feat(psci): add a helper function to ensure that non-boot PEs are offline
Introduce a helper function that ensures that non-boot PEs are offline.
This function will be used by DRTM implementation to ensure that system
is running with only single PE.
Signed-off-by: Manish V Badarkhe <manish.badarkhe@arm.com>
Signed-off-by: Lucian Paul-Trifu <lucian.paultrifu@gmail.com>
Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: I521ebefa49297026b02554629b1710a232148e01
diff --git a/include/lib/psci/psci_lib.h b/include/lib/psci/psci_lib.h
index 1ac45ad..43e2f96 100644
--- a/include/lib/psci/psci_lib.h
+++ b/include/lib/psci/psci_lib.h
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2022, Arm Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -91,6 +91,8 @@
entry_point_info_t *next_image_info);
int psci_stop_other_cores(unsigned int wait_ms,
void (*stop_func)(u_register_t mpidr));
+bool psci_is_last_on_cpu_safe(void);
+
#endif /* __ASSEMBLER__ */
#endif /* PSCI_LIB_H */
diff --git a/lib/psci/psci_common.c b/lib/psci/psci_common.c
index 170777f..22d66bf 100644
--- a/lib/psci/psci_common.c
+++ b/lib/psci/psci_common.c
@@ -1022,3 +1022,56 @@
return PSCI_E_SUCCESS;
}
+
+/*******************************************************************************
+ * This function verifies that all the other cores in the system have been
+ * turned OFF and the current CPU is the last running CPU in the system.
+ * Returns true if the current CPU is the last ON CPU or false otherwise.
+ *
+ * This API has following differences with psci_is_last_on_cpu
+ * 1. PSCI states are locked
+ * 2. It caters for "forest" topology instead of just "tree"
+ * TODO : Revisit both API's and unify them
+ ******************************************************************************/
+bool psci_is_last_on_cpu_safe(void)
+{
+ unsigned int this_core = plat_my_core_pos();
+ unsigned int parent_nodes[PLAT_MAX_PWR_LVL] = {0};
+ unsigned int i = 0;
+
+ /*
+ * Traverse the forest of PSCI nodes, nodes with no parents
+ * (invalid-nodes) are the root nodes.
+ */
+ while ((psci_non_cpu_pd_nodes[i].parent_node ==
+ PSCI_PARENT_NODE_INVALID) &&
+ (i < PSCI_NUM_NON_CPU_PWR_DOMAINS)) {
+ psci_get_parent_pwr_domain_nodes(
+ psci_non_cpu_pd_nodes[i].cpu_start_idx,
+ PLAT_MAX_PWR_LVL, parent_nodes);
+
+ psci_acquire_pwr_domain_locks(PLAT_MAX_PWR_LVL, parent_nodes);
+
+ for (unsigned int core = 0U;
+ core < psci_non_cpu_pd_nodes[i].ncpus; core++) {
+ if (core == this_core) {
+ continue;
+ }
+
+ if (psci_get_aff_info_state_by_idx(core) !=
+ AFF_STATE_OFF) {
+ psci_release_pwr_domain_locks(PLAT_MAX_PWR_LVL,
+ parent_nodes);
+ VERBOSE("core=%u other than boot core=%u %s\n",
+ core, this_core, "running in the system");
+
+ return false;
+ }
+ }
+
+ psci_release_pwr_domain_locks(PLAT_MAX_PWR_LVL, parent_nodes);
+ i++;
+ }
+
+ return true;
+}
diff --git a/lib/psci/psci_private.h b/lib/psci/psci_private.h
index 72bd6bd..61bd966 100644
--- a/lib/psci/psci_private.h
+++ b/lib/psci/psci_private.h
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2022, Arm Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -47,6 +47,9 @@
*/
#define PSCI_MAX_CPUS_INDEX 0xFFFFU
+/* Invalid parent */
+#define PSCI_PARENT_NODE_INVALID 0xFFFFFFFFU
+
/*
* Helper functions to get/set the fields of PSCI per-cpu data.
*/