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| author | Martin Fuzzey <mfuzzey@parkeon.com> | 2016-01-13 23:36:26 -0500 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2016-01-25 18:37:44 +0000 |
| commit | 8d1a0ae724ad74ef7946a45e3b2d3e01f39df02b (patch) | |
| tree | 95c4e633c5ef8ae16bd3233ecee9f5e1e2b66623 /arch | |
| parent | 92e963f50fc74041b5e9e744c330dca48e04f08d (diff) | |
| download | linux-8d1a0ae724ad74ef7946a45e3b2d3e01f39df02b.tar.bz2 | |
ARM: perf: Set ARMv7 SDER SUNIDEN bit
ARMv7 counters other than the CPU cycle counter only work if the Secure
Debug Enable Register (SDER) SUNIDEN bit is set.
Since access to the SDER is only possible in secure state, it will
only be done if the device tree property "secure-reg-access" is set.
Without this:
Performance counter stats for 'sleep 1':
14606094 cycles # 0.000 GHz
0 instructions # 0.00 insns per cycle
After applying:
Performance counter stats for 'sleep 1':
5843809 cycles
2566484 instructions # 0.44 insns per cycle
1.020144000 seconds time elapsed
Some platforms (eg i.MX53) may also need additional platform specific
setup.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Martin Fuzzey <mfuzzey@parkeon.com>
Signed-off-by: Pooya Keshavarzi <Pooya.Keshavarzi@de.bosch.com>
Signed-off-by: George G. Davis <george_davis@mentor.com>
[will: add warning if property is found on arm64]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/kernel/perf_event_v7.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/arch/arm/kernel/perf_event_v7.c b/arch/arm/kernel/perf_event_v7.c index 4152158f6e6a..15063851cd10 100644 --- a/arch/arm/kernel/perf_event_v7.c +++ b/arch/arm/kernel/perf_event_v7.c @@ -712,6 +712,11 @@ static const struct attribute_group *armv7_pmuv2_attr_groups[] = { #define ARMV7_EXCLUDE_USER (1 << 30) #define ARMV7_INCLUDE_HYP (1 << 27) +/* + * Secure debug enable reg + */ +#define ARMV7_SDER_SUNIDEN BIT(1) /* Permit non-invasive debug */ + static inline u32 armv7_pmnc_read(void) { u32 val; @@ -1094,7 +1099,13 @@ static int armv7pmu_set_event_filter(struct hw_perf_event *event, static void armv7pmu_reset(void *info) { struct arm_pmu *cpu_pmu = (struct arm_pmu *)info; - u32 idx, nb_cnt = cpu_pmu->num_events; + u32 idx, nb_cnt = cpu_pmu->num_events, val; + + if (cpu_pmu->secure_access) { + asm volatile("mrc p15, 0, %0, c1, c1, 1" : "=r" (val)); + val |= ARMV7_SDER_SUNIDEN; + asm volatile("mcr p15, 0, %0, c1, c1, 1" : : "r" (val)); + } /* The counter and interrupt enable registers are unknown at reset. */ for (idx = ARMV7_IDX_CYCLE_COUNTER; idx < nb_cnt; ++idx) { |