From: Konrad Rzeszutek Wilk <[email protected]> 3.4.108-rc1 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 <[email protected]> Signed-off-by: Konrad Rzeszutek Wilk <[email protected]> Acked-by: David S. Miller <[email protected]> Acked-by: Prashant Sreedharan <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Michael Chan <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> Cc: Ben Hutchings <[email protected]> [lizf: Backported to 3.4: adjust context] Signed-off-by: Zefan Li <[email protected]> --- arch/x86/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 917c109..eda8cb9 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -129,7 +129,7 @@ config SBUS bool config NEED_DMA_MAP_STATE - def_bool (X86_64 || INTEL_IOMMU || DMA_API_DEBUG) + def_bool (X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB) config NEED_SG_DMA_LENGTH def_bool y -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
