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coresight: etm4x: Hook CPU PM callbacks

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Add a helper etm4_pm_save_needed() to detect if need save context for
self-hosted PM mode and hook pm_save_disable() and pm_restore_enable()
callbacks through etm4_cs_pm_ops structure.  With this, ETMv4 PM
save/restore is integrated into the core layer's CPU PM.

Organize etm4_cs_ops and etm4_cs_pm_ops together for more readable.

The CPU PM notifier in the ETMv4 driver is no longer needed, remove it
along with its registration and unregistration code.

Reviewed-by: James Clark <james.clark@linaro.org>
Tested-by: James Clark <james.clark@linaro.org>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Tested-by: Jie Gan <jie.gan@oss.qualcomm.com>
Signed-off-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20260515-arm_coresight_path_power_management_improvement-v14-12-f88c4a3ecfe9@arm.com
This commit is contained in:
Leo Yan
2026-05-15 21:08:19 +01:00
committed by Suzuki K Poulose
parent 4d8dd98ee5
commit 0f5e588c70
1 changed files with 23 additions and 50 deletions
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73
drivers/hwtracing/coresight/coresight-etm4x-core.c
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@@ -1195,11 +1195,6 @@ static const struct coresight_ops_source etm4_source_ops = {
.pause_perf = etm4_pause_perf,
};
static const struct coresight_ops etm4_cs_ops = {
.trace_id = coresight_etm_get_trace_id,
.source_ops = &etm4_source_ops,
};
static bool cpu_supports_sysreg_trace(void)
{
u64 dfr0 = read_sysreg_s(SYS_ID_AA64DFR0_EL1);
@@ -1853,6 +1848,11 @@ static int etm4_dying_cpu(unsigned int cpu)
return 0;
}
static inline bool etm4_pm_save_needed(struct etmv4_drvdata *drvdata)
{
return !!drvdata->save_state;
}
static int __etm4_cpu_save(struct etmv4_drvdata *drvdata)
{
int i, ret = 0;
@@ -1995,11 +1995,12 @@ static int __etm4_cpu_save(struct etmv4_drvdata *drvdata)
return ret;
}
static int etm4_cpu_save(struct etmv4_drvdata *drvdata)
static int etm4_cpu_save(struct coresight_device *csdev)
{
struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
int ret = 0;
if (!drvdata->save_state)
if (!etm4_pm_save_needed(drvdata))
return 0;
/*
@@ -2112,47 +2113,27 @@ static void __etm4_cpu_restore(struct etmv4_drvdata *drvdata)
etm4_cs_lock(drvdata, csa);
}
static void etm4_cpu_restore(struct etmv4_drvdata *drvdata)
static void etm4_cpu_restore(struct coresight_device *csdev)
{
if (!drvdata->save_state)
struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
if (!etm4_pm_save_needed(drvdata))
return;
if (coresight_get_mode(drvdata->csdev))
__etm4_cpu_restore(drvdata);
}
static int etm4_cpu_pm_notify(struct notifier_block *nb, unsigned long cmd,
void *v)
{
struct etmv4_drvdata *drvdata;
unsigned int cpu = smp_processor_id();
static const struct coresight_ops etm4_cs_ops = {
.trace_id = coresight_etm_get_trace_id,
.source_ops = &etm4_source_ops,
};
if (!etmdrvdata[cpu])
return NOTIFY_OK;
drvdata = etmdrvdata[cpu];
if (WARN_ON_ONCE(drvdata->cpu != cpu))
return NOTIFY_BAD;
switch (cmd) {
case CPU_PM_ENTER:
if (etm4_cpu_save(drvdata))
return NOTIFY_BAD;
break;
case CPU_PM_EXIT:
case CPU_PM_ENTER_FAILED:
etm4_cpu_restore(drvdata);
break;
default:
return NOTIFY_DONE;
}
return NOTIFY_OK;
}
static struct notifier_block etm4_cpu_pm_nb = {
.notifier_call = etm4_cpu_pm_notify,
static const struct coresight_ops etm4_cs_pm_ops = {
.trace_id = coresight_etm_get_trace_id,
.source_ops = &etm4_source_ops,
.pm_save_disable = etm4_cpu_save,
.pm_restore_enable = etm4_cpu_restore,
};
/* Setup PM. Deals with error conditions and counts */
@@ -2160,16 +2141,12 @@ static int __init etm4_pm_setup(void)
{
int ret;
ret = cpu_pm_register_notifier(&etm4_cpu_pm_nb);
if (ret)
return ret;
ret = cpuhp_setup_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING,
"arm/coresight4:starting",
etm4_starting_cpu, etm4_dying_cpu);
if (ret)
goto unregister_notifier;
return ret;
ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
"arm/coresight4:online",
@@ -2183,15 +2160,11 @@ static int __init etm4_pm_setup(void)
/* failed dyn state - remove others */
cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING);
unregister_notifier:
cpu_pm_unregister_notifier(&etm4_cpu_pm_nb);
return ret;
}
static void etm4_pm_clear(void)
{
cpu_pm_unregister_notifier(&etm4_cpu_pm_nb);
cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING);
if (hp_online) {
cpuhp_remove_state_nocalls(hp_online);
@@ -2270,7 +2243,7 @@ static int etm4_add_coresight_dev(struct etm4_init_arg *init_arg)
desc.type = CORESIGHT_DEV_TYPE_SOURCE;
desc.subtype.source_subtype = CORESIGHT_DEV_SUBTYPE_SOURCE_PROC;
desc.ops = &etm4_cs_ops;
desc.ops = etm4_pm_save_needed(drvdata) ? &etm4_cs_pm_ops : &etm4_cs_ops;
desc.pdata = pdata;
desc.dev = dev;
desc.groups = coresight_etmv4_groups;