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| author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2015-04-17 15:04:48 -0400 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2015-08-07 00:32:18 +0100 |
| commit | 38e4433dfdc1e90e878c48c8fa954250de542111 (patch) | |
| tree | e36a614f97ea40695f0bcde2e364271affa92225 | |
| parent | f09662ea912a4b11372e5a709960fcfdc125011a (diff) | |
| download | lwn-38e4433dfdc1e90e878c48c8fa954250de542111.tar.gz lwn-38e4433dfdc1e90e878c48c8fa954250de542111.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>
[bwh: Backported to 3.2: also change the def_bool (cond) to
def_bool y + depends]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | arch/x86/Kconfig | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 28a1bca3b2bd..d720208f6018 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -133,7 +133,8 @@ config SBUS bool config NEED_DMA_MAP_STATE - def_bool (X86_64 || INTEL_IOMMU || DMA_API_DEBUG) + def_bool y + depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB config NEED_SG_DMA_LENGTH def_bool y |