From mboxrd@z Thu Jan 1 00:00:00 1970 From: Glauber Costa Subject: [PATCH 22/28] x86: use a fallback dev for i386 Date: Tue, 8 Apr 2008 13:21:04 -0300 Message-ID: <12076718132980-git-send-email-gcosta@redhat.com> References: <12076716702129-git-send-email-gcosta@redhat.com> Cc: akpm@linux-foundation.org, glommer@gmail.com, mingo@elte.hu, tglx@linutronix.de, kvm-devel@lists.sourceforge.net, amit.shah@qumranet.com, avi@qumranet.com, Glauber Costa To: linux-kernel@vger.kernel.org Return-path: In-Reply-To: <12076716702129-git-send-email-gcosta@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org 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 --- 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 f6cf434..0e9ec11 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) { @@ -77,6 +87,9 @@ 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; + dma_mask = dev->coherent_dma_mask; if (dma_mask == 0) dma_mask = DMA_32BIT_MASK; -- 1.5.0.6