Merge pull request #1154 from soby-mathew/sm/fix_psci_stat

Fix PSCI STAT time stamp collection

lib/psci/psci_common.c

@@ -767,12 +767,12 @@ void psci_warmboot_entrypoint(void)
 	psci_acquire_pwr_domain_locks(end_pwrlvl,
 				      cpu_idx);
 
+	psci_get_target_local_pwr_states(end_pwrlvl, &state_info);
+
 #if ENABLE_PSCI_STAT
 	plat_psci_stat_accounting_stop(&state_info);
 #endif
 
-	psci_get_target_local_pwr_states(end_pwrlvl, &state_info);
-
 	/*
 	 * This CPU could be resuming from suspend or it could have just been
 	 * turned on. To distinguish between these 2 cases, we examine the

lib/psci/psci_suspend.c

@@ -37,6 +37,11 @@ static void psci_suspend_to_standby_finisher(unsigned int cpu_idx,
 	 */
 	psci_get_target_local_pwr_states(end_pwrlvl, &state_info);
 
+#if ENABLE_PSCI_STAT
+	plat_psci_stat_accounting_stop(&state_info);
+	psci_stats_update_pwr_up(end_pwrlvl, &state_info);
+#endif
+
 	/*
 	 * Plat. management: Allow the platform to do operations
 	 * on waking up from retention.
@@ -236,10 +241,6 @@ exit:
 	    PMF_NO_CACHE_MAINT);
 #endif
 
-#if ENABLE_PSCI_STAT
-	plat_psci_stat_accounting_start(state_info);
-#endif
-
 	/*
 	 * We will reach here if only retention/standby states have been
 	 * requested at multiple power levels. This means that the cpu
@@ -247,11 +248,6 @@ exit:
 	 */
 	wfi();
 
-#if ENABLE_PSCI_STAT
-	plat_psci_stat_accounting_stop(state_info);
-	psci_stats_update_pwr_up(end_pwrlvl, state_info);
-#endif
-
 #if ENABLE_RUNTIME_INSTRUMENTATION
 	PMF_CAPTURE_TIMESTAMP(rt_instr_svc,
 	    RT_INSTR_EXIT_HW_LOW_PWR,

plat/common/plat_psci_common.c

@@ -18,6 +18,13 @@
 /* Ticks elapsed in one second by a signal of 1 MHz */
 #define MHZ_TICKS_PER_SEC 1000000
 
+/* Maximum time-stamp value read from architectural counters */
+#ifdef AARCH32
+#define MAX_TS	UINT32_MAX
+#else
+#define MAX_TS	UINT64_MAX
+#endif
+
 /* Following are used as ID's to capture time-stamp */
 #define PSCI_STAT_ID_ENTER_LOW_PWR		0
 #define PSCI_STAT_ID_EXIT_LOW_PWR		1
@@ -45,7 +52,7 @@ static u_register_t calc_stat_residency(unsigned long long pwrupts,
 	assert(residency_div);
 
 	if (pwrupts < pwrdnts)
-		res = UINT64_MAX - pwrdnts + pwrupts;
+		res = MAX_TS - pwrdnts + pwrupts;
 	else
 		res = pwrupts - pwrdnts;