iommu/amd: Optimize dma_ops_free_addresses

Don't flush the iommu tlb when we free something behind the
current next_bit pointer. Update the next_bit pointer
instead and let the flush happen on the next wraparound in
the allocation path.

Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 39a2048a6cd25948f82490ee5366665a5d25aece..c657e48f0aed0d8c1b6417689f2ecba7d8f4b8cb 100644 (file)
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -1633,8 +1633,7 @@ static void dma_ops_free_addresses(struct dma_ops_domain *dom,
                return;
 #endif
 
-       if (amd_iommu_unmap_flush ||
-           (address + pages > range->next_bit)) {
+       if (amd_iommu_unmap_flush) {
                domain_flush_tlb(&dom->domain);
                domain_flush_complete(&dom->domain);
        }
@@ -1642,6 +1641,8 @@ static void dma_ops_free_addresses(struct dma_ops_domain *dom,
        address = (address % APERTURE_RANGE_SIZE) >> PAGE_SHIFT;
 
        spin_lock_irqsave(&range->bitmap_lock, flags);
+       if (address + pages > range->next_bit)
+               range->next_bit = address + pages;
        bitmap_clear(range->bitmap, address, pages);
        spin_unlock_irqrestore(&range->bitmap_lock, flags);