1/*
2 * Copyright (C) 2014 Marvell Technology Group Ltd.
3 *
4 * Antoine Ténart <antoine.tenart@free-electrons.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include <linux/io.h>
12#include <linux/delay.h>
13#include <linux/of.h>
14#include <linux/of_address.h>
15
16#include <asm/cacheflush.h>
17#include <asm/smp_plat.h>
18#include <asm/smp_scu.h>
19
20#define CPU_RESET		0x00
21
22#define RESET_VECT		0x00
23#define SW_RESET_ADDR		0x94
24
25extern u32 boot_inst;
26
27static void __iomem *cpu_ctrl;
28
29static inline void berlin_perform_reset_cpu(unsigned int cpu)
30{
31	u32 val;
32
33	val = readl(cpu_ctrl + CPU_RESET);
34	val |= BIT(cpu_logical_map(cpu));
35	writel(val, cpu_ctrl + CPU_RESET);
36}
37
38static int berlin_boot_secondary(unsigned int cpu, struct task_struct *idle)
39{
40	if (!cpu_ctrl)
41		return -EFAULT;
42
43	/*
44	 * Reset the CPU, making it to execute the instruction in the reset
45	 * exception vector.
46	 */
47	berlin_perform_reset_cpu(cpu);
48
49	return 0;
50}
51
52static void __init berlin_smp_prepare_cpus(unsigned int max_cpus)
53{
54	struct device_node *np;
55	void __iomem *scu_base;
56	void __iomem *vectors_base;
57
58	np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
59	scu_base = of_iomap(np, 0);
60	of_node_put(np);
61	if (!scu_base)
62		return;
63
64	np = of_find_compatible_node(NULL, NULL, "marvell,berlin-cpu-ctrl");
65	cpu_ctrl = of_iomap(np, 0);
66	of_node_put(np);
67	if (!cpu_ctrl)
68		goto unmap_scu;
69
70	vectors_base = ioremap(CONFIG_VECTORS_BASE, SZ_32K);
71	if (!vectors_base)
72		goto unmap_scu;
73
74	scu_enable(scu_base);
75	flush_cache_all();
76
77	/*
78	 * Write the first instruction the CPU will execute after being reset
79	 * in the reset exception vector.
80	 */
81	writel(boot_inst, vectors_base + RESET_VECT);
82
83	/*
84	 * Write the secondary startup address into the SW reset address
85	 * vector. This is used by boot_inst.
86	 */
87	writel(virt_to_phys(secondary_startup), vectors_base + SW_RESET_ADDR);
88
89	iounmap(vectors_base);
90unmap_scu:
91	iounmap(scu_base);
92}
93
94static struct smp_operations berlin_smp_ops __initdata = {
95	.smp_prepare_cpus	= berlin_smp_prepare_cpus,
96	.smp_boot_secondary	= berlin_boot_secondary,
97};
98CPU_METHOD_OF_DECLARE(berlin_smp, "marvell,berlin-smp", &berlin_smp_ops);
99