Re: [PATCH] dma_declare_coherent_memory wrong allocation

From: Guennadi Liakhovetski
Date: Sun Apr 22 2007 - 18:50:03 EST


On Mon, 23 Apr 2007, Guennadi Liakhovetski wrote:

> to also allow for size not an integer number of pages as Andrew noticed?
> This could be done in 2 patches:

patch 2:

---
Fix bitmap allocation and size non-multiple of PAGE_SIZE in
dma_declare_coherent_memory implementations. i386 compile-tested.

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..0a9317a 100644
--- a/arch/i386/kernel/pci-dma.c
+++ b/arch/i386/kernel/pci-dma.c
@@ -76,8 +76,8 @@ int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
dma_addr_t device_addr, size_t size, int flags)
{
void __iomem *mem_base = NULL;
- int pages = size >> PAGE_SHIFT;
- int bitmap_size = (pages + 31)/32;
+ int pages = DIV_ROUND_UP(size, PAGE_SIZE);
+ int bitmap_size = BITS_TO_LONGS(pages) * BYTES_PER_LONG;

if ((flags & (DMA_MEMORY_MAP | DMA_MEMORY_IO)) == 0)
goto out;
diff --git a/arch/cris/arch-v32/drivers/pci/dma.c b/arch/cris/arch-v32/drivers/pci/dma.c
index d634347..99f760e 100644
--- a/arch/cris/arch-v32/drivers/pci/dma.c
+++ b/arch/cris/arch-v32/drivers/pci/dma.c
@@ -75,8 +75,8 @@ int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
dma_addr_t device_addr, size_t size, int flags)
{
void __iomem *mem_base;
- int pages = size >> PAGE_SHIFT;
- int bitmap_size = (pages + 31)/32;
+ int pages = DIV_ROUND_UP(size, PAGE_SIZE);
+ int bitmap_size = BITS_TO_LONGS(pages) * BYTES_PER_LONG;

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