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/module.h>
 34#include <linux/ramfs.h>
 35#include <linux/shmem_fs.h>
 36#include <linux/dma-buf.h>
 37#include "vgem_drv.h"
 38
 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
 44
 45void vgem_gem_put_pages(struct drm_vgem_gem_object *obj)
 46{
 47	drm_gem_put_pages(&obj->base, obj->pages, false, false);
 48	obj->pages = NULL;
 49}
 50
 51static void vgem_gem_free_object(struct drm_gem_object *obj)
 52{
 53	struct drm_vgem_gem_object *vgem_obj = to_vgem_bo(obj);
 54
 55	drm_gem_free_mmap_offset(obj);
 56
 57	if (vgem_obj->use_dma_buf && obj->dma_buf) {
 58		dma_buf_put(obj->dma_buf);
 59		obj->dma_buf = NULL;
 60	}
 61
 62	drm_gem_object_release(obj);
 63
 64	if (vgem_obj->pages)
 65		vgem_gem_put_pages(vgem_obj);
 66
 67	vgem_obj->pages = NULL;
 68
 69	kfree(vgem_obj);
 70}
 71
 72int vgem_gem_get_pages(struct drm_vgem_gem_object *obj)
 73{
 74	struct page **pages;
 75
 76	if (obj->pages || obj->use_dma_buf)
 77		return 0;
 78
 79	pages = drm_gem_get_pages(&obj->base);
 80	if (IS_ERR(pages)) {
 81		return PTR_ERR(pages);
 82	}
 83
 84	obj->pages = pages;
 85
 86	return 0;
 87}
 88
 89static int vgem_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 90{
 91	struct drm_vgem_gem_object *obj = vma->vm_private_data;
 92	struct drm_device *dev = obj->base.dev;
 93	loff_t num_pages;
 94	pgoff_t page_offset;
 95	int ret;
 96
 97	/* We don't use vmf->pgoff since that has the fake offset */
 98	page_offset = ((unsigned long)vmf->virtual_address - vma->vm_start) >>
 99		PAGE_SHIFT;
100
101	num_pages = DIV_ROUND_UP(obj->base.size, PAGE_SIZE);
102
103	if (page_offset > num_pages)
104		return VM_FAULT_SIGBUS;
105
106	mutex_lock(&dev->struct_mutex);
107
108	ret = vm_insert_page(vma, (unsigned long)vmf->virtual_address,
109			     obj->pages[page_offset]);
110
111	mutex_unlock(&dev->struct_mutex);
112	switch (ret) {
113	case 0:
114		return VM_FAULT_NOPAGE;
115	case -ENOMEM:
116		return VM_FAULT_OOM;
117	case -EBUSY:
118		return VM_FAULT_RETRY;
119	case -EFAULT:
120	case -EINVAL:
121		return VM_FAULT_SIGBUS;
122	default:
123		WARN_ON(1);
124		return VM_FAULT_SIGBUS;
125	}
126}
127
128static 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/* ioctls */
135
136static struct drm_gem_object *vgem_gem_create(struct drm_device *dev,
137					      struct drm_file *file,
138					      unsigned int *handle,
139					      unsigned long size)
140{
141	struct drm_vgem_gem_object *obj;
142	struct drm_gem_object *gem_object;
143	int err;
144
145	size = roundup(size, PAGE_SIZE);
146
147	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
148	if (!obj)
149		return ERR_PTR(-ENOMEM);
150
151	gem_object = &obj->base;
152
153	err = drm_gem_object_init(dev, gem_object, size);
154	if (err)
155		goto out;
156
157	err = drm_gem_handle_create(file, gem_object, handle);
158	if (err)
159		goto handle_out;
160
161	drm_gem_object_unreference_unlocked(gem_object);
162
163	return gem_object;
164
165handle_out:
166	drm_gem_object_release(gem_object);
167out:
168	kfree(obj);
169	return ERR_PTR(err);
170}
171
172static int vgem_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
173				struct drm_mode_create_dumb *args)
174{
175	struct drm_gem_object *gem_object;
176	uint64_t size;
177	uint64_t pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
178
179	size = args->height * pitch;
180	if (size == 0)
181		return -EINVAL;
182
183	gem_object = vgem_gem_create(dev, file, &args->handle, size);
184
185	if (IS_ERR(gem_object)) {
186		DRM_DEBUG_DRIVER("object creation failed\n");
187		return PTR_ERR(gem_object);
188	}
189
190	args->size = gem_object->size;
191	args->pitch = pitch;
192
193	DRM_DEBUG_DRIVER("Created object of size %lld\n", size);
194
195	return 0;
196}
197
198int vgem_gem_dumb_map(struct drm_file *file, struct drm_device *dev,
199		      uint32_t handle, uint64_t *offset)
200{
201	int ret = 0;
202	struct drm_gem_object *obj;
203
204	mutex_lock(&dev->struct_mutex);
205	obj = drm_gem_object_lookup(dev, file, handle);
206	if (!obj) {
207		ret = -ENOENT;
208		goto unlock;
209	}
210
211	if (!drm_vma_node_has_offset(&obj->vma_node)) {
212		ret = drm_gem_create_mmap_offset(obj);
213		if (ret)
214			goto unref;
215	}
216
217	BUG_ON(!obj->filp);
218
219	obj->filp->private_data = obj;
220
221	ret = vgem_gem_get_pages(to_vgem_bo(obj));
222	if (ret)
223		goto fail_get_pages;
224
225	*offset = drm_vma_node_offset_addr(&obj->vma_node);
226
227	goto unref;
228
229fail_get_pages:
230	drm_gem_free_mmap_offset(obj);
231unref:
232	drm_gem_object_unreference(obj);
233unlock:
234	mutex_unlock(&dev->struct_mutex);
235	return ret;
236}
237
238static struct drm_ioctl_desc vgem_ioctls[] = {
239};
240
241static const struct file_operations vgem_driver_fops = {
242	.owner		= THIS_MODULE,
243	.open		= drm_open,
244	.mmap		= drm_gem_mmap,
245	.poll		= drm_poll,
246	.read		= drm_read,
247	.unlocked_ioctl = drm_ioctl,
248	.release	= drm_release,
249};
250
251static struct drm_driver vgem_driver = {
252	.driver_features		= DRIVER_GEM,
253	.gem_free_object		= vgem_gem_free_object,
254	.gem_vm_ops			= &vgem_gem_vm_ops,
255	.ioctls				= vgem_ioctls,
256	.fops				= &vgem_driver_fops,
257	.dumb_create			= vgem_gem_dumb_create,
258	.dumb_map_offset		= vgem_gem_dumb_map,
259	.name	= DRIVER_NAME,
260	.desc	= DRIVER_DESC,
261	.date	= DRIVER_DATE,
262	.major	= DRIVER_MAJOR,
263	.minor	= DRIVER_MINOR,
264};
265
266struct drm_device *vgem_device;
267
268static int __init vgem_init(void)
269{
270	int ret;
271
272	vgem_device = drm_dev_alloc(&vgem_driver, NULL);
273	if (!vgem_device) {
274		ret = -ENOMEM;
275		goto out;
276	}
277
278	drm_dev_set_unique(vgem_device, "vgem");
279
280	ret  = drm_dev_register(vgem_device, 0);
281
282	if (ret)
283		goto out_unref;
284
285	return 0;
286
287out_unref:
288	drm_dev_unref(vgem_device);
289out:
290	return ret;
291}
292
293static void __exit vgem_exit(void)
294{
295	drm_dev_unregister(vgem_device);
296	drm_dev_unref(vgem_device);
297}
298
299module_init(vgem_init);
300module_exit(vgem_exit);
301
302MODULE_AUTHOR("Red Hat, Inc.");
303MODULE_DESCRIPTION(DRIVER_DESC);
304MODULE_LICENSE("GPL and additional rights");