xref: /openbmc/linux/arch/arm/mach-socfpga/platsmp.c (revision 9a29f5fc)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2010-2011 Calxeda, Inc.
4  * Copyright 2012 Pavel Machek <pavel@denx.de>
5  * Based on platsmp.c, Copyright (C) 2002 ARM Ltd.
6  * Copyright (C) 2012 Altera Corporation
7  */
8 #include <linux/delay.h>
9 #include <linux/init.h>
10 #include <linux/smp.h>
11 #include <linux/io.h>
12 #include <linux/of.h>
13 #include <linux/of_address.h>
14 
15 #include <asm/cacheflush.h>
16 #include <asm/smp_scu.h>
17 #include <asm/smp_plat.h>
18 
19 #include "core.h"
20 
21 static int socfpga_boot_secondary(unsigned int cpu, struct task_struct *idle)
22 {
23 	int trampoline_size = secondary_trampoline_end - secondary_trampoline;
24 
25 	if (socfpga_cpu1start_addr) {
26 		/* This will put CPU #1 into reset. */
27 		writel(RSTMGR_MPUMODRST_CPU1,
28 		       rst_manager_base_addr + SOCFPGA_RSTMGR_MODMPURST);
29 
30 		memcpy(phys_to_virt(0), secondary_trampoline, trampoline_size);
31 
32 		writel(__pa_symbol(secondary_startup),
33 		       sys_manager_base_addr + (socfpga_cpu1start_addr & 0x000000ff));
34 
35 		flush_cache_all();
36 		smp_wmb();
37 		outer_clean_range(0, trampoline_size);
38 
39 		/* This will release CPU #1 out of reset. */
40 		writel(0, rst_manager_base_addr + SOCFPGA_RSTMGR_MODMPURST);
41 	}
42 
43 	return 0;
44 }
45 
46 static int socfpga_a10_boot_secondary(unsigned int cpu, struct task_struct *idle)
47 {
48 	int trampoline_size = secondary_trampoline_end - secondary_trampoline;
49 
50 	if (socfpga_cpu1start_addr) {
51 		writel(RSTMGR_MPUMODRST_CPU1, rst_manager_base_addr +
52 		       SOCFPGA_A10_RSTMGR_MODMPURST);
53 		memcpy(phys_to_virt(0), secondary_trampoline, trampoline_size);
54 
55 		writel(__pa_symbol(secondary_startup),
56 		       sys_manager_base_addr + (socfpga_cpu1start_addr & 0x00000fff));
57 
58 		flush_cache_all();
59 		smp_wmb();
60 		outer_clean_range(0, trampoline_size);
61 
62 		/* This will release CPU #1 out of reset. */
63 		writel(0, rst_manager_base_addr + SOCFPGA_A10_RSTMGR_MODMPURST);
64 	}
65 
66 	return 0;
67 }
68 
69 static void __init socfpga_smp_prepare_cpus(unsigned int max_cpus)
70 {
71 	struct device_node *np;
72 	void __iomem *socfpga_scu_base_addr;
73 
74 	np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
75 	if (!np) {
76 		pr_err("%s: missing scu\n", __func__);
77 		return;
78 	}
79 
80 	socfpga_scu_base_addr = of_iomap(np, 0);
81 	if (!socfpga_scu_base_addr)
82 		return;
83 	scu_enable(socfpga_scu_base_addr);
84 }
85 
86 #ifdef CONFIG_HOTPLUG_CPU
87 /*
88  * platform-specific code to shutdown a CPU
89  *
90  * Called with IRQs disabled
91  */
92 static void socfpga_cpu_die(unsigned int cpu)
93 {
94 	/* Do WFI. If we wake up early, go back into WFI */
95 	while (1)
96 		cpu_do_idle();
97 }
98 
99 /*
100  * We need a dummy function so that platform_can_cpu_hotplug() knows
101  * we support CPU hotplug. However, the function does not need to do
102  * anything, because CPUs going offline just do WFI. We could reset
103  * the CPUs but it would increase power consumption.
104  */
105 static int socfpga_cpu_kill(unsigned int cpu)
106 {
107 	return 1;
108 }
109 #endif
110 
111 static const struct smp_operations socfpga_smp_ops __initconst = {
112 	.smp_prepare_cpus	= socfpga_smp_prepare_cpus,
113 	.smp_boot_secondary	= socfpga_boot_secondary,
114 #ifdef CONFIG_HOTPLUG_CPU
115 	.cpu_die		= socfpga_cpu_die,
116 	.cpu_kill		= socfpga_cpu_kill,
117 #endif
118 };
119 
120 static const struct smp_operations socfpga_a10_smp_ops __initconst = {
121 	.smp_prepare_cpus	= socfpga_smp_prepare_cpus,
122 	.smp_boot_secondary	= socfpga_a10_boot_secondary,
123 #ifdef CONFIG_HOTPLUG_CPU
124 	.cpu_die		= socfpga_cpu_die,
125 	.cpu_kill		= socfpga_cpu_kill,
126 #endif
127 };
128 
129 CPU_METHOD_OF_DECLARE(socfpga_smp, "altr,socfpga-smp", &socfpga_smp_ops);
130 CPU_METHOD_OF_DECLARE(socfpga_a10_smp, "altr,socfpga-a10-smp", &socfpga_a10_smp_ops);
131