From 8fd307ffd602b760634a2be6e2e67033e8c056bd Mon Sep 17 00:00:00 2001 From: Roberto Vargas Date: Mon, 13 Nov 2017 08:24:07 +0000 Subject: Flush the affinity data in psci_affinity_info There is an edge case where the cache maintaince done in psci_do_cpu_off may not seen by some cores. This case is handled in psci_cpu_on_start but it hasn't handled in psci_affinity_info. Change-Id: I4d64f3d1ca9528e364aea8d04e2d254f201e1702 Signed-off-by: Roberto Vargas --- lib/psci/psci_main.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'lib') diff --git a/lib/psci/psci_main.c b/lib/psci/psci_main.c index 4105e63b..8e41cf02 100644 --- a/lib/psci/psci_main.c +++ b/lib/psci/psci_main.c @@ -220,6 +220,23 @@ int psci_affinity_info(u_register_t target_affinity, if (target_idx == -1) return PSCI_E_INVALID_PARAMS; + /* + * Generic management: + * 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); + return psci_get_aff_info_state_by_idx(target_idx); } -- cgit v1.2.3