[PATCH] x86_64: Remove CONFIG_UNORDERED_IO

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@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index 6fc6314..31bab72 100644 (file)
--- a/arch/x86_64/Kconfig
+++ b/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"

diff --git a/include/asm-x86_64/io.h b/include/asm-x86_64/io.h
index ac12bda..cafdfb3 100644 (file)
--- a/include/asm-x86_64/io.h
+++ b/include/asm-x86_64/io.h
@@ -200,23 +200,6 @@ static inline __u64 __readq(const volatile void __iomem *addr)
 
 #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, volatile void __iomem *addr)
 {
        *(__force volatile __u64 *)addr = b;
 }
-#endif
 static inline void __writeb(__u8 b, volatile void __iomem *addr)
 {
        *(__force volatile __u8 *)addr = b;