/*
* Top-level Standard Service SMC handler. This handler will in turn dispatch
* calls to PSCI SMC handler
*/
static uintptr_t std_svc_smc_handler(uint32_t smc_fid,
u_register_t x1,
u_register_t x2,
u_register_t x3,
u_register_t x4,
void *cookie,
void *handle,
u_register_t flags)
{
/*
* Dispatch PSCI calls to PSCI SMC handler and return its return
* value
*/
if (is_psci_fid(smc_fid)) {
uint64_t ret;
#if ENABLE_RUNTIME_INSTRUMENTATION
/*
* Flush cache line so that even if CPU power down happens
* the timestamp update is reflected in memory.
*/
PMF_WRITE_TIMESTAMP(rt_instr_svc,
RT_INSTR_ENTER_PSCI,
PMF_CACHE_MAINT,
get_cpu_data(cpu_data_pmf_ts[CPU_DATA_PMF_TS0_IDX]));
#endif
ret = psci_smc_handler(smc_fid, x1, x2, x3, x4,
cookie, handle, flags);
#if ENABLE_RUNTIME_INSTRUMENTATION
PMF_CAPTURE_TIMESTAMP(rt_instr_svc,
RT_INSTR_EXIT_PSCI,
PMF_NO_CACHE_MAINT);
#endif
SMC_RET1(handle, ret);
}
#if ENABLE_SPM && SPM_DEPRECATED
/*
* Dispatch SPM calls to SPM SMC handler and return its return
* value
*/
if (is_spm_fid(smc_fid)) {
return spm_smc_handler(smc_fid, x1, x2, x3, x4, cookie,
handle, flags);
}
#endif
#if SDEI_SUPPORT
if (is_sdei_fid(smc_fid)) {
return sdei_smc_handler(smc_fid, x1, x2, x3, x4, cookie, handle,
flags);
}
#endif
switch (smc_fid) {
case ARM_STD_SVC_CALL_COUNT:
/*
* Return the number of Standard Service Calls. PSCI is the only
* standard service implemented; so return number of PSCI calls
*/
SMC_RET1(handle, PSCI_NUM_CALLS);
case ARM_STD_SVC_UID:
/* Return UID to the caller */
SMC_UUID_RET(handle, arm_svc_uid);
case ARM_STD_SVC_VERSION:
/* Return the version of current implementation */
SMC_RET2(handle, STD_SVC_VERSION_MAJOR, STD_SVC_VERSION_MINOR);
default:
WARN("Unimplemented Standard Service Call: 0x%x \n", smc_fid);
SMC_RET1(handle, SMC_UNK);
}
}
/******************************************************************************
* 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;
}
