path: root/arch
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authorMichael Ellerman <michael@ellerman.id.au>2013-04-25 19:28:23 (GMT)
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2013-04-26 06:11:07 (GMT)
commit7a7868326d77416018e8f3b4c4697a3c57444549 (patch)
tree168f28c65ea7b92080c0dec5b68b8896744dc40e /arch
parent240686c1368775b5dc80aae863301189b25f9bfa (diff)
powerpc/perf: Add an explict flag indicating presence of SLOT field
In perf_ip_adjust() we potentially use the MMCRA[SLOT] field to adjust the reported IP of a sampled instruction. Currently the logic is written so that if the backend does NOT have the PPMU_ALT_SIPR flag set then we assume MMCRA[SLOT] exists. However on power8 we do not want to set ALT_SIPR (it's in a third location), and we also do not have MMCRA[SLOT]. So add a new flag which only indicates whether MMCRA[SLOT] exists. Naively we'd set it on everything except power6/7, because they set ALT_SIPR, and we've reversed the polarity of the flag. But it's more complicated than that. mpc7450 is 32-bit, and uses its own version of perf_ip_adjust() which doesn't use MMCRA[SLOT], so it doesn't need the new flag set and the behaviour is unchanged. PPC970 (and I assume power4) don't have MMCRA[SLOT], so shouldn't have the new flag set. This is a behaviour change on those cpus, though we were probably getting lucky and the bits in question were 0. power5 and power5+ set the new flag, behaviour unchanged. power6 & power7 do not set the new flag, behaviour unchanged. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch')
4 files changed, 5 insertions, 2 deletions
diff --git a/arch/powerpc/include/asm/perf_event_server.h b/arch/powerpc/include/asm/perf_event_server.h
index d0aec72..7074aec 100644
--- a/arch/powerpc/include/asm/perf_event_server.h
+++ b/arch/powerpc/include/asm/perf_event_server.h
@@ -52,6 +52,7 @@ struct power_pmu {
#define PPMU_NO_SIPR 0x00000004 /* no SIPR/HV in MMCRA at all */
#define PPMU_NO_CONT_SAMPLING 0x00000008 /* no continuous sampling */
#define PPMU_SIAR_VALID 0x00000010 /* Processor has SIAR Valid bit */
+#define PPMU_HAS_SSLOT 0x00000020 /* Has sampled slot in MMCRA */
* Values for flags to get_alternatives()
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index 65362e9..eb64480 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -98,11 +98,12 @@ static inline unsigned long perf_ip_adjust(struct pt_regs *regs)
unsigned long mmcra = regs->dsisr;
- if ((mmcra & MMCRA_SAMPLE_ENABLE) && !(ppmu->flags & PPMU_ALT_SIPR)) {
+ if ((ppmu->flags & PPMU_HAS_SSLOT) && (mmcra & MMCRA_SAMPLE_ENABLE)) {
unsigned long slot = (mmcra & MMCRA_SLOT) >> MMCRA_SLOT_SHIFT;
if (slot > 1)
return 4 * (slot - 1);
return 0;
diff --git a/arch/powerpc/perf/power5+-pmu.c b/arch/powerpc/perf/power5+-pmu.c
index a8757ba..b03b6dc 100644
--- a/arch/powerpc/perf/power5+-pmu.c
+++ b/arch/powerpc/perf/power5+-pmu.c
@@ -671,7 +671,7 @@ static struct power_pmu power5p_pmu = {
.get_alternatives = power5p_get_alternatives,
.disable_pmc = power5p_disable_pmc,
.limited_pmc_event = power5p_limited_pmc_event,
- .flags = PPMU_LIMITED_PMC5_6,
.n_generic = ARRAY_SIZE(power5p_generic_events),
.generic_events = power5p_generic_events,
.cache_events = &power5p_cache_events,
diff --git a/arch/powerpc/perf/power5-pmu.c b/arch/powerpc/perf/power5-pmu.c
index e7f06eb..1e8ce42 100644
--- a/arch/powerpc/perf/power5-pmu.c
+++ b/arch/powerpc/perf/power5-pmu.c
@@ -615,6 +615,7 @@ static struct power_pmu power5_pmu = {
.n_generic = ARRAY_SIZE(power5_generic_events),
.generic_events = power5_generic_events,
.cache_events = &power5_cache_events,
+ .flags = PPMU_HAS_SSLOT,
static int __init init_power5_pmu(void)

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