Commit 5fa78ca7 authored by Glauber Costa's avatar Glauber Costa Committed by Ingo Molnar
Browse files

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: default avatarGlauber Costa <gcosta@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 8779f2fc

arch/x86/kernel/pci-dma_32.c

+29 −5
Original line number Diff line number Diff line
@@ -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);

	{

		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));



			/* 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;

}

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