From: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> 3.12-stable review patch. If anyone has any objections, please let me know. =============== 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@xxxxxxxxxxxxx> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> Acked-by: David S. Miller <davem@xxxxxxxxxxxxx> Acked-by: Prashant Sreedharan <prashant@xxxxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Michael Chan <mchan@xxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: boris.ostrovsky@xxxxxxxxxx Cc: cascardo@xxxxxxxxxxxxxxxxxx Cc: david.vrabel@xxxxxxxxxx Cc: sanjeevb@xxxxxxxxxxxx Cc: siva.kallam@xxxxxxxxxxxx Cc: vyasevich@xxxxxxxxx Cc: xen-devel@xxxxxxxxxxxxxxxxxxx Link: http://lkml.kernel.org/r/20150417190448.GA9462@xxxxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> --- 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 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html