ARM platforms: Make arm_validate_ns_entrypoint() common

The function arm_validate_ns_entrypoint() validates a given non-secure
physical address. This function however specifically returns PSCI error
codes.

Non-secure physical address validation is potentially useful across ARM
platforms, even for non-PSCI use cases. Therefore make this function
common by returning 0 for success or -1 otherwise.

Having made the function common, make arm_validate_psci_entrypoint() a
wrapper around arm_validate_ns_entrypoint() which only translates return
value into PSCI error codes. This wrapper is now used where
arm_validate_ns_entrypoint() was currently used for PSCI entry point
validation.

Change-Id: Ic781fc3105d6d199fd8f53f01aba5baea0ebc310
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
diff --git a/plat/arm/common/arm_pm.c b/plat/arm/common/arm_pm.c
index 5e7e047..44ac5b5 100644
--- a/plat/arm/common/arm_pm.c
+++ b/plat/arm/common/arm_pm.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -112,7 +112,7 @@
 
 /*******************************************************************************
  * ARM standard platform handler called to check the validity of the non secure
- * entrypoint.
+ * entrypoint. Returns 0 if the entrypoint is valid, or -1 otherwise.
  ******************************************************************************/
 int arm_validate_ns_entrypoint(uintptr_t entrypoint)
 {
@@ -121,15 +121,23 @@
 	 * secure DRAM.
 	 */
 	if ((entrypoint >= ARM_NS_DRAM1_BASE) && (entrypoint <
-			(ARM_NS_DRAM1_BASE + ARM_NS_DRAM1_SIZE)))
-		return PSCI_E_SUCCESS;
+			(ARM_NS_DRAM1_BASE + ARM_NS_DRAM1_SIZE))) {
+		return 0;
+	}
 #ifndef AARCH32
 	if ((entrypoint >= ARM_DRAM2_BASE) && (entrypoint <
-			(ARM_DRAM2_BASE + ARM_DRAM2_SIZE)))
-		return PSCI_E_SUCCESS;
+			(ARM_DRAM2_BASE + ARM_DRAM2_SIZE))) {
+		return 0;
+	}
 #endif
 
-	return PSCI_E_INVALID_ADDRESS;
+	return -1;
+}
+
+int arm_validate_psci_entrypoint(uintptr_t entrypoint)
+{
+	return arm_validate_ns_entrypoint(entrypoint) == 0 ? PSCI_E_SUCCESS :
+		PSCI_E_INVALID_ADDRESS;
 }
 
 /******************************************************************************