1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2014 Marvell Technology Group Ltd.
4 *
5 * Antoine T��nart <antoine.tenart@free-electrons.com>
6 */
7
8#include <linux/io.h>
9#include <linux/delay.h>
10#include <linux/of.h>
11#include <linux/of_address.h>
12
13#include <asm/cacheflush.h>
14#include <asm/cp15.h>
15#include <asm/page.h>
16#include <asm/smp_plat.h>
17#include <asm/smp_scu.h>
18
19/*
20 * There are two reset registers, one with self-clearing (SC)
21 * reset and one with non-self-clearing reset (NON_SC).
22 */
23#define CPU_RESET_SC		0x00
24#define CPU_RESET_NON_SC	0x20
25
26#define RESET_VECT		0x00
27#define SW_RESET_ADDR		0x94
28
29extern u32 boot_inst;
30
31static void __iomem *cpu_ctrl;
32
33static inline void berlin_perform_reset_cpu(unsigned int cpu)
34{
35	u32 val;
36
37	val = readl(cpu_ctrl + CPU_RESET_NON_SC);
38	val &= ~BIT(cpu_logical_map(cpu));
39	writel(val, cpu_ctrl + CPU_RESET_NON_SC);
40	val |= BIT(cpu_logical_map(cpu));
41	writel(val, cpu_ctrl + CPU_RESET_NON_SC);
42}
43
44static int berlin_boot_secondary(unsigned int cpu, struct task_struct *idle)
45{
46	if (!cpu_ctrl)
47		return -EFAULT;
48
49	/*
50	 * Reset the CPU, making it to execute the instruction in the reset
51	 * exception vector.
52	 */
53	berlin_perform_reset_cpu(cpu);
54
55	return 0;
56}
57
58static void __init berlin_smp_prepare_cpus(unsigned int max_cpus)
59{
60	struct device_node *np;
61	void __iomem *scu_base;
62	void __iomem *vectors_base;
63
64	np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
65	scu_base = of_iomap(np, 0);
66	of_node_put(np);
67	if (!scu_base)
68		return;
69
70	np = of_find_compatible_node(NULL, NULL, "marvell,berlin-cpu-ctrl");
71	cpu_ctrl = of_iomap(np, 0);
72	of_node_put(np);
73	if (!cpu_ctrl)
74		goto unmap_scu;
75
76	vectors_base = ioremap(VECTORS_BASE, SZ_32K);
77	if (!vectors_base)
78		goto unmap_scu;
79
80	scu_enable(scu_base);
81
82	/*
83	 * Write the first instruction the CPU will execute after being reset
84	 * in the reset exception vector.
85	 */
86	writel(boot_inst, vectors_base + RESET_VECT);
87
88	/*
89	 * Write the secondary startup address into the SW reset address
90	 * vector. This is used by boot_inst.
91	 */
92	writel(__pa_symbol(secondary_startup), vectors_base + SW_RESET_ADDR);
93
94	iounmap(vectors_base);
95unmap_scu:
96	iounmap(scu_base);
97}
98
99#ifdef CONFIG_HOTPLUG_CPU
100static void berlin_cpu_die(unsigned int cpu)
101{
102	v7_exit_coherency_flush(louis);
103	while (1)
104		cpu_do_idle();
105}
106
107static int berlin_cpu_kill(unsigned int cpu)
108{
109	u32 val;
110
111	val = readl(cpu_ctrl + CPU_RESET_NON_SC);
112	val &= ~BIT(cpu_logical_map(cpu));
113	writel(val, cpu_ctrl + CPU_RESET_NON_SC);
114
115	return 1;
116}
117#endif
118
119static const struct smp_operations berlin_smp_ops __initconst = {
120	.smp_prepare_cpus	= berlin_smp_prepare_cpus,
121	.smp_boot_secondary	= berlin_boot_secondary,
122#ifdef CONFIG_HOTPLUG_CPU
123	.cpu_die		= berlin_cpu_die,
124	.cpu_kill		= berlin_cpu_kill,
125#endif
126};
127CPU_METHOD_OF_DECLARE(berlin_smp, "marvell,berlin-smp", &berlin_smp_ops);
128