From f25f64ed5bd3c2932493681bdfdb483ea707da0a Mon Sep 17 00:00:00 2001 From: Juergen Beisert Date: Sun, 22 Jul 2007 11:12:38 +0200 Subject: [PATCH] x86: Replace NSC/Cyrix specific chipset access macros by inlined functions. Due to index register access ordering problems, when using macros a line like this fails (and does nothing): setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x88); With inlined functions this line will work as expected. Note about a side effect: Seems on Geode GX1 based systems the "suspend on halt power saving feature" was never enabled due to this wrong macro expansion. With inlined functions it will be enabled, but this will stop the TSC when the CPU runs into a HLT instruction. Kernel output something like this: Clocksource tsc unstable (delta = -472746897 ns) This is the 3rd version of this patch. - Adding missed arch/i386/kernel/cpu/mtrr/state.c Thanks to Andres Salomon - Adding some big fat comments into the new header file Suggested by Andi Kleen AK: fixed x86-64 compilation Signed-off-by: Juergen Beisert Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- arch/i386/kernel/cpu/cpufreq/gx-suspmod.c | 2 +- arch/i386/kernel/cpu/cyrix.c | 2 +- arch/i386/kernel/cpu/mtrr/cyrix.c | 1 + arch/i386/kernel/cpu/mtrr/state.c | 1 + include/asm-i386/processor-cyrix.h | 30 +++++++++++++++++++++++ include/asm-i386/processor.h | 11 --------- include/asm-x86_64/processor.h | 11 --------- 7 files changed, 34 insertions(+), 24 deletions(-) create mode 100644 include/asm-i386/processor-cyrix.h diff --git a/arch/i386/kernel/cpu/cpufreq/gx-suspmod.c b/arch/i386/kernel/cpu/cpufreq/gx-suspmod.c index 194144539a6..461dabc4e49 100644 --- a/arch/i386/kernel/cpu/cpufreq/gx-suspmod.c +++ b/arch/i386/kernel/cpu/cpufreq/gx-suspmod.c @@ -79,7 +79,7 @@ #include #include #include -#include +#include #include /* PCI config registers, all at F0 */ diff --git a/arch/i386/kernel/cpu/cyrix.c b/arch/i386/kernel/cpu/cyrix.c index e88d2fba156..122d2d75aa9 100644 --- a/arch/i386/kernel/cpu/cyrix.c +++ b/arch/i386/kernel/cpu/cyrix.c @@ -4,7 +4,7 @@ #include #include #include -#include +#include #include #include #include diff --git a/arch/i386/kernel/cpu/mtrr/cyrix.c b/arch/i386/kernel/cpu/mtrr/cyrix.c index 1001f1e0fe6..2287d4863a8 100644 --- a/arch/i386/kernel/cpu/mtrr/cyrix.c +++ b/arch/i386/kernel/cpu/mtrr/cyrix.c @@ -3,6 +3,7 @@ #include #include #include +#include #include "mtrr.h" int arr3_protected; diff --git a/arch/i386/kernel/cpu/mtrr/state.c b/arch/i386/kernel/cpu/mtrr/state.c index 7b39a2f954d..c9014ca4a57 100644 --- a/arch/i386/kernel/cpu/mtrr/state.c +++ b/arch/i386/kernel/cpu/mtrr/state.c @@ -3,6 +3,7 @@ #include #include #include +#include #include "mtrr.h" diff --git a/include/asm-i386/processor-cyrix.h b/include/asm-i386/processor-cyrix.h new file mode 100644 index 00000000000..97568ada1f9 --- /dev/null +++ b/include/asm-i386/processor-cyrix.h @@ -0,0 +1,30 @@ +/* + * NSC/Cyrix CPU indexed register access. Must be inlined instead of + * macros to ensure correct access ordering + * Access order is always 0x22 (=offset), 0x23 (=value) + * + * When using the old macros a line like + * setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x88); + * gets expanded to: + * do { + * outb((CX86_CCR2), 0x22); + * outb((({ + * outb((CX86_CCR2), 0x22); + * inb(0x23); + * }) | 0x88), 0x23); + * } while (0); + * + * which in fact violates the access order (= 0x22, 0x22, 0x23, 0x23). + */ + +static inline u8 getCx86(u8 reg) +{ + outb(reg, 0x22); + return inb(0x23); +} + +static inline void setCx86(u8 reg, u8 data) +{ + outb(reg, 0x22); + outb(data, 0x23); +} diff --git a/include/asm-i386/processor.h b/include/asm-i386/processor.h index 48a7f69bb76..3845fe72383 100644 --- a/include/asm-i386/processor.h +++ b/include/asm-i386/processor.h @@ -168,17 +168,6 @@ static inline void clear_in_cr4 (unsigned long mask) write_cr4(cr4); } -/* - * NSC/Cyrix CPU indexed register access macros - */ - -#define getCx86(reg) ({ outb((reg), 0x22); inb(0x23); }) - -#define setCx86(reg, data) do { \ - outb((reg), 0x22); \ - outb((data), 0x23); \ -} while (0) - /* Stop speculative execution */ static inline void sync_core(void) { diff --git a/include/asm-x86_64/processor.h b/include/asm-x86_64/processor.h index a1645bbc03b..19525175b91 100644 --- a/include/asm-x86_64/processor.h +++ b/include/asm-x86_64/processor.h @@ -389,17 +389,6 @@ static inline void prefetchw(void *x) #define cpu_relax() rep_nop() -/* - * NSC/Cyrix CPU indexed register access macros - */ - -#define getCx86(reg) ({ outb((reg), 0x22); inb(0x23); }) - -#define setCx86(reg, data) do { \ - outb((reg), 0x22); \ - outb((data), 0x23); \ -} while (0) - static inline void serialize_cpu(void) { __asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx"); -- 2.41.1