--- /dev/null
+From a6dfa128ce5c414ab46b1d690f7a1b8decb8526d Mon Sep 17 00:00:00 2001
+From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Date: Fri, 17 Apr 2015 15:04:48 -0400
+Subject: config: Enable NEED_DMA_MAP_STATE by default when SWIOTLB is selected
+
+From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+
+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>
+
+---
+ arch/x86/Kconfig | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/arch/x86/Kconfig
++++ b/arch/x86/Kconfig
+@@ -177,7 +177,7 @@ 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