1 files changed, 56 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/ipath/ipath_user_pages.c b/drivers/infiniband/hw/ipath/ipath_user_pages.c
index e32fca9faf8..413754b1d8a 100644
--- a/drivers/infiniband/hw/ipath/ipath_user_pages.c
+++ b/drivers/infiniband/hw/ipath/ipath_user_pages.c
@@ -90,6 +90,62 @@ bail:
 }
 
 /**
+ * ipath_map_page - a safety wrapper around pci_map_page()
+ *
+ * A dma_addr of all 0's is interpreted by the chip as "disabled".
+ * Unfortunately, it can also be a valid dma_addr returned on some
+ * architectures.
+ *
+ * The powerpc iommu assigns dma_addrs in ascending order, so we don't
+ * have to bother with retries or mapping a dummy page to insure we
+ * don't just get the same mapping again.
+ *
+ * I'm sure we won't be so lucky with other iommu's, so FIXME.
+ */
+dma_addr_t ipath_map_page(struct pci_dev *hwdev, struct page *page,
+	unsigned long offset, size_t size, int direction)
+{
+	dma_addr_t phys;
+
+	phys = pci_map_page(hwdev, page, offset, size, direction);
+
+	if (phys == 0) {
+		pci_unmap_page(hwdev, phys, size, direction);
+		phys = pci_map_page(hwdev, page, offset, size, direction);
+		/*
+		 * FIXME: If we get 0 again, we should keep this page,
+		 * map another, then free the 0 page.
+		 */
+	}
+
+	return phys;
+}
+
+/**
+ * ipath_map_single - a safety wrapper around pci_map_single()
+ *
+ * Same idea as ipath_map_page().
+ */
+dma_addr_t ipath_map_single(struct pci_dev *hwdev, void *ptr, size_t size,
+	int direction)
+{
+	dma_addr_t phys;
+
+	phys = pci_map_single(hwdev, ptr, size, direction);
+
+	if (phys == 0) {
+		pci_unmap_single(hwdev, phys, size, direction);
+		phys = pci_map_single(hwdev, ptr, size, direction);
+		/*
+		 * FIXME: If we get 0 again, we should keep this page,
+		 * map another, then free the 0 page.
+		 */
+	}
+
+	return phys;
+}
+
+/**
  * ipath_get_user_pages - lock user pages into memory
  * @start_page: the start page
  * @num_pages: the number of pages