diff options
| -rw-r--r-- | arch/x86/kernel/pci-dma_32.c | 13 |
1 files changed, 13 insertions, 0 deletions
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 <linux/module.h> #include <asm/io.h> +/* 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; |