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Commit d751751a authored by Marek Szyprowski's avatar Marek Szyprowski Committed by Joerg Roedel
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iommu/iova: Consolidate code for adding new node to iovad domain rbtree 



This patch consolidates almost the same code used in iova_insert_rbtree()
and __alloc_and_insert_iova_range() functions. While touching this code,
replace BUG() with WARN_ON(1) to avoid taking down the whole system in
case of corrupted iova tree or incorrect calls.

Signed-off-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 97da3854

drivers/iommu/iova.c

+33 −54
Original line number Diff line number Diff line
@@ -100,6 +100,34 @@ __cached_rbnode_delete_update(struct iova_domain *iovad, struct iova *free) 
	}

}



/* 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
@@ -157,35 +185,8 @@ static int __alloc_and_insert_iova_range(struct iova_domain *iovad, 
	new->pfn_lo = limit_pfn - (size + pad_size) + 1;

	new->pfn_hi = new->pfn_lo + size - 1;



	/* Insert the new_iova into domain rbtree by holding writer lock */

	/* Add new node and rebalance tree. */

	{

		struct rb_node **entry, *parent = NULL;



		/* If we have 'prev', it's a valid place to start the

		   insertion. Otherwise, start from the root. */

		if (prev)

			entry = &prev;

		else

			entry = &iovad->rbroot.rb_node;



		/* Figure out where to put new node */

		while (*entry) {

			struct iova *this = rb_entry(*entry, struct iova, node);

			parent = *entry;



			if (new->pfn_lo < this->pfn_lo)

				entry = &((*entry)->rb_left);

			else if (new->pfn_lo > this->pfn_lo)

				entry = &((*entry)->rb_right);

			else

				BUG(); /* this should not happen */

		}



		/* Add new node and rebalance tree. */

		rb_link_node(&new->node, parent, entry);

		rb_insert_color(&new->node, &iovad->rbroot);

	}

	/* 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);
@@ -194,28 +195,6 @@ static int __alloc_and_insert_iova_range(struct iova_domain *iovad, 
	return 0;

}



static void

iova_insert_rbtree(struct rb_root *root, struct iova *iova)

{

	struct rb_node **new = &(root->rb_node), *parent = NULL;

	/* 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

			BUG(); /* this should not happen */

	}

	/* Add new node and rebalance tree. */

	rb_link_node(&iova->node, parent, new);

	rb_insert_color(&iova->node, root);

}



static struct kmem_cache *iova_cache;

static unsigned int iova_cache_users;

static DEFINE_MUTEX(iova_cache_mutex);
@@ -505,7 +484,7 @@ __insert_new_range(struct iova_domain *iovad, 


	iova = alloc_and_init_iova(pfn_lo, pfn_hi);

	if (iova)

		iova_insert_rbtree(&iovad->rbroot, iova);

		iova_insert_rbtree(&iovad->rbroot, iova, NULL);



	return iova;

}
@@ -612,11 +591,11 @@ split_and_remove_iova(struct iova_domain *iovad, struct iova *iova, 
	rb_erase(&iova->node, &iovad->rbroot);



	if (prev) {

		iova_insert_rbtree(&iovad->rbroot, prev);

		iova_insert_rbtree(&iovad->rbroot, prev, NULL);

		iova->pfn_lo = pfn_lo;

	}

	if (next) {

		iova_insert_rbtree(&iovad->rbroot, next);

		iova_insert_rbtree(&iovad->rbroot, next, NULL);

		iova->pfn_hi = pfn_hi;

	}

	spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);