PSCI: Decouple PSCI stat residency calculation from PMF
This patch introduces the following three platform interfaces:
* void plat_psci_stat_accounting_start(const psci_power_state_t *state_info)
This is an optional hook that platforms can implement in order
to perform accounting before entering a low power state. This
typically involves capturing a timestamp.
* void plat_psci_stat_accounting_stop(const psci_power_state_t *state_info)
This is an optional hook that platforms can implement in order
to perform accounting after exiting from a low power state. This
typically involves capturing a timestamp.
* u_register_t plat_psci_stat_get_residency(unsigned int lvl,
const psci_power_state_t *state_info,
unsigned int last_cpu_index)
This is an optional hook that platforms can implement in order
to calculate the PSCI stat residency.
If any of these interfaces are overridden by the platform, it is
recommended that all of them are.
By default `ENABLE_PSCI_STAT` is disabled. If `ENABLE_PSCI_STAT`
is set but `ENABLE_PMF` is not set then an alternative PSCI stat
collection backend must be provided. If both are set, then default
weak definitions of these functions are provided, using PMF to
calculate the residency.
NOTE: Previously, platforms did not have to explicitly set
`ENABLE_PMF` since this was automatically done by the top-level
Makefile.
Change-Id: I17b47804dea68c77bc284df15ee1ccd66bc4b79b
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>
diff --git a/lib/psci/psci_stat.c b/lib/psci/psci_stat.c
index ecbe592..d8034a5 100644
--- a/lib/psci/psci_stat.c
+++ b/lib/psci/psci_stat.c
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
@@ -38,9 +38,6 @@
#define PLAT_MAX_PWR_LVL_STATES 2
#endif
-/* Ticks elapsed in one second by a signal of 1 MHz */
-#define MHZ_TICKS_PER_SEC 1000000
-
/* Following structure is used for PSCI STAT */
typedef struct psci_stat {
u_register_t residency;
@@ -62,28 +59,7 @@
static psci_stat_t psci_non_cpu_stat[PSCI_NUM_NON_CPU_PWR_DOMAINS]
[PLAT_MAX_PWR_LVL_STATES];
-/* Register PMF PSCI service */
-PMF_REGISTER_SERVICE(psci_svc, PMF_PSCI_STAT_SVC_ID,
- PSCI_STAT_TOTAL_IDS, PMF_STORE_ENABLE)
-
-/* The divisor to use to convert raw timestamp into microseconds */
-u_register_t residency_div;
-
/*
- * This macro calculates the stats residency in microseconds,
- * taking in account the wrap around condition.
- */
-#define calc_stat_residency(_pwrupts, _pwrdnts, _res) \
- do { \
- if (_pwrupts < _pwrdnts) \
- _res = UINT64_MAX - _pwrdnts + _pwrupts;\
- else \
- _res = _pwrupts - _pwrdnts; \
- /* Convert timestamp into microseconds */ \
- _res = _res/residency_div; \
- } while (0)
-
-/*
* This functions returns the index into the `psci_stat_t` array given the
* local power state and power domain level. If the platform implements the
* `get_pwr_lvl_state_idx` pm hook, then that will be used to return the index.
@@ -150,44 +126,23 @@
* It is called with caches enabled and locks acquired(for NON-CPU domain)
******************************************************************************/
void psci_stats_update_pwr_up(unsigned int end_pwrlvl,
- const psci_power_state_t *state_info,
- unsigned int flags)
+ const psci_power_state_t *state_info)
{
int parent_idx, cpu_idx = plat_my_core_pos();
int lvl, stat_idx;
plat_local_state_t local_state;
- unsigned long long pwrup_ts = 0, pwrdn_ts = 0;
u_register_t residency;
assert(end_pwrlvl <= PLAT_MAX_PWR_LVL);
assert(state_info);
- /* Initialize the residency divisor if not already initialized */
- if (!residency_div) {
- /* Pre-calculate divisor so that it can be directly used to
- convert time-stamp into microseconds */
- residency_div = read_cntfrq_el0() / MHZ_TICKS_PER_SEC;
- assert(residency_div);
- }
-
- /* Get power down time-stamp for current CPU */
- PMF_GET_TIMESTAMP_BY_INDEX(psci_svc, PSCI_STAT_ID_ENTER_LOW_PWR,
- cpu_idx, flags, pwrdn_ts);
-
- /* In the case of 1st power on just return */
- if (!pwrdn_ts)
- return;
-
- /* Get power up time-stamp for current CPU */
- PMF_GET_TIMESTAMP_BY_INDEX(psci_svc, PSCI_STAT_ID_EXIT_LOW_PWR,
- cpu_idx, flags, pwrup_ts);
-
/* Get the index into the stats array */
local_state = state_info->pwr_domain_state[PSCI_CPU_PWR_LVL];
stat_idx = get_stat_idx(local_state, PSCI_CPU_PWR_LVL);
- /* Calculate stats residency */
- calc_stat_residency(pwrup_ts, pwrdn_ts, residency);
+ /* Call into platform interface to calculate residency. */
+ residency = plat_psci_stat_get_residency(PSCI_CPU_PWR_LVL,
+ state_info, cpu_idx);
/* Update CPU stats. */
psci_cpu_stat[cpu_idx][stat_idx].residency += residency;
@@ -207,10 +162,9 @@
assert(last_cpu_in_non_cpu_pd[parent_idx] != -1);
- /* Get power down time-stamp for last CPU */
- PMF_GET_TIMESTAMP_BY_INDEX(psci_svc, PSCI_STAT_ID_ENTER_LOW_PWR,
- last_cpu_in_non_cpu_pd[parent_idx],
- flags, pwrdn_ts);
+ /* Call into platform interface to calculate residency. */
+ residency = plat_psci_stat_get_residency(lvl, state_info,
+ last_cpu_in_non_cpu_pd[parent_idx]);
/* Initialize back to reset value */
last_cpu_in_non_cpu_pd[parent_idx] = -1;
@@ -218,9 +172,6 @@
/* Get the index into the stats array */
stat_idx = get_stat_idx(local_state, lvl);
- /* Calculate stats residency */
- calc_stat_residency(pwrup_ts, pwrdn_ts, residency);
-
/* Update non cpu stats */
psci_non_cpu_stat[parent_idx][stat_idx].residency += residency;
psci_non_cpu_stat[parent_idx][stat_idx].count++;