drivers: firmware: pmu_vendor: add cmd to enable tracing

Update pmu_vendor protocol to include a command to enable
tracing on cpucp to improve debugging.

Change-Id: I1210df14bd98a22f8fde74f27fb88b577b5c1f8b
Signed-off-by: Amir Vajid <avajid@codeaurora.org>

drivers/firmware/arm_scmi/pmu_vendor.c

@@ -6,7 +6,10 @@
 #include "common.h"
 #include <linux/scmi_pmu.h>
 
-#define SET_PMU_MAP		11
+enum scmi_c1dcvs_protocol_cmd {
+	SET_PMU_MAP = 11,
+	SET_ENABLE_TRACE,
+};
 
 struct pmu_map_msg {
 	uint8_t hw_cntrs[MAX_NUM_CPUS][MAX_CPUCP_EVT];
@@ -36,13 +39,39 @@ static int scmi_send_pmu_map(const struct scmi_protocol_handle *ph,
 	return ret;
 }
 
+static int scmi_send_tunable_pmu(const struct scmi_protocol_handle *ph,
+				    void *buf, u32 msg_id)
+{
+	int ret;
+	struct scmi_xfer *t;
+	unsigned int *msg;
+	unsigned int *src = buf;
+
+	ret = ph->xops->xfer_get_init(ph, msg_id, sizeof(*msg), sizeof(*msg),
+				      &t);
+	if (ret)
+		return ret;
+
+	msg = t->tx.buf;
+	*msg = cpu_to_le32(*src);
+	ret = ph->xops->do_xfer(ph, t);
+	ph->xops->xfer_put(ph, t);
+	return ret;
+}
+
 static int scmi_pmu_map(const struct scmi_protocol_handle *ph, void *buf)
 {
 	return scmi_send_pmu_map(ph, buf, SET_PMU_MAP);
 }
 
+static int scmi_set_enable_trace(const struct scmi_protocol_handle *ph, void *buf)
+{
+	return scmi_send_tunable_pmu(ph, buf, SET_ENABLE_TRACE);
+}
+
 static struct scmi_pmu_vendor_ops pmu_config_ops = {
-	.set_pmu_map = scmi_pmu_map,
+	.set_pmu_map		= scmi_pmu_map,
+	.set_enable_trace	= scmi_set_enable_trace,
 };
 
 static int scmi_pmu_protocol_init(const struct scmi_protocol_handle *ph)

drivers/soc/qcom/dcvs/pmu_lib.c

@@ -75,6 +75,8 @@ static DEFINE_SPINLOCK(idle_list_lock);
 static struct cpucp_hlos_map cpucp_map[MAX_CPUCP_EVT];
 static struct kobject pmu_kobj;
 static bool pmu_counters_enabled = true;
+static unsigned int pmu_enable_trace;
+
 /*
  * is_amu_valid: Check if AMUs are supported and if the id corresponds to the
  * four supported AMU counters i.e. SYS_AMEVCNTR0_CONST_EL0,
@@ -957,7 +959,7 @@ struct qcom_pmu_attr {
 
 #define to_pmu_attr(_attr) \
 	container_of(_attr, struct qcom_pmu_attr, attr)
-#define PERF_ATTR_RW(_name)			\
+#define PMU_ATTR_RW(_name)			\
 static struct qcom_pmu_attr _name =		\
 __ATTR(_name, 0644, show_##_name, store_##_name)\
 
@@ -981,9 +983,40 @@ static ssize_t store_enable_counters(struct kobject *kobj,
 	return count;
 }
 
-PERF_ATTR_RW(enable_counters);
+static ssize_t show_enable_trace(struct kobject *kobj,
+				    struct attribute *attr, char *buf)
+{
+	return scnprintf(buf, PAGE_SIZE, "%u\n", pmu_enable_trace);
+}
+
+static ssize_t store_enable_trace(struct kobject *kobj,
+				     struct attribute *attr, const char *buf,
+				     size_t count)
+{
+	unsigned int var;
+	int ret;
+
+	if (!ops)
+		return -ENODEV;
+
+	ret = kstrtouint(buf, 10, &var);
+	if (ret < 0)
+		return ret;
+
+	ret = ops->set_enable_trace(ph, &var);
+	if (ret < 0)
+		return ret;
+
+	pmu_enable_trace = var;
+
+	return count;
+}
+
+PMU_ATTR_RW(enable_counters);
+PMU_ATTR_RW(enable_trace);
 static struct attribute *pmu_settings_attr[] = {
 	&enable_counters.attr,
+	&enable_trace.attr,
 	NULL,
 };
 

include/linux/scmi_pmu.h

@@ -38,5 +38,6 @@ struct scmi_protocol_handle;
  */
 struct scmi_pmu_vendor_ops {
 	int (*set_pmu_map)(const struct scmi_protocol_handle *ph, void *buf);
+	int (*set_enable_trace)(const struct scmi_protocol_handle *ph, void *buf);
 };
 #endif