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authorKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2015-04-17 15:04:48 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-07-03 19:49:04 -0700
commitd5d37cb10aa6a098aab22ac7ae4e0a96d5ac89f4 (patch)
tree77aa3d6975284f152e28f0619cf3b23d0f8eacb9
parentf3fb38ae7386eeff5913251950e285efa86a3b24 (diff)
downloadlwn-d5d37cb10aa6a098aab22ac7ae4e0a96d5ac89f4.tar.gz
lwn-d5d37cb10aa6a098aab22ac7ae4e0a96d5ac89f4.zip
config: Enable NEED_DMA_MAP_STATE by default when SWIOTLB is selected
commit a6dfa128ce5c414ab46b1d690f7a1b8decb8526d upstream. A huge amount of NIC drivers use the DMA API, however if compiled under 32-bit an very important part of the DMA API can be ommitted leading to the drivers not working at all (especially if used with 'swiotlb=force iommu=soft'). As Prashant Sreedharan explains it: "the driver [tg3] uses DEFINE_DMA_UNMAP_ADDR(), dma_unmap_addr_set() to keep a copy of the dma "mapping" and dma_unmap_addr() to get the "mapping" value. On most of the platforms this is a no-op, but ... with "iommu=soft and swiotlb=force" this house keeping is required, ... otherwise we pass 0 while calling pci_unmap_/pci_dma_sync_ instead of the DMA address." As such enable this even when using 32-bit kernels. Reported-by: Ian Jackson <Ian.Jackson@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Prashant Sreedharan <prashant@broadcom.com> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Chan <mchan@broadcom.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: boris.ostrovsky@oracle.com Cc: cascardo@linux.vnet.ibm.com Cc: david.vrabel@citrix.com Cc: sanjeevb@broadcom.com Cc: siva.kallam@broadcom.com Cc: vyasevich@gmail.com Cc: xen-devel@lists.xensource.com Link: http://lkml.kernel.org/r/20150417190448.GA9462@l.oracle.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/x86/Kconfig2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 2f645c90e4d8..5dab54accc56 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -160,7 +160,7 @@ config SBUS
config NEED_DMA_MAP_STATE
def_bool y
- depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
+ depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
config NEED_SG_DMA_LENGTH
def_bool y