1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *  linux/arch/arm/mach-vexpress/platsmp.c
4 *
5 *  Copyright (C) 2002 ARM Ltd.
6 *  All Rights Reserved
7 */
8#include <linux/init.h>
9#include <linux/errno.h>
10#include <linux/smp.h>
11#include <linux/io.h>
12#include <linux/of_address.h>
13#include <linux/vexpress.h>
14
15#include <asm/mcpm.h>
16#include <asm/smp_scu.h>
17#include <asm/mach/map.h>
18
19#include <plat/platsmp.h>
20
21#include "core.h"
22
23bool __init vexpress_smp_init_ops(void)
24{
25#ifdef CONFIG_MCPM
26	int cpu;
27	struct device_node *cpu_node, *cci_node;
28
29	/*
30	 * The best way to detect a multi-cluster configuration
31	 * is to detect if the kernel can take over CCI ports
32	 * control. Loop over possible CPUs and check if CCI
33	 * port control is available.
34	 * Override the default vexpress_smp_ops if so.
35	 */
36	for_each_possible_cpu(cpu) {
37		bool available;
38
39		cpu_node = of_get_cpu_node(cpu, NULL);
40		if (WARN(!cpu_node, "Missing cpu device node!"))
41			return false;
42
43		cci_node = of_parse_phandle(cpu_node, "cci-control-port", 0);
44		available = cci_node && of_device_is_available(cci_node);
45		of_node_put(cci_node);
46		of_node_put(cpu_node);
47
48		if (!available)
49			return false;
50	}
51
52	mcpm_smp_set_ops();
53	return true;
54#else
55	return false;
56#endif
57}
58
59static const struct of_device_id vexpress_smp_dt_scu_match[] __initconst = {
60	{ .compatible = "arm,cortex-a5-scu", },
61	{ .compatible = "arm,cortex-a9-scu", },
62	{}
63};
64
65static void __init vexpress_smp_dt_prepare_cpus(unsigned int max_cpus)
66{
67	struct device_node *scu = of_find_matching_node(NULL,
68			vexpress_smp_dt_scu_match);
69
70	if (scu)
71		scu_enable(of_iomap(scu, 0));
72
73	/*
74	 * Write the address of secondary startup into the
75	 * system-wide flags register. The boot monitor waits
76	 * until it receives a soft interrupt, and then the
77	 * secondary CPU branches to this address.
78	 */
79	vexpress_flags_set(__pa_symbol(versatile_secondary_startup));
80}
81
82#ifdef CONFIG_HOTPLUG_CPU
83static void vexpress_cpu_die(unsigned int cpu)
84{
85	versatile_immitation_cpu_die(cpu, 0x40);
86}
87#endif
88
89const struct smp_operations vexpress_smp_dt_ops __initconst = {
90	.smp_prepare_cpus	= vexpress_smp_dt_prepare_cpus,
91	.smp_secondary_init	= versatile_secondary_init,
92	.smp_boot_secondary	= versatile_boot_secondary,
93#ifdef CONFIG_HOTPLUG_CPU
94	.cpu_die		= vexpress_cpu_die,
95#endif
96};
97