[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>
 */

#define pr_fmt(fmt) "[TTM] " fmt

#include <ttm/ttm_module.h>
#include <ttm/ttm_bo_driver.h>
#include <ttm/ttm_placement.h>
#include <drm/drm_vma_manager.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 int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
				struct vm_area_struct *vma,
				struct vm_fault *vmf)
{
	struct ttm_bo_device *bdev = bo->bdev;
	int ret = 0;

	spin_lock(&bdev->fence_lock);
	if (likely(!test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)))
		goto out_unlock;

	/*
	 * Quick non-stalling check for idle.
	 */
	ret = ttm_bo_wait(bo, false, false, true);
	if (likely(ret == 0))
		goto out_unlock;

	/*
	 * If possible, avoid waiting for GPU with mmap_sem
	 * held.
	 */
	if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
		ret = VM_FAULT_RETRY;
		if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT)
			goto out_unlock;

		up_read(&vma->vm_mm->mmap_sem);
		(void) ttm_bo_wait(bo, false, true, false);
		goto out_unlock;
	}

	/*
	 * Ordinary wait.
	 */
	ret = ttm_bo_wait(bo, false, true, false);
	if (unlikely(ret != 0))
		ret = (ret != -ERESTARTSYS) ? VM_FAULT_SIGBUS :
			VM_FAULT_NOPAGE;

out_unlock:
	spin_unlock(&bdev->fence_lock);
	return ret;
}

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;
	struct ttm_mem_type_manager *man =
		&bdev->man[bo->mem.mem_type];
	struct vm_area_struct cvma;

	/*
	 * 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 waiting
	 * for the buffer to become unreserved.
	 */
	ret = ttm_bo_reserve(bo, true, true, false, NULL);
	if (unlikely(ret != 0)) {
		if (ret != -EBUSY)
			return VM_FAULT_NOPAGE;

		if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
			if (!(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
				up_read(&vma->vm_mm->mmap_sem);
				(void) ttm_bo_wait_unreserved(bo);
			}

			return VM_FAULT_RETRY;
		}

		/*
		 * If we'd want to change locking order to
		 * mmap_sem -> bo::reserve, we'd use a blocking reserve here
		 * instead of retrying the fault...
		 */
		return VM_FAULT_NOPAGE;
	}

	/*
	 * Refuse to fault imported pages. This should be handled
	 * (if at all) by redirecting mmap to the exporter.
	 */
	if (bo->ttm && (bo->ttm->page_flags & TTM_PAGE_FLAG_SG)) {
		retval = VM_FAULT_SIGBUS;
		goto out_unlock;
	}

	if (bdev->driver->fault_reserve_notify) {
		ret = bdev->driver->fault_reserve_notify(bo);
		switch (ret) {
		case 0:
			break;
		case -EBUSY:
		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.
	 */
	ret = ttm_bo_vm_fault_idle(bo, vma, vmf);
	if (unlikely(ret != 0)) {
		retval = ret;
		goto out_unlock;
	}

	ret = ttm_mem_io_lock(man, true);
	if (unlikely(ret != 0)) {
		retval = VM_FAULT_NOPAGE;
		goto out_unlock;
	}
	ret = ttm_mem_io_reserve_vm(bo);
	if (unlikely(ret != 0)) {
		retval = VM_FAULT_SIGBUS;
		goto out_io_unlock;
	}

	page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
		vma->vm_pgoff - drm_vma_node_start(&bo->vma_node);
	page_last = vma_pages(vma) + vma->vm_pgoff -
		drm_vma_node_start(&bo->vma_node);

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

	/*
	 * Make a local vma copy to modify the page_prot member
	 * and vm_flags if necessary. The vma parameter is protected
	 * by mmap_sem in write mode.
	 */
	cvma = *vma;
	cvma.vm_page_prot = vm_get_page_prot(cvma.vm_flags);

	if (bo->mem.bus.is_iomem) {
		cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
						cvma.vm_page_prot);
	} else {
		ttm = bo->ttm;
		if (!(bo->mem.placement & TTM_PL_FLAG_CACHED))
			cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
							cvma.vm_page_prot);

		/* Allocate all page at once, most common usage */
		if (ttm->bdev->driver->ttm_tt_populate(ttm)) {
			retval = VM_FAULT_OOM;
			goto out_io_unlock;
		}
	}

	/*
	 * 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->pages[page_offset];
			if (unlikely(!page && i == 0)) {
				retval = VM_FAULT_OOM;
				goto out_io_unlock;
			} else if (unlikely(!page)) {
				break;
			}
			page->mapping = vma->vm_file->f_mapping;
			page->index = drm_vma_node_start(&bo->vma_node) +
				page_offset;
			pfn = page_to_pfn(page);
		}

		if (vma->vm_flags & VM_MIXEDMAP)
			ret = vm_insert_mixed(&cvma, address, pfn);
		else
			ret = vm_insert_pfn(&cvma, 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_io_unlock;
		}

		address += PAGE_SIZE;
		if (unlikely(++page_offset >= page_last))
			break;
	}
out_io_unlock:
	ttm_mem_io_unlock(man);
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;

	WARN_ON(bo->bdev->dev_mapping != vma->vm_file->f_mapping);

	(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
};

static struct ttm_buffer_object *ttm_bo_vm_lookup(struct ttm_bo_device *bdev,
						  unsigned long offset,
						  unsigned long pages)
{
	struct drm_vma_offset_node *node;
	struct ttm_buffer_object *bo = NULL;

	drm_vma_offset_lock_lookup(&bdev->vma_manager);

	node = drm_vma_offset_lookup_locked(&bdev->vma_manager, offset, pages);
	if (likely(node)) {
		bo = container_of(node, struct ttm_buffer_object, vma_node);
		if (!kref_get_unless_zero(&bo->kref))
			bo = NULL;
	}

	drm_vma_offset_unlock_lookup(&bdev->vma_manager);

	if (!bo)
		pr_err("Could not find buffer object to map\n");

	return bo;
}

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;

	bo = ttm_bo_vm_lookup(bdev, vma->vm_pgoff, vma_pages(vma));
	if (unlikely(!bo))
		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;

	/*
	 * We'd like to use VM_PFNMAP on shared mappings, where
	 * (vma->vm_flags & VM_SHARED) != 0, for performance reasons,
	 * but for some reason VM_PFNMAP + x86 PAT + write-combine is very
	 * bad for performance. Until that has been sorted out, use
	 * VM_MIXEDMAP on all mappings. See freedesktop.org bug #75719
	 */
	vma->vm_flags |= VM_MIXEDMAP;
	vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
	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_MIXEDMAP;
	vma->vm_flags |= VM_IO | VM_DONTEXPAND;
	return 0;
}
EXPORT_SYMBOL(ttm_fbdev_mmap);
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
25d0479a JP	31	#define pr_fmt(fmt) "[TTM] " fmt
25d0479a JP	32
ba4e7d97 TH	33	#include <ttm/ttm_module.h>
	34	#include <ttm/ttm_bo_driver.h>
	35	#include <ttm/ttm_placement.h>
72525b3f	36	#include <drm/drm_vma_manager.h>
ba4e7d97	37	#include <linux/mm.h>
ba4e7d97 TH	38	#include <linux/rbtree.h>
	39	#include <linux/module.h>
	40	#include <linux/uaccess.h>
	41
	42	#define TTM_BO_VM_NUM_PREFAULT 16
	43
cbe12e74 TH	44	static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
	45	struct vm_area_struct *vma,
	46	struct vm_fault *vmf)
	47	{
	48	struct ttm_bo_device *bdev = bo->bdev;
	49	int ret = 0;
	50
	51	spin_lock(&bdev->fence_lock);
	52	if (likely(!test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)))
	53	goto out_unlock;
	54
	55	/*
	56	* Quick non-stalling check for idle.
	57	*/
	58	ret = ttm_bo_wait(bo, false, false, true);
	59	if (likely(ret == 0))
	60	goto out_unlock;
	61
	62	/*
	63	* If possible, avoid waiting for GPU with mmap_sem
	64	* held.
	65	*/
	66	if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
	67	ret = VM_FAULT_RETRY;
	68	if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT)
	69	goto out_unlock;
	70
	71	up_read(&vma->vm_mm->mmap_sem);
	72	(void) ttm_bo_wait(bo, false, true, false);
	73	goto out_unlock;
	74	}
	75
	76	/*
	77	* Ordinary wait.
	78	*/
	79	ret = ttm_bo_wait(bo, false, true, false);
	80	if (unlikely(ret != 0))
	81	ret = (ret != -ERESTARTSYS) ? VM_FAULT_SIGBUS :
	82	VM_FAULT_NOPAGE;
	83
	84	out_unlock:
	85	spin_unlock(&bdev->fence_lock);
	86	return ret;
	87	}
	88
ba4e7d97 TH	89	static int ttm_bo_vm_fault(struct vm_area_struct vma, struct vm_fault vmf)
	90	{
	91	struct ttm_buffer_object bo = (struct ttm_buffer_object )
	92	vma->vm_private_data;
	93	struct ttm_bo_device *bdev = bo->bdev;
ba4e7d97 TH	94	unsigned long page_offset;
	95	unsigned long page_last;
	96	unsigned long pfn;
	97	struct ttm_tt *ttm = NULL;
	98	struct page *page;
	99	int ret;
	100	int i;
ba4e7d97 TH	101	unsigned long address = (unsigned long)vmf->virtual_address;
ba4e7d97 TH	102	int retval = VM_FAULT_NOPAGE;
eba67093 TH	103	struct ttm_mem_type_manager *man =
eba67093 TH	104	&bdev->man[bo->mem.mem_type];
3943875e	105	struct vm_area_struct cvma;
ba4e7d97 TH	106
	107	/*
	108	* Work around locking order reversal in fault / nopfn
	109	* between mmap_sem and bo_reserve: Perform a trylock operation
c58f009e TH	110	* for reserve, and if it fails, retry the fault after waiting
c58f009e TH	111	* for the buffer to become unreserved.
ba4e7d97	112	*/
c58f009e	113	ret = ttm_bo_reserve(bo, true, true, false, NULL);
ba4e7d97	114	if (unlikely(ret != 0)) {
c58f009e TH	115	if (ret != -EBUSY)
	116	return VM_FAULT_NOPAGE;
	117
	118	if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
	119	if (!(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
	120	up_read(&vma->vm_mm->mmap_sem);
	121	(void) ttm_bo_wait_unreserved(bo);
	122	}
	123
	124	return VM_FAULT_RETRY;
	125	}
	126
	127	/*
	128	* If we'd want to change locking order to
	129	* mmap_sem -> bo::reserve, we'd use a blocking reserve here
	130	* instead of retrying the fault...
	131	*/
ba4e7d97 TH	132	return VM_FAULT_NOPAGE;
	133	}
	134
667a50db TH	135	/*
	136	* Refuse to fault imported pages. This should be handled
	137	* (if at all) by redirecting mmap to the exporter.
	138	*/
	139	if (bo->ttm && (bo->ttm->page_flags & TTM_PAGE_FLAG_SG)) {
	140	retval = VM_FAULT_SIGBUS;
	141	goto out_unlock;
	142	}
	143
82c5da6b JG	144	if (bdev->driver->fault_reserve_notify) {
	145	ret = bdev->driver->fault_reserve_notify(bo);
	146	switch (ret) {
	147	case 0:
	148	break;
	149	case -EBUSY:
82c5da6b JG	150	case -ERESTARTSYS:
	151	retval = VM_FAULT_NOPAGE;
	152	goto out_unlock;
	153	default:
	154	retval = VM_FAULT_SIGBUS;
	155	goto out_unlock;
	156	}
	157	}
e024e110	158
ba4e7d97 TH	159	/*
	160	* Wait for buffer data in transit, due to a pipelined
	161	* move.
	162	*/
cbe12e74 TH	163	ret = ttm_bo_vm_fault_idle(bo, vma, vmf);
	164	if (unlikely(ret != 0)) {
	165	retval = ret;
	166	goto out_unlock;
	167	}
ba4e7d97	168
eba67093 TH	169	ret = ttm_mem_io_lock(man, true);
	170	if (unlikely(ret != 0)) {
	171	retval = VM_FAULT_NOPAGE;
ba4e7d97 TH	172	goto out_unlock;
ba4e7d97 TH	173	}
eba67093 TH	174	ret = ttm_mem_io_reserve_vm(bo);
	175	if (unlikely(ret != 0)) {
	176	retval = VM_FAULT_SIGBUS;
	177	goto out_io_unlock;
	178	}
ba4e7d97	179
ba4e7d97	180	page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
d3867355 TH	181	vma->vm_pgoff - drm_vma_node_start(&bo->vma_node);
	182	page_last = vma_pages(vma) + vma->vm_pgoff -
	183	drm_vma_node_start(&bo->vma_node);
ba4e7d97 TH	184
	185	if (unlikely(page_offset >= bo->num_pages)) {
	186	retval = VM_FAULT_SIGBUS;
eba67093	187	goto out_io_unlock;
ba4e7d97 TH	188	}
	189
	190	/*
3943875e TH	191	* Make a local vma copy to modify the page_prot member
	192	* and vm_flags if necessary. The vma parameter is protected
	193	* by mmap_sem in write mode.
ba4e7d97	194	*/
3943875e TH	195	cvma = *vma;
	196	cvma.vm_page_prot = vm_get_page_prot(cvma.vm_flags);
	197
82c5da6b	198	if (bo->mem.bus.is_iomem) {
3943875e TH	199	cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
3943875e TH	200	cvma.vm_page_prot);
ba4e7d97 TH	201	} else {
ba4e7d97 TH	202	ttm = bo->ttm;
3943875e TH	203	if (!(bo->mem.placement & TTM_PL_FLAG_CACHED))
	204	cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
	205	cvma.vm_page_prot);
b1e5f172 JG	206
	207	/* Allocate all page at once, most common usage */
	208	if (ttm->bdev->driver->ttm_tt_populate(ttm)) {
	209	retval = VM_FAULT_OOM;
	210	goto out_io_unlock;
	211	}
ba4e7d97 TH	212	}
	213
	214	/*
	215	* Speculatively prefault a number of pages. Only error on
	216	* first page.
	217	*/
ba4e7d97	218	for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
82c5da6b JG	219	if (bo->mem.bus.is_iomem)
82c5da6b JG	220	pfn = ((bo->mem.bus.base + bo->mem.bus.offset) >> PAGE_SHIFT) + page_offset;
ba4e7d97	221	else {
b1e5f172	222	page = ttm->pages[page_offset];
ba4e7d97 TH	223	if (unlikely(!page && i == 0)) {
ba4e7d97 TH	224	retval = VM_FAULT_OOM;
eba67093	225	goto out_io_unlock;
ba4e7d97 TH	226	} else if (unlikely(!page)) {
	227	break;
	228	}
58aa6622 TH	229	page->mapping = vma->vm_file->f_mapping;
	230	page->index = drm_vma_node_start(&bo->vma_node) +
	231	page_offset;
ba4e7d97 TH	232	pfn = page_to_pfn(page);
	233	}
	234
7dfe8b61 TH	235	if (vma->vm_flags & VM_MIXEDMAP)
	236	ret = vm_insert_mixed(&cvma, address, pfn);
	237	else
	238	ret = vm_insert_pfn(&cvma, address, pfn);
	239
ba4e7d97 TH	240	/*
	241	* Somebody beat us to this PTE or prefaulting to
	242	* an already populated PTE, or prefaulting error.
	243	*/
	244
	245	if (unlikely((ret == -EBUSY) \|\| (ret != 0 && i > 0)))
	246	break;
	247	else if (unlikely(ret != 0)) {
	248	retval =
	249	(ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
eba67093	250	goto out_io_unlock;
ba4e7d97 TH	251	}
	252
	253	address += PAGE_SIZE;
	254	if (unlikely(++page_offset >= page_last))
	255	break;
	256	}
eba67093 TH	257	out_io_unlock:
eba67093 TH	258	ttm_mem_io_unlock(man);
ba4e7d97 TH	259	out_unlock:
	260	ttm_bo_unreserve(bo);
	261	return retval;
	262	}
	263
	264	static void ttm_bo_vm_open(struct vm_area_struct *vma)
	265	{
	266	struct ttm_buffer_object *bo =
	267	(struct ttm_buffer_object *)vma->vm_private_data;
	268
58aa6622 TH	269	WARN_ON(bo->bdev->dev_mapping != vma->vm_file->f_mapping);
58aa6622 TH	270
ba4e7d97 TH	271	(void)ttm_bo_reference(bo);
	272	}
	273
	274	static void ttm_bo_vm_close(struct vm_area_struct *vma)
	275	{
82c5da6b	276	struct ttm_buffer_object bo = (struct ttm_buffer_object )vma->vm_private_data;
ba4e7d97 TH	277
	278	ttm_bo_unref(&bo);
	279	vma->vm_private_data = NULL;
	280	}
	281
f0f37e2f	282	static const struct vm_operations_struct ttm_bo_vm_ops = {
ba4e7d97 TH	283	.fault = ttm_bo_vm_fault,
	284	.open = ttm_bo_vm_open,
	285	.close = ttm_bo_vm_close
	286	};
	287
72525b3f DH	288	static struct ttm_buffer_object ttm_bo_vm_lookup(struct ttm_bo_device bdev,
	289	unsigned long offset,
	290	unsigned long pages)
	291	{
	292	struct drm_vma_offset_node *node;
	293	struct ttm_buffer_object *bo = NULL;
	294
	295	drm_vma_offset_lock_lookup(&bdev->vma_manager);
	296
	297	node = drm_vma_offset_lookup_locked(&bdev->vma_manager, offset, pages);
	298	if (likely(node)) {
	299	bo = container_of(node, struct ttm_buffer_object, vma_node);
	300	if (!kref_get_unless_zero(&bo->kref))
	301	bo = NULL;
	302	}
	303
	304	drm_vma_offset_unlock_lookup(&bdev->vma_manager);
	305
	306	if (!bo)
	307	pr_err("Could not find buffer object to map\n");
	308
	309	return bo;
	310	}
	311
ba4e7d97 TH	312	int ttm_bo_mmap(struct file filp, struct vm_area_struct vma,
	313	struct ttm_bo_device *bdev)
	314	{
	315	struct ttm_bo_driver *driver;
	316	struct ttm_buffer_object *bo;
	317	int ret;
	318
72525b3f DH	319	bo = ttm_bo_vm_lookup(bdev, vma->vm_pgoff, vma_pages(vma));
72525b3f DH	320	if (unlikely(!bo))
ba4e7d97	321	return -EINVAL;
ba4e7d97 TH	322
	323	driver = bo->bdev->driver;
	324	if (unlikely(!driver->verify_access)) {
	325	ret = -EPERM;
	326	goto out_unref;
	327	}
	328	ret = driver->verify_access(bo, filp);
	329	if (unlikely(ret != 0))
	330	goto out_unref;
	331
	332	vma->vm_ops = &ttm_bo_vm_ops;
	333
	334	/*
	335	* Note: We're transferring the bo reference to
	336	* vma->vm_private_data here.
	337	*/
	338
	339	vma->vm_private_data = bo;
7dfe8b61 TH	340
7dfe8b61 TH	341	/*
0e6d6ec0 TH	342	* We'd like to use VM_PFNMAP on shared mappings, where
	343	* (vma->vm_flags & VM_SHARED) != 0, for performance reasons,
	344	* but for some reason VM_PFNMAP + x86 PAT + write-combine is very
	345	* bad for performance. Until that has been sorted out, use
	346	* VM_MIXEDMAP on all mappings. See freedesktop.org bug #75719
7dfe8b61	347	*/
0e6d6ec0	348	vma->vm_flags \|= VM_MIXEDMAP;
7dfe8b61	349	vma->vm_flags \|= VM_IO \| VM_DONTEXPAND \| VM_DONTDUMP;
ba4e7d97 TH	350	return 0;
	351	out_unref:
	352	ttm_bo_unref(&bo);
	353	return ret;
	354	}
	355	EXPORT_SYMBOL(ttm_bo_mmap);
	356
	357	int ttm_fbdev_mmap(struct vm_area_struct vma, struct ttm_buffer_object bo)
	358	{
	359	if (vma->vm_pgoff != 0)
	360	return -EACCES;
	361
	362	vma->vm_ops = &ttm_bo_vm_ops;
	363	vma->vm_private_data = ttm_bo_reference(bo);
0e6d6ec0	364	vma->vm_flags \|= VM_MIXEDMAP;
7dfe8b61	365	vma->vm_flags \|= VM_IO \| VM_DONTEXPAND;
ba4e7d97 TH	366	return 0;
	367	}
	368	EXPORT_SYMBOL(ttm_fbdev_mmap);