_pin,
423 .gem_prime_unpin = vgem_prime_unpin,
424 .gem_prime_import = vgem_prime_import,
425 .gem_prime_export = drm_gem_prime_export,
426 .gem_prime_import_sg_table = vgem_prime_import_sg_table,
427 .gem_prime_get_sg_table = vgem_prime_get_sg_table,
428 .gem_prime_vmap = vgem_prime_vmap,
429 .gem_prime_vunmap = vgem_prime_vunmap,
430 .gem_prime_mmap = vgem_prime_mmap,
435 .major = DRIVER_MAJOR,
436 .minor = DRIVER_MINOR,
439 static int __init vgem_init(void)
443 vgem_device = kzalloc(sizeof(*vgem_device), GFP_KERNEL);
447 vgem_device->platform =
448 platform_device_register_simple("vgem", -1, NULL, 0);
449 if (IS_ERR(vgem_device->platform)) {
450 ret = PTR_ERR(vgem_device->platform);
454 dma_coerce_mask_and_coherent(&vgem_device->platform->dev,
456 ret = drm_dev_init(&vgem_device->drm, &vgem_driver,
457 &vgem_device->platform->dev);
461 /* Final step: expose the device/driver to userspace */
462 ret = drm_dev_register(&vgem_device->drm, 0);
469 drm_dev_fini(&vgem_device->drm);
471 platform_device_unregister(vgem_device->platform);
477 static void __exit vgem_exit(void)
479 drm_dev_unregister(&vgem_device->drm);
480 drm_dev_unref(&vgem_device->drm);
483 module_init(vgem_init);
484 module_exit(vgem_exit);
486 MODULE_AUTHOR("Red Hat, Inc.");
487 MODULE_AUTHOR("Intel Corporation");
488 MODULE_DESCRIPTION(DRIVER_DESC);
489 MODULE_LICENSE("GPL and additional rights");