feat(tegra): implement 'pwr_domain_off_early' handler

This patch implements the pwr_domain_off_early handler for
Tegra platforms.

Powering off the boot core on some Tegra platforms is not
allowed and the SOC specific helper functions for Tegra194,
Tegra210 and Tegra186 implement this restriction.

Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
Change-Id: I9d06e0eee12314764adb0422e023a5bec6ed9c1e
diff --git a/plat/nvidia/tegra/common/aarch64/tegra_helpers.S b/plat/nvidia/tegra/common/aarch64/tegra_helpers.S
index 6c8c4f0..72ecd54 100644
--- a/plat/nvidia/tegra/common/aarch64/tegra_helpers.S
+++ b/plat/nvidia/tegra/common/aarch64/tegra_helpers.S
@@ -125,15 +125,18 @@
 .endm
 
 	/* -----------------------------------------------------
-	 * unsigned int plat_is_my_cpu_primary(void);
+	 * bool plat_is_my_cpu_primary(void);
 	 *
 	 * This function checks if this is the Primary CPU
+	 *
+	 * Registers clobbered: x0, x1
 	 * -----------------------------------------------------
 	 */
 func plat_is_my_cpu_primary
 	mrs	x0, mpidr_el1
-	and	x0, x0, #(MPIDR_CLUSTER_MASK | MPIDR_CPU_MASK)
-	cmp	x0, #TEGRA_PRIMARY_CPU
+	adr	x1, tegra_primary_cpu_mpid
+	ldr	x1, [x1]
+	cmp	x0, x1
 	cset	x0, eq
 	ret
 endfunc plat_is_my_cpu_primary
@@ -251,6 +254,14 @@
 	adr	x18, bl31_entrypoint
 	str	x18, [x17]
 
+	/* -----------------------------------
+	 * save the boot CPU MPID value
+	 * -----------------------------------
+	 */
+	mrs	x0, mpidr_el1
+	adr	x1, tegra_primary_cpu_mpid
+	str	x0, [x1]
+
 1:	cpu_init_common
 
 	ret
@@ -426,3 +437,10 @@
 	 */
 tegra_console_base:
 	.quad	0
+
+	/* --------------------------------------------------
+	 * MPID value for the boot CPU
+	 * --------------------------------------------------
+	 */
+tegra_primary_cpu_mpid:
+	.quad	0
diff --git a/plat/nvidia/tegra/common/tegra_pm.c b/plat/nvidia/tegra/common/tegra_pm.c
index ec34a85..8edb024 100644
--- a/plat/nvidia/tegra/common/tegra_pm.c
+++ b/plat/nvidia/tegra/common/tegra_pm.c
@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2015-2020, ARM Limited and Contributors. All rights reserved.
- * Copyright (c) 2020, NVIDIA Corporation. All rights reserved.
+ * Copyright (c) 2020-2023, NVIDIA Corporation. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -92,6 +92,16 @@
 /*******************************************************************************
  * Handler called when a power domain is about to be turned off. The
  * target_state encodes the power state that each level should transition to.
+ * Return error if CPU off sequence is not allowed for the current core.
+ ******************************************************************************/
+static int tegra_pwr_domain_off_early(const psci_power_state_t *target_state)
+{
+	return tegra_soc_pwr_domain_off_early(target_state);
+}
+
+/*******************************************************************************
+ * Handler called when a power domain is about to be turned off. The
+ * target_state encodes the power state that each level should transition to.
  ******************************************************************************/
 static void tegra_pwr_domain_off(const psci_power_state_t *target_state)
 {
@@ -268,6 +278,7 @@
 static plat_psci_ops_t tegra_plat_psci_ops = {
 	.cpu_standby			= tegra_cpu_standby,
 	.pwr_domain_on			= tegra_pwr_domain_on,
+	.pwr_domain_off_early		= tegra_pwr_domain_off_early,
 	.pwr_domain_off			= tegra_pwr_domain_off,
 	.pwr_domain_suspend_pwrdown_early = tegra_pwr_domain_suspend_pwrdown_early,
 	.pwr_domain_suspend		= tegra_pwr_domain_suspend,