1/*
2 * Symmetric Multi Processing (SMP) support for Marvell EBU Cortex-A9
3 * based SOCs (Armada 375/38x).
4 *
5 * Copyright (C) 2014 Marvell
6 *
7 * Gregory CLEMENT <gregory.clement@free-electrons.com>
8 * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
9 *
10 * This file is licensed under the terms of the GNU General Public
11 * License version 2.  This program is licensed "as is" without any
12 * warranty of any kind, whether express or implied.
13 */
14
15#include <linux/init.h>
16#include <linux/io.h>
17#include <linux/of.h>
18#include <linux/smp.h>
19#include <linux/mbus.h>
20#include <asm/smp_scu.h>
21#include <asm/smp_plat.h>
22#include "common.h"
23#include "pmsu.h"
24
25extern void mvebu_cortex_a9_secondary_startup(void);
26
27static int __cpuinit mvebu_cortex_a9_boot_secondary(unsigned int cpu,
28						    struct task_struct *idle)
29{
30	int ret, hw_cpu;
31
32	pr_info("Booting CPU %d\n", cpu);
33
34	/*
35	 * Write the address of secondary startup into the system-wide
36	 * flags register. The boot monitor waits until it receives a
37	 * soft interrupt, and then the secondary CPU branches to this
38	 * address.
39	 */
40	hw_cpu = cpu_logical_map(cpu);
41	if (of_machine_is_compatible("marvell,armada375"))
42		mvebu_system_controller_set_cpu_boot_addr(mvebu_cortex_a9_secondary_startup);
43	else
44		mvebu_pmsu_set_cpu_boot_addr(hw_cpu, mvebu_cortex_a9_secondary_startup);
45	smp_wmb();
46
47	/*
48	 * Doing this before deasserting the CPUs is needed to wake up CPUs
49	 * in the offline state after using CPU hotplug.
50	 */
51	arch_send_wakeup_ipi_mask(cpumask_of(cpu));
52
53	ret = mvebu_cpu_reset_deassert(hw_cpu);
54	if (ret) {
55		pr_err("Could not start the secondary CPU: %d\n", ret);
56		return ret;
57	}
58
59	return 0;
60}
61/*
62 * When a CPU is brought back online, either through CPU hotplug, or
63 * because of the boot of a kexec'ed kernel, the PMSU configuration
64 * for this CPU might be in the deep idle state, preventing this CPU
65 * from receiving interrupts. Here, we therefore take out the current
66 * CPU from this state, which was entered by armada_38x_cpu_die()
67 * below.
68 */
69static void armada_38x_secondary_init(unsigned int cpu)
70{
71	mvebu_v7_pmsu_idle_exit();
72}
73
74#ifdef CONFIG_HOTPLUG_CPU
75static void armada_38x_cpu_die(unsigned int cpu)
76{
77	/*
78	 * CPU hotplug is implemented by putting offline CPUs into the
79	 * deep idle sleep state.
80	 */
81	armada_38x_do_cpu_suspend(true);
82}
83
84/*
85 * We need a dummy function, so that platform_can_cpu_hotplug() knows
86 * we support CPU hotplug. However, the function does not need to do
87 * anything, because CPUs going offline can enter the deep idle state
88 * by themselves, without any help from a still alive CPU.
89 */
90static int armada_38x_cpu_kill(unsigned int cpu)
91{
92	return 1;
93}
94#endif
95
96static struct smp_operations mvebu_cortex_a9_smp_ops __initdata = {
97	.smp_boot_secondary	= mvebu_cortex_a9_boot_secondary,
98};
99
100static struct smp_operations armada_38x_smp_ops __initdata = {
101	.smp_boot_secondary	= mvebu_cortex_a9_boot_secondary,
102	.smp_secondary_init     = armada_38x_secondary_init,
103#ifdef CONFIG_HOTPLUG_CPU
104	.cpu_die		= armada_38x_cpu_die,
105	.cpu_kill               = armada_38x_cpu_kill,
106#endif
107};
108
109CPU_METHOD_OF_DECLARE(mvebu_armada_375_smp, "marvell,armada-375-smp",
110		      &mvebu_cortex_a9_smp_ops);
111CPU_METHOD_OF_DECLARE(mvebu_armada_380_smp, "marvell,armada-380-smp",
112		      &armada_38x_smp_ops);
113CPU_METHOD_OF_DECLARE(mvebu_armada_390_smp, "marvell,armada-390-smp",
114		      &armada_38x_smp_ops);
115