Re: [PATCH 1/4] perf/x86/amd: AMD support for bp_len > HW_BREAKPOINT_LEN_8

Frederic Weisbecker
2014-05-30T13:33:51Z

Hi Jacob, Suravee,

On Thu, May 29, 2014 at 05:26:50PM +0200, Frederic Weisbecker wrote:
> From: Jacob Shin <jacob.w.shin@gmail.com>
>
> Implement hardware breakpoint address mask for AMD Family 16h and
> above processors. CPUID feature bit indicates hardware support for
> DRn_ADDR_MASK MSRs. These masks further qualify DRn/DR7 hardware
> breakpoint addresses to allow matching of larger addresses ranges.
>
> Valuable advice and pseudo code from Oleg Nesterov <oleg@redhat.com>
>
> Signed-off-by: Jacob Shin <jacob.w.shin@gmail.com>
> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: Jiri Olsa <jolsa@redhat.com>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Cc: Oleg Nesterov <oleg@redhat.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: xiakaixu <xiakaixu@huawei.com>
> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
> ---
> arch/x86/include/asm/cpufeature.h | 2 ++
> arch/x86/include/asm/debugreg.h | 5 +++++
> arch/x86/include/asm/hw_breakpoint.h | 1 +
> arch/x86/include/uapi/asm/msr-index.h | 4 ++++
> arch/x86/kernel/cpu/amd.c | 19 +++++++++++++++++++
> arch/x86/kernel/hw_breakpoint.c | 20 ++++++++++++++++----
> 6 files changed, 47 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
> index e265ff9..6bd564d 100644
> --- a/arch/x86/include/asm/cpufeature.h
> +++ b/arch/x86/include/asm/cpufeature.h
> @@ -170,6 +170,7 @@
> #define X86_FEATURE_TOPOEXT (6*32+22) /* topology extensions CPUID leafs */
> #define X86_FEATURE_PERFCTR_CORE (6*32+23) /* core performance counter extensions */
> #define X86_FEATURE_PERFCTR_NB (6*32+24) /* NB performance counter extensions */
> +#define X86_FEATURE_BPEXT (6*32+26) /* data breakpoint extension */
> #define X86_FEATURE_PERFCTR_L2 (6*32+28) /* L2 performance counter extensions */
>
> /*
> @@ -338,6 +339,7 @@ extern const char * const x86_power_flags[32];
> #define cpu_has_cx16 boot_cpu_has(X86_FEATURE_CX16)
> #define cpu_has_eager_fpu boot_cpu_has(X86_FEATURE_EAGER_FPU)
> #define cpu_has_topoext boot_cpu_has(X86_FEATURE_TOPOEXT)
> +#define cpu_has_bpext boot_cpu_has(X86_FEATURE_BPEXT)
>
> #ifdef CONFIG_X86_64
>
> diff --git a/arch/x86/include/asm/debugreg.h b/arch/x86/include/asm/debugreg.h
> index 4b528a9..145b009 100644
> --- a/arch/x86/include/asm/debugreg.h
> +++ b/arch/x86/include/asm/debugreg.h
> @@ -114,5 +114,10 @@ static inline void debug_stack_usage_inc(void) { }
> static inline void debug_stack_usage_dec(void) { }
> #endif /* X86_64 */
>
> +#ifdef CONFIG_CPU_SUP_AMD
> +extern void set_dr_addr_mask(unsigned long mask, int dr);
> +#else
> +static inline void set_dr_addr_mask(unsigned long mask, int dr) { }
> +#endif

I see this symbol in the code but it's not defined anywhere in a Kconfig file.
Maybe you (or I) forgot to include a file in your patches?

Thanks.