[deliverable/linux.git] / drivers / gpu / drm / ttm / ttm_bo_vm.c

/**************************************************************************
 *
 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 **************************************************************************/
/*
 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
 */

#include <ttm/ttm_module.h>
#include <ttm/ttm_bo_driver.h>
#include <ttm/ttm_placement.h>
#include <linux/mm.h>
#include <linux/rbtree.h>
#include <linux/module.h>
#include <linux/uaccess.h>

#define TTM_BO_VM_NUM_PREFAULT 16

static struct ttm_buffer_object *ttm_bo_vm_lookup_rb(struct ttm_bo_device *bdev,
						     unsigned long page_start,
						     unsigned long num_pages)
{
	struct rb_node *cur = bdev->addr_space_rb.rb_node;
	unsigned long cur_offset;
	struct ttm_buffer_object *bo;
	struct ttm_buffer_object *best_bo = NULL;

	while (likely(cur != NULL)) {
		bo = rb_entry(cur, struct ttm_buffer_object, vm_rb);
		cur_offset = bo->vm_node->start;
		if (page_start >= cur_offset) {
			cur = cur->rb_right;
			best_bo = bo;
			if (page_start == cur_offset)
				break;
		} else
			cur = cur->rb_left;
	}

	if (unlikely(best_bo == NULL))
		return NULL;

	if (unlikely((best_bo->vm_node->start + best_bo->num_pages) <
		     (page_start + num_pages)))
		return NULL;

	return best_bo;
}

static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
	struct ttm_buffer_object *bo = (struct ttm_buffer_object *)
	    vma->vm_private_data;
	struct ttm_bo_device *bdev = bo->bdev;
	unsigned long bus_base;
	unsigned long bus_offset;
	unsigned long bus_size;
	unsigned long page_offset;
	unsigned long page_last;
	unsigned long pfn;
	struct ttm_tt *ttm = NULL;
	struct page *page;
	int ret;
	int i;
	bool is_iomem;
	unsigned long address = (unsigned long)vmf->virtual_address;
	int retval = VM_FAULT_NOPAGE;

	/*
	 * Work around locking order reversal in fault / nopfn
	 * between mmap_sem and bo_reserve: Perform a trylock operation
	 * for reserve, and if it fails, retry the fault after scheduling.
	 */

	ret = ttm_bo_reserve(bo, true, true, false, 0);
	if (unlikely(ret != 0)) {
		if (ret == -EBUSY)
			set_need_resched();
		return VM_FAULT_NOPAGE;
	}

	/*
	 * Wait for buffer data in transit, due to a pipelined
	 * move.
	 */

	spin_lock(&bo->lock);
	if (test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)) {
		ret = ttm_bo_wait(bo, false, true, false);
		spin_unlock(&bo->lock);
		if (unlikely(ret != 0)) {
			retval = (ret != -ERESTART) ?
			    VM_FAULT_SIGBUS : VM_FAULT_NOPAGE;
			goto out_unlock;
		}
	} else
		spin_unlock(&bo->lock);


	ret = ttm_bo_pci_offset(bdev, &bo->mem, &bus_base, &bus_offset,
				&bus_size);
	if (unlikely(ret != 0)) {
		retval = VM_FAULT_SIGBUS;
		goto out_unlock;
	}

	is_iomem = (bus_size != 0);

	page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
	    bo->vm_node->start - vma->vm_pgoff;
	page_last = ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) +
	    bo->vm_node->start - vma->vm_pgoff;

	if (unlikely(page_offset >= bo->num_pages)) {
		retval = VM_FAULT_SIGBUS;
		goto out_unlock;
	}

	/*
	 * Strictly, we're not allowed to modify vma->vm_page_prot here,
	 * since the mmap_sem is only held in read mode. However, we
	 * modify only the caching bits of vma->vm_page_prot and
	 * consider those bits protected by
	 * the bo->mutex, as we should be the only writers.
	 * There shouldn't really be any readers of these bits except
	 * within vm_insert_mixed()? fork?
	 *
	 * TODO: Add a list of vmas to the bo, and change the
	 * vma->vm_page_prot when the object changes caching policy, with
	 * the correct locks held.
	 */

	if (is_iomem) {
		vma->vm_page_prot = ttm_io_prot(bo->mem.placement,
						vma->vm_page_prot);
	} else {
		ttm = bo->ttm;
		vma->vm_page_prot = (bo->mem.placement & TTM_PL_FLAG_CACHED) ?
		    vm_get_page_prot(vma->vm_flags) :
		    ttm_io_prot(bo->mem.placement, vma->vm_page_prot);
	}

	/*
	 * Speculatively prefault a number of pages. Only error on
	 * first page.
	 */

	for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {

		if (is_iomem)
			pfn = ((bus_base + bus_offset) >> PAGE_SHIFT) +
			    page_offset;
		else {
			page = ttm_tt_get_page(ttm, page_offset);
			if (unlikely(!page && i == 0)) {
				retval = VM_FAULT_OOM;
				goto out_unlock;
			} else if (unlikely(!page)) {
				break;
			}
			pfn = page_to_pfn(page);
		}

		ret = vm_insert_mixed(vma, address, pfn);
		/*
		 * Somebody beat us to this PTE or prefaulting to
		 * an already populated PTE, or prefaulting error.
		 */

		if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
			break;
		else if (unlikely(ret != 0)) {
			retval =
			    (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
			goto out_unlock;

		}

		address += PAGE_SIZE;
		if (unlikely(++page_offset >= page_last))
			break;
	}

out_unlock:
	ttm_bo_unreserve(bo);
	return retval;
}

static void ttm_bo_vm_open(struct vm_area_struct *vma)
{
	struct ttm_buffer_object *bo =
	    (struct ttm_buffer_object *)vma->vm_private_data;

	(void)ttm_bo_reference(bo);
}

static void ttm_bo_vm_close(struct vm_area_struct *vma)
{
	struct ttm_buffer_object *bo =
	    (struct ttm_buffer_object *)vma->vm_private_data;

	ttm_bo_unref(&bo);
	vma->vm_private_data = NULL;
}

static struct vm_operations_struct ttm_bo_vm_ops = {
	.fault = ttm_bo_vm_fault,
	.open = ttm_bo_vm_open,
	.close = ttm_bo_vm_close
};

int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
		struct ttm_bo_device *bdev)
{
	struct ttm_bo_driver *driver;
	struct ttm_buffer_object *bo;
	int ret;

	read_lock(&bdev->vm_lock);
	bo = ttm_bo_vm_lookup_rb(bdev, vma->vm_pgoff,
				 (vma->vm_end - vma->vm_start) >> PAGE_SHIFT);
	if (likely(bo != NULL))
		ttm_bo_reference(bo);
	read_unlock(&bdev->vm_lock);

	if (unlikely(bo == NULL)) {
		printk(KERN_ERR TTM_PFX
		       "Could not find buffer object to map.\n");
		return -EINVAL;
	}

	driver = bo->bdev->driver;
	if (unlikely(!driver->verify_access)) {
		ret = -EPERM;
		goto out_unref;
	}
	ret = driver->verify_access(bo, filp);
	if (unlikely(ret != 0))
		goto out_unref;

	vma->vm_ops = &ttm_bo_vm_ops;

	/*
	 * Note: We're transferring the bo reference to
	 * vma->vm_private_data here.
	 */

	vma->vm_private_data = bo;
	vma->vm_flags |= VM_RESERVED | VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
	return 0;
out_unref:
	ttm_bo_unref(&bo);
	return ret;
}
EXPORT_SYMBOL(ttm_bo_mmap);

int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
{
	if (vma->vm_pgoff != 0)
		return -EACCES;

	vma->vm_ops = &ttm_bo_vm_ops;
	vma->vm_private_data = ttm_bo_reference(bo);
	vma->vm_flags |= VM_RESERVED | VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
	return 0;
}
EXPORT_SYMBOL(ttm_fbdev_mmap);


ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
		  const char __user *wbuf, char __user *rbuf, size_t count,
		  loff_t *f_pos, bool write)
{
	struct ttm_buffer_object *bo;
	struct ttm_bo_driver *driver;
	struct ttm_bo_kmap_obj map;
	unsigned long dev_offset = (*f_pos >> PAGE_SHIFT);
	unsigned long kmap_offset;
	unsigned long kmap_end;
	unsigned long kmap_num;
	size_t io_size;
	unsigned int page_offset;
	char *virtual;
	int ret;
	bool no_wait = false;
	bool dummy;

	read_lock(&bdev->vm_lock);
	bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1);
	if (likely(bo != NULL))
		ttm_bo_reference(bo);
	read_unlock(&bdev->vm_lock);

	if (unlikely(bo == NULL))
		return -EFAULT;

	driver = bo->bdev->driver;
	if (unlikely(driver->verify_access)) {
		ret = -EPERM;
		goto out_unref;
	}

	ret = driver->verify_access(bo, filp);
	if (unlikely(ret != 0))
		goto out_unref;

	kmap_offset = dev_offset - bo->vm_node->start;
	if (unlikely(kmap_offset) >= bo->num_pages) {
		ret = -EFBIG;
		goto out_unref;
	}

	page_offset = *f_pos & ~PAGE_MASK;
	io_size = bo->num_pages - kmap_offset;
	io_size = (io_size << PAGE_SHIFT) - page_offset;
	if (count < io_size)
		io_size = count;

	kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
	kmap_num = kmap_end - kmap_offset + 1;

	ret = ttm_bo_reserve(bo, true, no_wait, false, 0);

	switch (ret) {
	case 0:
		break;
	case -ERESTART:
		ret = -EINTR;
		goto out_unref;
	case -EBUSY:
		ret = -EAGAIN;
		goto out_unref;
	default:
		goto out_unref;
	}

	ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
	if (unlikely(ret != 0)) {
		ttm_bo_unreserve(bo);
		goto out_unref;
	}

	virtual = ttm_kmap_obj_virtual(&map, &dummy);
	virtual += page_offset;

	if (write)
		ret = copy_from_user(virtual, wbuf, io_size);
	else
		ret = copy_to_user(rbuf, virtual, io_size);

	ttm_bo_kunmap(&map);
	ttm_bo_unreserve(bo);
	ttm_bo_unref(&bo);

	if (unlikely(ret != 0))
		return -EFBIG;

	*f_pos += io_size;

	return io_size;
out_unref:
	ttm_bo_unref(&bo);
	return ret;
}

ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object *bo, const char __user *wbuf,
			char __user *rbuf, size_t count, loff_t *f_pos,
			bool write)
{
	struct ttm_bo_kmap_obj map;
	unsigned long kmap_offset;
	unsigned long kmap_end;
	unsigned long kmap_num;
	size_t io_size;
	unsigned int page_offset;
	char *virtual;
	int ret;
	bool no_wait = false;
	bool dummy;

	kmap_offset = (*f_pos >> PAGE_SHIFT);
	if (unlikely(kmap_offset) >= bo->num_pages)
		return -EFBIG;

	page_offset = *f_pos & ~PAGE_MASK;
	io_size = bo->num_pages - kmap_offset;
	io_size = (io_size << PAGE_SHIFT) - page_offset;
	if (count < io_size)
		io_size = count;

	kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
	kmap_num = kmap_end - kmap_offset + 1;

	ret = ttm_bo_reserve(bo, true, no_wait, false, 0);

	switch (ret) {
	case 0:
		break;
	case -ERESTART:
		return -EINTR;
	case -EBUSY:
		return -EAGAIN;
	default:
		return ret;
	}

	ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
	if (unlikely(ret != 0)) {
		ttm_bo_unreserve(bo);
		return ret;
	}

	virtual = ttm_kmap_obj_virtual(&map, &dummy);
	virtual += page_offset;

	if (write)
		ret = copy_from_user(virtual, wbuf, io_size);
	else
		ret = copy_to_user(rbuf, virtual, io_size);

	ttm_bo_kunmap(&map);
	ttm_bo_unreserve(bo);
	ttm_bo_unref(&bo);

	if (unlikely(ret != 0))
		return ret;

	*f_pos += io_size;

	return io_size;
}
Commit	Line	Data
ba4e7d97 TH	1	/**************************************************************************
	2	*
	3	* Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
	4	* All Rights Reserved.
	5	*
	6	* Permission is hereby granted, free of charge, to any person obtaining a
	7	* copy of this software and associated documentation files (the
	8	* "Software"), to deal in the Software without restriction, including
	9	* without limitation the rights to use, copy, modify, merge, publish,
	10	* distribute, sub license, and/or sell copies of the Software, and to
	11	* permit persons to whom the Software is furnished to do so, subject to
	12	* the following conditions:
	13	*
	14	* The above copyright notice and this permission notice (including the
	15	* next paragraph) shall be included in all copies or substantial portions
	16	* of the Software.
	17	*
	18	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	19	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	20	* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
	21	* THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
	22	* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
	23	* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
	24	* USE OR OTHER DEALINGS IN THE SOFTWARE.
	25	*
	26	**************************************************************************/
	27	/*
	28	* Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
	29	*/
	30
	31	#include <ttm/ttm_module.h>
	32	#include <ttm/ttm_bo_driver.h>
	33	#include <ttm/ttm_placement.h>
	34	#include <linux/mm.h>
ba4e7d97 TH	35	#include <linux/rbtree.h>
	36	#include <linux/module.h>
	37	#include <linux/uaccess.h>
	38
	39	#define TTM_BO_VM_NUM_PREFAULT 16
	40
	41	static struct ttm_buffer_object ttm_bo_vm_lookup_rb(struct ttm_bo_device bdev,
	42	unsigned long page_start,
	43	unsigned long num_pages)
	44	{
	45	struct rb_node *cur = bdev->addr_space_rb.rb_node;
	46	unsigned long cur_offset;
	47	struct ttm_buffer_object *bo;
	48	struct ttm_buffer_object *best_bo = NULL;
	49
	50	while (likely(cur != NULL)) {
	51	bo = rb_entry(cur, struct ttm_buffer_object, vm_rb);
	52	cur_offset = bo->vm_node->start;
	53	if (page_start >= cur_offset) {
	54	cur = cur->rb_right;
	55	best_bo = bo;
	56	if (page_start == cur_offset)
	57	break;
	58	} else
	59	cur = cur->rb_left;
	60	}
	61
	62	if (unlikely(best_bo == NULL))
	63	return NULL;
	64
	65	if (unlikely((best_bo->vm_node->start + best_bo->num_pages) <
	66	(page_start + num_pages)))
	67	return NULL;
	68
	69	return best_bo;
	70	}
	71
	72	static int ttm_bo_vm_fault(struct vm_area_struct vma, struct vm_fault vmf)
	73	{
	74	struct ttm_buffer_object bo = (struct ttm_buffer_object )
	75	vma->vm_private_data;
	76	struct ttm_bo_device *bdev = bo->bdev;
	77	unsigned long bus_base;
	78	unsigned long bus_offset;
	79	unsigned long bus_size;
	80	unsigned long page_offset;
	81	unsigned long page_last;
	82	unsigned long pfn;
	83	struct ttm_tt *ttm = NULL;
	84	struct page *page;
	85	int ret;
	86	int i;
	87	bool is_iomem;
	88	unsigned long address = (unsigned long)vmf->virtual_address;
	89	int retval = VM_FAULT_NOPAGE;
	90
	91	/*
	92	* Work around locking order reversal in fault / nopfn
	93	* between mmap_sem and bo_reserve: Perform a trylock operation
	94	* for reserve, and if it fails, retry the fault after scheduling.
	95	*/
	96
	97	ret = ttm_bo_reserve(bo, true, true, false, 0);
	98	if (unlikely(ret != 0)) {
99	if (ret == -EBUSY)
100	set_need_resched();
101	return VM_FAULT_NOPAGE;
102	}
103
104	/*
105	* Wait for buffer data in transit, due to a pipelined
106	* move.
107	*/
108
109	spin_lock(&bo->lock);
110	if (test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)) {
111	ret = ttm_bo_wait(bo, false, true, false);
112	spin_unlock(&bo->lock);
113	if (unlikely(ret != 0)) {
114	retval = (ret != -ERESTART) ?
115	VM_FAULT_SIGBUS : VM_FAULT_NOPAGE;
116	goto out_unlock;
117	}
118	} else
119	spin_unlock(&bo->lock);
120
121
122	ret = ttm_bo_pci_offset(bdev, &bo->mem, &bus_base, &bus_offset,
123	&bus_size);
124	if (unlikely(ret != 0)) {
125	retval = VM_FAULT_SIGBUS;
126	goto out_unlock;
127	}
128
129	is_iomem = (bus_size != 0);
130
131	page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
132	bo->vm_node->start - vma->vm_pgoff;
133	page_last = ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) +
134	bo->vm_node->start - vma->vm_pgoff;
135
136	if (unlikely(page_offset >= bo->num_pages)) {
137	retval = VM_FAULT_SIGBUS;
138	goto out_unlock;
139	}
140
141	/*
142	* Strictly, we're not allowed to modify vma->vm_page_prot here,
143	* since the mmap_sem is only held in read mode. However, we
144	* modify only the caching bits of vma->vm_page_prot and
145	* consider those bits protected by
146	* the bo->mutex, as we should be the only writers.
147	* There shouldn't really be any readers of these bits except
148	* within vm_insert_mixed()? fork?
149	*
150	* TODO: Add a list of vmas to the bo, and change the
151	* vma->vm_page_prot when the object changes caching policy, with
152	* the correct locks held.
153	*/
154
155	if (is_iomem) {
156	vma->vm_page_prot = ttm_io_prot(bo->mem.placement,
157	vma->vm_page_prot);
158	} else {
159	ttm = bo->ttm;
160	vma->vm_page_prot = (bo->mem.placement & TTM_PL_FLAG_CACHED) ?
161	vm_get_page_prot(vma->vm_flags) :
162	ttm_io_prot(bo->mem.placement, vma->vm_page_prot);
163	}
164
165	/*
166	* Speculatively prefault a number of pages. Only error on
167	* first page.
168	*/
169
170	for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
171
172	if (is_iomem)
173	pfn = ((bus_base + bus_offset) >> PAGE_SHIFT) +
174	page_offset;
175	else {
176	page = ttm_tt_get_page(ttm, page_offset);
177	if (unlikely(!page && i == 0)) {
178	retval = VM_FAULT_OOM;
179	goto out_unlock;
180	} else if (unlikely(!page)) {
181	break;
182	}
183	pfn = page_to_pfn(page);
184	}
185
186	ret = vm_insert_mixed(vma, address, pfn);
187	/*
188	* Somebody beat us to this PTE or prefaulting to
189	* an already populated PTE, or prefaulting error.
190	*/
191
192	if (unlikely((ret == -EBUSY) \|\| (ret != 0 && i > 0)))
193	break;
194	else if (unlikely(ret != 0)) {
195	retval =
196	(ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
197	goto out_unlock;
198
199	}
200
201	address += PAGE_SIZE;
202	if (unlikely(++page_offset >= page_last))
203	break;
204	}
205
206	out_unlock:
207	ttm_bo_unreserve(bo);
208	return retval;
209	}
210
211	static void ttm_bo_vm_open(struct vm_area_struct *vma)
212	{
213	struct ttm_buffer_object *bo =
214	(struct ttm_buffer_object *)vma->vm_private_data;
215
216	(void)ttm_bo_reference(bo);
217	}
218
219	static void ttm_bo_vm_close(struct vm_area_struct *vma)
220	{
221	struct ttm_buffer_object *bo =
222	(struct ttm_buffer_object *)vma->vm_private_data;
223
224	ttm_bo_unref(&bo);
225	vma->vm_private_data = NULL;
226	}
227
228	static struct vm_operations_struct ttm_bo_vm_ops = {
229	.fault = ttm_bo_vm_fault,
230	.open = ttm_bo_vm_open,
231	.close = ttm_bo_vm_close
232	};
233
234	int ttm_bo_mmap(struct file filp, struct vm_area_struct vma,
235	struct ttm_bo_device *bdev)
236	{
237	struct ttm_bo_driver *driver;
238	struct ttm_buffer_object *bo;
239	int ret;
240
241	read_lock(&bdev->vm_lock);
242	bo = ttm_bo_vm_lookup_rb(bdev, vma->vm_pgoff,
243	(vma->vm_end - vma->vm_start) >> PAGE_SHIFT);
244	if (likely(bo != NULL))
245	ttm_bo_reference(bo);
246	read_unlock(&bdev->vm_lock);
247
248	if (unlikely(bo == NULL)) {
249	printk(KERN_ERR TTM_PFX
250	"Could not find buffer object to map.\n");
251	return -EINVAL;
252	}
253
254	driver = bo->bdev->driver;
255	if (unlikely(!driver->verify_access)) {
256	ret = -EPERM;
257	goto out_unref;
258	}
259	ret = driver->verify_access(bo, filp);
260	if (unlikely(ret != 0))
261	goto out_unref;
262
263	vma->vm_ops = &ttm_bo_vm_ops;
264
265	/*
266	* Note: We're transferring the bo reference to
267	* vma->vm_private_data here.
268	*/
269
270	vma->vm_private_data = bo;
271	vma->vm_flags \|= VM_RESERVED \| VM_IO \| VM_MIXEDMAP \| VM_DONTEXPAND;
272	return 0;
273	out_unref:
274	ttm_bo_unref(&bo);
275	return ret;
276	}
277	EXPORT_SYMBOL(ttm_bo_mmap);
278
279	int ttm_fbdev_mmap(struct vm_area_struct vma, struct ttm_buffer_object bo)
280	{
281	if (vma->vm_pgoff != 0)
282	return -EACCES;
283
284	vma->vm_ops = &ttm_bo_vm_ops;
285	vma->vm_private_data = ttm_bo_reference(bo);
286	vma->vm_flags \|= VM_RESERVED \| VM_IO \| VM_MIXEDMAP \| VM_DONTEXPAND;
287	return 0;
288	}
289	EXPORT_SYMBOL(ttm_fbdev_mmap);
290
291
292	ssize_t ttm_bo_io(struct ttm_bo_device bdev, struct file filp,
293	const char __user wbuf, char __user rbuf, size_t count,
294	loff_t *f_pos, bool write)
295	{
296	struct ttm_buffer_object *bo;
297	struct ttm_bo_driver *driver;
298	struct ttm_bo_kmap_obj map;
299	unsigned long dev_offset = (*f_pos >> PAGE_SHIFT);
300	unsigned long kmap_offset;
301	unsigned long kmap_end;
302	unsigned long kmap_num;
303	size_t io_size;
304	unsigned int page_offset;
305	char *virtual;
306	int ret;
307	bool no_wait = false;
308	bool dummy;
309
310	read_lock(&bdev->vm_lock);
311	bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1);
312	if (likely(bo != NULL))
313	ttm_bo_reference(bo);
314	read_unlock(&bdev->vm_lock);
315
316	if (unlikely(bo == NULL))
317	return -EFAULT;
318
319	driver = bo->bdev->driver;
320	if (unlikely(driver->verify_access)) {
321	ret = -EPERM;
322	goto out_unref;
323	}
324
325	ret = driver->verify_access(bo, filp);
326	if (unlikely(ret != 0))
327	goto out_unref;
328
329	kmap_offset = dev_offset - bo->vm_node->start;
330	if (unlikely(kmap_offset) >= bo->num_pages) {
331	ret = -EFBIG;
332	goto out_unref;
333	}
334
335	page_offset = *f_pos & ~PAGE_MASK;
336	io_size = bo->num_pages - kmap_offset;
337	io_size = (io_size << PAGE_SHIFT) - page_offset;
338	if (count < io_size)
339	io_size = count;
340
341	kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
342	kmap_num = kmap_end - kmap_offset + 1;
343
344	ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
345
346	switch (ret) {
347	case 0:
348	break;
349	case -ERESTART:
350	ret = -EINTR;
351	goto out_unref;
352	case -EBUSY:
353	ret = -EAGAIN;
354	goto out_unref;
355	default:
356	goto out_unref;
357	}
358
359	ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
360	if (unlikely(ret != 0)) {
361	ttm_bo_unreserve(bo);
362	goto out_unref;
363	}
364
365	virtual = ttm_kmap_obj_virtual(&map, &dummy);
366	virtual += page_offset;
367
368	if (write)
369	ret = copy_from_user(virtual, wbuf, io_size);
370	else
371	ret = copy_to_user(rbuf, virtual, io_size);
372
373	ttm_bo_kunmap(&map);
374	ttm_bo_unreserve(bo);
375	ttm_bo_unref(&bo);
376
377	if (unlikely(ret != 0))
378	return -EFBIG;
379
380	*f_pos += io_size;
381
382	return io_size;
383	out_unref:
384	ttm_bo_unref(&bo);
385	return ret;
386	}
387
388	ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object bo, const char __user wbuf,
389	char __user rbuf, size_t count, loff_t f_pos,
390	bool write)
391	{
392	struct ttm_bo_kmap_obj map;
393	unsigned long kmap_offset;
394	unsigned long kmap_end;
395	unsigned long kmap_num;
396	size_t io_size;
397	unsigned int page_offset;
398	char *virtual;
399	int ret;
400	bool no_wait = false;
401	bool dummy;
402
403	kmap_offset = (*f_pos >> PAGE_SHIFT);
404	if (unlikely(kmap_offset) >= bo->num_pages)
405	return -EFBIG;
406
407	page_offset = *f_pos & ~PAGE_MASK;
408	io_size = bo->num_pages - kmap_offset;
409	io_size = (io_size << PAGE_SHIFT) - page_offset;
410	if (count < io_size)
411	io_size = count;
412
413	kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
414	kmap_num = kmap_end - kmap_offset + 1;
415
416	ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
417
418	switch (ret) {
419	case 0:
420	break;
421	case -ERESTART:
422	return -EINTR;
423	case -EBUSY:
424	return -EAGAIN;
425	default:
426	return ret;
427	}
428
429	ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
430	if (unlikely(ret != 0)) {
431	ttm_bo_unreserve(bo);
432	return ret;
433	}
434
435	virtual = ttm_kmap_obj_virtual(&map, &dummy);
436	virtual += page_offset;
437
438	if (write)
439	ret = copy_from_user(virtual, wbuf, io_size);
440	else
441	ret = copy_to_user(rbuf, virtual, io_size);
442
443	ttm_bo_kunmap(&map);
444	ttm_bo_unreserve(bo);
445	ttm_bo_unref(&bo);
446
447	if (unlikely(ret != 0))
448	return ret;
449
450	*f_pos += io_size;
451
452	return io_size;
453	}