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 <roberto.vargas@arm.com>
This commit is contained in:
Roberto Vargas 2017-11-13 08:24:07 +00:00
parent 203444c500
commit 8fd307ffd6
1 changed files with 17 additions and 0 deletions

View File

@ -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);
}