coresight: etm4x: Remove redundant checks in PM save and restore

ETMv4 driver save/restore callbacks still re-check conditions that are
already validated by the core layer before the callbacks are invoked.

Remove the duplicated checks and fold the two-level functions into
direct callback implementations.  The obsolete WARN_ON() checks are
removed as well.

Reviewed-by: Mike Leach <mike.leach@linaro.org>
Tested-by: James Clark <james.clark@linaro.org>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Reviewed-by: James Clark <james.clark@linaro.org>
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-v14-13-f88c4a3ecfe9@arm.com

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 5cd70f0f3710a5ec6406a89c034d30230f782b13..fef1270439e9d770fc0459e9ab8cab7cb40827ee 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -1853,17 +1853,14 @@ static inline bool etm4_pm_save_needed(struct etmv4_drvdata *drvdata)
        return !!drvdata->save_state;
 }
 
-static int __etm4_cpu_save(struct etmv4_drvdata *drvdata)
+static int etm4_cpu_save(struct coresight_device *csdev)
 {
        int i, ret = 0;
+       struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
        struct etmv4_save_state *state;
-       struct coresight_device *csdev = drvdata->csdev;
        struct csdev_access *csa;
        struct device *etm_dev;
 
-       if (WARN_ON(!csdev))
-               return -ENODEV;
-
        etm_dev = &csdev->dev;
        csa = &csdev->access;
 
@@ -1995,32 +1992,13 @@ out:
        return ret;
 }
 
-static int etm4_cpu_save(struct coresight_device *csdev)
-{
-       struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
-       int ret = 0;
-
-       if (!etm4_pm_save_needed(drvdata))
-               return 0;
-
-       /*
-        * Save and restore the ETM Trace registers only if
-        * the ETM is active.
-        */
-       if (coresight_get_mode(drvdata->csdev))
-               ret = __etm4_cpu_save(drvdata);
-       return ret;
-}
-
-static void __etm4_cpu_restore(struct etmv4_drvdata *drvdata)
+static void etm4_cpu_restore(struct coresight_device *csdev)
 {
        int i;
+       struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
        struct etmv4_save_state *state = drvdata->save_state;
        struct csdev_access *csa = &drvdata->csdev->access;
 
-       if (WARN_ON(!drvdata->csdev))
-               return;
-
        etm4_cs_unlock(drvdata, csa);
        etm4x_relaxed_write32(csa, state->trcclaimset, TRCCLAIMSET);
 
@@ -2113,17 +2091,6 @@ static void __etm4_cpu_restore(struct etmv4_drvdata *drvdata)
        etm4_cs_lock(drvdata, csa);
 }
 
-static void etm4_cpu_restore(struct coresight_device *csdev)
-{
-       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 const struct coresight_ops etm4_cs_ops = {
        .trace_id       = coresight_etm_get_trace_id,
        .source_ops     = &etm4_source_ops,