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 void vgem_gem_put_pages(struct drm_vgem_gem_object *obj)
47 drm_gem_put_pages(&obj->base, obj->pages, false, false);
51 static void vgem_gem_free_object(struct drm_gem_object *obj)
53 struct drm_vgem_gem_object *vgem_obj = to_vgem_bo(obj);
55 drm_gem_free_mmap_offset(obj);
57 if (vgem_obj->use_dma_buf && obj->dma_buf) {
58 dma_buf_put(obj->dma_buf);
62 drm_gem_object_release(obj);
65 vgem_gem_put_pages(vgem_obj);
67 vgem_obj->pages = NULL;
72 int vgem_gem_get_pages(struct drm_vgem_gem_object *obj)
76 if (obj->pages || obj->use_dma_buf)
79 pages = drm_gem_get_pages(&obj->base);
81 return PTR_ERR(pages);
89 static int vgem_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
91 struct drm_vgem_gem_object *obj = vma->vm_private_data;
96 /* We don't use vmf->pgoff since that has the fake offset */
97 page_offset = ((unsigned long)vmf->virtual_address - vma->vm_start) >>
100 num_pages = DIV_ROUND_UP(obj->base.size, PAGE_SIZE);
102 if (page_offset > num_pages)
103 return VM_FAULT_SIGBUS;
105 ret = vm_insert_page(vma, (unsigned long)vmf->virtual_address,
106 obj->pages[page_offset]);
109 return VM_FAULT_NOPAGE;
113 return VM_FAULT_RETRY;
116 return VM_FAULT_SIGBUS;
119 return VM_FAULT_SIGBUS;
123 static const struct vm_operations_struct vgem_gem_vm_ops = {
124 .fault = vgem_gem_fault,
125 .open = drm_gem_vm_open,
126 .close = drm_gem_vm_close,
131 static struct drm_gem_object *vgem_gem_create(struct drm_device *dev,
132 struct drm_file *file,
133 unsigned int *handle,
136 struct drm_vgem_gem_object *obj;
137 struct drm_gem_object *gem_object;
140 size = roundup(size, PAGE_SIZE);
142 obj = kzalloc(sizeof(*obj), GFP_KERNEL);
144 return ERR_PTR(-ENOMEM);
146 gem_object = &obj->base;
148 err = drm_gem_object_init(dev, gem_object, size);
152 err = vgem_gem_get_pages(obj);
156 err = drm_gem_handle_create(file, gem_object, handle);
160 drm_gem_object_unreference_unlocked(gem_object);
165 drm_gem_object_release(gem_object);
171 static int vgem_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
172 struct drm_mode_create_dumb *args)
174 struct drm_gem_object *gem_object;
176 uint64_t pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
178 size = args->height * pitch;
182 gem_object = vgem_gem_create(dev, file, &args->handle, size);
184 if (IS_ERR(gem_object)) {
185 DRM_DEBUG_DRIVER("object creation failed\n");
186 return PTR_ERR(gem_object);
189 args->size = gem_object->size;
192 DRM_DEBUG_DRIVER("Created object of size %lld\n", size);
197 int vgem_gem_dumb_map(struct drm_file *file, struct drm_device *dev,
198 uint32_t handle, uint64_t *offset)
201 struct drm_gem_object *obj;
203 obj = drm_gem_object_lookup(file, handle);
207 ret = drm_gem_create_mmap_offset(obj);
213 obj->filp->private_data = obj;
215 *offset = drm_vma_node_offset_addr(&obj->vma_node);
218 drm_gem_object_unreference_unlocked(obj);
223 static struct drm_ioctl_desc vgem_ioctls[] = {
226 static const struct file_operations vgem_driver_fops = {
227 .owner = THIS_MODULE,
229 .mmap = drm_gem_mmap,
232 .unlocked_ioctl = drm_ioctl,
233 .release = drm_release,
236 static struct drm_driver vgem_driver = {
237 .driver_features = DRIVER_GEM,
238 .gem_free_object = vgem_gem_free_object,
239 .gem_vm_ops = &vgem_gem_vm_ops,
240 .ioctls = vgem_ioctls,
241 .fops = &vgem_driver_fops,
242 .dumb_create = vgem_gem_dumb_create,
243 .dumb_map_offset = vgem_gem_dumb_map,
247 .major = DRIVER_MAJOR,
248 .minor = DRIVER_MINOR,
251 struct drm_device *vgem_device;
253 static int __init vgem_init(void)
257 vgem_device = drm_dev_alloc(&vgem_driver, NULL);
263 drm_dev_set_unique(vgem_device, "vgem");
265 ret = drm_dev_register(vgem_device, 0);
273 drm_dev_unref(vgem_device);
278 static void __exit vgem_exit(void)
280 drm_dev_unregister(vgem_device);
281 drm_dev_unref(vgem_device);
284 module_init(vgem_init);
285 module_exit(vgem_exit);
287 MODULE_AUTHOR("Red Hat, Inc.");
288 MODULE_DESCRIPTION(DRIVER_DESC);
289 MODULE_LICENSE("GPL and additional rights");