Merge tag 'staging-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging/IIO updates from Greg KH:
 "Here is the big staging tree update for 4.12-rc1.

  It's a big one, adding about 350k new lines of crap^Wcode, mostly all
  in a big dump of media drivers from Intel. But there's other new
  drivers in here as well, yet-another-wifi driver, new IIO drivers, and
  a new crypto accelerator.

  We also deleted a bunch of stuff, mostly in patch cleanups, but also
  the Android ION code has shrunk a lot, and the Android low memory
  killer driver was finally deleted, much to the celebration of the -mm
  developers.

  All of these have been in linux-next with a few build issues that will
  show up when you merge to your tree"

Merge conflicts in the new rtl8723bs driver (due to the wifi changes
this merge window) handled as per linux-next, courtesy of Stephen
Rothwell.

* tag 'staging-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (1182 commits)
  staging: fsl-mc/dpio: add cpu <--> LE conversion for dpaa2_fd
  staging: ks7010: remove line continuations in quoted strings
  staging: vt6656: use tabs instead of spaces
  staging: android: ion: Fix unnecessary initialization of static variable
  staging: media: atomisp: fix range checking on clk_num
  staging: media: atomisp: fix misspelled word in comment
  staging: media: atomisp: kmap() can't fail
  staging: atomisp: remove #ifdef for runtime PM functions
  staging: atomisp: satm include directory is gone
  atomisp: remove some more unused files
  atomisp: remove hmm_load/store/clear indirections
  atomisp: kill off mmgr_free
  atomisp: clean up the hmm init/cleanup indirections
  atomisp: handle allocation calls before init in the hmm layer
  staging: fsl-dpaa2/eth: Add maintainer for Ethernet driver
  staging: fsl-dpaa2/eth: Add TODO file
  staging: fsl-dpaa2/eth: Add trace points
  staging: fsl-dpaa2/eth: Add driver specific stats
  staging: fsl-dpaa2/eth: Add ethtool support
  staging: fsl-dpaa2/eth: Add Freescale DPAA2 Ethernet driver
  ...

1 files changed, 1543 insertions, 0 deletions

diff --git a/drivers/staging/media/atomisp/pci/atomisp2/hmm/hmm_bo.c b/drivers/staging/media/atomisp/pci/atomisp2/hmm/hmm_bo.c
new file mode 100644
index 000000000000..40ac3582fb7a
--- /dev/null
+++ b/drivers/staging/media/atomisp/pci/atomisp2/hmm/hmm_bo.c
@@ -0,0 +1,1543 @@
+/*
+ * Support for Medifield PNW Camera Imaging ISP subsystem.
+ *
+ * Copyright (c) 2010 Intel Corporation. All Rights Reserved.
+ *
+ * Copyright (c) 2010 Silicon Hive www.siliconhive.com.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ */
+/*
+ * This file contains functions for buffer object structure management
+ */
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/gfp.h>		/* for GFP_ATOMIC */
+#include <linux/mm.h>
+#include <linux/mm_types.h>
+#include <linux/hugetlb.h>
+#include <linux/highmem.h>
+#include <linux/slab.h>		/* for kmalloc */
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/string.h>
+#include <linux/list.h>
+#include <linux/errno.h>
+#include <asm/cacheflush.h>
+#include <linux/io.h>
+#include <asm/current.h>
+#include <linux/sched/signal.h>
+#include <linux/file.h>
+
+#include "atomisp_internal.h"
+#include "hmm/hmm_common.h"
+#include "hmm/hmm_pool.h"
+#include "hmm/hmm_bo.h"
+
+static unsigned int order_to_nr(unsigned int order)
+{
+	return 1U << order;
+}
+
+static unsigned int nr_to_order_bottom(unsigned int nr)
+{
+	return fls(nr) - 1;
+}
+
+struct hmm_buffer_object *__bo_alloc(struct kmem_cache *bo_cache)
+{
+	struct hmm_buffer_object *bo;
+
+	bo = kmem_cache_alloc(bo_cache, GFP_KERNEL);
+	if (!bo)
+		dev_err(atomisp_dev, "%s: failed!\n", __func__);
+
+	return bo;
+}
+
+static int __bo_init(struct hmm_bo_device *bdev, struct hmm_buffer_object *bo,
+					unsigned int pgnr)
+{
+	check_bodev_null_return(bdev, -EINVAL);
+	var_equal_return(hmm_bo_device_inited(bdev), 0, -EINVAL,
+			"hmm_bo_device not inited yet.\n");
+	/* prevent zero size buffer object */
+	if (pgnr == 0) {
+		dev_err(atomisp_dev, "0 size buffer is not allowed.\n");
+		return -EINVAL;
+	}
+
+	memset(bo, 0, sizeof(*bo));
+	mutex_init(&bo->mutex);
+
+	/* init the bo->list HEAD as an element of entire_bo_list */
+	INIT_LIST_HEAD(&bo->list);
+
+	bo->bdev = bdev;
+	bo->vmap_addr = NULL;
+	bo->status = HMM_BO_FREE;
+	bo->start = bdev->start;
+	bo->pgnr = pgnr;
+	bo->end = bo->start + pgnr_to_size(pgnr);
+	bo->prev = NULL;
+	bo->next = NULL;
+
+	return 0;
+}
+
+struct hmm_buffer_object *__bo_search_and_remove_from_free_rbtree(
+				struct rb_node *node, unsigned int pgnr)
+{
+	struct hmm_buffer_object *this, *ret_bo, *temp_bo;
+
+	this = rb_entry(node, struct hmm_buffer_object, node);
+	if (this->pgnr == pgnr ||
+		(this->pgnr > pgnr && this->node.rb_left == NULL)) {
+		goto remove_bo_and_return;
+	} else {
+		if (this->pgnr < pgnr) {
+			if (!this->node.rb_right)
+				return NULL;
+			ret_bo = __bo_search_and_remove_from_free_rbtree(
+				this->node.rb_right, pgnr);
+		} else {
+			ret_bo = __bo_search_and_remove_from_free_rbtree(
+				this->node.rb_left, pgnr);
+		}
+		if (!ret_bo) {
+			if (this->pgnr > pgnr)
+				goto remove_bo_and_return;
+			else
+				return NULL;
+		}
+		return ret_bo;
+	}
+
+remove_bo_and_return:
+	/* NOTE: All nodes on free rbtree have a 'prev' that points to NULL.
+	 * 1. check if 'this->next' is NULL:
+	 *	yes: erase 'this' node and rebalance rbtree, return 'this'.
+	 */
+	if (this->next == NULL) {
+		rb_erase(&this->node, &this->bdev->free_rbtree);
+		return this;
+	}
+	/* NOTE: if 'this->next' is not NULL, always return 'this->next' bo.
+	 * 2. check if 'this->next->next' is NULL:
+	 *	yes: change the related 'next/prev' pointer,
+	 *		return 'this->next' but the rbtree stays unchanged.
+	 */
+	temp_bo = this->next;
+	this->next = temp_bo->next;
+	if (temp_bo->next)
+		temp_bo->next->prev = this;
+	temp_bo->next = NULL;
+	temp_bo->prev = NULL;
+	return temp_bo;
+}
+
+struct hmm_buffer_object *__bo_search_by_addr(struct rb_root *root,
+							ia_css_ptr start)
+{
+	struct rb_node *n = root->rb_node;
+	struct hmm_buffer_object *bo;
+
+	do {
+		bo = rb_entry(n, struct hmm_buffer_object, node);
+
+		if (bo->start > start) {
+			if (n->rb_left == NULL)
+				return NULL;
+			n = n->rb_left;
+		} else if (bo->start < start) {
+			if (n->rb_right == NULL)
+				return NULL;
+			n = n->rb_right;
+		} else {
+			return bo;
+		}
+	} while (n);
+
+	return NULL;
+}
+
+struct hmm_buffer_object *__bo_search_by_addr_in_range(struct rb_root *root,
+					unsigned int start)
+{
+	struct rb_node *n = root->rb_node;
+	struct hmm_buffer_object *bo;
+
+	do {
+		bo = rb_entry(n, struct hmm_buffer_object, node);
+
+		if (bo->start > start) {
+			if (n->rb_left == NULL)
+				return NULL;
+			n = n->rb_left;
+		} else {
+			if (bo->end > start)
+				return bo;
+			if (n->rb_right == NULL)
+				return NULL;
+			n = n->rb_right;
+		}
+	} while (n);
+
+	return NULL;
+}
+
+static void __bo_insert_to_free_rbtree(struct rb_root *root,
+					struct hmm_buffer_object *bo)
+{
+	struct rb_node **new = &(root->rb_node);
+	struct rb_node *parent = NULL;
+	struct hmm_buffer_object *this;
+	unsigned int pgnr = bo->pgnr;
+
+	while (*new) {
+		parent = *new;
+		this = container_of(*new, struct hmm_buffer_object, node);
+
+		if (pgnr < this->pgnr) {
+			new = &((*new)->rb_left);
+		} else if (pgnr > this->pgnr) {
+			new = &((*new)->rb_right);
+		} else {
+			bo->prev = this;
+			bo->next = this->next;
+			if (this->next)
+				this->next->prev = bo;
+			this->next = bo;
+			bo->status = (bo->status & ~HMM_BO_MASK) | HMM_BO_FREE;
+			return;
+		}
+	}
+
+	bo->status = (bo->status & ~HMM_BO_MASK) | HMM_BO_FREE;
+
+	rb_link_node(&bo->node, parent, new);
+	rb_insert_color(&bo->node, root);
+}
+
+static void __bo_insert_to_alloc_rbtree(struct rb_root *root,
+					struct hmm_buffer_object *bo)
+{
+	struct rb_node **new = &(root->rb_node);
+	struct rb_node *parent = NULL;
+	struct hmm_buffer_object *this;
+	unsigned int start = bo->start;
+
+	while (*new) {
+		parent = *new;
+		this = container_of(*new, struct hmm_buffer_object, node);
+
+		if (start < this->start)
+			new = &((*new)->rb_left);
+		else
+			new = &((*new)->rb_right);
+	}
+
+	kref_init(&bo->kref);
+	bo->status = (bo->status & ~HMM_BO_MASK) | HMM_BO_ALLOCED;
+
+	rb_link_node(&bo->node, parent, new);
+	rb_insert_color(&bo->node, root);
+}
+
+struct hmm_buffer_object *__bo_break_up(struct hmm_bo_device *bdev,
+					struct hmm_buffer_object *bo,
+					unsigned int pgnr)
+{
+	struct hmm_buffer_object *new_bo;
+	unsigned long flags;
+	int ret;
+
+	new_bo = __bo_alloc(bdev->bo_cache);
+	if (!new_bo) {
+		dev_err(atomisp_dev, "%s: __bo_alloc failed!\n", __func__);
+		return NULL;
+	}
+	ret = __bo_init(bdev, new_bo, pgnr);
+	if (ret) {
+		dev_err(atomisp_dev, "%s: __bo_init failed!\n", __func__);
+		kmem_cache_free(bdev->bo_cache, new_bo);
+		return NULL;
+	}
+
+	new_bo->start = bo->start;
+	new_bo->end = new_bo->start + pgnr_to_size(pgnr);
+	bo->start = new_bo->end;
+	bo->pgnr = bo->pgnr - pgnr;
+
+	spin_lock_irqsave(&bdev->list_lock, flags);
+	list_add_tail(&new_bo->list, &bo->list);
+	spin_unlock_irqrestore(&bdev->list_lock, flags);
+
+	return new_bo;
+}
+
+static void __bo_take_off_handling(struct hmm_buffer_object *bo)
+{
+	struct hmm_bo_device *bdev = bo->bdev;
+	/* There are 4 situations when we take off a known bo from free rbtree:
+	 * 1. if bo->next && bo->prev == NULL, bo is a rbtree node
+	 *	and does not have a linked list after bo, to take off this bo,
+	 *	we just need erase bo directly and rebalance the free rbtree
+	 */
+	if (bo->prev == NULL && bo->next == NULL) {
+		rb_erase(&bo->node, &bdev->free_rbtree);
+	/* 2. when bo->next != NULL && bo->prev == NULL, bo is a rbtree node,
+	 *	and has a linked list,to take off this bo we need erase bo
+	 *	first, then, insert bo->next into free rbtree and rebalance
+	 *	the free rbtree
+	 */
+	} else if (bo->prev == NULL && bo->next != NULL) {
+		bo->next->prev = NULL;
+		rb_erase(&bo->node, &bdev->free_rbtree);
+		__bo_insert_to_free_rbtree(&bdev->free_rbtree, bo->next);
+		bo->next = NULL;
+	/* 3. when bo->prev != NULL && bo->next == NULL, bo is not a rbtree
+	 *	node, bo is the last element of the linked list after rbtree
+	 *	node, to take off this bo, we just need set the "prev/next"
+	 *	pointers to NULL, the free rbtree stays unchaged
+	 */
+	} else if (bo->prev != NULL && bo->next == NULL) {
+		bo->prev->next = NULL;
+		bo->prev = NULL;
+	/* 4. when bo->prev != NULL && bo->next != NULL ,bo is not a rbtree
+	 *	node, bo is in the middle of the linked list after rbtree node,
+	 *	to take off this bo, we just set take the "prev/next" pointers
+	 *	to NULL, the free rbtree stays unchaged
+	 */
+	} else {
+		bo->next->prev = bo->prev;
+		bo->prev->next = bo->next;
+		bo->next = NULL;
+		bo->prev = NULL;
+	}
+}
+
+struct hmm_buffer_object *__bo_merge(struct hmm_buffer_object *bo,
+					struct hmm_buffer_object *next_bo)
+{
+	struct hmm_bo_device *bdev;
+	unsigned long flags;
+
+	bdev = bo->bdev;
+	next_bo->start = bo->start;
+	next_bo->pgnr = next_bo->pgnr + bo->pgnr;
+
+	spin_lock_irqsave(&bdev->list_lock, flags);
+	list_del(&bo->list);
+	spin_unlock_irqrestore(&bdev->list_lock, flags);
+
+	kmem_cache_free(bo->bdev->bo_cache, bo);
+
+	return next_bo;
+}
+
+/*
+ * hmm_bo_device functions.
+ */
+int hmm_bo_device_init(struct hmm_bo_device *bdev,
+				struct isp_mmu_client *mmu_driver,
+				unsigned int vaddr_start,
+				unsigned int size)
+{
+	struct hmm_buffer_object *bo;
+	unsigned long flags;
+	int ret;
+
+	check_bodev_null_return(bdev, -EINVAL);
+
+	ret = isp_mmu_init(&bdev->mmu, mmu_driver);
+	if (ret) {
+		dev_err(atomisp_dev, "isp_mmu_init failed.\n");
+		return ret;
+	}
+
+	bdev->start = vaddr_start;
+	bdev->pgnr = size_to_pgnr_ceil(size);
+	bdev->size = pgnr_to_size(bdev->pgnr);
+
+	spin_lock_init(&bdev->list_lock);
+	mutex_init(&bdev->rbtree_mutex);
+
+	bdev->flag = HMM_BO_DEVICE_INITED;
+
+	INIT_LIST_HEAD(&bdev->entire_bo_list);
+	bdev->allocated_rbtree = RB_ROOT;
+	bdev->free_rbtree = RB_ROOT;
+
+	bdev->bo_cache = kmem_cache_create("bo_cache",
+				sizeof(struct hmm_buffer_object), 0, 0, NULL);
+	if (!bdev->bo_cache) {
+		dev_err(atomisp_dev, "%s: create cache failed!\n", __func__);
+		isp_mmu_exit(&bdev->mmu);
+		return -ENOMEM;
+	}
+
+	bo = __bo_alloc(bdev->bo_cache);
+	if (!bo) {
+		dev_err(atomisp_dev, "%s: __bo_alloc failed!\n", __func__);
+		isp_mmu_exit(&bdev->mmu);
+		return -ENOMEM;
+	}
+
+	ret = __bo_init(bdev, bo, bdev->pgnr);
+	if (ret) {
+		dev_err(atomisp_dev, "%s: __bo_init failed!\n", __func__);
+		kmem_cache_free(bdev->bo_cache, bo);
+		isp_mmu_exit(&bdev->mmu);
+		return -EINVAL;
+	}
+
+	spin_lock_irqsave(&bdev->list_lock, flags);
+	list_add_tail(&bo->list, &bdev->entire_bo_list);
+	spin_unlock_irqrestore(&bdev->list_lock, flags);
+
+	__bo_insert_to_free_rbtree(&bdev->free_rbtree, bo);
+
+	return 0;
+}
+
+struct hmm_buffer_object *hmm_bo_alloc(struct hmm_bo_device *bdev,
+					unsigned int pgnr)
+{
+	struct hmm_buffer_object *bo, *new_bo;
+	struct rb_root *root = &bdev->free_rbtree;
+
+	check_bodev_null_return(bdev, NULL);
+	var_equal_return(hmm_bo_device_inited(bdev), 0, NULL,
+			"hmm_bo_device not inited yet.\n");
+
+	if (pgnr == 0) {
+		dev_err(atomisp_dev, "0 size buffer is not allowed.\n");
+		return NULL;
+	}
+
+	mutex_lock(&bdev->rbtree_mutex);
+	bo = __bo_search_and_remove_from_free_rbtree(root->rb_node, pgnr);
+	if (!bo) {
+		mutex_unlock(&bdev->rbtree_mutex);
+		dev_err(atomisp_dev, "%s: Out of Memory! hmm_bo_alloc failed",
+			__func__);
+		return NULL;
+	}
+
+	if (bo->pgnr > pgnr) {
+		new_bo = __bo_break_up(bdev, bo, pgnr);
+		if (!new_bo) {
+			mutex_unlock(&bdev->rbtree_mutex);
+			dev_err(atomisp_dev, "%s: __bo_break_up failed!\n",
+				__func__);
+			return NULL;
+		}
+
+		__bo_insert_to_alloc_rbtree(&bdev->allocated_rbtree, new_bo);
+		__bo_insert_to_free_rbtree(&bdev->free_rbtree, bo);
+
+		mutex_unlock(&bdev->rbtree_mutex);
+		return new_bo;
+	}
+
+	__bo_insert_to_alloc_rbtree(&bdev->allocated_rbtree, bo);
+
+	mutex_unlock(&bdev->rbtree_mutex);
+	return bo;
+}
+
+void hmm_bo_release(struct hmm_buffer_object *bo)
+{
+	struct hmm_bo_device *bdev = bo->bdev;
+	struct hmm_buffer_object *next_bo, *prev_bo;
+
+	mutex_lock(&bdev->rbtree_mutex);
+
+	/*
+	 * FIX ME:
+	 *
+	 * how to destroy the bo when it is stilled MMAPED?
+	 *
+	 * ideally, this will not happened as hmm_bo_release
+	 * will only be called when kref reaches 0, and in mmap
+	 * operation the hmm_bo_ref will eventually be called.
+	 * so, if this happened, something goes wrong.
+	 */
+	if (bo->status & HMM_BO_MMAPED) {
+		mutex_unlock(&bdev->rbtree_mutex);
+		dev_dbg(atomisp_dev, "destroy bo which is MMAPED, do nothing\n");
+		return;
+	}
+
+	if (bo->status & HMM_BO_BINDED) {
+		dev_warn(atomisp_dev, "the bo is still binded, unbind it first...\n");
+		hmm_bo_unbind(bo);
+	}
+
+	if (bo->status & HMM_BO_PAGE_ALLOCED) {
+		dev_warn(atomisp_dev, "the pages is not freed, free pages first\n");
+		hmm_bo_free_pages(bo);
+	}
+	if (bo->status & HMM_BO_VMAPED || bo->status & HMM_BO_VMAPED_CACHED) {
+		dev_warn(atomisp_dev, "the vunmap is not done, do it...\n");
+		hmm_bo_vunmap(bo);
+	}
+
+	rb_erase(&bo->node, &bdev->allocated_rbtree);
+
+	prev_bo = list_entry(bo->list.prev, struct hmm_buffer_object, list);
+	next_bo = list_entry(bo->list.next, struct hmm_buffer_object, list);
+
+	if (bo->list.prev != &bdev->entire_bo_list &&
+		prev_bo->end == bo->start &&
+		(prev_bo->status & HMM_BO_MASK) == HMM_BO_FREE) {
+		__bo_take_off_handling(prev_bo);
+		bo = __bo_merge(prev_bo, bo);
+	}
+
+	if (bo->list.next != &bdev->entire_bo_list &&
+		next_bo->start == bo->end &&
+		(next_bo->status & HMM_BO_MASK) == HMM_BO_FREE) {
+		__bo_take_off_handling(next_bo);
+		bo = __bo_merge(bo, next_bo);
+	}
+
+	__bo_insert_to_free_rbtree(&bdev->free_rbtree, bo);
+
+	mutex_unlock(&bdev->rbtree_mutex);
+	return;
+}
+
+void hmm_bo_device_exit(struct hmm_bo_device *bdev)
+{
+	struct hmm_buffer_object *bo;
+	unsigned long flags;
+
+	dev_dbg(atomisp_dev, "%s: entering!\n", __func__);
+
+	check_bodev_null_return_void(bdev);
+
+	/*
+	 * release all allocated bos even they a in use
+	 * and all bos will be merged into a big bo
+	 */
+	while (!RB_EMPTY_ROOT(&bdev->allocated_rbtree))
+		hmm_bo_release(
+			rbtree_node_to_hmm_bo(bdev->allocated_rbtree.rb_node));
+
+	dev_dbg(atomisp_dev, "%s: finished releasing all allocated bos!\n",
+		__func__);
+
+	/* free all bos to release all ISP virtual memory */
+	while (!list_empty(&bdev->entire_bo_list)) {
+		bo = list_to_hmm_bo(bdev->entire_bo_list.next);
+
+		spin_lock_irqsave(&bdev->list_lock, flags);
+		list_del(&bo->list);
+		spin_unlock_irqrestore(&bdev->list_lock, flags);
+
+		kmem_cache_free(bdev->bo_cache, bo);
+	}
+
+	dev_dbg(atomisp_dev, "%s: finished to free all bos!\n", __func__);
+
+	kmem_cache_destroy(bdev->bo_cache);
+
+	isp_mmu_exit(&bdev->mmu);
+}
+
+int hmm_bo_device_inited(struct hmm_bo_device *bdev)
+{
+	check_bodev_null_return(bdev, -EINVAL);
+
+	return bdev->flag == HMM_BO_DEVICE_INITED;
+}
+
+int hmm_bo_allocated(struct hmm_buffer_object *bo)
+{
+	check_bo_null_return(bo, 0);
+
+	return bo->status & HMM_BO_ALLOCED;
+}
+
+struct hmm_buffer_object *hmm_bo_device_search_start(
+	struct hmm_bo_device *bdev, ia_css_ptr vaddr)
+{
+	struct hmm_buffer_object *bo;
+
+	check_bodev_null_return(bdev, NULL);
+
+	mutex_lock(&bdev->rbtree_mutex);
+	bo = __bo_search_by_addr(&bdev->allocated_rbtree, vaddr);
+	if (!bo) {
+		mutex_unlock(&bdev->rbtree_mutex);
+		dev_err(atomisp_dev, "%s can not find bo with addr: 0x%x\n",
+			__func__, vaddr);
+		return NULL;
+	}
+	mutex_unlock(&bdev->rbtree_mutex);
+
+	return bo;
+}
+
+struct hmm_buffer_object *hmm_bo_device_search_in_range(
+	struct hmm_bo_device *bdev, unsigned int vaddr)
+{
+	struct hmm_buffer_object *bo;
+
+	check_bodev_null_return(bdev, NULL);
+
+	mutex_lock(&bdev->rbtree_mutex);
+	bo = __bo_search_by_addr_in_range(&bdev->allocated_rbtree, vaddr);
+	if (!bo) {
+		mutex_unlock(&bdev->rbtree_mutex);
+		dev_err(atomisp_dev, "%s can not find bo contain addr: 0x%x\n",
+			__func__, vaddr);
+		return NULL;
+	}
+	mutex_unlock(&bdev->rbtree_mutex);
+
+	return bo;
+}
+
+struct hmm_buffer_object *hmm_bo_device_search_vmap_start(
+	struct hmm_bo_device *bdev, const void *vaddr)
+{
+	struct list_head *pos;
+	struct hmm_buffer_object *bo;
+	unsigned long flags;
+
+	check_bodev_null_return(bdev, NULL);
+
+	spin_lock_irqsave(&bdev->list_lock, flags);
+	list_for_each(pos, &bdev->entire_bo_list) {
+		bo = list_to_hmm_bo(pos);
+		/* pass bo which has no vm_node allocated */
+		if ((bo->status & HMM_BO_MASK) == HMM_BO_FREE)
+			continue;
+		if (bo->vmap_addr == vaddr)
+			goto found;
+	}
+	spin_unlock_irqrestore(&bdev->list_lock, flags);
+	return NULL;
+found:
+	spin_unlock_irqrestore(&bdev->list_lock, flags);
+	return bo;
+
+}
+
+
+static void free_private_bo_pages(struct hmm_buffer_object *bo,
+				struct hmm_pool *dypool,
+				struct hmm_pool *repool,
+				int free_pgnr)
+{
+	int i, ret;
+
+	for (i = 0; i < free_pgnr; i++) {
+		switch (bo->page_obj[i].type) {
+		case HMM_PAGE_TYPE_RESERVED:
+			if (repool->pops
+			    && repool->pops->pool_free_pages) {
+				repool->pops->pool_free_pages(repool->pool_info,
+							&bo->page_obj[i]);
+				hmm_mem_stat.res_cnt--;
+			}
+			break;
+		/*
+		 * HMM_PAGE_TYPE_GENERAL indicates that pages are from system
+		 * memory, so when free them, they should be put into dynamic
+		 * pool.
+		 */
+		case HMM_PAGE_TYPE_DYNAMIC:
+		case HMM_PAGE_TYPE_GENERAL:
+			if (dypool->pops
+			    && dypool->pops->pool_inited
+			    && dypool->pops->pool_inited(dypool->pool_info)) {
+				if (dypool->pops->pool_free_pages)
+					dypool->pops->pool_free_pages(
+							      dypool->pool_info,
+							      &bo->page_obj[i]);
+				break;
+			}
+
+			/*
+			 * if dynamic memory pool doesn't exist, need to free
+			 * pages to system directly.
+			 */
+		default:
+			ret = set_pages_wb(bo->page_obj[i].page, 1);
+			if (ret)
+				dev_err(atomisp_dev,
+						"set page to WB err ...ret = %d\n",
+							ret);
+			/*
+			W/A: set_pages_wb seldom return value = -EFAULT
+			indicate that address of page is not in valid
+			range(0xffff880000000000~0xffffc7ffffffffff)
+			then, _free_pages would panic; Do not know why page
+			address be valid,it maybe memory corruption by lowmemory
+			*/
+			if (!ret) {
+				__free_pages(bo->page_obj[i].page, 0);
+				hmm_mem_stat.sys_size--;
+			}
+			break;
+		}
+	}
+
+	return;
+}
+
+/*Allocate pages which will be used only by ISP*/
+static int alloc_private_pages(struct hmm_buffer_object *bo,
+				int from_highmem,
+				bool cached,
+				struct hmm_pool *dypool,
+				struct hmm_pool *repool)
+{
+	int ret;
+	unsigned int pgnr, order, blk_pgnr, alloc_pgnr;
+	struct page *pages;
+	gfp_t gfp = GFP_NOWAIT | __GFP_NOWARN; /* REVISIT: need __GFP_FS too? */
+	int i, j;
+	int failure_number = 0;
+	bool reduce_order = false;
+	bool lack_mem = true;
+
+	if (from_highmem)
+		gfp |= __GFP_HIGHMEM;
+
+	pgnr = bo->pgnr;
+
+	bo->page_obj = kmalloc(sizeof(struct hmm_page_object) * pgnr,
+				GFP_KERNEL);
+	if (unlikely(!bo->page_obj)) {
+		dev_err(atomisp_dev, "out of memory for bo->page_obj\n");
+		return -ENOMEM;
+	}
+
+	i = 0;
+	alloc_pgnr = 0;
+
+	/*
+	 * get physical pages from dynamic pages pool.
+	 */
+	if (dypool->pops && dypool->pops->pool_alloc_pages) {
+		alloc_pgnr = dypool->pops->pool_alloc_pages(dypool->pool_info,
+							bo->page_obj, pgnr,
+							cached);
+		hmm_mem_stat.dyc_size -= alloc_pgnr;
+
+		if (alloc_pgnr == pgnr)
+			return 0;
+	}
+
+	pgnr -= alloc_pgnr;
+	i += alloc_pgnr;
+
+	/*
+	 * get physical pages from reserved pages pool for atomisp.
+	 */
+	if (repool->pops && repool->pops->pool_alloc_pages) {
+		alloc_pgnr = repool->pops->pool_alloc_pages(repool->pool_info,
+							&bo->page_obj[i], pgnr,
+							cached);
+		hmm_mem_stat.res_cnt += alloc_pgnr;
+		if (alloc_pgnr == pgnr)
+			return 0;
+	}
+
+	pgnr -= alloc_pgnr;
+	i += alloc_pgnr;
+
+	while (pgnr) {
+		order = nr_to_order_bottom(pgnr);
+		/*
+		 * if be short of memory, we will set order to 0
+		 * everytime.
+		 */
+		if (lack_mem)
+			order = HMM_MIN_ORDER;
+		else if (order > HMM_MAX_ORDER)
+			order = HMM_MAX_ORDER;
+retry:
+		/*
+		 * When order > HMM_MIN_ORDER, for performance reasons we don't
+		 * want alloc_pages() to sleep. In case it fails and fallbacks
+		 * to HMM_MIN_ORDER or in case the requested order is originally
+		 * the minimum value, we can allow alloc_pages() to sleep for
+		 * robustness purpose.
+		 *
+		 * REVISIT: why __GFP_FS is necessary?
+		 */
+		if (order == HMM_MIN_ORDER) {
+			gfp &= ~GFP_NOWAIT;
+			gfp |= __GFP_RECLAIM | __GFP_FS;
+		}
+
+		pages = alloc_pages(gfp, order);
+		if (unlikely(!pages)) {
+			/*
+			 * in low memory case, if allocation page fails,
+			 * we turn to try if order=0 allocation could
+			 * succeed. if order=0 fails too, that means there is
+			 * no memory left.
+			 */
+			if (order == HMM_MIN_ORDER) {
+				dev_err(atomisp_dev,
+					"%s: cannot allocate pages\n",
+					 __func__);
+				goto cleanup;
+			}
+			order = HMM_MIN_ORDER;
+			failure_number++;
+			reduce_order = true;
+			/*
+			 * if fail two times continuously, we think be short
+			 * of memory now.
+			 */
+			if (failure_number == 2) {
+				lack_mem = true;
+				failure_number = 0;
+			}
+			goto retry;
+		} else {
+			blk_pgnr = order_to_nr(order);
+
+			if (!cached) {
+				/*
+				 * set memory to uncacheable -- UC_MINUS
+				 */
+				ret = set_pages_uc(pages, blk_pgnr);
+				if (ret) {
+					dev_err(atomisp_dev,
+						     "set page uncacheable"
+							"failed.\n");
+
+					__free_pages(pages, order);
+
+					goto cleanup;
+				}
+			}
+
+			for (j = 0; j < blk_pgnr; j++) {
+				bo->page_obj[i].page = pages + j;
+				bo->page_obj[i++].type = HMM_PAGE_TYPE_GENERAL;
+			}
+
+			pgnr -= blk_pgnr;
+			hmm_mem_stat.sys_size += blk_pgnr;
+
+			/*
+			 * if order is not reduced this time, clear
+			 * failure_number.
+			 */
+			if (reduce_order)
+				reduce_order = false;
+			else
+				failure_number = 0;
+		}
+	}
+
+	return 0;
+cleanup:
+	alloc_pgnr = i;
+	free_private_bo_pages(bo, dypool, repool, alloc_pgnr);
+
+	kfree(bo->page_obj);
+
+	return -ENOMEM;
+}
+
+static void free_private_pages(struct hmm_buffer_object *bo,
+				struct hmm_pool *dypool,
+				struct hmm_pool *repool)
+{
+	free_private_bo_pages(bo, dypool, repool, bo->pgnr);
+
+	kfree(bo->page_obj);
+}
+
+/*
+ * Hacked from kernel function __get_user_pages in mm/memory.c
+ *
+ * Handle buffers allocated by other kernel space driver and mmaped into user
+ * space, function Ignore the VM_PFNMAP and VM_IO flag in VMA structure
+ *
+ * Get physical pages from user space virtual address and update into page list
+ */
+static int __get_pfnmap_pages(struct task_struct *tsk, struct mm_struct *mm,
+			      unsigned long start, int nr_pages,
+			      unsigned int gup_flags, struct page **pages,
+			      struct vm_area_struct **vmas)
+{
+	int i, ret;
+	unsigned long vm_flags;
+
+	if (nr_pages <= 0)
+		return 0;
+
+	VM_BUG_ON(!!pages != !!(gup_flags & FOLL_GET));
+
+	/*
+	 * Require read or write permissions.
+	 * If FOLL_FORCE is set, we only require the "MAY" flags.
+	 */
+	vm_flags  = (gup_flags & FOLL_WRITE) ?
+			(VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD);
+	vm_flags &= (gup_flags & FOLL_FORCE) ?
+			(VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE);
+	i = 0;
+
+	do {
+		struct vm_area_struct *vma;
+
+		vma = find_vma(mm, start);
+		if (!vma) {
+			dev_err(atomisp_dev, "find_vma failed\n");
+			return i ? : -EFAULT;
+		}
+
+		if (is_vm_hugetlb_page(vma)) {
+			/*
+			i = follow_hugetlb_page(mm, vma, pages, vmas,
+					&start, &nr_pages, i, gup_flags);
+			*/
+			continue;
+		}
+
+		do {
+			struct page *page;
+			unsigned long pfn;
+
+			/*
+			 * If we have a pending SIGKILL, don't keep faulting
+			 * pages and potentially allocating memory.
+			 */
+			if (unlikely(fatal_signal_pending(current))) {
+				dev_err(atomisp_dev,
+					"fatal_signal_pending in %s\n",
+					__func__);
+				return i ? i : -ERESTARTSYS;
+			}
+
+			ret = follow_pfn(vma, start, &pfn);
+			if (ret) {
+				dev_err(atomisp_dev, "follow_pfn() failed\n");
+				return i ? : -EFAULT;
+			}
+
+			page = pfn_to_page(pfn);
+			if (IS_ERR(page))
+				return i ? i : PTR_ERR(page);
+			if (pages) {
+				pages[i] = page;
+				get_page(page);
+				flush_anon_page(vma, page, start);
+				flush_dcache_page(page);
+			}
+			if (vmas)
+				vmas[i] = vma;
+			i++;
+			start += PAGE_SIZE;
+			nr_pages--;
+		} while (nr_pages && start < vma->vm_end);
+	} while (nr_pages);
+
+	return i;
+}
+
+static int get_pfnmap_pages(struct task_struct *tsk, struct mm_struct *mm,
+		     unsigned long start, int nr_pages, int write, int force,
+		     struct page **pages, struct vm_area_struct **vmas)
+{
+	int flags = FOLL_TOUCH;
+
+	if (pages)
+		flags |= FOLL_GET;
+	if (write)
+		flags |= FOLL_WRITE;
+	if (force)
+		flags |= FOLL_FORCE;
+
+	return __get_pfnmap_pages(tsk, mm, start, nr_pages, flags, pages, vmas);
+}
+
+/*
+ * Convert user space virtual address into pages list
+ */
+static int alloc_user_pages(struct hmm_buffer_object *bo,
+			      void *userptr, bool cached)
+{
+	int page_nr;
+	int i;
+	struct vm_area_struct *vma;
+	struct page **pages;
+
+	pages = kmalloc(sizeof(struct page *) * bo->pgnr, GFP_KERNEL);
+	if (unlikely(!pages)) {
+		dev_err(atomisp_dev, "out of memory for pages...\n");
+		return -ENOMEM;
+	}
+
+	bo->page_obj = kmalloc(sizeof(struct hmm_page_object) * bo->pgnr,
+		GFP_KERNEL);
+	if (unlikely(!bo->page_obj)) {
+		dev_err(atomisp_dev, "out of memory for bo->page_obj...\n");
+		kfree(pages);
+		return -ENOMEM;
+	}
+
+	mutex_unlock(&bo->mutex);
+	down_read(&current->mm->mmap_sem);
+	vma = find_vma(current->mm, (unsigned long)userptr);
+	up_read(&current->mm->mmap_sem);
+	if (vma == NULL) {
+		dev_err(atomisp_dev, "find_vma failed\n");
+		kfree(bo->page_obj);
+		kfree(pages);
+		mutex_lock(&bo->mutex);
+		return -EFAULT;
+	}
+	mutex_lock(&bo->mutex);
+	/*
+	 * Handle frame buffer allocated in other kerenl space driver
+	 * and map to user space
+	 */
+	if (vma->vm_flags & (VM_IO | VM_PFNMAP)) {
+		page_nr = get_pfnmap_pages(current, current->mm,
+					   (unsigned long)userptr,
+					   (int)(bo->pgnr), 1, 0,
+					   pages, NULL);
+		bo->mem_type = HMM_BO_MEM_TYPE_PFN;
+	} else {
+		/*Handle frame buffer allocated in user space*/
+		mutex_unlock(&bo->mutex);
+		down_read(&current->mm->mmap_sem);
+		page_nr = get_user_pages((unsigned long)userptr,
+					 (int)(bo->pgnr), 1, pages, NULL);
+		up_read(&current->mm->mmap_sem);
+		mutex_lock(&bo->mutex);
+		bo->mem_type = HMM_BO_MEM_TYPE_USER;
+	}
+
+	/* can be written by caller, not forced */
+	if (page_nr != bo->pgnr) {
+		dev_err(atomisp_dev,
+				"get_user_pages err: bo->pgnr = %d, "
+				"pgnr actually pinned = %d.\n",
+				bo->pgnr, page_nr);
+		goto out_of_mem;
+	}
+
+	for (i = 0; i < bo->pgnr; i++) {
+		bo->page_obj[i].page = pages[i];
+		bo->page_obj[i].type = HMM_PAGE_TYPE_GENERAL;
+	}
+	hmm_mem_stat.usr_size += bo->pgnr;
+	kfree(pages);
+
+	return 0;
+
+out_of_mem:
+	for (i = 0; i < page_nr; i++)
+		put_page(pages[i]);
+	kfree(pages);
+	kfree(bo->page_obj);
+
+	return -ENOMEM;
+}
+
+static void free_user_pages(struct hmm_buffer_object *bo)
+{
+	int i;
+
+	for (i = 0; i < bo->pgnr; i++)
+		put_page(bo->page_obj[i].page);
+	hmm_mem_stat.usr_size -= bo->pgnr;
+
+	kfree(bo->page_obj);
+}
+
+/*
+ * allocate/free physical pages for the bo.
+ *
+ * type indicate where are the pages from. currently we have 3 types
+ * of memory: HMM_BO_PRIVATE, HMM_BO_USER, HMM_BO_SHARE.
+ *
+ * from_highmem is only valid when type is HMM_BO_PRIVATE, it will
+ * try to alloc memory from highmem if from_highmem is set.
+ *
+ * userptr is only valid when type is HMM_BO_USER, it indicates
+ * the start address from user space task.
+ *
+ * from_highmem and userptr will both be ignored when type is
+ * HMM_BO_SHARE.
+ */
+int hmm_bo_alloc_pages(struct hmm_buffer_object *bo,
+		       enum hmm_bo_type type, int from_highmem,
+		       void *userptr, bool cached)
+{
+	int ret = -EINVAL;
+
+	check_bo_null_return(bo, -EINVAL);
+
+	mutex_lock(&bo->mutex);
+	check_bo_status_no_goto(bo, HMM_BO_PAGE_ALLOCED, status_err);
+
+	/*
+	 * TO DO:
+	 * add HMM_BO_USER type
+	 */
+	if (type == HMM_BO_PRIVATE) {
+		ret = alloc_private_pages(bo, from_highmem,
+				cached, &dynamic_pool, &reserved_pool);
+	} else if (type == HMM_BO_USER) {
+		ret = alloc_user_pages(bo, userptr, cached);
+	} else {
+		dev_err(atomisp_dev, "invalid buffer type.\n");
+		ret = -EINVAL;
+	}
+	if (ret)
+		goto alloc_err;
+
+	bo->type = type;
+
+	bo->status |= HMM_BO_PAGE_ALLOCED;
+
+	mutex_unlock(&bo->mutex);
+
+	return 0;
+
+alloc_err:
+	mutex_unlock(&bo->mutex);
+	dev_err(atomisp_dev, "alloc pages err...\n");
+	return ret;
+status_err:
+	mutex_unlock(&bo->mutex);
+	dev_err(atomisp_dev,
+			"buffer object has already page allocated.\n");
+	return -EINVAL;
+}
+
+/*
+ * free physical pages of the bo.
+ */
+void hmm_bo_free_pages(struct hmm_buffer_object *bo)
+{
+	check_bo_null_return_void(bo);
+
+	mutex_lock(&bo->mutex);
+
+	check_bo_status_yes_goto(bo, HMM_BO_PAGE_ALLOCED, status_err2);
+
+	/* clear the flag anyway. */
+	bo->status &= (~HMM_BO_PAGE_ALLOCED);
+
+	if (bo->type == HMM_BO_PRIVATE)
+		free_private_pages(bo, &dynamic_pool, &reserved_pool);
+	else if (bo->type == HMM_BO_USER)
+		free_user_pages(bo);
+	else
+		dev_err(atomisp_dev, "invalid buffer type.\n");
+	mutex_unlock(&bo->mutex);
+
+	return;
+
+status_err2:
+	mutex_unlock(&bo->mutex);
+	dev_err(atomisp_dev,
+			"buffer object not page allocated yet.\n");
+}
+
+int hmm_bo_page_allocated(struct hmm_buffer_object *bo)
+{
+	int ret;
+
+	check_bo_null_return(bo, 0);
+
+	ret = bo->status & HMM_BO_PAGE_ALLOCED;
+
+	return ret;
+}
+
+/*
+ * get physical page info of the bo.
+ */
+int hmm_bo_get_page_info(struct hmm_buffer_object *bo,
+			 struct hmm_page_object **page_obj, int *pgnr)
+{
+	check_bo_null_return(bo, -EINVAL);
+
+	mutex_lock(&bo->mutex);
+
+	check_bo_status_yes_goto(bo, HMM_BO_PAGE_ALLOCED, status_err);
+
+	*page_obj = bo->page_obj;
+	*pgnr = bo->pgnr;
+
+	mutex_unlock(&bo->mutex);
+
+	return 0;
+
+status_err:
+	dev_err(atomisp_dev,
+			"buffer object not page allocated yet.\n");
+	mutex_unlock(&bo->mutex);
+	return -EINVAL;
+}
+
+/*
+ * bind the physical pages to a virtual address space.
+ */
+int hmm_bo_bind(struct hmm_buffer_object *bo)
+{
+	int ret;
+	unsigned int virt;
+	struct hmm_bo_device *bdev;
+	unsigned int i;
+
+	check_bo_null_return(bo, -EINVAL);
+
+	mutex_lock(&bo->mutex);
+
+	check_bo_status_yes_goto(bo,
+				   HMM_BO_PAGE_ALLOCED | HMM_BO_ALLOCED,
+				   status_err1);
+
+	check_bo_status_no_goto(bo, HMM_BO_BINDED, status_err2);
+
+	bdev = bo->bdev;
+
+	virt = bo->start;
+
+	for (i = 0; i < bo->pgnr; i++) {
+		ret =
+		    isp_mmu_map(&bdev->mmu, virt,
+				page_to_phys(bo->page_obj[i].page), 1);
+		if (ret)
+			goto map_err;
+		virt += (1 << PAGE_SHIFT);
+	}
+
+	/*
+	 * flush TBL here.
+	 *
+	 * theoretically, we donot need to flush TLB as we didnot change
+	 * any existed address mappings, but for Silicon Hive's MMU, its
+	 * really a bug here. I guess when fetching PTEs (page table entity)
+	 * to TLB, its MMU will fetch additional INVALID PTEs automatically
+	 * for performance issue. EX, we only set up 1 page address mapping,
+	 * meaning updating 1 PTE, but the MMU fetches 4 PTE at one time,
+	 * so the additional 3 PTEs are invalid.
+	 */
+	if (bo->start != 0x0)
+		isp_mmu_flush_tlb_range(&bdev->mmu, bo->start,
+						(bo->pgnr << PAGE_SHIFT));
+
+	bo->status |= HMM_BO_BINDED;
+
+	mutex_unlock(&bo->mutex);
+
+	return 0;
+
+map_err:
+	/* unbind the physical pages with related virtual address space */
+	virt = bo->start;
+	for ( ; i > 0; i--) {
+		isp_mmu_unmap(&bdev->mmu, virt, 1);
+		virt += pgnr_to_size(1);
+	}
+
+	mutex_unlock(&bo->mutex);
+	dev_err(atomisp_dev,
+			"setup MMU address mapping failed.\n");
+	return ret;
+
+status_err2:
+	mutex_unlock(&bo->mutex);
+	dev_err(atomisp_dev, "buffer object already binded.\n");
+	return -EINVAL;
+status_err1:
+	mutex_unlock(&bo->mutex);
+	dev_err(atomisp_dev,
+		     "buffer object vm_node or page not allocated.\n");
+	return -EINVAL;
+}
+
+/*
+ * unbind the physical pages with related virtual address space.
+ */
+void hmm_bo_unbind(struct hmm_buffer_object *bo)
+{
+	unsigned int virt;
+	struct hmm_bo_device *bdev;
+	unsigned int i;
+
+	check_bo_null_return_void(bo);
+
+	mutex_lock(&bo->mutex);
+
+	check_bo_status_yes_goto(bo,
+				   HMM_BO_PAGE_ALLOCED |
+				   HMM_BO_ALLOCED |
+				   HMM_BO_BINDED, status_err);
+
+	bdev = bo->bdev;
+
+	virt = bo->start;
+
+	for (i = 0; i < bo->pgnr; i++) {
+		isp_mmu_unmap(&bdev->mmu, virt, 1);
+		virt += pgnr_to_size(1);
+	}
+
+	/*
+	 * flush TLB as the address mapping has been removed and
+	 * related TLBs should be invalidated.
+	 */
+	isp_mmu_flush_tlb_range(&bdev->mmu, bo->start,
+				(bo->pgnr << PAGE_SHIFT));
+
+	bo->status &= (~HMM_BO_BINDED);
+
+	mutex_unlock(&bo->mutex);
+
+	return;
+
+status_err:
+	mutex_unlock(&bo->mutex);
+	dev_err(atomisp_dev,
+		     "buffer vm or page not allocated or not binded yet.\n");
+}
+
+int hmm_bo_binded(struct hmm_buffer_object *bo)
+{
+	int ret;
+
+	check_bo_null_return(bo, 0);
+
+	mutex_lock(&bo->mutex);
+
+	ret = bo->status & HMM_BO_BINDED;
+
+	mutex_unlock(&bo->mutex);
+
+	return ret;
+}
+
+void *hmm_bo_vmap(struct hmm_buffer_object *bo, bool cached)
+{
+	struct page **pages;
+	int i;
+
+	check_bo_null_return(bo, NULL);
+
+	mutex_lock(&bo->mutex);
+	if (((bo->status & HMM_BO_VMAPED) && !cached) ||
+	    ((bo->status & HMM_BO_VMAPED_CACHED) && cached)) {
+		mutex_unlock(&bo->mutex);
+		return bo->vmap_addr;
+	}
+
+	/* cached status need to be changed, so vunmap first */
+	if (bo->status & HMM_BO_VMAPED || bo->status & HMM_BO_VMAPED_CACHED) {
+		vunmap(bo->vmap_addr);
+		bo->vmap_addr = NULL;
+		bo->status &= ~(HMM_BO_VMAPED | HMM_BO_VMAPED_CACHED);
+	}
+
+	pages = kmalloc(sizeof(*pages) * bo->pgnr, GFP_KERNEL);
+	if (unlikely(!pages)) {
+		mutex_unlock(&bo->mutex);
+		dev_err(atomisp_dev, "out of memory for pages...\n");
+		return NULL;
+	}
+
+	for (i = 0; i < bo->pgnr; i++)
+		pages[i] = bo->page_obj[i].page;
+
+	bo->vmap_addr = vmap(pages, bo->pgnr, VM_MAP,
+		cached ? PAGE_KERNEL : PAGE_KERNEL_NOCACHE);
+	if (unlikely(!bo->vmap_addr)) {
+		kfree(pages);
+		mutex_unlock(&bo->mutex);
+		dev_err(atomisp_dev, "vmap failed...\n");
+		return NULL;
+	}
+	bo->status |= (cached ? HMM_BO_VMAPED_CACHED : HMM_BO_VMAPED);
+
+	kfree(pages);
+
+	mutex_unlock(&bo->mutex);
+	return bo->vmap_addr;
+}
+
+void hmm_bo_flush_vmap(struct hmm_buffer_object *bo)
+{
+	check_bo_null_return_void(bo);
+
+	mutex_lock(&bo->mutex);
+	if (!(bo->status & HMM_BO_VMAPED_CACHED) || !bo->vmap_addr) {
+		mutex_unlock(&bo->mutex);
+		return;
+	}
+
+	clflush_cache_range(bo->vmap_addr, bo->pgnr * PAGE_SIZE);
+	mutex_unlock(&bo->mutex);
+}
+
+void hmm_bo_vunmap(struct hmm_buffer_object *bo)
+{
+	check_bo_null_return_void(bo);
+
+	mutex_lock(&bo->mutex);
+	if (bo->status & HMM_BO_VMAPED || bo->status & HMM_BO_VMAPED_CACHED) {
+		vunmap(bo->vmap_addr);
+		bo->vmap_addr = NULL;
+		bo->status &= ~(HMM_BO_VMAPED | HMM_BO_VMAPED_CACHED);
+	}
+
+	mutex_unlock(&bo->mutex);
+	return;
+}
+
+void hmm_bo_ref(struct hmm_buffer_object *bo)
+{
+	check_bo_null_return_void(bo);
+
+	kref_get(&bo->kref);
+}
+
+static void kref_hmm_bo_release(struct kref *kref)
+{
+	if (!kref)
+		return;
+
+	hmm_bo_release(kref_to_hmm_bo(kref));
+}
+
+void hmm_bo_unref(struct hmm_buffer_object *bo)
+{
+	check_bo_null_return_void(bo);
+
+	kref_put(&bo->kref, kref_hmm_bo_release);
+}
+
+static void hmm_bo_vm_open(struct vm_area_struct *vma)
+{
+	struct hmm_buffer_object *bo =
+	    (struct hmm_buffer_object *)vma->vm_private_data;
+
+	check_bo_null_return_void(bo);
+
+	hmm_bo_ref(bo);
+
+	mutex_lock(&bo->mutex);
+
+	bo->status |= HMM_BO_MMAPED;
+
+	bo->mmap_count++;
+
+	mutex_unlock(&bo->mutex);
+}
+
+static void hmm_bo_vm_close(struct vm_area_struct *vma)
+{
+	struct hmm_buffer_object *bo =
+	    (struct hmm_buffer_object *)vma->vm_private_data;
+
+	check_bo_null_return_void(bo);
+
+	hmm_bo_unref(bo);
+
+	mutex_lock(&bo->mutex);
+
+	bo->mmap_count--;
+
+	if (!bo->mmap_count) {
+		bo->status &= (~HMM_BO_MMAPED);
+		vma->vm_private_data = NULL;
+	}
+
+	mutex_unlock(&bo->mutex);
+}
+
+static const struct vm_operations_struct hmm_bo_vm_ops = {
+	.open = hmm_bo_vm_open,
+	.close = hmm_bo_vm_close,
+};
+
+/*
+ * mmap the bo to user space.
+ */
+int hmm_bo_mmap(struct vm_area_struct *vma, struct hmm_buffer_object *bo)
+{
+	unsigned int start, end;
+	unsigned int virt;
+	unsigned int pgnr, i;
+	unsigned int pfn;
+
+	check_bo_null_return(bo, -EINVAL);
+
+	check_bo_status_yes_goto(bo, HMM_BO_PAGE_ALLOCED, status_err);
+
+	pgnr = bo->pgnr;
+	start = vma->vm_start;
+	end = vma->vm_end;
+
+	/*
+	 * check vma's virtual address space size and buffer object's size.
+	 * must be the same.
+	 */
+	if ((start + pgnr_to_size(pgnr)) != end) {
+		dev_warn(atomisp_dev,
+			     "vma's address space size not equal"
+			     " to buffer object's size");
+		return -EINVAL;
+	}
+
+	virt = vma->vm_start;
+	for (i = 0; i < pgnr; i++) {
+		pfn = page_to_pfn(bo->page_obj[i].page);
+		if (remap_pfn_range(vma, virt, pfn, PAGE_SIZE, PAGE_SHARED)) {
+			dev_warn(atomisp_dev,
+					"remap_pfn_range failed:"
+					" virt = 0x%x, pfn = 0x%x,"
+					" mapped_pgnr = %d\n", virt, pfn, 1);
+			return -EINVAL;
+		}
+		virt += PAGE_SIZE;
+	}
+
+	vma->vm_private_data = bo;
+
+	vma->vm_ops = &hmm_bo_vm_ops;
+	vma->vm_flags |= VM_IO|VM_DONTEXPAND|VM_DONTDUMP;
+
+	/*
+	 * call hmm_bo_vm_open explictly.
+	 */
+	hmm_bo_vm_open(vma);
+
+	return 0;
+
+status_err:
+	dev_err(atomisp_dev, "buffer page not allocated yet.\n");
+	return -EINVAL;
+}