diff mbox

iommu: iova: Consolidate code for adding new node to iovad domain rbtree

Message ID 1487837853-3195-1-git-send-email-m.szyprowski@samsung.com
State Superseded
Headers show

Commit Message

Marek Szyprowski Feb. 23, 2017, 8:17 a.m. UTC
This patch consolidates almost the same code used in iova_insert_rbtree()
and __alloc_and_insert_iova_range() functions. There is no functional change.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

---
 drivers/iommu/iova.c | 85 +++++++++++++++++++---------------------------------
 1 file changed, 31 insertions(+), 54 deletions(-)

-- 
1.9.1

Comments

Robin Murphy Feb. 23, 2017, 11:59 a.m. UTC | #1
On 23/02/17 08:17, Marek Szyprowski wrote:
> This patch consolidates almost the same code used in iova_insert_rbtree()

> and __alloc_and_insert_iova_range() functions. There is no functional change.

> 

> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

> ---

>  drivers/iommu/iova.c | 85 +++++++++++++++++++---------------------------------

>  1 file changed, 31 insertions(+), 54 deletions(-)

> 

> diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c

> index b7268a14184f..32b9c2fb37b6 100644

> --- a/drivers/iommu/iova.c

> +++ b/drivers/iommu/iova.c

> @@ -100,6 +100,32 @@ static unsigned long iova_rcache_get(struct iova_domain *iovad,

>  	}

>  }

>  

> +/* 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

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


Ooh, if we're touching this, can we downgrade it to a WARN()? Granted,
allocating an IOVA region of size 0 is not a reasonable thing to do
intentionally, but the fact that it's guaranteed to take down the kernel
is perhaps a bit much (I hit it soooo many times back when debugging the
iommu_dma_map_sg() stuff).

Nice tidyup otherwise, though.

Robin.

> +	}

> +	/* 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 +183,8 @@ 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 +193,6 @@ 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 +482,7 @@ void put_iova_domain(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 +589,11 @@ struct 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);

>
diff mbox

Patch

diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index b7268a14184f..32b9c2fb37b6 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -100,6 +100,32 @@  static unsigned long iova_rcache_get(struct iova_domain *iovad,
 	}
 }
 
+/* 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
+			BUG(); /* this should not happen */
+	}
+	/* 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 +183,8 @@  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 +193,6 @@  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 +482,7 @@  void put_iova_domain(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 +589,11 @@  struct 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);