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 
20 static const struct of_device_id realview_scu_match[] = {
21 	{ .compatible = "arm,arm11mp-scu", },
22 	{ .compatible = "arm,cortex-a9-scu", },
23 	{ .compatible = "arm,cortex-a5-scu", },
24 	{ }
25 };
26 
27 static const struct of_device_id realview_syscon_match[] = {
28         { .compatible = "arm,core-module-integrator", },
29         { .compatible = "arm,realview-eb-syscon", },
30         { .compatible = "arm,realview-pb11mp-syscon", },
31         { .compatible = "arm,realview-pbx-syscon", },
32         { },
33 };
34 
realview_smp_prepare_cpus(unsigned int max_cpus)35 static void __init realview_smp_prepare_cpus(unsigned int max_cpus)
36 {
37 	struct device_node *np;
38 	void __iomem *scu_base;
39 	struct regmap *map;
40 	unsigned int ncores;
41 	int i;
42 
43 	np = of_find_matching_node(NULL, realview_scu_match);
44 	if (!np) {
45 		pr_err("PLATSMP: No SCU base address\n");
46 		return;
47 	}
48 	scu_base = of_iomap(np, 0);
49 	of_node_put(np);
50 	if (!scu_base) {
51 		pr_err("PLATSMP: No SCU remap\n");
52 		return;
53 	}
54 
55 	scu_enable(scu_base);
56 	ncores = scu_get_core_count(scu_base);
57 	pr_info("SCU: %d cores detected\n", ncores);
58 	for (i = 0; i < ncores; i++)
59 		set_cpu_possible(i, true);
60 	iounmap(scu_base);
61 
62 	/* The syscon contains the magic SMP start address registers */
63 	np = of_find_matching_node(NULL, realview_syscon_match);
64 	if (!np) {
65 		pr_err("PLATSMP: No syscon match\n");
66 		return;
67 	}
68 	map = syscon_node_to_regmap(np);
69 	if (IS_ERR(map)) {
70 		pr_err("PLATSMP: No syscon regmap\n");
71 		return;
72 	}
73 	/* Put the boot address in this magic register */
74 	regmap_write(map, REALVIEW_SYS_FLAGSSET_OFFSET,
75 		     __pa_symbol(versatile_secondary_startup));
76 }
77 
78 #ifdef CONFIG_HOTPLUG_CPU
realview_cpu_die(unsigned int cpu)79 static void realview_cpu_die(unsigned int cpu)
80 {
81 	return versatile_immitation_cpu_die(cpu, 0x20);
82 }
83 #endif
84 
85 static const struct smp_operations realview_dt_smp_ops __initconst = {
86 	.smp_prepare_cpus	= realview_smp_prepare_cpus,
87 	.smp_secondary_init	= versatile_secondary_init,
88 	.smp_boot_secondary	= versatile_boot_secondary,
89 #ifdef CONFIG_HOTPLUG_CPU
90 	.cpu_die		= realview_cpu_die,
91 #endif
92 };
93 CPU_METHOD_OF_DECLARE(realview_smp, "arm,realview-smp", &realview_dt_smp_ops);
94