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-rw-r--r--lib/psci/psci_on.c13
-rw-r--r--lib/psci/psci_suspend.c11
2 files changed, 24 insertions, 0 deletions
diff --git a/lib/psci/psci_on.c b/lib/psci/psci_on.c
index 16b22c2a..d3d0e2ff 100644
--- a/lib/psci/psci_on.c
+++ b/lib/psci/psci_on.c
@@ -64,7 +64,20 @@ int psci_cpu_on_start(u_register_t target_cpu,
/*
* Generic management: Ensure that the cpu is off to be
* turned on.
+ * Perform cache maintanence ahead of reading the target CPU state to
+ * ensure that the data is not stale.
+ * There is a theoretical edge case where the cache may contain stale
+ * data for the target CPU data - this can occur under the following
+ * conditions:
+ * - the target CPU is in another cluster from the current
+ * - the target CPU was the last CPU to shutdown on its cluster
+ * - the cluster was removed from coherency as part of the CPU shutdown
+ *
+ * In this case the cache maintenace that was performed as part of the
+ * target CPUs shutdown was not seen by the current CPU's cluster. And
+ * so the cache may contain stale data for the target CPU.
*/
+ flush_cpu_data_by_index(target_idx, psci_svc_cpu_data.aff_info_state);
rc = cpu_on_validate_state(psci_get_aff_info_state_by_idx(target_idx));
if (rc != PSCI_E_SUCCESS)
goto exit;
diff --git a/lib/psci/psci_suspend.c b/lib/psci/psci_suspend.c
index 0d1589ee..40ecdeea 100644
--- a/lib/psci/psci_suspend.c
+++ b/lib/psci/psci_suspend.c
@@ -80,6 +80,17 @@ static void psci_suspend_to_pwrdown_start(unsigned int end_pwrlvl,
if (psci_spd_pm && psci_spd_pm->svc_suspend)
psci_spd_pm->svc_suspend(max_off_lvl);
+#if !HW_ASSISTED_COHERENCY
+ /*
+ * Plat. management: Allow the platform to perform any early
+ * actions required to power down the CPU. This might be useful for
+ * HW_ASSISTED_COHERENCY = 0 platforms that can safely perform these
+ * actions with data caches enabled.
+ */
+ if (psci_plat_pm_ops->pwr_domain_suspend_pwrdown_early)
+ psci_plat_pm_ops->pwr_domain_suspend_pwrdown_early(state_info);
+#endif
+
/*
* Store the re-entry information for the non-secure world.
*/