summaryrefslogtreecommitdiffstats
path: root/drivers
diff options
context:
space:
mode:
authorAnshuman Khandual <anshuman.khandual@arm.com>2023-09-21 05:36:30 +0200
committerSuzuki K Poulose <suzuki.poulose@arm.com>2023-11-16 12:35:06 +0100
commit94566c5b07744c7cf5c7cc0ad42b15996ba0b054 (patch)
treea5c652aac5e5d90c788aa156e4a842c54b9e6c8d /drivers
parentcoresight: etm: Override TRCIDR3.CCITMIN on errata affected cpus (diff)
downloadlinux-94566c5b07744c7cf5c7cc0ad42b15996ba0b054.tar.xz
linux-94566c5b07744c7cf5c7cc0ad42b15996ba0b054.zip
coresight: etm: Make cycle count threshold user configurable
When cycle counting is enabled, we use a default threshold value i.e 0x100 for the instruction trace cycle counting. This patch makes the cycle threshold user configurable via perf event attributes( 'cc_threshold' => event->attr.config3[11:0] ), falling back to the current default if unspecified. 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> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Link: https://lore.kernel.org/r/20230921033631.1298723-3-anshuman.khandual@arm.com
Diffstat (limited to 'drivers')
-rw-r--r--drivers/hwtracing/coresight/coresight-etm-perf.c2
-rw-r--r--drivers/hwtracing/coresight/coresight-etm4x-core.c9
2 files changed, 9 insertions, 2 deletions
diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index 89e8ed214ea4..a52cfcce25d6 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 5feb2bd41ee5..285539104bcc 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -644,7 +644,7 @@ 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));
@@ -667,7 +667,12 @@ 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)
+ cc_threshold = ETM_CYC_THRESHOLD_DEFAULT;
+ if (cc_threshold < drvdata->ccitmin)
+ cc_threshold = drvdata->ccitmin;
+ config->ccctlr = cc_threshold;
}
if (attr->config & BIT(ETM_OPT_TS)) {
/*