From 0a46e2c3408ed719294de834177363d9adfeca06 Mon Sep 17 00:00:00 2001 From: Achin Gupta Date: Thu, 31 Jul 2014 11:19:11 +0100 Subject: Add APIs to preserve highest affinity level in OFF state This patch adds APIs to find, save and retrieve the highest affinity level which will enter or exit from the physical OFF state during a PSCI power management operation. The level is stored in per-cpu data. It then reworks the PSCI implementation to perform cache maintenance only when the handler for the highest affinity level to enter/exit the OFF state is called. For example. during a CPU_SUSPEND operation, state management is done prior to calling the affinity level specific handlers. The highest affinity level which will be turned off is determined using the psci_find_max_phys_off_afflvl() API. This level is saved using the psci_set_max_phys_off_afflvl() API. In the code that does generic handling for each level, prior to performing cache maintenance it is first determined if the current affinity level matches the value returned by psci_get_max_phys_off_afflvl(). Cache maintenance is done if the values match. This change allows the last CPU in a cluster to perform cache maintenance independently. Earlier, cache maintenance was started in the level 0 handler and finished in the level 1 handler. This change in approach will facilitate implementation of tf-issues#98. Change-Id: I57233f0a27b3ddd6ddca6deb6a88b234525b0ae6 --- services/std_svc/psci/psci_setup.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'services/std_svc/psci/psci_setup.c') diff --git a/services/std_svc/psci/psci_setup.c b/services/std_svc/psci/psci_setup.c index 9e4955dc..b49b6e81 100644 --- a/services/std_svc/psci/psci_setup.c +++ b/services/std_svc/psci/psci_setup.c @@ -201,6 +201,15 @@ static void psci_init_aff_map_node(unsigned long mpidr, psci_svc_cpu_data.power_state, PSCI_INVALID_DATA); + /* + * There is no state associated with the current execution + * context so ensure that any reads of the highest affinity + * level in a powered down state return PSCI_INVALID_DATA. + */ + set_cpu_data_by_index(linear_id, + psci_svc_cpu_data.max_phys_off_afflvl, + PSCI_INVALID_DATA); + cm_set_context_by_mpidr(mpidr, (void *) &psci_ns_context[linear_id], NON_SECURE); -- cgit