[Feature]add MT2731_MP2_MR2_SVN388 baseline version

Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/drivers/iommu/iova.c b/src/kernel/linux/v4.14/drivers/iommu/iova.c
new file mode 100644
index 0000000..2c97d25
--- /dev/null
+++ b/src/kernel/linux/v4.14/drivers/iommu/iova.c
@@ -0,0 +1,1096 @@
+/*
+ * Copyright © 2006-2009, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * Author: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
+ */
+
+#include <linux/iova.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/smp.h>
+#include <linux/bitops.h>
+#include <linux/cpu.h>
+
+static bool iova_rcache_insert(struct iova_domain *iovad,
+			       unsigned long pfn,
+			       unsigned long size);
+static unsigned long iova_rcache_get(struct iova_domain *iovad,
+				     unsigned long size,
+				     unsigned long limit_pfn);
+static void init_iova_rcaches(struct iova_domain *iovad);
+static void free_iova_rcaches(struct iova_domain *iovad);
+static void fq_destroy_all_entries(struct iova_domain *iovad);
+static void fq_flush_timeout(unsigned long data);
+
+void
+init_iova_domain(struct iova_domain *iovad, unsigned long granule,
+	unsigned long start_pfn, unsigned long pfn_32bit)
+{
+	/*
+	 * IOVA granularity will normally be equal to the smallest
+	 * supported IOMMU page size; both *must* be capable of
+	 * representing individual CPU pages exactly.
+	 */
+	BUG_ON((granule > PAGE_SIZE) || !is_power_of_2(granule));
+
+	spin_lock_init(&iovad->iova_rbtree_lock);
+	iovad->rbroot = RB_ROOT;
+	iovad->cached32_node = NULL;
+	iovad->granule = granule;
+	iovad->start_pfn = start_pfn;
+	iovad->dma_32bit_pfn = pfn_32bit + 1;
+	iovad->flush_cb = NULL;
+	iovad->fq = NULL;
+	init_iova_rcaches(iovad);
+}
+EXPORT_SYMBOL_GPL(init_iova_domain);
+
+bool has_iova_flush_queue(struct iova_domain *iovad)
+{
+	return !!iovad->fq;
+}
+
+static void free_iova_flush_queue(struct iova_domain *iovad)
+{
+	if (!has_iova_flush_queue(iovad))
+		return;
+
+	if (timer_pending(&iovad->fq_timer))
+		del_timer(&iovad->fq_timer);
+
+	fq_destroy_all_entries(iovad);
+
+	free_percpu(iovad->fq);
+
+	iovad->fq         = NULL;
+	iovad->flush_cb   = NULL;
+	iovad->entry_dtor = NULL;
+}
+
+int init_iova_flush_queue(struct iova_domain *iovad,
+			  iova_flush_cb flush_cb, iova_entry_dtor entry_dtor)
+{
+	struct iova_fq __percpu *queue;
+	int cpu;
+
+	atomic64_set(&iovad->fq_flush_start_cnt,  0);
+	atomic64_set(&iovad->fq_flush_finish_cnt, 0);
+
+	queue = alloc_percpu(struct iova_fq);
+	if (!queue)
+		return -ENOMEM;
+
+	iovad->flush_cb   = flush_cb;
+	iovad->entry_dtor = entry_dtor;
+
+	for_each_possible_cpu(cpu) {
+		struct iova_fq *fq;
+
+		fq = per_cpu_ptr(queue, cpu);
+		fq->head = 0;
+		fq->tail = 0;
+
+		spin_lock_init(&fq->lock);
+	}
+
+	smp_wmb();
+
+	iovad->fq = queue;
+
+	setup_timer(&iovad->fq_timer, fq_flush_timeout, (unsigned long)iovad);
+	atomic_set(&iovad->fq_timer_on, 0);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(init_iova_flush_queue);
+
+static struct rb_node *
+__get_cached_rbnode(struct iova_domain *iovad, unsigned long *limit_pfn)
+{
+	if ((*limit_pfn > iovad->dma_32bit_pfn) ||
+		(iovad->cached32_node == NULL))
+		return rb_last(&iovad->rbroot);
+	else {
+		struct rb_node *prev_node = rb_prev(iovad->cached32_node);
+		struct iova *curr_iova =
+			rb_entry(iovad->cached32_node, struct iova, node);
+		*limit_pfn = curr_iova->pfn_lo;
+		return prev_node;
+	}
+}
+
+static void
+__cached_rbnode_insert_update(struct iova_domain *iovad,
+	unsigned long limit_pfn, struct iova *new)
+{
+	if (limit_pfn != iovad->dma_32bit_pfn)
+		return;
+	iovad->cached32_node = &new->node;
+}
+
+static void
+__cached_rbnode_delete_update(struct iova_domain *iovad, struct iova *free)
+{
+	struct iova *cached_iova;
+	struct rb_node *curr;
+
+	if (!iovad->cached32_node)
+		return;
+	curr = iovad->cached32_node;
+	cached_iova = rb_entry(curr, struct iova, node);
+
+	if (free->pfn_lo >= cached_iova->pfn_lo) {
+		struct rb_node *node = rb_next(&free->node);
+		struct iova *iova = rb_entry(node, struct iova, node);
+
+		/* only cache if it's below 32bit pfn */
+		if (node && iova->pfn_lo < iovad->dma_32bit_pfn)
+			iovad->cached32_node = node;
+		else
+			iovad->cached32_node = NULL;
+	}
+}
+
+/* Insert the iova into domain rbtree by holding writer lock */
+static void
+iova_insert_rbtree(struct rb_root *root, struct iova *iova,
+		   struct rb_node *start)
+{
+	struct rb_node **new, *parent = NULL;
+
+	new = (start) ? &start : &(root->rb_node);
+	/* Figure out where to put new node */
+	while (*new) {
+		struct iova *this = rb_entry(*new, struct iova, node);
+
+		parent = *new;
+
+		if (iova->pfn_lo < this->pfn_lo)
+			new = &((*new)->rb_left);
+		else if (iova->pfn_lo > this->pfn_lo)
+			new = &((*new)->rb_right);
+		else {
+			WARN_ON(1); /* this should not happen */
+			return;
+		}
+	}
+	/* Add new node and rebalance tree. */
+	rb_link_node(&iova->node, parent, new);
+	rb_insert_color(&iova->node, root);
+}
+
+/*
+ * Computes the padding size required, to make the start address
+ * naturally aligned on the power-of-two order of its size
+ */
+static unsigned int
+iova_get_pad_size(unsigned int size, unsigned int limit_pfn)
+{
+	return (limit_pfn - size) & (__roundup_pow_of_two(size) - 1);
+}
+
+static int __alloc_and_insert_iova_range(struct iova_domain *iovad,
+		unsigned long size, unsigned long limit_pfn,
+			struct iova *new, bool size_aligned)
+{
+	struct rb_node *prev, *curr = NULL;
+	unsigned long flags;
+	unsigned long saved_pfn;
+	unsigned int pad_size = 0;
+
+	/* Walk the tree backwards */
+	spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
+	saved_pfn = limit_pfn;
+	curr = __get_cached_rbnode(iovad, &limit_pfn);
+	prev = curr;
+	while (curr) {
+		struct iova *curr_iova = rb_entry(curr, struct iova, node);
+
+		if (limit_pfn <= curr_iova->pfn_lo) {
+			goto move_left;
+		} else if (limit_pfn > curr_iova->pfn_hi) {
+			if (size_aligned)
+				pad_size = iova_get_pad_size(size, limit_pfn);
+			if ((curr_iova->pfn_hi + size + pad_size) < limit_pfn)
+				break;	/* found a free slot */
+		}
+		limit_pfn = curr_iova->pfn_lo;
+move_left:
+		prev = curr;
+		curr = rb_prev(curr);
+	}
+
+	if (!curr) {
+		if (size_aligned)
+			pad_size = iova_get_pad_size(size, limit_pfn);
+		if ((iovad->start_pfn + size + pad_size) > limit_pfn) {
+			spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+			return -ENOMEM;
+		}
+	}
+
+	/* pfn_lo will point to size aligned address if size_aligned is set */
+	new->pfn_lo = limit_pfn - (size + pad_size);
+	new->pfn_hi = new->pfn_lo + size - 1;
+
+	/* If we have 'prev', it's a valid place to start the insertion. */
+	iova_insert_rbtree(&iovad->rbroot, new, prev);
+	__cached_rbnode_insert_update(iovad, saved_pfn, new);
+
+	spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+
+
+	return 0;
+}
+
+static struct kmem_cache *iova_cache;
+static unsigned int iova_cache_users;
+static DEFINE_MUTEX(iova_cache_mutex);
+
+struct iova *alloc_iova_mem(void)
+{
+	return kmem_cache_alloc(iova_cache, GFP_ATOMIC);
+}
+EXPORT_SYMBOL(alloc_iova_mem);
+
+void free_iova_mem(struct iova *iova)
+{
+	kmem_cache_free(iova_cache, iova);
+}
+EXPORT_SYMBOL(free_iova_mem);
+
+int iova_cache_get(void)
+{
+	mutex_lock(&iova_cache_mutex);
+	if (!iova_cache_users) {
+		iova_cache = kmem_cache_create(
+			"iommu_iova", sizeof(struct iova), 0,
+			SLAB_HWCACHE_ALIGN, NULL);
+		if (!iova_cache) {
+			mutex_unlock(&iova_cache_mutex);
+			printk(KERN_ERR "Couldn't create iova cache\n");
+			return -ENOMEM;
+		}
+	}
+
+	iova_cache_users++;
+	mutex_unlock(&iova_cache_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(iova_cache_get);
+
+void iova_cache_put(void)
+{
+	mutex_lock(&iova_cache_mutex);
+	if (WARN_ON(!iova_cache_users)) {
+		mutex_unlock(&iova_cache_mutex);
+		return;
+	}
+	iova_cache_users--;
+	if (!iova_cache_users)
+		kmem_cache_destroy(iova_cache);
+	mutex_unlock(&iova_cache_mutex);
+}
+EXPORT_SYMBOL_GPL(iova_cache_put);
+
+/**
+ * alloc_iova - allocates an iova
+ * @iovad: - iova domain in question
+ * @size: - size of page frames to allocate
+ * @limit_pfn: - max limit address
+ * @size_aligned: - set if size_aligned address range is required
+ * This function allocates an iova in the range iovad->start_pfn to limit_pfn,
+ * searching top-down from limit_pfn to iovad->start_pfn. If the size_aligned
+ * flag is set then the allocated address iova->pfn_lo will be naturally
+ * aligned on roundup_power_of_two(size).
+ */
+struct iova *
+alloc_iova(struct iova_domain *iovad, unsigned long size,
+	unsigned long limit_pfn,
+	bool size_aligned)
+{
+	struct iova *new_iova;
+	int ret;
+
+	new_iova = alloc_iova_mem();
+	if (!new_iova)
+		return NULL;
+
+	ret = __alloc_and_insert_iova_range(iovad, size, limit_pfn + 1,
+			new_iova, size_aligned);
+
+	if (ret) {
+		free_iova_mem(new_iova);
+		return NULL;
+	}
+
+	return new_iova;
+}
+EXPORT_SYMBOL_GPL(alloc_iova);
+
+static struct iova *
+private_find_iova(struct iova_domain *iovad, unsigned long pfn)
+{
+	struct rb_node *node = iovad->rbroot.rb_node;
+
+	assert_spin_locked(&iovad->iova_rbtree_lock);
+
+	while (node) {
+		struct iova *iova = rb_entry(node, struct iova, node);
+
+		/* If pfn falls within iova's range, return iova */
+		if ((pfn >= iova->pfn_lo) && (pfn <= iova->pfn_hi)) {
+			return iova;
+		}
+
+		if (pfn < iova->pfn_lo)
+			node = node->rb_left;
+		else if (pfn > iova->pfn_lo)
+			node = node->rb_right;
+	}
+
+	return NULL;
+}
+
+static void private_free_iova(struct iova_domain *iovad, struct iova *iova)
+{
+	assert_spin_locked(&iovad->iova_rbtree_lock);
+	__cached_rbnode_delete_update(iovad, iova);
+	rb_erase(&iova->node, &iovad->rbroot);
+	free_iova_mem(iova);
+}
+
+/**
+ * find_iova - finds an iova for a given pfn
+ * @iovad: - iova domain in question.
+ * @pfn: - page frame number
+ * This function finds and returns an iova belonging to the
+ * given doamin which matches the given pfn.
+ */
+struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn)
+{
+	unsigned long flags;
+	struct iova *iova;
+
+	/* Take the lock so that no other thread is manipulating the rbtree */
+	spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
+	iova = private_find_iova(iovad, pfn);
+	spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+	return iova;
+}
+EXPORT_SYMBOL_GPL(find_iova);
+
+/**
+ * __free_iova - frees the given iova
+ * @iovad: iova domain in question.
+ * @iova: iova in question.
+ * Frees the given iova belonging to the giving domain
+ */
+void
+__free_iova(struct iova_domain *iovad, struct iova *iova)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
+	private_free_iova(iovad, iova);
+	spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+}
+EXPORT_SYMBOL_GPL(__free_iova);
+
+/**
+ * free_iova - finds and frees the iova for a given pfn
+ * @iovad: - iova domain in question.
+ * @pfn: - pfn that is allocated previously
+ * This functions finds an iova for a given pfn and then
+ * frees the iova from that domain.
+ */
+void
+free_iova(struct iova_domain *iovad, unsigned long pfn)
+{
+	struct iova *iova = find_iova(iovad, pfn);
+
+	if (iova)
+		__free_iova(iovad, iova);
+
+}
+EXPORT_SYMBOL_GPL(free_iova);
+
+/**
+ * alloc_iova_fast - allocates an iova from rcache
+ * @iovad: - iova domain in question
+ * @size: - size of page frames to allocate
+ * @limit_pfn: - max limit address
+ * This function tries to satisfy an iova allocation from the rcache,
+ * and falls back to regular allocation on failure.
+*/
+unsigned long
+alloc_iova_fast(struct iova_domain *iovad, unsigned long size,
+		unsigned long limit_pfn)
+{
+	bool flushed_rcache = false;
+	unsigned long iova_pfn;
+	struct iova *new_iova;
+
+	iova_pfn = iova_rcache_get(iovad, size, limit_pfn);
+	if (iova_pfn)
+		return iova_pfn;
+
+retry:
+	new_iova = alloc_iova(iovad, size, limit_pfn, true);
+	if (!new_iova) {
+		unsigned int cpu;
+
+		if (flushed_rcache)
+			return 0;
+
+		/* Try replenishing IOVAs by flushing rcache. */
+		flushed_rcache = true;
+		for_each_online_cpu(cpu)
+			free_cpu_cached_iovas(cpu, iovad);
+		goto retry;
+	}
+
+	return new_iova->pfn_lo;
+}
+EXPORT_SYMBOL_GPL(alloc_iova_fast);
+
+/**
+ * free_iova_fast - free iova pfn range into rcache
+ * @iovad: - iova domain in question.
+ * @pfn: - pfn that is allocated previously
+ * @size: - # of pages in range
+ * This functions frees an iova range by trying to put it into the rcache,
+ * falling back to regular iova deallocation via free_iova() if this fails.
+ */
+void
+free_iova_fast(struct iova_domain *iovad, unsigned long pfn, unsigned long size)
+{
+	if (iova_rcache_insert(iovad, pfn, size))
+		return;
+
+	free_iova(iovad, pfn);
+}
+EXPORT_SYMBOL_GPL(free_iova_fast);
+
+#define fq_ring_for_each(i, fq) \
+	for ((i) = (fq)->head; (i) != (fq)->tail; (i) = ((i) + 1) % IOVA_FQ_SIZE)
+
+static inline bool fq_full(struct iova_fq *fq)
+{
+	assert_spin_locked(&fq->lock);
+	return (((fq->tail + 1) % IOVA_FQ_SIZE) == fq->head);
+}
+
+static inline unsigned fq_ring_add(struct iova_fq *fq)
+{
+	unsigned idx = fq->tail;
+
+	assert_spin_locked(&fq->lock);
+
+	fq->tail = (idx + 1) % IOVA_FQ_SIZE;
+
+	return idx;
+}
+
+static void fq_ring_free(struct iova_domain *iovad, struct iova_fq *fq)
+{
+	u64 counter = atomic64_read(&iovad->fq_flush_finish_cnt);
+	unsigned idx;
+
+	assert_spin_locked(&fq->lock);
+
+	fq_ring_for_each(idx, fq) {
+
+		if (fq->entries[idx].counter >= counter)
+			break;
+
+		if (iovad->entry_dtor)
+			iovad->entry_dtor(fq->entries[idx].data);
+
+		free_iova_fast(iovad,
+			       fq->entries[idx].iova_pfn,
+			       fq->entries[idx].pages);
+
+		fq->head = (fq->head + 1) % IOVA_FQ_SIZE;
+	}
+}
+
+static void iova_domain_flush(struct iova_domain *iovad)
+{
+	atomic64_inc(&iovad->fq_flush_start_cnt);
+	iovad->flush_cb(iovad);
+	atomic64_inc(&iovad->fq_flush_finish_cnt);
+}
+
+static void fq_destroy_all_entries(struct iova_domain *iovad)
+{
+	int cpu;
+
+	/*
+	 * This code runs when the iova_domain is being detroyed, so don't
+	 * bother to free iovas, just call the entry_dtor on all remaining
+	 * entries.
+	 */
+	if (!iovad->entry_dtor)
+		return;
+
+	for_each_possible_cpu(cpu) {
+		struct iova_fq *fq = per_cpu_ptr(iovad->fq, cpu);
+		int idx;
+
+		fq_ring_for_each(idx, fq)
+			iovad->entry_dtor(fq->entries[idx].data);
+	}
+}
+
+static void fq_flush_timeout(unsigned long data)
+{
+	struct iova_domain *iovad = (struct iova_domain *)data;
+	int cpu;
+
+	atomic_set(&iovad->fq_timer_on, 0);
+	iova_domain_flush(iovad);
+
+	for_each_possible_cpu(cpu) {
+		unsigned long flags;
+		struct iova_fq *fq;
+
+		fq = per_cpu_ptr(iovad->fq, cpu);
+		spin_lock_irqsave(&fq->lock, flags);
+		fq_ring_free(iovad, fq);
+		spin_unlock_irqrestore(&fq->lock, flags);
+	}
+}
+
+void queue_iova(struct iova_domain *iovad,
+		unsigned long pfn, unsigned long pages,
+		unsigned long data)
+{
+	struct iova_fq *fq = get_cpu_ptr(iovad->fq);
+	unsigned long flags;
+	unsigned idx;
+
+	spin_lock_irqsave(&fq->lock, flags);
+
+	/*
+	 * First remove all entries from the flush queue that have already been
+	 * flushed out on another CPU. This makes the fq_full() check below less
+	 * likely to be true.
+	 */
+	fq_ring_free(iovad, fq);
+
+	if (fq_full(fq)) {
+		iova_domain_flush(iovad);
+		fq_ring_free(iovad, fq);
+	}
+
+	idx = fq_ring_add(fq);
+
+	fq->entries[idx].iova_pfn = pfn;
+	fq->entries[idx].pages    = pages;
+	fq->entries[idx].data     = data;
+	fq->entries[idx].counter  = atomic64_read(&iovad->fq_flush_start_cnt);
+
+	spin_unlock_irqrestore(&fq->lock, flags);
+
+	/* Avoid false sharing as much as possible. */
+	if (!atomic_read(&iovad->fq_timer_on) &&
+	    !atomic_cmpxchg(&iovad->fq_timer_on, 0, 1))
+		mod_timer(&iovad->fq_timer,
+			  jiffies + msecs_to_jiffies(IOVA_FQ_TIMEOUT));
+
+	put_cpu_ptr(iovad->fq);
+}
+EXPORT_SYMBOL_GPL(queue_iova);
+
+/**
+ * put_iova_domain - destroys the iova doamin
+ * @iovad: - iova domain in question.
+ * All the iova's in that domain are destroyed.
+ */
+void put_iova_domain(struct iova_domain *iovad)
+{
+	struct rb_node *node;
+	unsigned long flags;
+
+	free_iova_flush_queue(iovad);
+	free_iova_rcaches(iovad);
+	spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
+	node = rb_first(&iovad->rbroot);
+	while (node) {
+		struct iova *iova = rb_entry(node, struct iova, node);
+
+		rb_erase(node, &iovad->rbroot);
+		free_iova_mem(iova);
+		node = rb_first(&iovad->rbroot);
+	}
+	spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+}
+EXPORT_SYMBOL_GPL(put_iova_domain);
+
+static int
+__is_range_overlap(struct rb_node *node,
+	unsigned long pfn_lo, unsigned long pfn_hi)
+{
+	struct iova *iova = rb_entry(node, struct iova, node);
+
+	if ((pfn_lo <= iova->pfn_hi) && (pfn_hi >= iova->pfn_lo))
+		return 1;
+	return 0;
+}
+
+static inline struct iova *
+alloc_and_init_iova(unsigned long pfn_lo, unsigned long pfn_hi)
+{
+	struct iova *iova;
+
+	iova = alloc_iova_mem();
+	if (iova) {
+		iova->pfn_lo = pfn_lo;
+		iova->pfn_hi = pfn_hi;
+	}
+
+	return iova;
+}
+
+static struct iova *
+__insert_new_range(struct iova_domain *iovad,
+	unsigned long pfn_lo, unsigned long pfn_hi)
+{
+	struct iova *iova;
+
+	iova = alloc_and_init_iova(pfn_lo, pfn_hi);
+	if (iova)
+		iova_insert_rbtree(&iovad->rbroot, iova, NULL);
+
+	return iova;
+}
+
+static void
+__adjust_overlap_range(struct iova *iova,
+	unsigned long *pfn_lo, unsigned long *pfn_hi)
+{
+	if (*pfn_lo < iova->pfn_lo)
+		iova->pfn_lo = *pfn_lo;
+	if (*pfn_hi > iova->pfn_hi)
+		*pfn_lo = iova->pfn_hi + 1;
+}
+
+/**
+ * reserve_iova - reserves an iova in the given range
+ * @iovad: - iova domain pointer
+ * @pfn_lo: - lower page frame address
+ * @pfn_hi:- higher pfn adderss
+ * This function allocates reserves the address range from pfn_lo to pfn_hi so
+ * that this address is not dished out as part of alloc_iova.
+ */
+struct iova *
+reserve_iova(struct iova_domain *iovad,
+	unsigned long pfn_lo, unsigned long pfn_hi)
+{
+	struct rb_node *node;
+	unsigned long flags;
+	struct iova *iova;
+	unsigned int overlap = 0;
+
+	spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
+	for (node = rb_first(&iovad->rbroot); node; node = rb_next(node)) {
+		if (__is_range_overlap(node, pfn_lo, pfn_hi)) {
+			iova = rb_entry(node, struct iova, node);
+			__adjust_overlap_range(iova, &pfn_lo, &pfn_hi);
+			if ((pfn_lo >= iova->pfn_lo) &&
+				(pfn_hi <= iova->pfn_hi))
+				goto finish;
+			overlap = 1;
+
+		} else if (overlap)
+				break;
+	}
+
+	/* We are here either because this is the first reserver node
+	 * or need to insert remaining non overlap addr range
+	 */
+	iova = __insert_new_range(iovad, pfn_lo, pfn_hi);
+finish:
+
+	spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+	return iova;
+}
+EXPORT_SYMBOL_GPL(reserve_iova);
+
+/**
+ * copy_reserved_iova - copies the reserved between domains
+ * @from: - source doamin from where to copy
+ * @to: - destination domin where to copy
+ * This function copies reserved iova's from one doamin to
+ * other.
+ */
+void
+copy_reserved_iova(struct iova_domain *from, struct iova_domain *to)
+{
+	unsigned long flags;
+	struct rb_node *node;
+
+	spin_lock_irqsave(&from->iova_rbtree_lock, flags);
+	for (node = rb_first(&from->rbroot); node; node = rb_next(node)) {
+		struct iova *iova = rb_entry(node, struct iova, node);
+		struct iova *new_iova;
+
+		new_iova = reserve_iova(to, iova->pfn_lo, iova->pfn_hi);
+		if (!new_iova)
+			printk(KERN_ERR "Reserve iova range %lx@%lx failed\n",
+				iova->pfn_lo, iova->pfn_lo);
+	}
+	spin_unlock_irqrestore(&from->iova_rbtree_lock, flags);
+}
+EXPORT_SYMBOL_GPL(copy_reserved_iova);
+
+struct iova *
+split_and_remove_iova(struct iova_domain *iovad, struct iova *iova,
+		      unsigned long pfn_lo, unsigned long pfn_hi)
+{
+	unsigned long flags;
+	struct iova *prev = NULL, *next = NULL;
+
+	spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
+	if (iova->pfn_lo < pfn_lo) {
+		prev = alloc_and_init_iova(iova->pfn_lo, pfn_lo - 1);
+		if (prev == NULL)
+			goto error;
+	}
+	if (iova->pfn_hi > pfn_hi) {
+		next = alloc_and_init_iova(pfn_hi + 1, iova->pfn_hi);
+		if (next == NULL)
+			goto error;
+	}
+
+	__cached_rbnode_delete_update(iovad, iova);
+	rb_erase(&iova->node, &iovad->rbroot);
+
+	if (prev) {
+		iova_insert_rbtree(&iovad->rbroot, prev, NULL);
+		iova->pfn_lo = pfn_lo;
+	}
+	if (next) {
+		iova_insert_rbtree(&iovad->rbroot, next, NULL);
+		iova->pfn_hi = pfn_hi;
+	}
+	spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+
+	return iova;
+
+error:
+	spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+	if (prev)
+		free_iova_mem(prev);
+	return NULL;
+}
+
+/*
+ * Magazine caches for IOVA ranges.  For an introduction to magazines,
+ * see the USENIX 2001 paper "Magazines and Vmem: Extending the Slab
+ * Allocator to Many CPUs and Arbitrary Resources" by Bonwick and Adams.
+ * For simplicity, we use a static magazine size and don't implement the
+ * dynamic size tuning described in the paper.
+ */
+
+#define IOVA_MAG_SIZE 128
+
+struct iova_magazine {
+	unsigned long size;
+	unsigned long pfns[IOVA_MAG_SIZE];
+};
+
+struct iova_cpu_rcache {
+	spinlock_t lock;
+	struct iova_magazine *loaded;
+	struct iova_magazine *prev;
+};
+
+static struct iova_magazine *iova_magazine_alloc(gfp_t flags)
+{
+	return kzalloc(sizeof(struct iova_magazine), flags);
+}
+
+static void iova_magazine_free(struct iova_magazine *mag)
+{
+	kfree(mag);
+}
+
+static void
+iova_magazine_free_pfns(struct iova_magazine *mag, struct iova_domain *iovad)
+{
+	unsigned long flags;
+	int i;
+
+	if (!mag)
+		return;
+
+	spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
+
+	for (i = 0 ; i < mag->size; ++i) {
+		struct iova *iova = private_find_iova(iovad, mag->pfns[i]);
+
+		if (WARN_ON(!iova))
+			continue;
+
+		private_free_iova(iovad, iova);
+	}
+
+	spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+
+	mag->size = 0;
+}
+
+static bool iova_magazine_full(struct iova_magazine *mag)
+{
+	return (mag && mag->size == IOVA_MAG_SIZE);
+}
+
+static bool iova_magazine_empty(struct iova_magazine *mag)
+{
+	return (!mag || mag->size == 0);
+}
+
+static unsigned long iova_magazine_pop(struct iova_magazine *mag,
+				       unsigned long limit_pfn)
+{
+	BUG_ON(iova_magazine_empty(mag));
+
+	if (mag->pfns[mag->size - 1] >= limit_pfn)
+		return 0;
+
+	return mag->pfns[--mag->size];
+}
+
+static void iova_magazine_push(struct iova_magazine *mag, unsigned long pfn)
+{
+	BUG_ON(iova_magazine_full(mag));
+
+	mag->pfns[mag->size++] = pfn;
+}
+
+static void init_iova_rcaches(struct iova_domain *iovad)
+{
+	struct iova_cpu_rcache *cpu_rcache;
+	struct iova_rcache *rcache;
+	unsigned int cpu;
+	int i;
+
+	for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
+		rcache = &iovad->rcaches[i];
+		spin_lock_init(&rcache->lock);
+		rcache->depot_size = 0;
+		rcache->cpu_rcaches = __alloc_percpu(sizeof(*cpu_rcache), cache_line_size());
+		if (WARN_ON(!rcache->cpu_rcaches))
+			continue;
+		for_each_possible_cpu(cpu) {
+			cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu);
+			spin_lock_init(&cpu_rcache->lock);
+			cpu_rcache->loaded = iova_magazine_alloc(GFP_KERNEL);
+			cpu_rcache->prev = iova_magazine_alloc(GFP_KERNEL);
+		}
+	}
+}
+
+/*
+ * Try inserting IOVA range starting with 'iova_pfn' into 'rcache', and
+ * return true on success.  Can fail if rcache is full and we can't free
+ * space, and free_iova() (our only caller) will then return the IOVA
+ * range to the rbtree instead.
+ */
+static bool __iova_rcache_insert(struct iova_domain *iovad,
+				 struct iova_rcache *rcache,
+				 unsigned long iova_pfn)
+{
+	struct iova_magazine *mag_to_free = NULL;
+	struct iova_cpu_rcache *cpu_rcache;
+	bool can_insert = false;
+	unsigned long flags;
+
+	cpu_rcache = raw_cpu_ptr(rcache->cpu_rcaches);
+	spin_lock_irqsave(&cpu_rcache->lock, flags);
+
+	if (!iova_magazine_full(cpu_rcache->loaded)) {
+		can_insert = true;
+	} else if (!iova_magazine_full(cpu_rcache->prev)) {
+		swap(cpu_rcache->prev, cpu_rcache->loaded);
+		can_insert = true;
+	} else {
+		struct iova_magazine *new_mag = iova_magazine_alloc(GFP_ATOMIC);
+
+		if (new_mag) {
+			spin_lock(&rcache->lock);
+			if (rcache->depot_size < MAX_GLOBAL_MAGS) {
+				rcache->depot[rcache->depot_size++] =
+						cpu_rcache->loaded;
+			} else {
+				mag_to_free = cpu_rcache->loaded;
+			}
+			spin_unlock(&rcache->lock);
+
+			cpu_rcache->loaded = new_mag;
+			can_insert = true;
+		}
+	}
+
+	if (can_insert)
+		iova_magazine_push(cpu_rcache->loaded, iova_pfn);
+
+	spin_unlock_irqrestore(&cpu_rcache->lock, flags);
+
+	if (mag_to_free) {
+		iova_magazine_free_pfns(mag_to_free, iovad);
+		iova_magazine_free(mag_to_free);
+	}
+
+	return can_insert;
+}
+
+static bool iova_rcache_insert(struct iova_domain *iovad, unsigned long pfn,
+			       unsigned long size)
+{
+	unsigned int log_size = order_base_2(size);
+
+	if (log_size >= IOVA_RANGE_CACHE_MAX_SIZE)
+		return false;
+
+	return __iova_rcache_insert(iovad, &iovad->rcaches[log_size], pfn);
+}
+
+/*
+ * Caller wants to allocate a new IOVA range from 'rcache'.  If we can
+ * satisfy the request, return a matching non-NULL range and remove
+ * it from the 'rcache'.
+ */
+static unsigned long __iova_rcache_get(struct iova_rcache *rcache,
+				       unsigned long limit_pfn)
+{
+	struct iova_cpu_rcache *cpu_rcache;
+	unsigned long iova_pfn = 0;
+	bool has_pfn = false;
+	unsigned long flags;
+
+	cpu_rcache = raw_cpu_ptr(rcache->cpu_rcaches);
+	spin_lock_irqsave(&cpu_rcache->lock, flags);
+
+	if (!iova_magazine_empty(cpu_rcache->loaded)) {
+		has_pfn = true;
+	} else if (!iova_magazine_empty(cpu_rcache->prev)) {
+		swap(cpu_rcache->prev, cpu_rcache->loaded);
+		has_pfn = true;
+	} else {
+		spin_lock(&rcache->lock);
+		if (rcache->depot_size > 0) {
+			iova_magazine_free(cpu_rcache->loaded);
+			cpu_rcache->loaded = rcache->depot[--rcache->depot_size];
+			has_pfn = true;
+		}
+		spin_unlock(&rcache->lock);
+	}
+
+	if (has_pfn)
+		iova_pfn = iova_magazine_pop(cpu_rcache->loaded, limit_pfn);
+
+	spin_unlock_irqrestore(&cpu_rcache->lock, flags);
+
+	return iova_pfn;
+}
+
+/*
+ * Try to satisfy IOVA allocation range from rcache.  Fail if requested
+ * size is too big or the DMA limit we are given isn't satisfied by the
+ * top element in the magazine.
+ */
+static unsigned long iova_rcache_get(struct iova_domain *iovad,
+				     unsigned long size,
+				     unsigned long limit_pfn)
+{
+	unsigned int log_size = order_base_2(size);
+
+	if (log_size >= IOVA_RANGE_CACHE_MAX_SIZE)
+		return 0;
+
+	return __iova_rcache_get(&iovad->rcaches[log_size], limit_pfn);
+}
+
+/*
+ * Free a cpu's rcache.
+ */
+static void free_cpu_iova_rcache(unsigned int cpu, struct iova_domain *iovad,
+				 struct iova_rcache *rcache)
+{
+	struct iova_cpu_rcache *cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu);
+	unsigned long flags;
+
+	spin_lock_irqsave(&cpu_rcache->lock, flags);
+
+	iova_magazine_free_pfns(cpu_rcache->loaded, iovad);
+	iova_magazine_free(cpu_rcache->loaded);
+
+	iova_magazine_free_pfns(cpu_rcache->prev, iovad);
+	iova_magazine_free(cpu_rcache->prev);
+
+	spin_unlock_irqrestore(&cpu_rcache->lock, flags);
+}
+
+/*
+ * free rcache data structures.
+ */
+static void free_iova_rcaches(struct iova_domain *iovad)
+{
+	struct iova_rcache *rcache;
+	unsigned long flags;
+	unsigned int cpu;
+	int i, j;
+
+	for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
+		rcache = &iovad->rcaches[i];
+		for_each_possible_cpu(cpu)
+			free_cpu_iova_rcache(cpu, iovad, rcache);
+		spin_lock_irqsave(&rcache->lock, flags);
+		free_percpu(rcache->cpu_rcaches);
+		for (j = 0; j < rcache->depot_size; ++j) {
+			iova_magazine_free_pfns(rcache->depot[j], iovad);
+			iova_magazine_free(rcache->depot[j]);
+		}
+		spin_unlock_irqrestore(&rcache->lock, flags);
+	}
+}
+
+/*
+ * free all the IOVA ranges cached by a cpu (used when cpu is unplugged)
+ */
+void free_cpu_cached_iovas(unsigned int cpu, struct iova_domain *iovad)
+{
+	struct iova_cpu_rcache *cpu_rcache;
+	struct iova_rcache *rcache;
+	unsigned long flags;
+	int i;
+
+	for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
+		rcache = &iovad->rcaches[i];
+		cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu);
+		spin_lock_irqsave(&cpu_rcache->lock, flags);
+		iova_magazine_free_pfns(cpu_rcache->loaded, iovad);
+		iova_magazine_free_pfns(cpu_rcache->prev, iovad);
+		spin_unlock_irqrestore(&cpu_rcache->lock, flags);
+	}
+}
+
+MODULE_AUTHOR("Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>");
+MODULE_LICENSE("GPL");