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

source code of linux/arch/arm/mach-versatile/platsmp-vexpress.c