/*******************************************************************************
* Generic handler which is called when a cpu is physically powered on. It
* traverses the node information and finds the highest power level powered
* off and performs generic, architectural, platform setup and state management
* to power on that power level and power levels below it.
* e.g. For a cpu that's been powered on, it will call the platform specific
* code to enable the gic cpu interface and for a cluster it will enable
* coherency at the interconnect level in addition to gic cpu interface.
******************************************************************************/
void psci_power_up_finish(void)
{
unsigned int end_pwrlvl, cpu_idx = plat_my_core_pos();
psci_power_state_t state_info = { {PSCI_LOCAL_STATE_RUN} };
/*
* Verify that we have been explicitly turned ON or resumed from
* suspend.
*/
if (psci_get_aff_info_state() == AFF_STATE_OFF) {
ERROR("Unexpected affinity info state");
panic();
}
/*
* Get the maximum power domain level to traverse to after this cpu
* has been physically powered up.
*/
end_pwrlvl = get_power_on_target_pwrlvl();
/*
* This function acquires the lock corresponding to each power level so
* that by the time all locks are taken, the system topology is snapshot
* and state management can be done safely.
*/
psci_acquire_pwr_domain_locks(end_pwrlvl,
cpu_idx);
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
* affinity state of the CPU:
* - If the affinity state is ON_PENDING then it has just been
* turned on.
* - Else it is resuming from suspend.
*
* Depending on the type of warm reset identified, choose the right set
* of power management handler and perform the generic, architecture
* and platform specific handling.
*/
if (psci_get_aff_info_state() == AFF_STATE_ON_PENDING)
psci_cpu_on_finish(cpu_idx, &state_info);
else
psci_cpu_suspend_finish(cpu_idx, &state_info);
/*
* Set the requested and target state of this CPU and all the higher
* power domains which are ancestors of this CPU to run.
*/
psci_set_pwr_domains_to_run(end_pwrlvl);
/*
* This loop releases the lock corresponding to each power level
* in the reverse order to which they were acquired.
*/
psci_release_pwr_domain_locks(end_pwrlvl,
cpu_idx);
}
/******************************************************************************
* Top level handler which is called when a cpu wants to power itself down.
* It's assumed that along with turning the cpu power domain off, power
* domains at higher levels will be turned off as far as possible. It finds
* the highest level where a domain has to be powered off by traversing the
* node information and then performs generic, architectural, platform setup
* and state management required to turn OFF that power domain and domains
* below it. e.g. For a cpu that's to be powered OFF, it could mean programming
* the power controller whereas for a cluster that's to be powered off, it will
* call the platform specific code which will disable coherency at the
* interconnect level if the cpu is the last in the cluster and also the
* program the power controller.
******************************************************************************/
int psci_do_cpu_off(unsigned int end_pwrlvl)
{
int rc = PSCI_E_SUCCESS, idx = plat_my_core_pos();
psci_power_state_t state_info;
/*
* This function must only be called on platforms where the
* CPU_OFF platform hooks have been implemented.
*/
assert(psci_plat_pm_ops->pwr_domain_off);
/*
* This function acquires the lock corresponding to each power
* level so that by the time all locks are taken, the system topology
* is snapshot and state management can be done safely.
*/
psci_acquire_pwr_domain_locks(end_pwrlvl,
idx);
/*
* Call the cpu off handler registered by the Secure Payload Dispatcher
* to let it do any bookkeeping. Assume that the SPD always reports an
* E_DENIED error if SP refuse to power down
*/
if (psci_spd_pm && psci_spd_pm->svc_off) {
rc = psci_spd_pm->svc_off(0);
if (rc)
goto exit;
}
/* Construct the psci_power_state for CPU_OFF */
psci_set_power_off_state(&state_info);
/*
* This function is passed the requested state info and
* it returns the negotiated state info for each power level upto
* the end level specified.
*/
psci_do_state_coordination(end_pwrlvl, &state_info);
#if ENABLE_PSCI_STAT
/* Update the last cpu for each level till end_pwrlvl */
psci_stats_update_pwr_down(end_pwrlvl, &state_info);
#endif
/*
* Arch. management. Perform the necessary steps to flush all
* cpu caches.
*/
psci_do_pwrdown_cache_maintenance(psci_find_max_off_lvl(&state_info));
/*
* Plat. management: Perform platform specific actions to turn this
* cpu off e.g. exit cpu coherency, program the power controller etc.
*/
psci_plat_pm_ops->pwr_domain_off(&state_info);
#if ENABLE_PSCI_STAT
/*
* Capture time-stamp while entering low power state.
* No cache maintenance needed because caches are off
* and writes are direct to main memory.
*/
PMF_CAPTURE_TIMESTAMP(psci_svc, PSCI_STAT_ID_ENTER_LOW_PWR,
PMF_NO_CACHE_MAINT);
#endif
exit:
/*
* Release the locks corresponding to each power level in the
* reverse order to which they were acquired.
*/
psci_release_pwr_domain_locks(end_pwrlvl,
idx);
/*
* Check if all actions needed to safely power down this cpu have
* successfully completed.
*/
if (rc == PSCI_E_SUCCESS) {
/*
* Set the affinity info state to OFF. This writes directly to
* main memory as caches are disabled, so cache maintenance is
* required to ensure that later cached reads of aff_info_state
* return AFF_STATE_OFF. A dsbish() ensures ordering of the
* update to the affinity info state prior to cache line
* invalidation.
*/
flush_cpu_data(psci_svc_cpu_data.aff_info_state);
psci_set_aff_info_state(AFF_STATE_OFF);
dsbish();
inv_cpu_data(psci_svc_cpu_data.aff_info_state);
#if ENABLE_RUNTIME_INSTRUMENTATION
/*
* Update the timestamp with cache off. We assume this
* timestamp can only be read from the current CPU and the
* timestamp cache line will be flushed before return to
* normal world on wakeup.
*/
PMF_CAPTURE_TIMESTAMP(rt_instr_svc,
RT_INSTR_ENTER_HW_LOW_PWR,
PMF_NO_CACHE_MAINT);
#endif
if (psci_plat_pm_ops->pwr_domain_pwr_down_wfi) {
/* This function must not return */
psci_plat_pm_ops->pwr_domain_pwr_down_wfi(&state_info);
} else {
/*
* Enter a wfi loop which will allow the power
* controller to physically power down this cpu.
*/
psci_power_down_wfi();
}
}
return rc;
}
