/*******************************************************************************
* PSCI Compatibility helper function to return the state id encoded in the
* 'power_state' parameter of the CPU specified by 'mpidr'. Returns
* PSCI_INVALID_DATA if the CPU is not in CPU_SUSPEND.
******************************************************************************/
int psci_get_suspend_stateid_by_mpidr(unsigned long mpidr)
{
int cpu_idx = plat_core_pos_by_mpidr(mpidr);
if (cpu_idx == -1)
return PSCI_INVALID_DATA;
/* Sanity check to verify that the CPU is in CPU_SUSPEND */
if (psci_get_aff_info_state_by_idx(cpu_idx) == AFF_STATE_ON &&
!is_local_state_run(psci_get_cpu_local_state_by_idx(cpu_idx)))
return psci_get_pstate_id(psci_power_state_compat[cpu_idx]);
return PSCI_INVALID_DATA;
}
/*******************************************************************************
* This function verifies that the all the other cores in the system have been
* turned OFF and the current CPU is the last running CPU in the system.
* Returns 1 (true) if the current CPU is the last ON CPU or 0 (false)
* otherwise.
******************************************************************************/
unsigned int psci_is_last_on_cpu(void)
{
unsigned int cpu_idx, my_idx = plat_my_core_pos();
for (cpu_idx = 0; cpu_idx < PLATFORM_CORE_COUNT; cpu_idx++) {
if (cpu_idx == my_idx) {
assert(psci_get_aff_info_state() == AFF_STATE_ON);
continue;
}
if (psci_get_aff_info_state_by_idx(cpu_idx) != AFF_STATE_OFF)
return 0;
}
return 1;
}
/*******************************************************************************
* Generic handler which is called to physically power on a cpu identified by
* its mpidr. It performs the generic, architectural, platform setup and state
* management to power on the target cpu e.g. it will ensure that
* enough information is stashed for it to resume execution in the non-secure
* security state.
*
* The state of all the relevant power domains are changed after calling the
* platform handler as it can return error.
******************************************************************************/
int psci_cpu_on_start(u_register_t target_cpu,
entry_point_info_t *ep)
{
int rc;
unsigned int target_idx = plat_core_pos_by_mpidr(target_cpu);
aff_info_state_t target_aff_state;
/* Calling function must supply valid input arguments */
assert((int) target_idx >= 0);
assert(ep != NULL);
/*
* This function must only be called on platforms where the
* CPU_ON platform hooks have been implemented.
*/
assert(psci_plat_pm_ops->pwr_domain_on &&
psci_plat_pm_ops->pwr_domain_on_finish);
/* Protect against multiple CPUs trying to turn ON the same target CPU */
psci_spin_lock_cpu(target_idx);
/*
* Generic management: Ensure that the cpu is off to be
* turned on.
* Perform cache maintanence ahead of reading the target CPU state to
* ensure that the data is not stale.
* There is a theoretical edge case where the cache may contain stale
* data for the target CPU data - this can occur under the following
* conditions:
* - the target CPU is in another cluster from the current
* - the target CPU was the last CPU to shutdown on its cluster
* - the cluster was removed from coherency as part of the CPU shutdown
*
* In this case the cache maintenace that was performed as part of the
* target CPUs shutdown was not seen by the current CPU's cluster. And
* so the cache may contain stale data for the target CPU.
*/
flush_cpu_data_by_index(target_idx, psci_svc_cpu_data.aff_info_state);
rc = cpu_on_validate_state(psci_get_aff_info_state_by_idx(target_idx));
if (rc != PSCI_E_SUCCESS)
goto exit;
/*
* Call the cpu on handler registered by the Secure Payload Dispatcher
* to let it do any bookeeping. If the handler encounters an error, it's
* expected to assert within
*/
if (psci_spd_pm && psci_spd_pm->svc_on)
psci_spd_pm->svc_on(target_cpu);
/*
* Set the Affinity info state of the target cpu to ON_PENDING.
* Flush aff_info_state as it will be accessed with caches
* turned OFF.
*/
psci_set_aff_info_state_by_idx(target_idx, AFF_STATE_ON_PENDING);
flush_cpu_data_by_index(target_idx, psci_svc_cpu_data.aff_info_state);
/*
* The cache line invalidation by the target CPU after setting the
* state to OFF (see psci_do_cpu_off()), could cause the update to
* aff_info_state to be invalidated. Retry the update if the target
* CPU aff_info_state is not ON_PENDING.
*/
target_aff_state = psci_get_aff_info_state_by_idx(target_idx);
if (target_aff_state != AFF_STATE_ON_PENDING) {
assert(target_aff_state == AFF_STATE_OFF);
psci_set_aff_info_state_by_idx(target_idx, AFF_STATE_ON_PENDING);
flush_cpu_data_by_index(target_idx, psci_svc_cpu_data.aff_info_state);
assert(psci_get_aff_info_state_by_idx(target_idx) == AFF_STATE_ON_PENDING);
}
/*
* Perform generic, architecture and platform specific handling.
*/
/*
* Plat. management: Give the platform the current state
* of the target cpu to allow it to perform the necessary
* steps to power on.
*/
rc = psci_plat_pm_ops->pwr_domain_on(target_cpu);
assert(rc == PSCI_E_SUCCESS || rc == PSCI_E_INTERN_FAIL);
if (rc == PSCI_E_SUCCESS)
/* Store the re-entry information for the non-secure world. */
cm_init_context_by_index(target_idx, ep);
else {
/* Restore the state on error. */
psci_set_aff_info_state_by_idx(target_idx, AFF_STATE_OFF);
flush_cpu_data_by_index(target_idx, psci_svc_cpu_data.aff_info_state);
}
exit:
psci_spin_unlock_cpu(target_idx);
return rc;
}
