1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2015 Linus Walleij
4 */
5#include <linux/smp.h>
6#include <linux/io.h>
7#include <linux/of.h>
8#include <linux/of_address.h>
9#include <linux/regmap.h>
10#include <linux/mfd/syscon.h>
11
12#include <asm/cacheflush.h>
13#include <asm/smp_plat.h>
14#include <asm/smp_scu.h>
15
16#include "platsmp.h"
17
18#define REALVIEW_SYS_FLAGSSET_OFFSET	0x30
19
20static const struct of_device_id realview_scu_match[] = {
21	/*
22	 * The ARM11MP SCU compatible is only provided as fallback for
23	 * old RealView EB Cortex-A9 device trees that were using this
24	 * compatible by mistake.
25	 */
26	{ .compatible = "arm,arm11mp-scu", },
27	{ .compatible = "arm,cortex-a9-scu", },
28	{ .compatible = "arm,cortex-a5-scu", },
29	{ }
30};
31
32static const struct of_device_id realview_syscon_match[] = {
33        { .compatible = "arm,core-module-integrator", },
34        { .compatible = "arm,realview-eb-syscon", },
35        { .compatible = "arm,realview-pbx-syscon", },
36        { },
37};
38
39static void __init realview_smp_prepare_cpus(unsigned int max_cpus)
40{
41	struct device_node *np;
42	void __iomem *scu_base;
43	struct regmap *map;
44	unsigned int ncores;
45	int i;
46
47	np = of_find_matching_node(NULL, realview_scu_match);
48	if (!np) {
49		pr_err("PLATSMP: No SCU base address\n");
50		return;
51	}
52	scu_base = of_iomap(np, 0);
53	of_node_put(np);
54	if (!scu_base) {
55		pr_err("PLATSMP: No SCU remap\n");
56		return;
57	}
58
59	scu_enable(scu_base);
60	ncores = scu_get_core_count(scu_base);
61	pr_info("SCU: %d cores detected\n", ncores);
62	for (i = 0; i < ncores; i++)
63		set_cpu_possible(i, true);
64	iounmap(scu_base);
65
66	/* The syscon contains the magic SMP start address registers */
67	np = of_find_matching_node(NULL, realview_syscon_match);
68	if (!np) {
69		pr_err("PLATSMP: No syscon match\n");
70		return;
71	}
72	map = syscon_node_to_regmap(np);
73	if (IS_ERR(map)) {
74		pr_err("PLATSMP: No syscon regmap\n");
75		return;
76	}
77	/* Put the boot address in this magic register */
78	regmap_write(map, REALVIEW_SYS_FLAGSSET_OFFSET,
79		     __pa_symbol(versatile_secondary_startup));
80}
81
82#ifdef CONFIG_HOTPLUG_CPU
83static void realview_cpu_die(unsigned int cpu)
84{
85	return versatile_immitation_cpu_die(cpu, 0x20);
86}
87#endif
88
89static const struct smp_operations realview_dt_smp_ops __initconst = {
90	.smp_prepare_cpus	= realview_smp_prepare_cpus,
91	.smp_secondary_init	= versatile_secondary_init,
92	.smp_boot_secondary	= versatile_boot_secondary,
93#ifdef CONFIG_HOTPLUG_CPU
94	.cpu_die		= realview_cpu_die,
95#endif
96};
97CPU_METHOD_OF_DECLARE(realview_smp, "arm,realview-smp", &realview_dt_smp_ops);
98