Message ID | 20230818112051.594986-3-anshuman.khandual@arm.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | coresight: etm: Make cycle count threshold user configurable | expand |
On 18/08/2023 12:20, Anshuman Khandual wrote: > Cycle counting is enabled, when requested and supported but with a default > threshold value ETM_CYC_THRESHOLD_DEFAULT i.e 0x100 getting into TRCCCCTLR, > representing the minimum interval between cycle count trace packets. > > This makes cycle threshold user configurable, from the user space via perf > event attributes. Although it falls back using ETM_CYC_THRESHOLD_DEFAULT, > in case no explicit request. As expected it creates a sysfs file as well. > > /sys/bus/event_source/devices/cs_etm/format/cc_threshold > > New 'cc_threshold' uses 'event->attr.config3' as no more space is available > in 'event->attr.config1' or 'event->attr.config2'. > > Cc: Suzuki K Poulose <suzuki.poulose@arm.com> > Cc: Mike Leach <mike.leach@linaro.org> > Cc: James Clark <james.clark@arm.com> > Cc: Leo Yan <leo.yan@linaro.org> > Cc: coresight@lists.linaro.org > Cc: linux-arm-kernel@lists.infradead.org > Cc: linux-doc@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Reviewed-by: Mike Leach <mike.leach@linaro.org> > Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> > --- > drivers/hwtracing/coresight/coresight-etm-perf.c | 2 ++ > drivers/hwtracing/coresight/coresight-etm4x-core.c | 12 ++++++++++-- > 2 files changed, 12 insertions(+), 2 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c > index 5ca6278baff4..09f75dffae60 100644 > --- a/drivers/hwtracing/coresight/coresight-etm-perf.c > +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c > @@ -68,6 +68,7 @@ PMU_FORMAT_ATTR(preset, "config:0-3"); > PMU_FORMAT_ATTR(sinkid, "config2:0-31"); > /* config ID - set if a system configuration is selected */ > PMU_FORMAT_ATTR(configid, "config2:32-63"); > +PMU_FORMAT_ATTR(cc_threshold, "config3:0-11"); > > > /* > @@ -101,6 +102,7 @@ static struct attribute *etm_config_formats_attr[] = { > &format_attr_preset.attr, > &format_attr_configid.attr, > &format_attr_branch_broadcast.attr, > + &format_attr_cc_threshold.attr, > NULL, > }; > > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c > index 591fab73ee79..3193dafa7618 100644 > --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c > +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c > @@ -635,7 +635,7 @@ static int etm4_parse_event_config(struct coresight_device *csdev, > struct etmv4_config *config = &drvdata->config; > struct perf_event_attr *attr = &event->attr; > unsigned long cfg_hash; > - int preset; > + int preset, cc_threshold; > > /* Clear configuration from previous run */ > memset(config, 0, sizeof(struct etmv4_config)); > @@ -658,7 +658,15 @@ static int etm4_parse_event_config(struct coresight_device *csdev, > if (attr->config & BIT(ETM_OPT_CYCACC)) { > config->cfg |= TRCCONFIGR_CCI; > /* TRM: Must program this for cycacc to work */ > - config->ccctlr = ETM_CYC_THRESHOLD_DEFAULT; > + cc_threshold = attr->config3 & ETM_CYC_THRESHOLD_MASK; > + if (cc_threshold) { > + if (cc_threshold < drvdata->ccitmin) > + config->ccctlr = drvdata->ccitmin; > + else > + config->ccctlr = cc_threshold; > + } else { > + config->ccctlr = ETM_CYC_THRESHOLD_DEFAULT; Ideally this must be the ccitmin ? Theoretically, default value could be bigger than the minimum value supported by the implementation (i.e., ccitmin) Suzuki > + } > } > if (attr->config & BIT(ETM_OPT_TS)) { > /*
On Fri, 18 Aug 2023 at 12:25, Suzuki K Poulose <suzuki.poulose@arm.com> wrote: > > On 18/08/2023 12:20, Anshuman Khandual wrote: > > Cycle counting is enabled, when requested and supported but with a default > > threshold value ETM_CYC_THRESHOLD_DEFAULT i.e 0x100 getting into TRCCCCTLR, > > representing the minimum interval between cycle count trace packets. > > > > This makes cycle threshold user configurable, from the user space via perf > > event attributes. Although it falls back using ETM_CYC_THRESHOLD_DEFAULT, > > in case no explicit request. As expected it creates a sysfs file as well. > > > > /sys/bus/event_source/devices/cs_etm/format/cc_threshold > > > > New 'cc_threshold' uses 'event->attr.config3' as no more space is available > > in 'event->attr.config1' or 'event->attr.config2'. > > > > Cc: Suzuki K Poulose <suzuki.poulose@arm.com> > > Cc: Mike Leach <mike.leach@linaro.org> > > Cc: James Clark <james.clark@arm.com> > > Cc: Leo Yan <leo.yan@linaro.org> > > Cc: coresight@lists.linaro.org > > Cc: linux-arm-kernel@lists.infradead.org > > Cc: linux-doc@vger.kernel.org > > Cc: linux-kernel@vger.kernel.org > > Reviewed-by: Mike Leach <mike.leach@linaro.org> > > Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> > > --- > > drivers/hwtracing/coresight/coresight-etm-perf.c | 2 ++ > > drivers/hwtracing/coresight/coresight-etm4x-core.c | 12 ++++++++++-- > > 2 files changed, 12 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c > > index 5ca6278baff4..09f75dffae60 100644 > > --- a/drivers/hwtracing/coresight/coresight-etm-perf.c > > +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c > > @@ -68,6 +68,7 @@ PMU_FORMAT_ATTR(preset, "config:0-3"); > > PMU_FORMAT_ATTR(sinkid, "config2:0-31"); > > /* config ID - set if a system configuration is selected */ > > PMU_FORMAT_ATTR(configid, "config2:32-63"); > > +PMU_FORMAT_ATTR(cc_threshold, "config3:0-11"); > > > > > > /* > > @@ -101,6 +102,7 @@ static struct attribute *etm_config_formats_attr[] = { > > &format_attr_preset.attr, > > &format_attr_configid.attr, > > &format_attr_branch_broadcast.attr, > > + &format_attr_cc_threshold.attr, > > NULL, > > }; > > > > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c > > index 591fab73ee79..3193dafa7618 100644 > > --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c > > +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c > > @@ -635,7 +635,7 @@ static int etm4_parse_event_config(struct coresight_device *csdev, > > struct etmv4_config *config = &drvdata->config; > > struct perf_event_attr *attr = &event->attr; > > unsigned long cfg_hash; > > - int preset; > > + int preset, cc_threshold; > > > > /* Clear configuration from previous run */ > > memset(config, 0, sizeof(struct etmv4_config)); > > @@ -658,7 +658,15 @@ static int etm4_parse_event_config(struct coresight_device *csdev, > > if (attr->config & BIT(ETM_OPT_CYCACC)) { > > config->cfg |= TRCCONFIGR_CCI; > > /* TRM: Must program this for cycacc to work */ > > - config->ccctlr = ETM_CYC_THRESHOLD_DEFAULT; > > + cc_threshold = attr->config3 & ETM_CYC_THRESHOLD_MASK; > > + if (cc_threshold) { > > + if (cc_threshold < drvdata->ccitmin) > > + config->ccctlr = drvdata->ccitmin; > > + else > > + config->ccctlr = cc_threshold; > > + } else { > > + config->ccctlr = ETM_CYC_THRESHOLD_DEFAULT; > > Ideally this must be the ccitmin ? Theoretically, default value could be > bigger than the minimum value supported by the implementation (i.e., > ccitmin) > > Suzuki > In order not to change existing behaviour unexpectedly this could be re-ordered... cc_threshold = attr->config3 & ETM_CYC_THRESHOLD_MASK; if (!cc_threshold) cc_threshold = ETM_CYC_THRESHOLD_DEFAULT; if (cc_threshold < drvdata->ccitmin) cc_threshold = drvdata->ccitmin config->ccctlr = cc_threshold; Mike > > + } > > } > > if (attr->config & BIT(ETM_OPT_TS)) { > > /* >
On 18/08/2023 14:01, Mike Leach wrote: > On Fri, 18 Aug 2023 at 12:25, Suzuki K Poulose <suzuki.poulose@arm.com> wrote: >> >> On 18/08/2023 12:20, Anshuman Khandual wrote: >>> Cycle counting is enabled, when requested and supported but with a default >>> threshold value ETM_CYC_THRESHOLD_DEFAULT i.e 0x100 getting into TRCCCCTLR, >>> representing the minimum interval between cycle count trace packets. >>> >>> This makes cycle threshold user configurable, from the user space via perf >>> event attributes. Although it falls back using ETM_CYC_THRESHOLD_DEFAULT, >>> in case no explicit request. As expected it creates a sysfs file as well. >>> >>> /sys/bus/event_source/devices/cs_etm/format/cc_threshold >>> >>> New 'cc_threshold' uses 'event->attr.config3' as no more space is available >>> in 'event->attr.config1' or 'event->attr.config2'. >>> >>> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> >>> Cc: Mike Leach <mike.leach@linaro.org> >>> Cc: James Clark <james.clark@arm.com> >>> Cc: Leo Yan <leo.yan@linaro.org> >>> Cc: coresight@lists.linaro.org >>> Cc: linux-arm-kernel@lists.infradead.org >>> Cc: linux-doc@vger.kernel.org >>> Cc: linux-kernel@vger.kernel.org >>> Reviewed-by: Mike Leach <mike.leach@linaro.org> >>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> >>> --- >>> drivers/hwtracing/coresight/coresight-etm-perf.c | 2 ++ >>> drivers/hwtracing/coresight/coresight-etm4x-core.c | 12 ++++++++++-- >>> 2 files changed, 12 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c >>> index 5ca6278baff4..09f75dffae60 100644 >>> --- a/drivers/hwtracing/coresight/coresight-etm-perf.c >>> +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c >>> @@ -68,6 +68,7 @@ PMU_FORMAT_ATTR(preset, "config:0-3"); >>> PMU_FORMAT_ATTR(sinkid, "config2:0-31"); >>> /* config ID - set if a system configuration is selected */ >>> PMU_FORMAT_ATTR(configid, "config2:32-63"); >>> +PMU_FORMAT_ATTR(cc_threshold, "config3:0-11"); >>> >>> >>> /* >>> @@ -101,6 +102,7 @@ static struct attribute *etm_config_formats_attr[] = { >>> &format_attr_preset.attr, >>> &format_attr_configid.attr, >>> &format_attr_branch_broadcast.attr, >>> + &format_attr_cc_threshold.attr, >>> NULL, >>> }; >>> >>> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c >>> index 591fab73ee79..3193dafa7618 100644 >>> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c >>> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c >>> @@ -635,7 +635,7 @@ static int etm4_parse_event_config(struct coresight_device *csdev, >>> struct etmv4_config *config = &drvdata->config; >>> struct perf_event_attr *attr = &event->attr; >>> unsigned long cfg_hash; >>> - int preset; >>> + int preset, cc_threshold; >>> >>> /* Clear configuration from previous run */ >>> memset(config, 0, sizeof(struct etmv4_config)); >>> @@ -658,7 +658,15 @@ static int etm4_parse_event_config(struct coresight_device *csdev, >>> if (attr->config & BIT(ETM_OPT_CYCACC)) { >>> config->cfg |= TRCCONFIGR_CCI; >>> /* TRM: Must program this for cycacc to work */ >>> - config->ccctlr = ETM_CYC_THRESHOLD_DEFAULT; >>> + cc_threshold = attr->config3 & ETM_CYC_THRESHOLD_MASK; >>> + if (cc_threshold) { >>> + if (cc_threshold < drvdata->ccitmin) >>> + config->ccctlr = drvdata->ccitmin; >>> + else >>> + config->ccctlr = cc_threshold; >>> + } else { >>> + config->ccctlr = ETM_CYC_THRESHOLD_DEFAULT; >> >> Ideally this must be the ccitmin ? Theoretically, default value could be >> bigger than the minimum value supported by the implementation (i.e., >> ccitmin) >> >> Suzuki >> > > In order not to change existing behaviour unexpectedly this could be > re-ordered... > > cc_threshold = attr->config3 & ETM_CYC_THRESHOLD_MASK; > if (!cc_threshold) > cc_threshold = ETM_CYC_THRESHOLD_DEFAULT; > if (cc_threshold < drvdata->ccitmin) > cc_threshold = drvdata->ccitmin > config->ccctlr = cc_threshold; That sounds better, Thanks Mike Suzuki > > Mike >>> + } >>> } >>> if (attr->config & BIT(ETM_OPT_TS)) { >>> /* >> > >
On 8/18/23 18:34, Suzuki K Poulose wrote: > On 18/08/2023 14:01, Mike Leach wrote: >> On Fri, 18 Aug 2023 at 12:25, Suzuki K Poulose <suzuki.poulose@arm.com> wrote: >>> >>> On 18/08/2023 12:20, Anshuman Khandual wrote: >>>> Cycle counting is enabled, when requested and supported but with a default >>>> threshold value ETM_CYC_THRESHOLD_DEFAULT i.e 0x100 getting into TRCCCCTLR, >>>> representing the minimum interval between cycle count trace packets. >>>> >>>> This makes cycle threshold user configurable, from the user space via perf >>>> event attributes. Although it falls back using ETM_CYC_THRESHOLD_DEFAULT, >>>> in case no explicit request. As expected it creates a sysfs file as well. >>>> >>>> /sys/bus/event_source/devices/cs_etm/format/cc_threshold >>>> >>>> New 'cc_threshold' uses 'event->attr.config3' as no more space is available >>>> in 'event->attr.config1' or 'event->attr.config2'. >>>> >>>> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> >>>> Cc: Mike Leach <mike.leach@linaro.org> >>>> Cc: James Clark <james.clark@arm.com> >>>> Cc: Leo Yan <leo.yan@linaro.org> >>>> Cc: coresight@lists.linaro.org >>>> Cc: linux-arm-kernel@lists.infradead.org >>>> Cc: linux-doc@vger.kernel.org >>>> Cc: linux-kernel@vger.kernel.org >>>> Reviewed-by: Mike Leach <mike.leach@linaro.org> >>>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> >>>> --- >>>> drivers/hwtracing/coresight/coresight-etm-perf.c | 2 ++ >>>> drivers/hwtracing/coresight/coresight-etm4x-core.c | 12 ++++++++++-- >>>> 2 files changed, 12 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c >>>> index 5ca6278baff4..09f75dffae60 100644 >>>> --- a/drivers/hwtracing/coresight/coresight-etm-perf.c >>>> +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c >>>> @@ -68,6 +68,7 @@ PMU_FORMAT_ATTR(preset, "config:0-3"); >>>> PMU_FORMAT_ATTR(sinkid, "config2:0-31"); >>>> /* config ID - set if a system configuration is selected */ >>>> PMU_FORMAT_ATTR(configid, "config2:32-63"); >>>> +PMU_FORMAT_ATTR(cc_threshold, "config3:0-11"); >>>> >>>> >>>> /* >>>> @@ -101,6 +102,7 @@ static struct attribute *etm_config_formats_attr[] = { >>>> &format_attr_preset.attr, >>>> &format_attr_configid.attr, >>>> &format_attr_branch_broadcast.attr, >>>> + &format_attr_cc_threshold.attr, >>>> NULL, >>>> }; >>>> >>>> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c >>>> index 591fab73ee79..3193dafa7618 100644 >>>> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c >>>> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c >>>> @@ -635,7 +635,7 @@ static int etm4_parse_event_config(struct coresight_device *csdev, >>>> struct etmv4_config *config = &drvdata->config; >>>> struct perf_event_attr *attr = &event->attr; >>>> unsigned long cfg_hash; >>>> - int preset; >>>> + int preset, cc_threshold; >>>> >>>> /* Clear configuration from previous run */ >>>> memset(config, 0, sizeof(struct etmv4_config)); >>>> @@ -658,7 +658,15 @@ static int etm4_parse_event_config(struct coresight_device *csdev, >>>> if (attr->config & BIT(ETM_OPT_CYCACC)) { >>>> config->cfg |= TRCCONFIGR_CCI; >>>> /* TRM: Must program this for cycacc to work */ >>>> - config->ccctlr = ETM_CYC_THRESHOLD_DEFAULT; >>>> + cc_threshold = attr->config3 & ETM_CYC_THRESHOLD_MASK; >>>> + if (cc_threshold) { >>>> + if (cc_threshold < drvdata->ccitmin) >>>> + config->ccctlr = drvdata->ccitmin; >>>> + else >>>> + config->ccctlr = cc_threshold; >>>> + } else { >>>> + config->ccctlr = ETM_CYC_THRESHOLD_DEFAULT; >>> >>> Ideally this must be the ccitmin ? Theoretically, default value could be >>> bigger than the minimum value supported by the implementation (i.e., >>> ccitmin) >>> >>> Suzuki >>> >> >> In order not to change existing behaviour unexpectedly this could be >> re-ordered... >> >> cc_threshold = attr->config3 & ETM_CYC_THRESHOLD_MASK; >> if (!cc_threshold) >> cc_threshold = ETM_CYC_THRESHOLD_DEFAULT; >> if (cc_threshold < drvdata->ccitmin) >> cc_threshold = drvdata->ccitmin >> config->ccctlr = cc_threshold; > > That sounds better, Thanks Mike Sure, will change as suggested.
diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c index 5ca6278baff4..09f75dffae60 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.c +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c @@ -68,6 +68,7 @@ PMU_FORMAT_ATTR(preset, "config:0-3"); PMU_FORMAT_ATTR(sinkid, "config2:0-31"); /* config ID - set if a system configuration is selected */ PMU_FORMAT_ATTR(configid, "config2:32-63"); +PMU_FORMAT_ATTR(cc_threshold, "config3:0-11"); /* @@ -101,6 +102,7 @@ static struct attribute *etm_config_formats_attr[] = { &format_attr_preset.attr, &format_attr_configid.attr, &format_attr_branch_broadcast.attr, + &format_attr_cc_threshold.attr, NULL, }; diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index 591fab73ee79..3193dafa7618 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -635,7 +635,7 @@ static int etm4_parse_event_config(struct coresight_device *csdev, struct etmv4_config *config = &drvdata->config; struct perf_event_attr *attr = &event->attr; unsigned long cfg_hash; - int preset; + int preset, cc_threshold; /* Clear configuration from previous run */ memset(config, 0, sizeof(struct etmv4_config)); @@ -658,7 +658,15 @@ static int etm4_parse_event_config(struct coresight_device *csdev, if (attr->config & BIT(ETM_OPT_CYCACC)) { config->cfg |= TRCCONFIGR_CCI; /* TRM: Must program this for cycacc to work */ - config->ccctlr = ETM_CYC_THRESHOLD_DEFAULT; + cc_threshold = attr->config3 & ETM_CYC_THRESHOLD_MASK; + if (cc_threshold) { + if (cc_threshold < drvdata->ccitmin) + config->ccctlr = drvdata->ccitmin; + else + config->ccctlr = cc_threshold; + } else { + config->ccctlr = ETM_CYC_THRESHOLD_DEFAULT; + } } if (attr->config & BIT(ETM_OPT_TS)) { /*