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/*
* Copyright (c) 2013-2015, 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:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of ARM nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <assert.h>
#include <bl_common.h>
#include <arch.h>
#include <arch_helpers.h>
#include <context.h>
#include <context_mgmt.h>
#include <cpu_data.h>
#include <debug.h>
#include <platform.h>
#include <runtime_svc.h>
#include <stddef.h>
#include "psci_private.h"
/*******************************************************************************
* This function does generic and platform specific operations after a wake-up
* from standby/retention states at multiple power levels.
******************************************************************************/
static void psci_suspend_to_standby_finisher(unsigned int cpu_idx,
psci_power_state_t *state_info,
unsigned int end_pwrlvl)
{
psci_acquire_pwr_domain_locks(end_pwrlvl,
cpu_idx);
/*
* Plat. management: Allow the platform to do operations
* on waking up from retention.
*/
psci_plat_pm_ops->pwr_domain_suspend_finish(state_info);
/*
* Set the requested and target state of this CPU and all the higher
* power domain levels for this CPU to run.
*/
psci_set_pwr_domains_to_run(end_pwrlvl);
psci_release_pwr_domain_locks(end_pwrlvl,
cpu_idx);
}
/*******************************************************************************
* This function does generic and platform specific suspend to power down
* operations.
******************************************************************************/
static void psci_suspend_to_pwrdown_start(unsigned int end_pwrlvl,
entry_point_info_t *ep,
psci_power_state_t *state_info)
{
unsigned int max_off_lvl = psci_find_max_off_lvl(state_info);
/* Save PSCI target power level for the suspend finisher handler */
psci_set_suspend_pwrlvl(end_pwrlvl);
/*
* Flush the target power level as it will be accessed on power up with
* Data cache disabled.
*/
flush_cpu_data(psci_svc_cpu_data.target_pwrlvl);
/*
* Call the cpu suspend handler registered by the Secure Payload
* Dispatcher to let it do any book-keeping. If the handler encounters an
* error, it's expected to assert within
*/
if (psci_spd_pm && psci_spd_pm->svc_suspend)
psci_spd_pm->svc_suspend(max_off_lvl);
/*
* Store the re-entry information for the non-secure world.
*/
cm_init_my_context(ep);
/*
* Arch. management. Perform the necessary steps to flush all
* cpu caches. Currently we assume that the power level correspond
* the cache level.
* TODO : Introduce a mechanism to query the cache level to flush
* and the cpu-ops power down to perform from the platform.
*/
psci_do_pwrdown_cache_maintenance(max_off_lvl);
}
/*******************************************************************************
* Top level handler which is called when a cpu wants to suspend its execution.
* It is assumed that along with suspending the cpu power domain, power domains
* at higher levels until the target power level will be suspended as well. It
* coordinates with the platform to negotiate the target state for each of
* the power domain level till the target power domain level. It then performs
* generic, architectural, platform setup and state management required to
* suspend that power domain level and power domain levels below it.
* e.g. For a cpu that's to be suspended, it could mean programming the
* power controller whereas for a cluster that's to be suspended, 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.
*
* All the required parameter checks are performed at the beginning and after
* the state transition has been done, no further error is expected and it is
* not possible to undo any of the actions taken beyond that point.
******************************************************************************/
void psci_cpu_suspend_start(entry_point_info_t *ep,
unsigned int end_pwrlvl,
psci_power_state_t *state_info,
unsigned int is_power_down_state)
{
int skip_wfi = 0;
unsigned int idx = plat_my_core_pos();
/*
* This function must only be called on platforms where the
* CPU_SUSPEND platform hooks have been implemented.
*/
assert(psci_plat_pm_ops->pwr_domain_suspend &&
psci_plat_pm_ops->pwr_domain_suspend_finish);
/*
* 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);
/*
* We check if there are any pending interrupts after the delay
* introduced by lock contention to increase the chances of early
* detection that a wake-up interrupt has fired.
*/
if (read_isr_el1()) {
skip_wfi = 1;
goto exit;
}
/*
* 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
if (is_power_down_state)
psci_suspend_to_pwrdown_start(end_pwrlvl, ep, state_info);
/*
* Plat. management: Allow the platform to perform the
* necessary actions to turn off this cpu e.g. set the
* platform defined mailbox with the psci entrypoint,
* program the power controller etc.
*/
psci_plat_pm_ops->pwr_domain_suspend(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);
if (skip_wfi)
return;
if (is_power_down_state) {
/* The function calls below must not return */
if (psci_plat_pm_ops->pwr_domain_pwr_down_wfi)
psci_plat_pm_ops->pwr_domain_pwr_down_wfi(state_info);
else
psci_power_down_wfi();
}
/*
* We will reach here if only retention/standby states have been
* requested at multiple power levels. This means that the cpu
* context will be preserved.
*/
wfi();
/*
* After we wake up from context retaining suspend, call the
* context retaining suspend finisher.
*/
psci_suspend_to_standby_finisher(idx, state_info, end_pwrlvl);
}
/*******************************************************************************
* The following functions finish an earlier suspend request. They
* are called by the common finisher routine in psci_common.c. The `state_info`
* is the psci_power_state from which this CPU has woken up from.
******************************************************************************/
void psci_cpu_suspend_finish(unsigned int cpu_idx,
psci_power_state_t *state_info)
{
unsigned int counter_freq;
unsigned int max_off_lvl;
/* Ensure we have been woken up from a suspended state */
assert(psci_get_aff_info_state() == AFF_STATE_ON && is_local_state_off(\
state_info->pwr_domain_state[PSCI_CPU_PWR_LVL]));
/*
* Plat. management: Perform the platform specific actions
* before we change the state of the cpu e.g. enabling the
* gic or zeroing the mailbox register. If anything goes
* wrong then assert as there is no way to recover from this
* situation.
*/
psci_plat_pm_ops->pwr_domain_suspend_finish(state_info);
/*
* Arch. management: Enable the data cache, manage stack memory and
* restore the stashed EL3 architectural context from the 'cpu_context'
* structure for this cpu.
*/
psci_do_pwrup_cache_maintenance();
/* Re-init the cntfrq_el0 register */
counter_freq = plat_get_syscnt_freq2();
write_cntfrq_el0(counter_freq);
/*
* Call the cpu suspend finish 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_suspend) {
max_off_lvl = psci_find_max_off_lvl(state_info);
assert (max_off_lvl != PSCI_INVALID_PWR_LVL);
psci_spd_pm->svc_suspend_finish(max_off_lvl);
}
/* Invalidate the suspend level for the cpu */
psci_set_suspend_pwrlvl(PSCI_INVALID_PWR_LVL);
/*
* Generic management: Now we just need to retrieve the
* information that we had stashed away during the suspend
* call to set this cpu on its way.
*/
cm_prepare_el3_exit(NON_SECURE);
}