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 void vgem_gem_free_object(struct drm_gem_object *obj)
47 struct drm_vgem_gem_object *vgem_obj = to_vgem_bo(obj);
49 drm_gem_object_release(obj);
53 static int vgem_gem_fault(struct vm_fault *vmf)
55 struct vm_area_struct *vma = vmf->vma;
56 struct drm_vgem_gem_object *obj = vma->vm_private_data;
57 /* We don't use vmf->pgoff since that has the fake offset */
58 unsigned long vaddr = vmf->address;
61 page = shmem_read_mapping_page(file_inode(obj->base.filp)->i_mapping,
62 (vaddr - vma->vm_start) >> PAGE_SHIFT);
66 } else switch (PTR_ERR(page)) {
71 return VM_FAULT_RETRY;
74 return VM_FAULT_SIGBUS;
76 WARN_ON_ONCE(PTR_ERR(page));
77 return VM_FAULT_SIGBUS;
81 static const struct vm_operations_struct vgem_gem_vm_ops = {
82 .fault = vgem_gem_fault,
83 .open = drm_gem_vm_open,
84 .close = drm_gem_vm_close,
87 static int vgem_open(struct drm_device *dev, struct drm_file *file)
89 struct vgem_file *vfile;
92 vfile = kzalloc(sizeof(*vfile), GFP_KERNEL);
96 file->driver_priv = vfile;
98 ret = vgem_fence_open(vfile);
107 static void vgem_postclose(struct drm_device *dev, struct drm_file *file)
109 struct vgem_file *vfile = file->driver_priv;
111 vgem_fence_close(vfile);
117 static struct drm_gem_object *vgem_gem_create(struct drm_device *dev,
118 struct drm_file *file,
119 unsigned int *handle,
122 struct drm_vgem_gem_object *obj;
125 obj = kzalloc(sizeof(*obj), GFP_KERNEL);
127 return ERR_PTR(-ENOMEM);
129 ret = drm_gem_object_init(dev, &obj->base, roundup(size, PAGE_SIZE));
133 ret = drm_gem_handle_create(file, &obj->base, handle);
134 drm_gem_object_unreference_unlocked(&obj->base);
146 static int vgem_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
147 struct drm_mode_create_dumb *args)
149 struct drm_gem_object *gem_object;
152 pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
153 size = args->height * pitch;
157 gem_object = vgem_gem_create(dev, file, &args->handle, size);
158 if (IS_ERR(gem_object))
159 return PTR_ERR(gem_object);
161 args->size = gem_object->size;
164 DRM_DEBUG_DRIVER("Created object of size %lld\n", size);
169 static int vgem_gem_dumb_map(struct drm_file *file, struct drm_device *dev,
170 uint32_t handle, uint64_t *offset)
172 struct drm_gem_object *obj;
175 obj = drm_gem_object_lookup(file, handle);
184 ret = drm_gem_create_mmap_offset(obj);
188 *offset = drm_vma_node_offset_addr(&obj->vma_node);
190 drm_gem_object_unreference_unlocked(obj);
195 static struct drm_ioctl_desc vgem_ioctls[] = {
196 DRM_IOCTL_DEF_DRV(VGEM_FENCE_ATTACH, vgem_fence_attach_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
197 DRM_IOCTL_DEF_DRV(VGEM_FENCE_SIGNAL, vgem_fence_signal_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
200 static int vgem_mmap(struct file *filp, struct vm_area_struct *vma)
202 unsigned long flags = vma->vm_flags;
205 ret = drm_gem_mmap(filp, vma);
209 /* Keep the WC mmaping set by drm_gem_mmap() but our pages
210 * are ordinary and not special.
212 vma->vm_flags = flags | VM_DONTEXPAND | VM_DONTDUMP;
216 static const struct file_operations vgem_driver_fops = {
217 .owner = THIS_MODULE,
222 .unlocked_ioctl = drm_ioctl,
223 .release = drm_release,
226 static int vgem_prime_pin(struct drm_gem_object *obj)
228 long n_pages = obj->size >> PAGE_SHIFT;
231 /* Flush the object from the CPU cache so that importers can rely
232 * on coherent indirect access via the exported dma-address.
234 pages = drm_gem_get_pages(obj);
236 return PTR_ERR(pages);
238 drm_clflush_pages(pages, n_pages);
239 drm_gem_put_pages(obj, pages, true, false);
244 static struct sg_table *vgem_prime_get_sg_table(struct drm_gem_object *obj)
249 pages = drm_gem_get_pages(obj);
251 return ERR_CAST(pages);
253 st = drm_prime_pages_to_sg(pages, obj->size >> PAGE_SHIFT);
254 drm_gem_put_pages(obj, pages, false, false);
259 static void *vgem_prime_vmap(struct drm_gem_object *obj)
261 long n_pages = obj->size >> PAGE_SHIFT;
265 pages = drm_gem_get_pages(obj);
269 addr = vmap(pages, n_pages, 0, pgprot_writecombine(PAGE_KERNEL));
270 drm_gem_put_pages(obj, pages, false, false);
275 static void vgem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
280 static int vgem_prime_mmap(struct drm_gem_object *obj,
281 struct vm_area_struct *vma)
285 if (obj->size < vma->vm_end - vma->vm_start)
291 ret = call_mmap(obj->filp, vma);
296 vma->vm_file = get_file(obj->filp);
297 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
298 vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
303 static struct drm_driver vgem_driver = {
304 .driver_features = DRIVER_GEM | DRIVER_PRIME,
306 .postclose = vgem_postclose,
307 .gem_free_object_unlocked = vgem_gem_free_object,
308 .gem_vm_ops = &vgem_gem_vm_ops,
309 .ioctls = vgem_ioctls,
310 .num_ioctls = ARRAY_SIZE(vgem_ioctls),
311 .fops = &vgem_driver_fops,
313 .dumb_create = vgem_gem_dumb_create,
314 .dumb_map_offset = vgem_gem_dumb_map,
316 .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
317 .gem_prime_pin = vgem_prime_pin,
318 .gem_prime_export = drm_gem_prime_export,
319 .gem_prime_get_sg_table = vgem_prime_get_sg_table,
320 .gem_prime_vmap = vgem_prime_vmap,
321 .gem_prime_vunmap = vgem_prime_vunmap,
322 .gem_prime_mmap = vgem_prime_mmap,
327 .major = DRIVER_MAJOR,
328 .minor = DRIVER_MINOR,
331 static struct drm_device *vgem_device;
333 static int __init vgem_init(void)
337 vgem_device = drm_dev_alloc(&vgem_driver, NULL);
338 if (IS_ERR(vgem_device)) {
339 ret = PTR_ERR(vgem_device);
343 ret = drm_dev_register(vgem_device, 0);
350 drm_dev_unref(vgem_device);
355 static void __exit vgem_exit(void)
357 drm_dev_unregister(vgem_device);
358 drm_dev_unref(vgem_device);
361 module_init(vgem_init);
362 module_exit(vgem_exit);
364 MODULE_AUTHOR("Red Hat, Inc.");
365 MODULE_AUTHOR("Intel Corporation");
366 MODULE_DESCRIPTION(DRIVER_DESC);
367 MODULE_LICENSE("GPL and additional rights");