1 files changed, 23 insertions, 5 deletions

diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index 2385f68c1751..550a19399bfa 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -49,6 +49,8 @@ static int novmerge = 1;
 
 static int protect4gb = 1;
 
+static void __iommu_free(struct iommu_table *, dma_addr_t, unsigned int);
+
 static inline unsigned long iommu_num_pages(unsigned long vaddr,
                                             unsigned long slen)
 {
@@ -191,6 +193,7 @@ static dma_addr_t iommu_alloc(struct device *dev, struct iommu_table *tbl,
 {
         unsigned long entry, flags;
         dma_addr_t ret = DMA_ERROR_CODE;
+        int build_fail;
 
         spin_lock_irqsave(&(tbl->it_lock), flags);
 
@@ -205,9 +208,21 @@ static dma_addr_t iommu_alloc(struct device *dev, struct iommu_table *tbl,
         ret = entry << IOMMU_PAGE_SHIFT;        /* Set the return dma address */
 
         /* Put the TCEs in the HW table */
-        ppc_md.tce_build(tbl, entry, npages, (unsigned long)page & IOMMU_PAGE_MASK,
-                         direction, attrs);
+        build_fail = ppc_md.tce_build(tbl, entry, npages,
+                                      (unsigned long)page & IOMMU_PAGE_MASK,
+                                      direction, attrs);
+
+        /* ppc_md.tce_build() only returns non-zero for transient errors.
+         * Clean up the table bitmap in this case and return
+         * DMA_ERROR_CODE. For all other errors the functionality is
+         * not altered.
+         */
+        if (unlikely(build_fail)) {
+                __iommu_free(tbl, ret, npages);
 
+                spin_unlock_irqrestore(&(tbl->it_lock), flags);
+                return DMA_ERROR_CODE;
+        }
 
         /* Flush/invalidate TLB caches if necessary */
         if (ppc_md.tce_flush)
@@ -276,7 +291,7 @@ int iommu_map_sg(struct device *dev, struct iommu_table *tbl,
         dma_addr_t dma_next = 0, dma_addr;
         unsigned long flags;
         struct scatterlist *s, *outs, *segstart;
-        int outcount, incount, i;
+        int outcount, incount, i, build_fail = 0;
         unsigned int align;
         unsigned long handle;
         unsigned int max_seg_size;
@@ -337,8 +352,11 @@ int iommu_map_sg(struct device *dev, struct iommu_table *tbl,
                             npages, entry, dma_addr);
 
                 /* Insert into HW table */
-                ppc_md.tce_build(tbl, entry, npages, vaddr & IOMMU_PAGE_MASK,
-                                 direction, attrs);
+                build_fail = ppc_md.tce_build(tbl, entry, npages,
+                                              vaddr & IOMMU_PAGE_MASK,
+                                              direction, attrs);
+                if(unlikely(build_fail))
+                        goto failure;
 
                 /* If we are in an open segment, try merging */
                 if (segstart != s) {