[PATCH RESEND] iommu/iova: Extend cached node lookup condition

[Robin Murphy]

When searching for a free IOVA range, we optimise the tree traversal
by starting from the cached32_node, instead of the last node, when
limit_pfn is equal to dma_32bit_pfn. However, if limit_pfn happens to
be smaller, then we'll go ahead and start from the top even though
dma_32bit_pfn is still a more suitable upper bound. Since this is
clearly a silly thing to do, adjust the lookup condition appropriately.

Signed-off-by: Robin Murphy <***@arm.com>
---
drivers/iommu/iova.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index e23001bfcfee..080beca0197d 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -56,7 +56,7 @@ EXPORT_SYMBOL_GPL(init_iova_domain);
static struct rb_node *
__get_cached_rbnode(struct iova_domain *iovad, unsigned long *limit_pfn)
{
- if ((*limit_pfn != iovad->dma_32bit_pfn) ||
+ if ((*limit_pfn > iovad->dma_32bit_pfn) ||
(iovad->cached32_node == NULL))
return rb_last(&iovad->rbroot);
else {

[Joerg Roedel]

Post by Robin Murphy
When searching for a free IOVA range, we optimise the tree traversal
by starting from the cached32_node, instead of the last node, when
limit_pfn is equal to dma_32bit_pfn. However, if limit_pfn happens to
be smaller, then we'll go ahead and start from the top even though
dma_32bit_pfn is still a more suitable upper bound. Since this is
clearly a silly thing to do, adjust the lookup condition appropriately.
---
drivers/iommu/iova.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

Applied, thanks.