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perf/x86/amd: AMD support for bp_len > HW_BREAKPOINT_LEN_8

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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>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: xiakaixu <xiakaixu@huawei.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
This commit is contained in:
Jacob Shin 2014-05-29 17:26:50 +02:00 committed by Frederic Weisbecker
parent 4e6e311e59
commit d6d55f0b9d
6 changed files with 47 additions and 4 deletions
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2
arch/x86/include/asm/cpufeature.h
View file

@ -174,6 +174,7 @@
#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 */
/*
@ -383,6 +384,7 @@ extern const char * const x86_bug_flags[NBUGINTS*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)
#if __GNUC__ >= 4
extern void warn_pre_alternatives(void);

5
arch/x86/include/asm/debugreg.h
View file

@ -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
#endif /* _ASM_X86_DEBUGREG_H */

1
arch/x86/include/asm/hw_breakpoint.h
View file

@ -12,6 +12,7 @@
*/
struct arch_hw_breakpoint {
unsigned long address;
unsigned long mask;
u8 len;
u8 type;
};

4
arch/x86/include/uapi/asm/msr-index.h
View file

@ -212,6 +212,10 @@
/* Fam 16h MSRs */
#define MSR_F16H_L2I_PERF_CTL 0xc0010230
#define MSR_F16H_L2I_PERF_CTR 0xc0010231
#define MSR_F16H_DR1_ADDR_MASK 0xc0011019
#define MSR_F16H_DR2_ADDR_MASK 0xc001101a
#define MSR_F16H_DR3_ADDR_MASK 0xc001101b
#define MSR_F16H_DR0_ADDR_MASK 0xc0011027
/* Fam 15h MSRs */
#define MSR_F15H_PERF_CTL 0xc0010200

19
arch/x86/kernel/cpu/amd.c
View file

@ -870,3 +870,22 @@ static bool cpu_has_amd_erratum(struct cpuinfo_x86 *cpu, const int *erratum)
return false;
}
void set_dr_addr_mask(unsigned long mask, int dr)
{
if (!cpu_has_bpext)
return;
switch (dr) {
case 0:
wrmsr(MSR_F16H_DR0_ADDR_MASK, mask, 0);
break;
case 1:
case 2:
case 3:
wrmsr(MSR_F16H_DR1_ADDR_MASK - 1 + dr, mask, 0);
break;
default:
break;
}
}

20
arch/x86/kernel/hw_breakpoint.c
View file

@ -126,6 +126,8 @@ int arch_install_hw_breakpoint(struct perf_event *bp)
*dr7 |= encode_dr7(i, info->len, info->type);
set_debugreg(*dr7, 7);
if (info->mask)
set_dr_addr_mask(info->mask, i);
return 0;
}
@ -161,6 +163,8 @@ void arch_uninstall_hw_breakpoint(struct perf_event *bp)
*dr7 &= ~__encode_dr7(i, info->len, info->type);
set_debugreg(*dr7, 7);
if (info->mask)
set_dr_addr_mask(0, i);
}
static int get_hbp_len(u8 hbp_len)
@ -277,6 +281,8 @@ static int arch_build_bp_info(struct perf_event *bp)
}
/* Len */
info->mask = 0;
switch (bp->attr.bp_len) {
case HW_BREAKPOINT_LEN_1:
info->len = X86_BREAKPOINT_LEN_1;
@ -293,11 +299,17 @@ static int arch_build_bp_info(struct perf_event *bp)
break;
#endif
default:
return -EINVAL;
if (!is_power_of_2(bp->attr.bp_len))
return -EINVAL;
if (!cpu_has_bpext)
return -EOPNOTSUPP;
info->mask = bp->attr.bp_len - 1;
info->len = X86_BREAKPOINT_LEN_1;
}
return 0;
}
/*
* Validate the arch-specific HW Breakpoint register settings
*/
@ -312,11 +324,11 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp)
if (ret)
return ret;
ret = -EINVAL;
switch (info->len) {
case X86_BREAKPOINT_LEN_1:
align = 0;
if (info->mask)
align = info->mask;
break;
case X86_BREAKPOINT_LEN_2:
align = 1;
@ -330,7 +342,7 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp)
break;
#endif
default:
return ret;
WARN_ON_ONCE(1);
}
/*