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(compat: "marvell,armada375" )) |
39 | mvebu_system_controller_set_cpu_boot_addr(boot_addr: mvebu_cortex_a9_secondary_startup); |
40 | else |
41 | mvebu_pmsu_set_cpu_boot_addr(hw_cpu, boot_addr: 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(cpu: 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(deepidle: 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 | |