Verify capabilities before handling PSCI calls

This patch implements conditional checks in psci_smc_handler() to verify
that the psci function invoked by the caller is supported by the platform
or SPD implementation. The level of support is saved in the 'psci_caps'
variable. This check allows the PSCI implementation to return an error
early.

As a result of the above verification, the checks performed within the psci
handlers for the pm hooks are now removed and replaced with assertions.

Change-Id: I9b5b646a01d8566dc28c4d77dd3aa54e9bf3981a

1 files changed, 5 insertions, 12 deletions

diff --git a/services/std_svc/psci/psci_system_off.c b/services/std_svc/psci/psci_system_off.c
index f2520b6d..970d4bb5 100644
--- a/services/std_svc/psci/psci_system_off.c
+++ b/services/std_svc/psci/psci_system_off.c
@@ -30,20 +30,17 @@
 
 #include <stddef.h>
 #include <arch_helpers.h>
+#include <assert.h>
 #include <debug.h>
 #include <platform.h>
 #include "psci_private.h"
 
 void psci_system_off(void)
 {
-	/* Check platform support */
-	if (!psci_plat_pm_ops->system_off) {
-		ERROR("Platform has not exported a PSCI System Off hook.\n");
-		panic();
-	}
-
 	psci_print_affinity_map();
 
+	assert(psci_plat_pm_ops->system_off);
+
 	/* Notify the Secure Payload Dispatcher */
 	if (psci_spd_pm && psci_spd_pm->svc_system_off) {
 		psci_spd_pm->svc_system_off();
@@ -57,14 +54,10 @@ void psci_system_off(void)
 
 void psci_system_reset(void)
 {
-	/* Check platform support */
-	if (!psci_plat_pm_ops->system_reset) {
-		ERROR("Platform has not exported a PSCI System Reset hook.\n");
-		panic();
-	}
-
 	psci_print_affinity_map();
 
+	assert(psci_plat_pm_ops->system_reset);
+
 	/* Notify the Secure Payload Dispatcher */
 	if (psci_spd_pm && psci_spd_pm->svc_system_reset) {
 		psci_spd_pm->svc_system_reset();