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 /*
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
32 static 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
realview_smp_prepare_cpus(unsigned int max_cpus)39 static 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 of_node_put(np);
74 if (IS_ERR(map)) {
75 pr_err("PLATSMP: No syscon regmap\n");
76 return;
77 }
78 /* Put the boot address in this magic register */
79 regmap_write(map, REALVIEW_SYS_FLAGSSET_OFFSET,
80 __pa_symbol(versatile_secondary_startup));
81 }
82
83 #ifdef CONFIG_HOTPLUG_CPU
realview_cpu_die(unsigned int cpu)84 static void realview_cpu_die(unsigned int cpu)
85 {
86 return versatile_immitation_cpu_die(cpu, 0x20);
87 }
88 #endif
89
90 static const struct smp_operations realview_dt_smp_ops __initconst = {
91 .smp_prepare_cpus = realview_smp_prepare_cpus,
92 .smp_secondary_init = versatile_secondary_init,
93 .smp_boot_secondary = versatile_boot_secondary,
94 #ifdef CONFIG_HOTPLUG_CPU
95 .cpu_die = realview_cpu_die,
96 #endif
97 };
98 CPU_METHOD_OF_DECLARE(realview_smp, "arm,realview-smp", &realview_dt_smp_ops);
99