x86: Introduce CONFIG_X86_DMA_REMAP

The default functions phys_to_dma, dma_to_phys implement identity
mapping as fast inline functions.  Some systems, however, may need a
custom function to implement its own mapping between CPU addresses and
device addresses. This new configuration option allows the functions
to be external when needed (such as for the ConneXt device)

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
Link: http://lkml.kernel.org/r/6e4329b772df675f1c442f68e59e844e4dd8c965.1333560789.git.rubini@gnudd.com
Acked-by: Giancarlo Asnaghi <giancarlo.asnaghi@st.com>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 07b412aed38b..95ca56036030 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2220,6 +2220,9 @@ config X86_DEV_DMA_OPS
         bool
         depends on X86_64
 
+config X86_DMA_REMAP
+        bool
+
 source "net/Kconfig"
 
 source "drivers/Kconfig"