[PATCH v2 15/18] powerpc/iommu: Implement put_page() if TCE had non-zero value

[Alexey Kardashevskiy]

Guests might put new TCEs without clearing them first and the PAPR spec
allows that.

This adds put_page() for TCEs which we just replaced.

Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
---
 arch/powerpc/kernel/iommu.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index ae57910..53155c4 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -1054,11 +1054,11 @@ int iommu_tce_build(struct iommu_table *tbl, unsigned long entry,
 
 	spin_lock(&(pool->lock));
 
-	oldtce = ppc_md.tce_get(tbl, entry);
-	/* Add new entry if it is not busy */
-	if (!(oldtce & (TCE_PCI_WRITE | TCE_PCI_READ)))
-		ret = ppc_md.tce_build(tbl, entry, 1, hwaddr, NULL,
-				direction, NULL);
+	ret = ppc_md.tce_build(tbl, entry, 1, hwaddr, &oldtce,
+			direction, NULL);
+
+	if (oldtce & (TCE_PCI_WRITE | TCE_PCI_READ))
+		put_page(pfn_to_page(__pa(oldtce) >> PAGE_SHIFT));
 
 	spin_unlock(&(pool->lock));
 
-- 
2.0.0