SPMD: add generic SPD PM handlers

This patch defines and registers the SPMD PM handler hooks.
This is intended to relay boot and PM events to the SPMC.

Change-Id: If5a758d22b8d2152cbbb83a0cad563b5e1c6bd49
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
Signed-off-by: Max Shvetsov <maksims.svecovs@arm.com>

services/std_svc/spmd/spmd_pm.c

+/*
+ * Copyright (c) 2020, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include "spmd_private.h"
+
+/*******************************************************************************
+ * This CPU has been turned on. Enter SPMC to initialise S-EL1 or S-EL2. As part
+ * of the SPMC initialization path, they will initialize any SPs that they
+ * manage. Entry into SPMC is done after initialising minimal architectural
+ * state that guarantees safe execution.
+ ******************************************************************************/
+static void spmd_cpu_on_finish_handler(u_register_t unused)
+{
+	unsigned int linear_id = plat_my_core_pos();
+	spmd_spm_core_context_t *ctx = spmd_get_context();
+	int rc;
+
+	assert(ctx->state != SPMC_STATE_ON);
+
+	rc = spmd_spm_core_sync_entry(ctx);
+	if (rc != 0) {
+		ERROR("SPMC initialisation failed (%d) on CPU%u\n", rc,
+		      linear_id);
+		ctx->state = SPMC_STATE_OFF;
+		return;
+	}
+
+	ctx->state = SPMC_STATE_ON;
+}
+
+/*******************************************************************************
+ * Structure populated by the SPM Dispatcher to perform any bookkeeping before
+ * PSCI executes a power mgmt. operation.
+ ******************************************************************************/
+const spd_pm_ops_t spmd_pm = {
+	.svc_on_finish = spmd_cpu_on_finish_handler,
+};