From 45a07e774950ef479f8996c0e2c5550dd6440453 Mon Sep 17 00:00:00 2001 From: Glauber Costa Date: Tue, 8 Apr 2008 13:21:04 -0300 Subject: [PATCH] x86: use a fallback dev for i386 We can use a fallback dev for cases of a NULL device being passed (mostly ISA) This comes from x86_64 implementation. Signed-off-by: Glauber Costa Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/pci-dma_32.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/x86/kernel/pci-dma_32.c b/arch/x86/kernel/pci-dma_32.c index 0d630ae3d91..0600a37ba83 100644 --- a/arch/x86/kernel/pci-dma_32.c +++ b/arch/x86/kernel/pci-dma_32.c @@ -14,6 +14,16 @@ #include #include +/* Dummy device used for NULL arguments (normally ISA). Better would + be probably a smaller DMA mask, but this is bug-to-bug compatible + to i386. */ +struct device fallback_dev = { + .bus_id = "fallback device", + .coherent_dma_mask = DMA_32BIT_MASK, + .dma_mask = &fallback_dev.coherent_dma_mask, +}; + + static int dma_alloc_from_coherent_mem(struct device *dev, ssize_t size, dma_addr_t *dma_handle, void **ret) { @@ -75,6 +85,9 @@ void *dma_alloc_coherent(struct device *dev, size_t size, if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff)) gfp |= GFP_DMA; + if (!dev) + dev = &fallback_dev; + page = dma_alloc_pages(dev, gfp, order); if (page == NULL) return NULL; -- 2.20.1