xref: /openbmc/linux/arch/arm/mach-socfpga/platsmp.c (revision 97da55fc)
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 #include <linux/irqchip/arm-gic.h>
26 
27 #include <asm/cacheflush.h>
28 #include <asm/smp_scu.h>
29 #include <asm/smp_plat.h>
30 
31 #include "core.h"
32 
33 extern void __iomem *sys_manager_base_addr;
34 extern void __iomem *rst_manager_base_addr;
35 
36 static void __cpuinit socfpga_secondary_init(unsigned int cpu)
37 {
38 	/*
39 	 * if any interrupts are already enabled for the primary
40 	 * core (e.g. timer irq), then they will not have been enabled
41 	 * for us: do so
42 	 */
43 	gic_secondary_init(0);
44 }
45 
46 static int __cpuinit socfpga_boot_secondary(unsigned int cpu, struct task_struct *idle)
47 {
48 	int trampoline_size = &secondary_trampoline_end - &secondary_trampoline;
49 
50 	if (cpu1start_addr) {
51 		memcpy(phys_to_virt(0), &secondary_trampoline, trampoline_size);
52 
53 		__raw_writel(virt_to_phys(socfpga_secondary_startup),
54 			(sys_manager_base_addr + (cpu1start_addr & 0x000000ff)));
55 
56 		flush_cache_all();
57 		smp_wmb();
58 		outer_clean_range(0, trampoline_size);
59 
60 		/* This will release CPU #1 out of reset.*/
61 		__raw_writel(0, rst_manager_base_addr + 0x10);
62 	}
63 
64 	return 0;
65 }
66 
67 /*
68  * Initialise the CPU possible map early - this describes the CPUs
69  * which may be present or become present in the system.
70  */
71 static void __init socfpga_smp_init_cpus(void)
72 {
73 	unsigned int i, ncores;
74 
75 	ncores = scu_get_core_count(socfpga_scu_base_addr);
76 
77 	for (i = 0; i < ncores; i++)
78 		set_cpu_possible(i, true);
79 
80 	/* sanity check */
81 	if (ncores > num_possible_cpus()) {
82 		pr_warn("socfpga: no. of cores (%d) greater than configured"
83 			"maximum of %d - clipping\n", ncores, num_possible_cpus());
84 		ncores = num_possible_cpus();
85 	}
86 
87 	for (i = 0; i < ncores; i++)
88 		set_cpu_possible(i, true);
89 }
90 
91 static void __init socfpga_smp_prepare_cpus(unsigned int max_cpus)
92 {
93 	scu_enable(socfpga_scu_base_addr);
94 }
95 
96 /*
97  * platform-specific code to shutdown a CPU
98  *
99  * Called with IRQs disabled
100  */
101 static void socfpga_cpu_die(unsigned int cpu)
102 {
103 	cpu_do_idle();
104 
105 	/* We should have never returned from idle */
106 	panic("cpu %d unexpectedly exit from shutdown\n", cpu);
107 }
108 
109 struct smp_operations socfpga_smp_ops __initdata = {
110 	.smp_init_cpus		= socfpga_smp_init_cpus,
111 	.smp_prepare_cpus	= socfpga_smp_prepare_cpus,
112 	.smp_secondary_init	= socfpga_secondary_init,
113 	.smp_boot_secondary	= socfpga_boot_secondary,
114 #ifdef CONFIG_HOTPLUG_CPU
115 	.cpu_die		= socfpga_cpu_die,
116 #endif
117 };
118