[PATCH] dma_declare_coherent_memory wrong allocation

From: Guennadi Liakhovetski
Date: Fri Apr 13 2007 - 14:08:51 EST


Hi

Either I've finally gone blind on this Friday 13th or... Looks like this
almost 3 year old function has a bug. Patch below compile-tested... in a
way.

Thanks
Guennadi
---
Guennadi Liakhovetski

dma_declare_coherent_memory() allocates a bitmap 1 bit per page, it
calculates the bitmap size based on size of long, but allocates bytes...

Signed-off-by: G. Liakhovetski <g.liakhovetski@xxxxxx>

diff --git a/arch/i386/kernel/pci-dma.c b/arch/i386/kernel/pci-dma.c
index 3ebcea0..3d55226 100644
--- a/arch/i386/kernel/pci-dma.c
+++ b/arch/i386/kernel/pci-dma.c
@@ -77,7 +77,7 @@ int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
{
void __iomem *mem_base = NULL;
int pages = size >> PAGE_SHIFT;
- int bitmap_size = (pages + 31)/32;
+ int bitmap_size = DIV_ROUND_UP(pages, 8);

if ((flags & (DMA_MEMORY_MAP | DMA_MEMORY_IO)) == 0)
goto out;
-
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