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x86: retry allocation if failed 

This patch puts in the code to retry allocation in case it fails. By its
own, it does not make much sense but making the code look like x86_64.
But later patches in this series will make we try to allocate from
zones other than DMA first, which will possibly fail.

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Glauber Costa 2008-04-09 13:18:05 -03:00 committed by Ingo Molnar
parent 8779f2fc3b
commit 5fa78ca75d
1 changed files with 28 additions and 4 deletions
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32
arch/x86/kernel/pci-dma_32.c
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@ -76,6 +76,8 @@ void *dma_alloc_coherent(struct device *dev, size_t size,
struct page *page;
dma_addr_t bus;
int order = get_order(size);
unsigned long dma_mask = 0;
/* ignore region specifiers */
gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
@ -85,15 +87,37 @@ void *dma_alloc_coherent(struct device *dev, size_t size,
if (!dev)
dev = &fallback_dev;
dma_mask = dev->coherent_dma_mask;
if (dma_mask == 0)
dma_mask = DMA_32BIT_MASK;
again:
page = dma_alloc_pages(dev, gfp, order);
if (page == NULL)
return NULL;
ret = page_address(page);
bus = page_to_phys(page);
{
int high, mmu;
bus = page_to_phys(page);
ret = page_address(page);
high = (bus + size) >= dma_mask;
mmu = high;
if (force_iommu && !(gfp & GFP_DMA))
mmu = 1;
else if (high) {
free_pages((unsigned long)ret,
get_order(size));
memset(ret, 0, size);
*dma_handle = bus;
/* Don't use the 16MB ZONE_DMA unless absolutely
needed. It's better to use remapping first. */
if (dma_mask < DMA_32BIT_MASK && !(gfp & GFP_DMA)) {
gfp = (gfp & ~GFP_DMA32) | GFP_DMA;
goto again;
}
}
memset(ret, 0, size);
*dma_handle = bus;
}
return ret;
}