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Diffstat (limited to 'lib/psci/psci_suspend.c')
| -rw-r--r-- | lib/psci/psci_suspend.c | 284 |
1 files changed, 284 insertions, 0 deletions
diff --git a/lib/psci/psci_suspend.c b/lib/psci/psci_suspend.c new file mode 100644 index 00000000..ee1ccef2 --- /dev/null +++ b/lib/psci/psci_suspend.c @@ -0,0 +1,284 @@ +/* + * Copyright (c) 2013-2016, 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); +} |