It was a failed experiment - all benchmarks done with it on both AMD
and Intel showed it was a loss. That was probably because the store
buffers of the CPUs for write combining traffic weren't large enough.
Signed-off-by: Andi Kleen <ak@xxxxxxx>
---
arch/x86_64/Kconfig | 10 ----------
include/asm-x86_64/io.h | 18 ------------------
2 files changed, 28 deletions(-)
Index: linux/arch/x86_64/Kconfig
===================================================================
--- linux.orig/arch/x86_64/Kconfig
+++ linux/arch/x86_64/Kconfig
@@ -520,16 +520,6 @@ config PCI_MMCONFIG
bool "Support mmconfig PCI config space access"
depends on PCI && ACPI
-config UNORDERED_IO
- bool "Unordered IO mapping access"
- depends on EXPERIMENTAL
- help
- Use unordered stores to access IO memory mappings in device drivers.
- Still very experimental. When a driver works on IA64/ppc64/pa-risc it should
- work with this option, but it makes the drivers behave differently
- from i386. Requires that the driver writer used memory barriers
- properly.
-
source "drivers/pci/pcie/Kconfig"
source "drivers/pci/Kconfig"
Index: linux/include/asm-x86_64/io.h
===================================================================
--- linux.orig/include/asm-x86_64/io.h
+++ linux/include/asm-x86_64/io.h
@@ -200,23 +200,6 @@ static inline __u64 __readq(const volati
#define mmiowb()
-#ifdef CONFIG_UNORDERED_IO
-static inline void __writel(__u32 val, volatile void __iomem *addr)
-{
- volatile __u32 __iomem *target = addr;
- asm volatile("movnti %1,%0"
- : "=m" (*target)
- : "r" (val) : "memory");
-}
-
-static inline void __writeq(__u64 val, volatile void __iomem *addr)
-{
- volatile __u64 __iomem *target = addr;
- asm volatile("movnti %1,%0"
- : "=m" (*target)
- : "r" (val) : "memory");
-}
-#else
static inline void __writel(__u32 b, volatile void __iomem *addr)
{
*(__force volatile __u32 *)addr = b;
@@ -225,7 +208,6 @@ static inline void __writeq(__u64 b, vol
{
*(__force volatile __u64 *)addr = b;
}
-#endif
static inline void __writeb(__u8 b, volatile void __iomem *addr)
{
*(__force volatile __u8 *)addr = b;
-
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