[PATCH 2/6] x86: introduce CONFIG_X86_DEV_DMA_OPS

From: Alessandro Rubini
Date: Fri Jan 06 2012 - 07:53:24 EST


32-bit x86 systems may need their own DMA operations, so add
a new config option, which is turned on for 64-bit systems. This
patch has no functional effect but it paves the way for supporting
the STA2x11 I/O Hub and possibly other chips.

Signed-off-by: Alessandro Rubini <rubini@xxxxxxxxx>
Acked-by: Giancarlo Asnaghi <giancarlo.asnaghi@xxxxxx>
Cc: Alan Cox <alan@xxxxxxxxxxxxxxx>
---
arch/x86/Kconfig | 5 +++++
arch/x86/include/asm/device.h | 4 ++--
arch/x86/include/asm/dma-mapping.h | 2 +-
3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 90cab6f..b630740 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -12,6 +12,7 @@ config X86_32

config X86_64
def_bool 64BIT
+ select X86_DEV_DMA_OPS

### Arch settings
config X86
@@ -2235,6 +2236,10 @@ config HAVE_TEXT_POKE_SMP
bool
select STOP_MACHINE if SMP

+config X86_DEV_DMA_OPS
+ bool
+ depends on X86_64
+
source "net/Kconfig"

source "drivers/Kconfig"
diff --git a/arch/x86/include/asm/device.h b/arch/x86/include/asm/device.h
index 63a2a03..93e1c55 100644
--- a/arch/x86/include/asm/device.h
+++ b/arch/x86/include/asm/device.h
@@ -5,8 +5,8 @@ struct dev_archdata {
#ifdef CONFIG_ACPI
void *acpi_handle;
#endif
-#ifdef CONFIG_X86_64
-struct dma_map_ops *dma_ops;
+#ifdef CONFIG_X86_DEV_DMA_OPS
+ struct dma_map_ops *dma_ops;
#endif
#if defined(CONFIG_INTEL_IOMMU) || defined(CONFIG_AMD_IOMMU)
void *iommu; /* hook for IOMMU specific extension */
diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
index ed3065f..53fb9dc 100644
--- a/arch/x86/include/asm/dma-mapping.h
+++ b/arch/x86/include/asm/dma-mapping.h
@@ -30,7 +30,7 @@ extern struct dma_map_ops *dma_ops;

static inline struct dma_map_ops *get_dma_ops(struct device *dev)
{
-#ifdef CONFIG_X86_32
+#ifndef CONFIG_X86_DEV_DMA_OPS
return dma_ops;
#else
if (unlikely(!dev) || !dev->archdata.dma_ops)
--
1.7.7.2
--
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