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ARM: dmabounce: separate out decision to bounce

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Move the decision to perform DMA bouncing out of map_single() into its
own stand-alone function.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King 2011-07-03 22:28:32 +01:00
parent 71695dd8b9
commit 23bc9873ba
1 changed files with 28 additions and 18 deletions
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46
arch/arm/common/dmabounce.c
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@ -219,36 +219,46 @@ static struct safe_buffer *find_safe_buffer_dev(struct device *dev,
return find_safe_buffer(dev->archdata.dmabounce, dma_addr);
}
static int needs_bounce(struct device *dev, dma_addr_t dma_addr, size_t size)
{
if (!dev || !dev->archdata.dmabounce)
return 0;
if (dev->dma_mask) {
unsigned long limit, mask = *dev->dma_mask;
limit = (mask + 1) & ~mask;
if (limit && size > limit) {
dev_err(dev, "DMA mapping too big (requested %#x "
"mask %#Lx)\n", size, *dev->dma_mask);
return -E2BIG;
}
/* Figure out if we need to bounce from the DMA mask. */
if ((dma_addr | (dma_addr + size - 1)) & ~mask)
return 1;
}
return dma_needs_bounce(dev, dma_addr, size) ? 1 : 0;
}
static inline dma_addr_t map_single(struct device *dev, void *ptr, size_t size,
enum dma_data_direction dir)
{
struct dmabounce_device_info *device_info = dev->archdata.dmabounce;
dma_addr_t dma_addr;
int needs_bounce = 0;
int ret;
if (device_info)
DO_STATS ( device_info->map_op_count++ );
dma_addr = virt_to_dma(dev, ptr);
if (dev->dma_mask) {
unsigned long mask = *dev->dma_mask;
unsigned long limit;
ret = needs_bounce(dev, dma_addr, size);
if (ret < 0)
return ~0;
limit = (mask + 1) & ~mask;
if (limit && size > limit) {
dev_err(dev, "DMA mapping too big (requested %#x "
"mask %#Lx)\n", size, *dev->dma_mask);
return ~0;
}
/*
* Figure out if we need to bounce from the DMA mask.
*/
needs_bounce = (dma_addr | (dma_addr + size - 1)) & ~mask;
}
if (device_info && (needs_bounce || dma_needs_bounce(dev, dma_addr, size))) {
if (ret > 0) {
struct safe_buffer *buf;
buf = alloc_safe_buffer(device_info, ptr, size, dir);