1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/arch/arm/mach-vexpress/platsmp.c
4 *
5 * Copyright (C) 2002 ARM Ltd.
6 * All Rights Reserved
7 */
8 #include <linux/init.h>
9 #include <linux/errno.h>
10 #include <linux/smp.h>
11 #include <linux/io.h>
12 #include <linux/of_address.h>
13 #include <linux/vexpress.h>
14
15 #include <asm/mcpm.h>
16 #include <asm/smp_scu.h>
17 #include <asm/mach/map.h>
18
19 #include <plat/platsmp.h>
20
21 #include "core.h"
22
vexpress_smp_init_ops(void)23 bool __init vexpress_smp_init_ops(void)
24 {
25 #ifdef CONFIG_MCPM
26 int cpu;
27 struct device_node *cpu_node, *cci_node;
28
29 /*
30 * The best way to detect a multi-cluster configuration
31 * is to detect if the kernel can take over CCI ports
32 * control. Loop over possible CPUs and check if CCI
33 * port control is available.
34 * Override the default vexpress_smp_ops if so.
35 */
36 for_each_possible_cpu(cpu) {
37 bool available;
38
39 cpu_node = of_get_cpu_node(cpu, NULL);
40 if (WARN(!cpu_node, "Missing cpu device node!"))
41 return false;
42
43 cci_node = of_parse_phandle(cpu_node, "cci-control-port", 0);
44 available = cci_node && of_device_is_available(cci_node);
45 of_node_put(cci_node);
46 of_node_put(cpu_node);
47
48 if (!available)
49 return false;
50 }
51
52 mcpm_smp_set_ops();
53 return true;
54 #else
55 return false;
56 #endif
57 }
58
59 static const struct of_device_id vexpress_smp_dt_scu_match[] __initconst = {
60 { .compatible = "arm,cortex-a5-scu", },
61 { .compatible = "arm,cortex-a9-scu", },
62 {}
63 };
64
vexpress_smp_dt_prepare_cpus(unsigned int max_cpus)65 static void __init vexpress_smp_dt_prepare_cpus(unsigned int max_cpus)
66 {
67 struct device_node *scu = of_find_matching_node(NULL,
68 vexpress_smp_dt_scu_match);
69
70 if (scu)
71 scu_enable(of_iomap(scu, 0));
72
73 /*
74 * Write the address of secondary startup into the
75 * system-wide flags register. The boot monitor waits
76 * until it receives a soft interrupt, and then the
77 * secondary CPU branches to this address.
78 */
79 vexpress_flags_set(__pa_symbol(versatile_secondary_startup));
80 }
81
82 #ifdef CONFIG_HOTPLUG_CPU
vexpress_cpu_die(unsigned int cpu)83 static void vexpress_cpu_die(unsigned int cpu)
84 {
85 versatile_immitation_cpu_die(cpu, 0x40);
86 }
87 #endif
88
89 const struct smp_operations vexpress_smp_dt_ops __initconst = {
90 .smp_prepare_cpus = vexpress_smp_dt_prepare_cpus,
91 .smp_secondary_init = versatile_secondary_init,
92 .smp_boot_secondary = versatile_boot_secondary,
93 #ifdef CONFIG_HOTPLUG_CPU
94 .cpu_die = vexpress_cpu_die,
95 #endif
96 };
97