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