PSCI: Validate non secure entrypoint on ARM platforms

This patch implements the platform power managment handler to verify
non secure entrypoint for ARM platforms. The handler ensures that the
entry point specified by the normal world during CPU_SUSPEND, CPU_ON
or SYSTEM_SUSPEND PSCI API is a valid address within the non secure
DRAM.

Change-Id: I4795452df99f67a24682b22f0e0967175c1de429

include/plat/arm/common/plat_arm.h

@@ -190,6 +190,7 @@ void arm_tzc_setup(void);
 /* PM utility functions */
 int arm_validate_power_state(unsigned int power_state,
 			    psci_power_state_t *req_state);
+int arm_validate_ns_entrypoint(uintptr_t entrypoint);
 
 /* Topology utility function */
 int arm_check_mpidr(u_register_t mpidr);

plat/arm/board/fvp/fvp_pm.c

@@ -304,7 +304,8 @@ static const plat_psci_ops_t fvp_plat_psci_ops = {
 	.pwr_domain_suspend_finish = fvp_pwr_domain_suspend_finish,
 	.system_off = fvp_system_off,
 	.system_reset = fvp_system_reset,
-	.validate_power_state = arm_validate_power_state
+	.validate_power_state = arm_validate_power_state,
+	.validate_ns_entrypoint = arm_validate_ns_entrypoint
 };
 
 /*******************************************************************************

plat/arm/common/arm_pm.c

@@ -29,6 +29,7 @@
  */
 
 #include <arch_helpers.h>
+#include <arm_def.h>
 #include <assert.h>
 #include <errno.h>
 #include <plat_arm.h>
@@ -123,3 +124,23 @@ int arm_validate_power_state(unsigned int power_state,
 	return PSCI_E_SUCCESS;
 }
 #endif /* __ARM_RECOM_STATE_ID_ENC__ */
+
+/*******************************************************************************
+ * ARM standard platform handler called to check the validity of the non secure
+ * entrypoint.
+ ******************************************************************************/
+int arm_validate_ns_entrypoint(uintptr_t entrypoint)
+{
+	/*
+	 * Check if the non secure entrypoint lies within the non
+	 * secure DRAM.
+	 */
+	if ((entrypoint >= ARM_NS_DRAM1_BASE) && (entrypoint <
+			(ARM_NS_DRAM1_BASE + ARM_NS_DRAM1_SIZE)))
+		return PSCI_E_SUCCESS;
+	if ((entrypoint >= ARM_DRAM2_BASE) && (entrypoint <
+			(ARM_DRAM2_BASE + ARM_DRAM2_SIZE)))
+		return PSCI_E_SUCCESS;
+
+	return PSCI_E_INVALID_ADDRESS;
+}

plat/arm/css/common/css_pm.c

@@ -267,7 +267,8 @@ static const plat_psci_ops_t css_ops = {
 	.pwr_domain_suspend_finish	= css_pwr_domain_suspend_finish,
 	.system_off		= css_system_off,
 	.system_reset		= css_system_reset,
-	.validate_power_state	= arm_validate_power_state
+	.validate_power_state	= arm_validate_power_state,
+	.validate_ns_entrypoint = arm_validate_ns_entrypoint
 };
 
 /*******************************************************************************