xref: /openbmc/linux/arch/arm/mach-socfpga/platsmp.c (revision 0edbfea5)
1 /*
2  * Copyright 2010-2011 Calxeda, Inc.
3  * Copyright 2012 Pavel Machek <pavel@denx.de>
4  * Based on platsmp.c, Copyright (C) 2002 ARM Ltd.
5  * Copyright (C) 2012 Altera Corporation
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms and conditions of the GNU General Public License,
9  * version 2, as published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14  * more details.
15  *
16  * You should have received a copy of the GNU General Public License along with
17  * this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 #include <linux/delay.h>
20 #include <linux/init.h>
21 #include <linux/smp.h>
22 #include <linux/io.h>
23 #include <linux/of.h>
24 #include <linux/of_address.h>
25 
26 #include <asm/cacheflush.h>
27 #include <asm/smp_scu.h>
28 #include <asm/smp_plat.h>
29 
30 #include "core.h"
31 
32 static int socfpga_boot_secondary(unsigned int cpu, struct task_struct *idle)
33 {
34 	int trampoline_size = &secondary_trampoline_end - &secondary_trampoline;
35 
36 	if (socfpga_cpu1start_addr) {
37 		/* This will put CPU #1 into reset. */
38 		writel(RSTMGR_MPUMODRST_CPU1,
39 		       rst_manager_base_addr + SOCFPGA_RSTMGR_MODMPURST);
40 
41 		memcpy(phys_to_virt(0), &secondary_trampoline, trampoline_size);
42 
43 		writel(virt_to_phys(secondary_startup),
44 		       sys_manager_base_addr + (socfpga_cpu1start_addr & 0x000000ff));
45 
46 		flush_cache_all();
47 		smp_wmb();
48 		outer_clean_range(0, trampoline_size);
49 
50 		/* This will release CPU #1 out of reset. */
51 		writel(0, rst_manager_base_addr + SOCFPGA_RSTMGR_MODMPURST);
52 	}
53 
54 	return 0;
55 }
56 
57 static int socfpga_a10_boot_secondary(unsigned int cpu, struct task_struct *idle)
58 {
59 	int trampoline_size = &secondary_trampoline_end - &secondary_trampoline;
60 
61 	if (socfpga_cpu1start_addr) {
62 		writel(RSTMGR_MPUMODRST_CPU1, rst_manager_base_addr +
63 		       SOCFPGA_A10_RSTMGR_MODMPURST);
64 		memcpy(phys_to_virt(0), &secondary_trampoline, trampoline_size);
65 
66 		writel(virt_to_phys(secondary_startup),
67 		       sys_manager_base_addr + (socfpga_cpu1start_addr & 0x00000fff));
68 
69 		flush_cache_all();
70 		smp_wmb();
71 		outer_clean_range(0, trampoline_size);
72 
73 		/* This will release CPU #1 out of reset. */
74 		writel(0, rst_manager_base_addr + SOCFPGA_A10_RSTMGR_MODMPURST);
75 	}
76 
77 	return 0;
78 }
79 
80 static void __init socfpga_smp_prepare_cpus(unsigned int max_cpus)
81 {
82 	struct device_node *np;
83 	void __iomem *socfpga_scu_base_addr;
84 
85 	np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
86 	if (!np) {
87 		pr_err("%s: missing scu\n", __func__);
88 		return;
89 	}
90 
91 	socfpga_scu_base_addr = of_iomap(np, 0);
92 	if (!socfpga_scu_base_addr)
93 		return;
94 	scu_enable(socfpga_scu_base_addr);
95 }
96 
97 #ifdef CONFIG_HOTPLUG_CPU
98 /*
99  * platform-specific code to shutdown a CPU
100  *
101  * Called with IRQs disabled
102  */
103 static void socfpga_cpu_die(unsigned int cpu)
104 {
105 	/* Do WFI. If we wake up early, go back into WFI */
106 	while (1)
107 		cpu_do_idle();
108 }
109 
110 /*
111  * We need a dummy function so that platform_can_cpu_hotplug() knows
112  * we support CPU hotplug. However, the function does not need to do
113  * anything, because CPUs going offline just do WFI. We could reset
114  * the CPUs but it would increase power consumption.
115  */
116 static int socfpga_cpu_kill(unsigned int cpu)
117 {
118 	return 1;
119 }
120 #endif
121 
122 static const struct smp_operations socfpga_smp_ops __initconst = {
123 	.smp_prepare_cpus	= socfpga_smp_prepare_cpus,
124 	.smp_boot_secondary	= socfpga_boot_secondary,
125 #ifdef CONFIG_HOTPLUG_CPU
126 	.cpu_die		= socfpga_cpu_die,
127 	.cpu_kill		= socfpga_cpu_kill,
128 #endif
129 };
130 
131 static const struct smp_operations socfpga_a10_smp_ops __initconst = {
132 	.smp_prepare_cpus	= socfpga_smp_prepare_cpus,
133 	.smp_boot_secondary	= socfpga_a10_boot_secondary,
134 #ifdef CONFIG_HOTPLUG_CPU
135 	.cpu_die		= socfpga_cpu_die,
136 	.cpu_kill		= socfpga_cpu_kill,
137 #endif
138 };
139 
140 CPU_METHOD_OF_DECLARE(socfpga_smp, "altr,socfpga-smp", &socfpga_smp_ops);
141 CPU_METHOD_OF_DECLARE(socfpga_a10_smp, "altr,socfpga-a10-smp", &socfpga_a10_smp_ops);
142