[net-next-2.6.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;
	}

	if (bdev->driver->fault_reserve_notify)
		bdev->driver->fault_reserve_notify(bo);

	/*
	 * 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
e024e110 DA	104	if (bdev->driver->fault_reserve_notify)
	105	bdev->driver->fault_reserve_notify(bo);
	106
ba4e7d97 TH	107	/*
	108	* Wait for buffer data in transit, due to a pipelined
	109	* move.
	110	*/
	111
	112	spin_lock(&bo->lock);
	113	if (test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)) {
	114	ret = ttm_bo_wait(bo, false, true, false);
	115	spin_unlock(&bo->lock);
	116	if (unlikely(ret != 0)) {
	117	retval = (ret != -ERESTART) ?
	118	VM_FAULT_SIGBUS : VM_FAULT_NOPAGE;
	119	goto out_unlock;
	120	}
	121	} else
	122	spin_unlock(&bo->lock);
	123
	124
	125	ret = ttm_bo_pci_offset(bdev, &bo->mem, &bus_base, &bus_offset,
	126	&bus_size);
	127	if (unlikely(ret != 0)) {
	128	retval = VM_FAULT_SIGBUS;
	129	goto out_unlock;
	130	}
	131
	132	is_iomem = (bus_size != 0);
	133
	134	page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
	135	bo->vm_node->start - vma->vm_pgoff;
	136	page_last = ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) +
	137	bo->vm_node->start - vma->vm_pgoff;
	138
	139	if (unlikely(page_offset >= bo->num_pages)) {
	140	retval = VM_FAULT_SIGBUS;
	141	goto out_unlock;
	142	}
	143
	144	/*
	145	* Strictly, we're not allowed to modify vma->vm_page_prot here,
	146	* since the mmap_sem is only held in read mode. However, we
	147	* modify only the caching bits of vma->vm_page_prot and
	148	* consider those bits protected by
	149	* the bo->mutex, as we should be the only writers.
	150	* There shouldn't really be any readers of these bits except
	151	* within vm_insert_mixed()? fork?
	152	*
	153	* TODO: Add a list of vmas to the bo, and change the
	154	* vma->vm_page_prot when the object changes caching policy, with
	155	* the correct locks held.
	156	*/
	157
	158	if (is_iomem) {
	159	vma->vm_page_prot = ttm_io_prot(bo->mem.placement,
	160	vma->vm_page_prot);
	161	} else {
	162	ttm = bo->ttm;
	163	vma->vm_page_prot = (bo->mem.placement & TTM_PL_FLAG_CACHED) ?
	164	vm_get_page_prot(vma->vm_flags) :
	165	ttm_io_prot(bo->mem.placement, vma->vm_page_prot);
	166	}
	167
	168	/*
	169	* Speculatively prefault a number of pages. Only error on
	170	* first page.
171	*/
172
173	for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
174
175	if (is_iomem)
176	pfn = ((bus_base + bus_offset) >> PAGE_SHIFT) +
177	page_offset;
178	else {
179	page = ttm_tt_get_page(ttm, page_offset);
180	if (unlikely(!page && i == 0)) {
181	retval = VM_FAULT_OOM;
182	goto out_unlock;
183	} else if (unlikely(!page)) {
184	break;
185	}
186	pfn = page_to_pfn(page);
187	}
188
189	ret = vm_insert_mixed(vma, address, pfn);
190	/*
191	* Somebody beat us to this PTE or prefaulting to
192	* an already populated PTE, or prefaulting error.
193	*/
194
195	if (unlikely((ret == -EBUSY) \|\| (ret != 0 && i > 0)))
196	break;
197	else if (unlikely(ret != 0)) {
198	retval =
199	(ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
200	goto out_unlock;
201
202	}
203
204	address += PAGE_SIZE;
205	if (unlikely(++page_offset >= page_last))
206	break;
207	}
208
209	out_unlock:
210	ttm_bo_unreserve(bo);
211	return retval;
212	}
213
214	static void ttm_bo_vm_open(struct vm_area_struct *vma)
215	{
216	struct ttm_buffer_object *bo =
217	(struct ttm_buffer_object *)vma->vm_private_data;
218
219	(void)ttm_bo_reference(bo);
220	}
221
222	static void ttm_bo_vm_close(struct vm_area_struct *vma)
223	{
224	struct ttm_buffer_object *bo =
225	(struct ttm_buffer_object *)vma->vm_private_data;
226
227	ttm_bo_unref(&bo);
228	vma->vm_private_data = NULL;
229	}
230
231	static struct vm_operations_struct ttm_bo_vm_ops = {
232	.fault = ttm_bo_vm_fault,
233	.open = ttm_bo_vm_open,
234	.close = ttm_bo_vm_close
235	};
236
237	int ttm_bo_mmap(struct file filp, struct vm_area_struct vma,
238	struct ttm_bo_device *bdev)
239	{
240	struct ttm_bo_driver *driver;
241	struct ttm_buffer_object *bo;
242	int ret;
243
244	read_lock(&bdev->vm_lock);
245	bo = ttm_bo_vm_lookup_rb(bdev, vma->vm_pgoff,
246	(vma->vm_end - vma->vm_start) >> PAGE_SHIFT);
247	if (likely(bo != NULL))
248	ttm_bo_reference(bo);
249	read_unlock(&bdev->vm_lock);
250
251	if (unlikely(bo == NULL)) {
252	printk(KERN_ERR TTM_PFX
253	"Could not find buffer object to map.\n");
254	return -EINVAL;
255	}
256
257	driver = bo->bdev->driver;
258	if (unlikely(!driver->verify_access)) {
259	ret = -EPERM;
260	goto out_unref;
261	}
262	ret = driver->verify_access(bo, filp);
263	if (unlikely(ret != 0))
264	goto out_unref;
265
266	vma->vm_ops = &ttm_bo_vm_ops;
267
268	/*
269	* Note: We're transferring the bo reference to
270	* vma->vm_private_data here.
271	*/
272
273	vma->vm_private_data = bo;
274	vma->vm_flags \|= VM_RESERVED \| VM_IO \| VM_MIXEDMAP \| VM_DONTEXPAND;
275	return 0;
276	out_unref:
277	ttm_bo_unref(&bo);
278	return ret;
279	}
280	EXPORT_SYMBOL(ttm_bo_mmap);
281
282	int ttm_fbdev_mmap(struct vm_area_struct vma, struct ttm_buffer_object bo)
283	{
284	if (vma->vm_pgoff != 0)
285	return -EACCES;
286
287	vma->vm_ops = &ttm_bo_vm_ops;
288	vma->vm_private_data = ttm_bo_reference(bo);
289	vma->vm_flags \|= VM_RESERVED \| VM_IO \| VM_MIXEDMAP \| VM_DONTEXPAND;
290	return 0;
291	}
292	EXPORT_SYMBOL(ttm_fbdev_mmap);
293
294
295	ssize_t ttm_bo_io(struct ttm_bo_device bdev, struct file filp,
296	const char __user wbuf, char __user rbuf, size_t count,
297	loff_t *f_pos, bool write)
298	{
299	struct ttm_buffer_object *bo;
300	struct ttm_bo_driver *driver;
301	struct ttm_bo_kmap_obj map;
302	unsigned long dev_offset = (*f_pos >> PAGE_SHIFT);
303	unsigned long kmap_offset;
304	unsigned long kmap_end;
305	unsigned long kmap_num;
306	size_t io_size;
307	unsigned int page_offset;
308	char *virtual;
309	int ret;
310	bool no_wait = false;
311	bool dummy;
312
313	read_lock(&bdev->vm_lock);
314	bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1);
315	if (likely(bo != NULL))
316	ttm_bo_reference(bo);
317	read_unlock(&bdev->vm_lock);
318
319	if (unlikely(bo == NULL))
320	return -EFAULT;
321
322	driver = bo->bdev->driver;
323	if (unlikely(driver->verify_access)) {
324	ret = -EPERM;
325	goto out_unref;
326	}
327
328	ret = driver->verify_access(bo, filp);
329	if (unlikely(ret != 0))
330	goto out_unref;
331
332	kmap_offset = dev_offset - bo->vm_node->start;
916635bf	333	if (unlikely(kmap_offset >= bo->num_pages)) {
ba4e7d97 TH	334	ret = -EFBIG;
	335	goto out_unref;
	336	}
	337
	338	page_offset = *f_pos & ~PAGE_MASK;
	339	io_size = bo->num_pages - kmap_offset;
	340	io_size = (io_size << PAGE_SHIFT) - page_offset;
	341	if (count < io_size)
	342	io_size = count;
	343
	344	kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
	345	kmap_num = kmap_end - kmap_offset + 1;
	346
	347	ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
	348
	349	switch (ret) {
	350	case 0:
	351	break;
	352	case -ERESTART:
	353	ret = -EINTR;
	354	goto out_unref;
	355	case -EBUSY:
	356	ret = -EAGAIN;
	357	goto out_unref;
	358	default:
	359	goto out_unref;
	360	}
	361
	362	ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
	363	if (unlikely(ret != 0)) {
	364	ttm_bo_unreserve(bo);
	365	goto out_unref;
	366	}
	367
	368	virtual = ttm_kmap_obj_virtual(&map, &dummy);
	369	virtual += page_offset;
	370
	371	if (write)
	372	ret = copy_from_user(virtual, wbuf, io_size);
	373	else
	374	ret = copy_to_user(rbuf, virtual, io_size);
	375
	376	ttm_bo_kunmap(&map);
	377	ttm_bo_unreserve(bo);
	378	ttm_bo_unref(&bo);
	379
	380	if (unlikely(ret != 0))
	381	return -EFBIG;
	382
	383	*f_pos += io_size;
	384
	385	return io_size;
	386	out_unref:
	387	ttm_bo_unref(&bo);
	388	return ret;
	389	}
	390
	391	ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object bo, const char __user wbuf,
	392	char __user rbuf, size_t count, loff_t f_pos,
	393	bool write)
	394	{
	395	struct ttm_bo_kmap_obj map;
	396	unsigned long kmap_offset;
	397	unsigned long kmap_end;
398	unsigned long kmap_num;
399	size_t io_size;
400	unsigned int page_offset;
401	char *virtual;
402	int ret;
403	bool no_wait = false;
404	bool dummy;
405
406	kmap_offset = (*f_pos >> PAGE_SHIFT);
916635bf	407	if (unlikely(kmap_offset >= bo->num_pages))
ba4e7d97 TH	408	return -EFBIG;
	409
	410	page_offset = *f_pos & ~PAGE_MASK;
	411	io_size = bo->num_pages - kmap_offset;
	412	io_size = (io_size << PAGE_SHIFT) - page_offset;
	413	if (count < io_size)
	414	io_size = count;
	415
	416	kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
	417	kmap_num = kmap_end - kmap_offset + 1;
	418
	419	ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
	420
	421	switch (ret) {
	422	case 0:
	423	break;
	424	case -ERESTART:
	425	return -EINTR;
	426	case -EBUSY:
	427	return -EAGAIN;
	428	default:
	429	return ret;
	430	}
	431
	432	ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
	433	if (unlikely(ret != 0)) {
	434	ttm_bo_unreserve(bo);
	435	return ret;
	436	}
	437
	438	virtual = ttm_kmap_obj_virtual(&map, &dummy);
	439	virtual += page_offset;
	440
	441	if (write)
	442	ret = copy_from_user(virtual, wbuf, io_size);
	443	else
	444	ret = copy_to_user(rbuf, virtual, io_size);
	445
	446	ttm_bo_kunmap(&map);
	447	ttm_bo_unreserve(bo);
	448	ttm_bo_unref(&bo);
	449
	450	if (unlikely(ret != 0))
	451	return ret;
	452
	453	*f_pos += io_size;
	454
	455	return io_size;
	456	}