refactor(psci): don't use PSCI_INVALID_PWR_LVL to signal OFF state
The target_pwrlvl field in the psci cpu data struct only stores the
highest power domain that a CPU_SUSPEND call affected, and is used to
resume those same domains on warm reset. If the cpu is otherwise OFF
(never turned on or CPU_OFF), then this needs to be the highest power
level because we don't know the highest level that will be off.
So skip the invalidation and always keep the field to the maximum value.
During suspend the field will be lowered to the appropriate value and
then put back after wakeup.
Also, do that in the suspend to standby path as well as it will have
been written before the sleep and it might end up incorrect.
Change-Id: I614272ec387e1d83023c94700780a0f538a9a6b6
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
diff --git a/include/lib/psci/psci.h b/include/lib/psci/psci.h
index c40f955..f12a4d6 100644
--- a/include/lib/psci/psci.h
+++ b/include/lib/psci/psci.h
@@ -302,7 +302,7 @@
/*
* Highest power level which takes part in a power management
- * operation.
+ * operation. May be lower while the core is in suspend state.
*/
unsigned int target_pwrlvl;
diff --git a/lib/psci/psci_common.c b/lib/psci/psci_common.c
index 3f6b89f..5c7993b 100644
--- a/lib/psci/psci_common.c
+++ b/lib/psci/psci_common.c
@@ -260,13 +260,9 @@
/*
* Assume that this cpu was suspended and retrieve its target power
- * level. If it is invalid then it could only have been turned off
- * earlier. PLAT_MAX_PWR_LVL will be the highest power level a
- * cpu can be turned off to.
+ * level. If it wasn't, the cpu is off so this will be PLAT_MAX_PWR_LVL.
*/
pwrlvl = psci_get_suspend_pwrlvl();
- if (pwrlvl == PSCI_INVALID_PWR_LVL)
- pwrlvl = PLAT_MAX_PWR_LVL;
assert(pwrlvl < PSCI_INVALID_PWR_LVL);
return pwrlvl;
}
diff --git a/lib/psci/psci_setup.c b/lib/psci/psci_setup.c
index 6bf1ff4..1afc918 100644
--- a/lib/psci/psci_setup.c
+++ b/lib/psci/psci_setup.c
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2013-2020, Arm Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2024, Arm Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -68,8 +68,8 @@
/* Set the Affinity Info for the cores as OFF */
svc_cpu_data->aff_info_state = AFF_STATE_OFF;
- /* Invalidate the suspend level for the cpu */
- svc_cpu_data->target_pwrlvl = PSCI_INVALID_PWR_LVL;
+ /* Default to the highest power level when the cpu is not suspending */
+ svc_cpu_data->target_pwrlvl = PLAT_MAX_PWR_LVL;
/* Set the power state to OFF state */
svc_cpu_data->local_state = PLAT_MAX_OFF_STATE;
diff --git a/lib/psci/psci_suspend.c b/lib/psci/psci_suspend.c
index cb12b83..3004666 100644
--- a/lib/psci/psci_suspend.c
+++ b/lib/psci/psci_suspend.c
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2013-2022, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2024, Arm Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -54,6 +54,9 @@
*/
psci_plat_pm_ops->pwr_domain_suspend_finish(&state_info);
+ /* This loses its meaning when not suspending, reset so it's correct for OFF */
+ psci_set_suspend_pwrlvl(PLAT_MAX_PWR_LVL);
+
/*
* Set the requested and target state of this CPU and all the higher
* power domain levels for this CPU to run.
@@ -363,8 +366,8 @@
psci_spd_pm->svc_suspend_finish(max_off_lvl);
}
- /* Invalidate the suspend level for the cpu */
- psci_set_suspend_pwrlvl(PSCI_INVALID_PWR_LVL);
+ /* This loses its meaning when not suspending, reset so it's correct for OFF */
+ psci_set_suspend_pwrlvl(PLAT_MAX_PWR_LVL);
PUBLISH_EVENT(psci_suspend_pwrdown_finish);
}