From b077ffb3b767c3efb44d00b998385a9cb127255c Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Fri, 16 Feb 2007 01:48:11 -0800 Subject: rdmsr_on_cpu, wrmsr_on_cpu There was OpenVZ specific bug rendering some cpufreq drivers unusable on SMP. In short, when cpufreq code thinks it confined itself to needed cpu by means of set_cpus_allowed() to execute rdmsr, some "virtual cpu" feature can migrate process to anywhere. This triggers bugons and does wrong things in general. This got fixed by introducing rdmsr_on_cpu and wrmsr_on_cpu executing rdmsr and wrmsr on given physical cpu by means of smp_call_function_single(). Dave Jones mentioned cpufreq might be not only user of rdmsr_on_cpu() and wrmsr_on_cpu(), so I'm putting them into arch/{i386,x86_64}/lib/ . Signed-off-by: Alexey Dobriyan Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Dave Jones --- include/asm-i386/msr.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/asm-i386') diff --git a/include/asm-i386/msr.h b/include/asm-i386/msr.h index 609a3899475..3516a1fb38e 100644 --- a/include/asm-i386/msr.h +++ b/include/asm-i386/msr.h @@ -83,6 +83,9 @@ static inline void wrmsrl (unsigned long msr, unsigned long long val) : "c" (counter)) #endif /* !CONFIG_PARAVIRT */ +void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h); +void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h); + /* symbolic names for some interesting MSRs */ /* Intel defined MSRs. */ #define MSR_IA32_P5_MC_ADDR 0 -- cgit v1.2.3-70-g09d2 From b44755cfaa72e7ed3d831a946bb4e7dfe7548966 Mon Sep 17 00:00:00 2001 From: Adrian Bunk Date: Tue, 20 Feb 2007 01:07:13 +0100 Subject: {rd,wr}msr_on_cpu SMP=n optimization Let's save a few bytes in the CONFIG_SMP=n case. Signed-off-by: Adrian Bunk Signed-off-by: Dave Jones --- arch/i386/lib/Makefile | 2 +- arch/i386/lib/msr-on-cpu.c | 12 ------------ arch/x86_64/lib/Makefile | 3 ++- include/asm-i386/msr.h | 11 +++++++++++ include/asm-x86_64/msr.h | 11 +++++++++++ 5 files changed, 25 insertions(+), 14 deletions(-) (limited to 'include/asm-i386') diff --git a/arch/i386/lib/Makefile b/arch/i386/lib/Makefile index 0d41223472c..22d8ac5815f 100644 --- a/arch/i386/lib/Makefile +++ b/arch/i386/lib/Makefile @@ -8,4 +8,4 @@ lib-y = checksum.o delay.o usercopy.o getuser.o putuser.o memcpy.o strstr.o \ lib-$(CONFIG_X86_USE_3DNOW) += mmx.o -obj-y = msr-on-cpu.o +obj-$(CONFIG_SMP) += msr-on-cpu.o diff --git a/arch/i386/lib/msr-on-cpu.c b/arch/i386/lib/msr-on-cpu.c index 2092ea15ba8..1c46bda409f 100644 --- a/arch/i386/lib/msr-on-cpu.c +++ b/arch/i386/lib/msr-on-cpu.c @@ -3,7 +3,6 @@ #include #include -#ifdef CONFIG_SMP struct msr_info { u32 msr_no; u32 l, h; @@ -54,17 +53,6 @@ void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h) } preempt_enable(); } -#else -void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h) -{ - rdmsr(msr_no, *l, *h); -} - -void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h) -{ - wrmsr(msr_no, l, h); -} -#endif EXPORT_SYMBOL(rdmsr_on_cpu); EXPORT_SYMBOL(wrmsr_on_cpu); diff --git a/arch/x86_64/lib/Makefile b/arch/x86_64/lib/Makefile index 0a43f07b029..43d051ff1fb 100644 --- a/arch/x86_64/lib/Makefile +++ b/arch/x86_64/lib/Makefile @@ -4,7 +4,8 @@ CFLAGS_csum-partial.o := -funroll-loops -obj-y := io.o iomap_copy.o msr-on-cpu.o +obj-y := io.o iomap_copy.o +obj-$(CONFIG_SMP) += msr-on-cpu.o lib-y := csum-partial.o csum-copy.o csum-wrappers.o delay.o \ usercopy.o getuser.o putuser.o \ diff --git a/include/asm-i386/msr.h b/include/asm-i386/msr.h index 3516a1fb38e..8c35f3d90a8 100644 --- a/include/asm-i386/msr.h +++ b/include/asm-i386/msr.h @@ -83,8 +83,19 @@ static inline void wrmsrl (unsigned long msr, unsigned long long val) : "c" (counter)) #endif /* !CONFIG_PARAVIRT */ +#ifdef CONFIG_SMP void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h); void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h); +#else /* CONFIG_SMP */ +static inline void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h) +{ + rdmsr(msr_no, *l, *h); +} +static inline void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h) +{ + wrmsr(msr_no, l, h); +} +#endif /* CONFIG_SMP */ /* symbolic names for some interesting MSRs */ /* Intel defined MSRs. */ diff --git a/include/asm-x86_64/msr.h b/include/asm-x86_64/msr.h index 995a2b5fb26..902f9a58617 100644 --- a/include/asm-x86_64/msr.h +++ b/include/asm-x86_64/msr.h @@ -160,8 +160,19 @@ static inline unsigned int cpuid_edx(unsigned int op) #define MSR_IA32_UCODE_WRITE 0x79 #define MSR_IA32_UCODE_REV 0x8b +#ifdef CONFIG_SMP void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h); void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h); +#else /* CONFIG_SMP */ +static inline void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h) +{ + rdmsr(msr_no, *l, *h); +} +static inline void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h) +{ + wrmsr(msr_no, l, h); +} +#endif /* CONFIG_SMP */ #endif -- cgit v1.2.3-70-g09d2