quoted

+/**
+ * arm_iommu_create_mapping
+ * @bus: pointer to the bus holding the client device (for IOMMU calls)
+ * @base: start address of the valid IO address space
+ * @size: size of the valid IO address space
+ * @order: accuracy of the IO addresses allocations
+ *
+ * Creates a mapping structure which holds information about used/unused
+ * IO address ranges, which is required to perform memory allocation and
+ * mapping with IOMMU aware functions.
+ *
+ * The client device need to be attached to the mapping with
+ * arm_iommu_attach_device function.
+ */
+struct dma_iommu_mapping *
+arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t base, size_t size,
+                        int order)
+{
+       unsigned int count = (size >> PAGE_SHIFT) - order;
+       unsigned int bitmap_size = BITS_TO_LONGS(count) * sizeof(long);
+       struct dma_iommu_mapping *mapping;
+       int err = -ENOMEM;
+
+       mapping = kzalloc(sizeof(struct dma_iommu_mapping), GFP_KERNEL);
+       if (!mapping)
+               goto err;
+
+       mapping->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
+       if (!mapping->bitmap)
+               goto err2;
+
+       mapping->base = base;
+       mapping->bits = bitmap_size;

Shouldn't the above be as below?

From 093c77ac6f19899679f2f2447a9d2c684eab7b2e Mon Sep 17 00:00:00 2001
From: Hiroshi DOYU <redacted>
Date: Mon, 5 Mar 2012 13:04:38 +0200
Subject: [PATCH 1/1] dma-mapping: Fix mapping->bits size

Amount of bits should be mutiplied by BITS_PER_BITE.

Signed-off-by: Hiroshi DOYU <redacted>
---
 arch/arm/mm/dma-mapping.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index e55f425..5ec7747 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c

@@ -1495,7 +1495,7 @@ arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t base, size_t

size,
 		goto err2;

 	mapping->base = base;
-	mapping->bits = bitmap_size;
+	mapping->bits = BITS_PER_BYTE * bitmap_size;
 	mapping->order = order;
 	spin_lock_init(&mapping->lock);