1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Symmetric Multi Processing (SMP) support for Marvell EBU Cortex-A9
4 * based SOCs (Armada 375/38x).
5 *
6 * Copyright (C) 2014 Marvell
7 *
8 * Gregory CLEMENT <gregory.clement@free-electrons.com>
9 * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
10 */
11
12 #include <linux/init.h>
13 #include <linux/io.h>
14 #include <linux/of.h>
15 #include <linux/smp.h>
16 #include <linux/mbus.h>
17 #include <asm/smp_scu.h>
18 #include <asm/smp_plat.h>
19 #include "common.h"
20 #include "pmsu.h"
21
22 extern void mvebu_cortex_a9_secondary_startup(void);
23
24 static int mvebu_cortex_a9_boot_secondary(unsigned int cpu,
25 struct task_struct *idle)
26 {
27 int ret, hw_cpu;
28
29 pr_info("Booting CPU %d\n", cpu);
30
31 /*
32 * Write the address of secondary startup into the system-wide
33 * flags register. The boot monitor waits until it receives a
34 * soft interrupt, and then the secondary CPU branches to this
35 * address.
36 */
37 hw_cpu = cpu_logical_map(cpu);
38 if (of_machine_is_compatible("marvell,armada375"))
39 mvebu_system_controller_set_cpu_boot_addr(mvebu_cortex_a9_secondary_startup);
40 else
41 mvebu_pmsu_set_cpu_boot_addr(hw_cpu, mvebu_cortex_a9_secondary_startup);
42 smp_wmb();
43
44 /*
45 * Doing this before deasserting the CPUs is needed to wake up CPUs
46 * in the offline state after using CPU hotplug.
47 */
48 arch_send_wakeup_ipi_mask(cpumask_of(cpu));
49
50 ret = mvebu_cpu_reset_deassert(hw_cpu);
51 if (ret) {
52 pr_err("Could not start the secondary CPU: %d\n", ret);
53 return ret;
54 }
55
56 return 0;
57 }
58 /*
59 * When a CPU is brought back online, either through CPU hotplug, or
60 * because of the boot of a kexec'ed kernel, the PMSU configuration
61 * for this CPU might be in the deep idle state, preventing this CPU
62 * from receiving interrupts. Here, we therefore take out the current
63 * CPU from this state, which was entered by armada_38x_cpu_die()
64 * below.
65 */
66 static void armada_38x_secondary_init(unsigned int cpu)
67 {
68 mvebu_v7_pmsu_idle_exit();
69 }
70
71 #ifdef CONFIG_HOTPLUG_CPU
72 static void armada_38x_cpu_die(unsigned int cpu)
73 {
74 /*
75 * CPU hotplug is implemented by putting offline CPUs into the
76 * deep idle sleep state.
77 */
78 armada_38x_do_cpu_suspend(true);
79 }
80
81 /*
82 * We need a dummy function, so that platform_can_cpu_hotplug() knows
83 * we support CPU hotplug. However, the function does not need to do
84 * anything, because CPUs going offline can enter the deep idle state
85 * by themselves, without any help from a still alive CPU.
86 */
87 static int armada_38x_cpu_kill(unsigned int cpu)
88 {
89 return 1;
90 }
91 #endif
92
93 static const struct smp_operations mvebu_cortex_a9_smp_ops __initconst = {
94 .smp_boot_secondary = mvebu_cortex_a9_boot_secondary,
95 };
96
97 static const struct smp_operations armada_38x_smp_ops __initconst = {
98 .smp_boot_secondary = mvebu_cortex_a9_boot_secondary,
99 .smp_secondary_init = armada_38x_secondary_init,
100 #ifdef CONFIG_HOTPLUG_CPU
101 .cpu_die = armada_38x_cpu_die,
102 .cpu_kill = armada_38x_cpu_kill,
103 #endif
104 };
105
106 CPU_METHOD_OF_DECLARE(mvebu_armada_375_smp, "marvell,armada-375-smp",
107 &mvebu_cortex_a9_smp_ops);
108 CPU_METHOD_OF_DECLARE(mvebu_armada_380_smp, "marvell,armada-380-smp",
109 &armada_38x_smp_ops);
110 CPU_METHOD_OF_DECLARE(mvebu_armada_390_smp, "marvell,armada-390-smp",
111 &armada_38x_smp_ops);
112
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