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-rw-r--r--lib/psci/psci_off.c181
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diff --git a/lib/psci/psci_off.c b/lib/psci/psci_off.c
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+/*
+ * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <string.h>
+
+#include <arch.h>
+#include <arch_helpers.h>
+#include <common/debug.h>
+#include <lib/pmf/pmf.h>
+#include <lib/runtime_instr.h>
+#include <plat/common/platform.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)
+{
+ unsigned 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(unsigned int end_pwrlvl)
+{
+ int rc = PSCI_E_SUCCESS;
+ unsigned int idx = plat_my_core_pos();
+ psci_power_state_t state_info;
+ unsigned int parent_nodes[PLAT_MAX_PWR_LVL] = {0};
+
+ /*
+ * 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 != NULL);
+
+ /* Construct the psci_power_state for CPU_OFF */
+ psci_set_power_off_state(&state_info);
+
+ /*
+ * Get the parent nodes here, this is important to do before we
+ * initiate the power down sequence as after that point the core may
+ * have exited coherency and its cache may be disabled, any access to
+ * shared memory after that (such as the parent node lookup in
+ * psci_cpu_pd_nodes) can cause coherency issues on some platforms.
+ */
+ psci_get_parent_pwr_domain_nodes(idx, end_pwrlvl, parent_nodes);
+
+ /*
+ * 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, parent_nodes);
+
+ /*
+ * 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 != NULL) && (psci_spd_pm->svc_off != NULL)) {
+ rc = psci_spd_pm->svc_off(0);
+ if (rc != 0)
+ 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 ENABLE_RUNTIME_INSTRUMENTATION
+
+ /*
+ * Flush cache line so that even if CPU power down happens
+ * the timestamp update is reflected in memory.
+ */
+ PMF_CAPTURE_TIMESTAMP(rt_instr_svc,
+ RT_INSTR_ENTER_CFLUSH,
+ PMF_CACHE_MAINT);
+#endif
+
+ /*
+ * Arch. management. Initiate power down sequence.
+ */
+ psci_pwrdown_cpu(psci_find_max_off_lvl(&state_info));
+
+#if ENABLE_RUNTIME_INSTRUMENTATION
+ PMF_CAPTURE_TIMESTAMP(rt_instr_svc,
+ RT_INSTR_EXIT_CFLUSH,
+ PMF_NO_CACHE_MAINT);
+#endif
+
+ /*
+ * 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
+ plat_psci_stat_accounting_start(&state_info);
+#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, parent_nodes);
+
+ /*
+ * 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. When caches are disabled,
+ * this writes directly to main memory, 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.
+ */
+ psci_flush_cpu_data(psci_svc_cpu_data.aff_info_state);
+ psci_set_aff_info_state(AFF_STATE_OFF);
+ psci_dsbish();
+ psci_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 != NULL) {
+ /* 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;
+}