PM: QoS: Simplify definitions of CPU latency QoS trace events

Modify the definitions of the CPU latency QoS trace events to take
one argument (since PM_QOS_CPU_DMA_LATENCY is always passed as the
pm_qos_class argument to them) and update the documentation of them
accordingly (while at it, make it explicitly mention CPU latency QoS
and relocate it after the device PM QoS trace events documentation).

The names and output format of the trace events do not change to
preserve user space compatibility.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <[e-mail]>
Reviewed-by: Ulf Hansson <[e-mail]>
Reviewed-by: Amit Kucheria <[e-mail]>
Tested-by: Amit Kucheria <[e-mail]>

Documentation/trace/events-power.rst

···
 target/flags update.
 ::
 
-  pm_qos_add_request                 "pm_qos_class=%s value=%d"
-  pm_qos_update_request              "pm_qos_class=%s value=%d"
-  pm_qos_remove_request              "pm_qos_class=%s value=%d"
-
-The first parameter gives the QoS class name (e.g. "CPU_DMA_LATENCY").
-The second parameter is value to be added/updated/removed.
-::
-
   pm_qos_update_target               "action=%s prev_value=%d curr_value=%d"
   pm_qos_update_flags                "action=%s prev_value=0x%x curr_value=0x%x"
 
···
 The second parameter is the previous QoS value.
 The third parameter is the current QoS value to update.
 
-And, there are also events used for device PM QoS add/update/remove request.
+There are also events used for device PM QoS add/update/remove request.
 ::
 
   dev_pm_qos_add_request             "device=%s type=%s new_value=%d"
···
 QoS requests.
 The second parameter gives the request type (e.g. "DEV_PM_QOS_RESUME_LATENCY").
 The third parameter is value to be added/updated/removed.
+
+And, there are events used for CPU latency QoS add/update/remove request.
+::
+
+  pm_qos_add_request        "value=%d"
+  pm_qos_update_request     "value=%d"
+  pm_qos_remove_request     "value=%d"
+
+The parameter is the value to be added/updated/removed.

include/trace/events/power.h

···
 );
 
 /*
- * The pm qos events are used for pm qos update
+ * CPU latency QoS events used for global CPU latency QoS list updates
  */
-DECLARE_EVENT_CLASS(pm_qos_request,
+DECLARE_EVENT_CLASS(cpu_latency_qos_request,
 
-	TP_PROTO(int pm_qos_class, s32 value),
+	TP_PROTO(s32 value),
 
-	TP_ARGS(pm_qos_class, value),
+	TP_ARGS(value),
 
 	TP_STRUCT__entry(
-		__field( int,                    pm_qos_class   )
 		__field( s32,                    value          )
 	),
 
 	TP_fast_assign(
-		__entry->pm_qos_class = pm_qos_class;
 		__entry->value = value;
 	),
 
-	TP_printk("pm_qos_class=%s value=%d",
-		  __print_symbolic(__entry->pm_qos_class,
-			{ PM_QOS_CPU_DMA_LATENCY,	"CPU_DMA_LATENCY" }),
+	TP_printk("CPU_DMA_LATENCY value=%d",
 		  __entry->value)
 );
 
-DEFINE_EVENT(pm_qos_request, pm_qos_add_request,
+DEFINE_EVENT(cpu_latency_qos_request, pm_qos_add_request,
 
-	TP_PROTO(int pm_qos_class, s32 value),
+	TP_PROTO(s32 value),
 
-	TP_ARGS(pm_qos_class, value)
+	TP_ARGS(value)
 );
 
-DEFINE_EVENT(pm_qos_request, pm_qos_update_request,
+DEFINE_EVENT(cpu_latency_qos_request, pm_qos_update_request,
 
-	TP_PROTO(int pm_qos_class, s32 value),
+	TP_PROTO(s32 value),
 
-	TP_ARGS(pm_qos_class, value)
+	TP_ARGS(value)
 );
 
-DEFINE_EVENT(pm_qos_request, pm_qos_remove_request,
+DEFINE_EVENT(cpu_latency_qos_request, pm_qos_remove_request,
 
-	TP_PROTO(int pm_qos_class, s32 value),
+	TP_PROTO(s32 value),
 
-	TP_ARGS(pm_qos_class, value)
+	TP_ARGS(value)
 );
 
+/*
+ * General PM QoS events used for updates of PM QoS request lists
+ */
 DECLARE_EVENT_CLASS(pm_qos_update,
 
 	TP_PROTO(enum pm_qos_req_action action, int prev_value, int curr_value),

kernel/power/qos.c

···
 }
 EXPORT_SYMBOL_GPL(pm_qos_request_active);
 
-static void cpu_latency_qos_update(struct pm_qos_request *req,
-				   enum pm_qos_req_action action, s32 value)
+static void cpu_latency_qos_apply(struct pm_qos_request *req,
+				  enum pm_qos_req_action action, s32 value)
 {
 	int ret = pm_qos_update_target(req->qos, &req->node, action, value);
 	if (ret > 0)
···
 		return;
 	}
 
-	trace_pm_qos_add_request(PM_QOS_CPU_DMA_LATENCY, value);
+	trace_pm_qos_add_request(value);
 
 	req->qos = &cpu_latency_constraints;
-	cpu_latency_qos_update(req, PM_QOS_ADD_REQ, value);
+	cpu_latency_qos_apply(req, PM_QOS_ADD_REQ, value);
 }
 EXPORT_SYMBOL_GPL(pm_qos_add_request);
 
···
 		return;
 	}
 
-	trace_pm_qos_update_request(PM_QOS_CPU_DMA_LATENCY, new_value);
+	trace_pm_qos_update_request(new_value);
 
 	if (new_value == req->node.prio)
 		return;
 
-	cpu_latency_qos_update(req, PM_QOS_UPDATE_REQ, new_value);
+	cpu_latency_qos_apply(req, PM_QOS_UPDATE_REQ, new_value);
 }
 EXPORT_SYMBOL_GPL(pm_qos_update_request);
 
···
 		return;
 	}
 
-	trace_pm_qos_remove_request(PM_QOS_CPU_DMA_LATENCY, PM_QOS_DEFAULT_VALUE);
+	trace_pm_qos_remove_request(PM_QOS_DEFAULT_VALUE);
 
-	cpu_latency_qos_update(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
+	cpu_latency_qos_apply(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
 	memset(req, 0, sizeof(*req));
 }
 EXPORT_SYMBOL_GPL(pm_qos_remove_request);