Messages in this thread Patch in this message | | | From | Jiri Slaby <> | Subject | [PATCH 3.12 005/111] config: Enable NEED_DMA_MAP_STATE by default when SWIOTLB is selected | Date | Wed, 10 Jun 2015 17:25:54 +0200 |
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From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
3.12-stable review patch. If anyone has any objections, please let me know.
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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> Signed-off-by: Jiri Slaby <jslaby@suse.cz> --- arch/x86/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 5b5c6ea1a76c..0cda30450825 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -156,7 +156,7 @@ 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 -- 2.4.2
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