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