From 5fa78ca75d8e67063948a01b51594a0904af5710 Mon Sep 17 00:00:00 2001 From: Glauber Costa Date: Wed, 9 Apr 2008 13:18:05 -0300 Subject: [PATCH] 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 Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/pci-dma_32.c | 34 +++++++++++++++++++++++++++++----- 1 file changed, 29 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/pci-dma_32.c b/arch/x86/kernel/pci-dma_32.c index debe9119b72..11f100a5f03 100644 --- a/arch/x86/kernel/pci-dma_32.c +++ b/arch/x86/kernel/pci-dma_32.c @@ -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); - - memset(ret, 0, size); - *dma_handle = bus; + { + 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; } -- 2.41.0