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Diffstat (limited to 'services/std_svc/psci/psci_off.c')
| -rw-r--r-- | services/std_svc/psci/psci_off.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/services/std_svc/psci/psci_off.c b/services/std_svc/psci/psci_off.c new file mode 100644 index 00000000..28fa52c0 --- /dev/null +++ b/services/std_svc/psci/psci_off.c @@ -0,0 +1,142 @@ +/* + * 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 <arch.h> +#include <arch_helpers.h> +#include <assert.h> +#include <debug.h> +#include <platform.h> +#include <string.h> +#include "psci_private.h" + +/****************************************************************************** + * Construct the psci_power_state to request power OFF at all power levels. + ******************************************************************************/ +static void psci_set_power_off_state(psci_power_state_t *state_info) +{ + int lvl; + + for (lvl = PSCI_CPU_PWR_LVL; lvl <= PLAT_MAX_PWR_LVL; lvl++) + state_info->pwr_domain_state[lvl] = PLAT_MAX_OFF_STATE; +} + +/****************************************************************************** + * 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(int end_pwrlvl) +{ + int rc, 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); + + /* + * 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); + +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); + + /* + * 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. + */ + flush_cpu_data(psci_svc_cpu_data.aff_info_state); + psci_set_aff_info_state(AFF_STATE_OFF); + inv_cpu_data(psci_svc_cpu_data.aff_info_state); + + /* + * Check if all actions needed to safely power down this cpu have + * successfully completed. Enter a wfi loop which will allow the + * power controller to physically power down this cpu. + */ + if (rc == PSCI_E_SUCCESS) + psci_power_down_wfi(); + + return rc; +} |