[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 page_offset;
	unsigned long page_last;
	unsigned long pfn;
	struct ttm_tt *ttm = NULL;
	struct page *page;
	int ret;
	int i;
	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) {
		ret = bdev->driver->fault_reserve_notify(bo);
		switch (ret) {
		case 0:
			break;
		case -EBUSY:
			set_need_resched();
		case -ERESTARTSYS:
			retval = VM_FAULT_NOPAGE;
			goto out_unlock;
		default:
			retval = VM_FAULT_SIGBUS;
			goto out_unlock;
		}
	}

	/*
	 * 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 != -ERESTARTSYS) ?
			    VM_FAULT_SIGBUS : VM_FAULT_NOPAGE;
			goto out_unlock;
		}
	} else
		spin_unlock(&bo->lock);


	ret = ttm_mem_io_reserve(bdev, &bo->mem);
	if (ret) {
		retval = VM_FAULT_SIGBUS;
		goto out_unlock;
	}

	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 (bo->mem.bus.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 (bo->mem.bus.is_iomem)
			pfn = ((bo->mem.bus.base + bo->mem.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 const 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 -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 -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;
ba4e7d97 TH	77	unsigned long page_offset;
	78	unsigned long page_last;
	79	unsigned long pfn;
	80	struct ttm_tt *ttm = NULL;
	81	struct page *page;
	82	int ret;
	83	int i;
ba4e7d97 TH	84	unsigned long address = (unsigned long)vmf->virtual_address;
	85	int retval = VM_FAULT_NOPAGE;
	86
	87	/*
	88	* Work around locking order reversal in fault / nopfn
	89	* between mmap_sem and bo_reserve: Perform a trylock operation
	90	* for reserve, and if it fails, retry the fault after scheduling.
	91	*/
	92
	93	ret = ttm_bo_reserve(bo, true, true, false, 0);
	94	if (unlikely(ret != 0)) {
	95	if (ret == -EBUSY)
	96	set_need_resched();
	97	return VM_FAULT_NOPAGE;
	98	}
	99
82c5da6b JG	100	if (bdev->driver->fault_reserve_notify) {
	101	ret = bdev->driver->fault_reserve_notify(bo);
	102	switch (ret) {
	103	case 0:
	104	break;
	105	case -EBUSY:
	106	set_need_resched();
	107	case -ERESTARTSYS:
	108	retval = VM_FAULT_NOPAGE;
	109	goto out_unlock;
	110	default:
	111	retval = VM_FAULT_SIGBUS;
	112	goto out_unlock;
	113	}
	114	}
e024e110	115
ba4e7d97 TH	116	/*
	117	* Wait for buffer data in transit, due to a pipelined
	118	* move.
	119	*/
	120
	121	spin_lock(&bo->lock);
	122	if (test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)) {
	123	ret = ttm_bo_wait(bo, false, true, false);
	124	spin_unlock(&bo->lock);
	125	if (unlikely(ret != 0)) {
98ffc415	126	retval = (ret != -ERESTARTSYS) ?
ba4e7d97 TH	127	VM_FAULT_SIGBUS : VM_FAULT_NOPAGE;
	128	goto out_unlock;
	129	}
	130	} else
	131	spin_unlock(&bo->lock);
	132
	133
82c5da6b JG	134	ret = ttm_mem_io_reserve(bdev, &bo->mem);
82c5da6b JG	135	if (ret) {
ba4e7d97 TH	136	retval = VM_FAULT_SIGBUS;
	137	goto out_unlock;
	138	}
	139
ba4e7d97 TH	140	page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
	141	bo->vm_node->start - vma->vm_pgoff;
	142	page_last = ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) +
	143	bo->vm_node->start - vma->vm_pgoff;
	144
	145	if (unlikely(page_offset >= bo->num_pages)) {
	146	retval = VM_FAULT_SIGBUS;
	147	goto out_unlock;
	148	}
	149
	150	/*
	151	* Strictly, we're not allowed to modify vma->vm_page_prot here,
	152	* since the mmap_sem is only held in read mode. However, we
	153	* modify only the caching bits of vma->vm_page_prot and
	154	* consider those bits protected by
	155	* the bo->mutex, as we should be the only writers.
	156	* There shouldn't really be any readers of these bits except
	157	* within vm_insert_mixed()? fork?
	158	*
	159	* TODO: Add a list of vmas to the bo, and change the
	160	* vma->vm_page_prot when the object changes caching policy, with
	161	* the correct locks held.
	162	*/
82c5da6b	163	if (bo->mem.bus.is_iomem) {
ba4e7d97 TH	164	vma->vm_page_prot = ttm_io_prot(bo->mem.placement,
	165	vma->vm_page_prot);
	166	} else {
	167	ttm = bo->ttm;
	168	vma->vm_page_prot = (bo->mem.placement & TTM_PL_FLAG_CACHED) ?
	169	vm_get_page_prot(vma->vm_flags) :
	170	ttm_io_prot(bo->mem.placement, vma->vm_page_prot);
	171	}
	172
	173	/*
	174	* Speculatively prefault a number of pages. Only error on
	175	* first page.
	176	*/
	177
	178	for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
82c5da6b JG	179	if (bo->mem.bus.is_iomem)
82c5da6b JG	180	pfn = ((bo->mem.bus.base + bo->mem.bus.offset) >> PAGE_SHIFT) + page_offset;
ba4e7d97 TH	181	else {
	182	page = ttm_tt_get_page(ttm, page_offset);
	183	if (unlikely(!page && i == 0)) {
	184	retval = VM_FAULT_OOM;
	185	goto out_unlock;
	186	} else if (unlikely(!page)) {
	187	break;
	188	}
	189	pfn = page_to_pfn(page);
	190	}
	191
	192	ret = vm_insert_mixed(vma, address, pfn);
	193	/*
	194	* Somebody beat us to this PTE or prefaulting to
	195	* an already populated PTE, or prefaulting error.
	196	*/
	197
	198	if (unlikely((ret == -EBUSY) \|\| (ret != 0 && i > 0)))
	199	break;
	200	else if (unlikely(ret != 0)) {
	201	retval =
	202	(ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
	203	goto out_unlock;
ba4e7d97 TH	204	}
	205
	206	address += PAGE_SIZE;
	207	if (unlikely(++page_offset >= page_last))
	208	break;
	209	}
	210
	211	out_unlock:
	212	ttm_bo_unreserve(bo);
	213	return retval;
	214	}
	215
	216	static void ttm_bo_vm_open(struct vm_area_struct *vma)
	217	{
	218	struct ttm_buffer_object *bo =
	219	(struct ttm_buffer_object *)vma->vm_private_data;
	220
	221	(void)ttm_bo_reference(bo);
	222	}
	223
	224	static void ttm_bo_vm_close(struct vm_area_struct *vma)
	225	{
82c5da6b	226	struct ttm_buffer_object bo = (struct ttm_buffer_object )vma->vm_private_data;
ba4e7d97 TH	227
	228	ttm_bo_unref(&bo);
	229	vma->vm_private_data = NULL;
	230	}
	231
f0f37e2f	232	static const struct vm_operations_struct ttm_bo_vm_ops = {
ba4e7d97 TH	233	.fault = ttm_bo_vm_fault,
	234	.open = ttm_bo_vm_open,
	235	.close = ttm_bo_vm_close
	236	};
	237
	238	int ttm_bo_mmap(struct file filp, struct vm_area_struct vma,
	239	struct ttm_bo_device *bdev)
	240	{
	241	struct ttm_bo_driver *driver;
	242	struct ttm_buffer_object *bo;
	243	int ret;
	244
	245	read_lock(&bdev->vm_lock);
	246	bo = ttm_bo_vm_lookup_rb(bdev, vma->vm_pgoff,
	247	(vma->vm_end - vma->vm_start) >> PAGE_SHIFT);
	248	if (likely(bo != NULL))
	249	ttm_bo_reference(bo);
	250	read_unlock(&bdev->vm_lock);
	251
	252	if (unlikely(bo == NULL)) {
	253	printk(KERN_ERR TTM_PFX
	254	"Could not find buffer object to map.\n");
	255	return -EINVAL;
	256	}
	257
	258	driver = bo->bdev->driver;
	259	if (unlikely(!driver->verify_access)) {
	260	ret = -EPERM;
	261	goto out_unref;
	262	}
	263	ret = driver->verify_access(bo, filp);
	264	if (unlikely(ret != 0))
	265	goto out_unref;
	266
	267	vma->vm_ops = &ttm_bo_vm_ops;
	268
	269	/*
	270	* Note: We're transferring the bo reference to
	271	* vma->vm_private_data here.
	272	*/
	273
	274	vma->vm_private_data = bo;
	275	vma->vm_flags \|= VM_RESERVED \| VM_IO \| VM_MIXEDMAP \| VM_DONTEXPAND;
	276	return 0;
	277	out_unref:
	278	ttm_bo_unref(&bo);
	279	return ret;
	280	}
	281	EXPORT_SYMBOL(ttm_bo_mmap);
	282
	283	int ttm_fbdev_mmap(struct vm_area_struct vma, struct ttm_buffer_object bo)
	284	{
	285	if (vma->vm_pgoff != 0)
	286	return -EACCES;
	287
	288	vma->vm_ops = &ttm_bo_vm_ops;
	289	vma->vm_private_data = ttm_bo_reference(bo);
	290	vma->vm_flags \|= VM_RESERVED \| VM_IO \| VM_MIXEDMAP \| VM_DONTEXPAND;
	291	return 0;
	292	}
	293	EXPORT_SYMBOL(ttm_fbdev_mmap);
	294
	295
	296	ssize_t ttm_bo_io(struct ttm_bo_device bdev, struct file filp,
297	const char __user wbuf, char __user rbuf, size_t count,
298	loff_t *f_pos, bool write)
299	{
300	struct ttm_buffer_object *bo;
301	struct ttm_bo_driver *driver;
302	struct ttm_bo_kmap_obj map;
303	unsigned long dev_offset = (*f_pos >> PAGE_SHIFT);
304	unsigned long kmap_offset;
305	unsigned long kmap_end;
306	unsigned long kmap_num;
307	size_t io_size;
308	unsigned int page_offset;
309	char *virtual;
310	int ret;
311	bool no_wait = false;
312	bool dummy;
313
314	read_lock(&bdev->vm_lock);
315	bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1);
316	if (likely(bo != NULL))
317	ttm_bo_reference(bo);
318	read_unlock(&bdev->vm_lock);
319
320	if (unlikely(bo == NULL))
321	return -EFAULT;
322
323	driver = bo->bdev->driver;
b8ff7357	324	if (unlikely(!driver->verify_access)) {
ba4e7d97 TH	325	ret = -EPERM;
	326	goto out_unref;
	327	}
	328
	329	ret = driver->verify_access(bo, filp);
	330	if (unlikely(ret != 0))
	331	goto out_unref;
	332
	333	kmap_offset = dev_offset - bo->vm_node->start;
916635bf	334	if (unlikely(kmap_offset >= bo->num_pages)) {
ba4e7d97 TH	335	ret = -EFBIG;
	336	goto out_unref;
	337	}
	338
	339	page_offset = *f_pos & ~PAGE_MASK;
	340	io_size = bo->num_pages - kmap_offset;
	341	io_size = (io_size << PAGE_SHIFT) - page_offset;
	342	if (count < io_size)
	343	io_size = count;
	344
	345	kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
	346	kmap_num = kmap_end - kmap_offset + 1;
	347
	348	ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
	349
	350	switch (ret) {
	351	case 0:
	352	break;
ba4e7d97 TH	353	case -EBUSY:
	354	ret = -EAGAIN;
	355	goto out_unref;
	356	default:
	357	goto out_unref;
	358	}
	359
	360	ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
	361	if (unlikely(ret != 0)) {
	362	ttm_bo_unreserve(bo);
	363	goto out_unref;
	364	}
	365
	366	virtual = ttm_kmap_obj_virtual(&map, &dummy);
	367	virtual += page_offset;
	368
	369	if (write)
	370	ret = copy_from_user(virtual, wbuf, io_size);
	371	else
	372	ret = copy_to_user(rbuf, virtual, io_size);
	373
	374	ttm_bo_kunmap(&map);
	375	ttm_bo_unreserve(bo);
	376	ttm_bo_unref(&bo);
	377
	378	if (unlikely(ret != 0))
	379	return -EFBIG;
	380
	381	*f_pos += io_size;
	382
	383	return io_size;
	384	out_unref:
	385	ttm_bo_unref(&bo);
	386	return ret;
	387	}
	388
	389	ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object bo, const char __user wbuf,
	390	char __user rbuf, size_t count, loff_t f_pos,
	391	bool write)
	392	{
	393	struct ttm_bo_kmap_obj map;
	394	unsigned long kmap_offset;
	395	unsigned long kmap_end;
	396	unsigned long kmap_num;
	397	size_t io_size;
	398	unsigned int page_offset;
	399	char *virtual;
	400	int ret;
	401	bool no_wait = false;
	402	bool dummy;
	403
	404	kmap_offset = (*f_pos >> PAGE_SHIFT);
916635bf	405	if (unlikely(kmap_offset >= bo->num_pages))
ba4e7d97 TH	406	return -EFBIG;
	407
	408	page_offset = *f_pos & ~PAGE_MASK;
	409	io_size = bo->num_pages - kmap_offset;
	410	io_size = (io_size << PAGE_SHIFT) - page_offset;
	411	if (count < io_size)
	412	io_size = count;
	413
	414	kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
	415	kmap_num = kmap_end - kmap_offset + 1;
	416
	417	ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
	418
	419	switch (ret) {
	420	case 0:
	421	break;
ba4e7d97 TH	422	case -EBUSY:
	423	return -EAGAIN;
	424	default:
	425	return ret;
	426	}
	427
	428	ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
	429	if (unlikely(ret != 0)) {
	430	ttm_bo_unreserve(bo);
	431	return ret;
	432	}
	433
	434	virtual = ttm_kmap_obj_virtual(&map, &dummy);
	435	virtual += page_offset;
	436
	437	if (write)
	438	ret = copy_from_user(virtual, wbuf, io_size);
	439	else
	440	ret = copy_to_user(rbuf, virtual, io_size);
	441
	442	ttm_bo_kunmap(&map);
	443	ttm_bo_unreserve(bo);
	444	ttm_bo_unref(&bo);
	445
	446	if (unlikely(ret != 0))
	447	return ret;
	448
	449	*f_pos += io_size;
	450
	451	return io_size;
	452	}