xref: /linux/arch/arm/mach-shmobile/smp-sh73a0.c (revision 6ed7ffddcf61f668114edb676417e5fb33773b59)
1 /*
2  * SMP support for R-Mobile / SH-Mobile - sh73a0 portion
3  *
4  * Copyright (C) 2010  Magnus Damm
5  * Copyright (C) 2010  Takashi Yoshii
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; version 2 of the License.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
19  */
20 #include <linux/kernel.h>
21 #include <linux/init.h>
22 #include <linux/smp.h>
23 #include <linux/spinlock.h>
24 #include <linux/io.h>
25 #include <linux/delay.h>
26 #include <linux/irqchip/arm-gic.h>
27 #include <mach/common.h>
28 #include <asm/cacheflush.h>
29 #include <asm/smp_plat.h>
30 #include <mach/sh73a0.h>
31 #include <asm/smp_scu.h>
32 #include <asm/smp_twd.h>
33 
34 #define WUPCR		IOMEM(0xe6151010)
35 #define SRESCR		IOMEM(0xe6151018)
36 #define PSTR		IOMEM(0xe6151040)
37 #define SBAR		IOMEM(0xe6180020)
38 #define APARMBAREA	IOMEM(0xe6f10020)
39 
40 #define PSTR_SHUTDOWN_MODE	3
41 
42 static void __iomem *scu_base_addr(void)
43 {
44 	return (void __iomem *)0xf0000000;
45 }
46 
47 #ifdef CONFIG_HAVE_ARM_TWD
48 static DEFINE_TWD_LOCAL_TIMER(twd_local_timer, 0xf0000600, 29);
49 void __init sh73a0_register_twd(void)
50 {
51 	twd_local_timer_register(&twd_local_timer);
52 }
53 #endif
54 
55 static unsigned int __init sh73a0_get_core_count(void)
56 {
57 	void __iomem *scu_base = scu_base_addr();
58 
59 	return scu_get_core_count(scu_base);
60 }
61 
62 static void __cpuinit sh73a0_secondary_init(unsigned int cpu)
63 {
64 	gic_secondary_init(0);
65 }
66 
67 static int __cpuinit sh73a0_boot_secondary(unsigned int cpu, struct task_struct *idle)
68 {
69 	cpu = cpu_logical_map(cpu);
70 
71 	if (((__raw_readl(PSTR) >> (4 * cpu)) & 3) == 3)
72 		__raw_writel(1 << cpu, WUPCR);	/* wake up */
73 	else
74 		__raw_writel(1 << cpu, SRESCR);	/* reset */
75 
76 	return 0;
77 }
78 
79 static void __init sh73a0_smp_prepare_cpus(unsigned int max_cpus)
80 {
81 	scu_enable(scu_base_addr());
82 
83 	/* Map the reset vector (in headsmp-sh73a0.S) */
84 	__raw_writel(0, APARMBAREA);      /* 4k */
85 	__raw_writel(__pa(sh73a0_secondary_vector), SBAR);
86 
87 	/* enable cache coherency on booting CPU */
88 	scu_power_mode(scu_base_addr(), SCU_PM_NORMAL);
89 }
90 
91 static void __init sh73a0_smp_init_cpus(void)
92 {
93 	unsigned int ncores = sh73a0_get_core_count();
94 
95 	shmobile_smp_init_cpus(ncores);
96 }
97 
98 #ifdef CONFIG_HOTPLUG_CPU
99 static int sh73a0_cpu_kill(unsigned int cpu)
100 {
101 
102 	int k;
103 	u32 pstr;
104 
105 	/*
106 	 * wait until the power status register confirms the shutdown of the
107 	 * offline target
108 	 */
109 	for (k = 0; k < 1000; k++) {
110 		pstr = (__raw_readl(PSTR) >> (4 * cpu)) & 3;
111 		if (pstr == PSTR_SHUTDOWN_MODE)
112 			return 1;
113 
114 		mdelay(1);
115 	}
116 
117 	return 0;
118 }
119 
120 static void sh73a0_cpu_die(unsigned int cpu)
121 {
122 	/*
123 	 * The ARM MPcore does not issue a cache coherency request for the L1
124 	 * cache when powering off single CPUs. We must take care of this and
125 	 * further caches.
126 	 */
127 	dsb();
128 	flush_cache_all();
129 
130 	/* Set power off mode. This takes the CPU out of the MP cluster */
131 	scu_power_mode(scu_base_addr(), SCU_PM_POWEROFF);
132 
133 	/* Enter shutdown mode */
134 	cpu_do_idle();
135 }
136 #endif /* CONFIG_HOTPLUG_CPU */
137 
138 struct smp_operations sh73a0_smp_ops __initdata = {
139 	.smp_init_cpus		= sh73a0_smp_init_cpus,
140 	.smp_prepare_cpus	= sh73a0_smp_prepare_cpus,
141 	.smp_secondary_init	= sh73a0_secondary_init,
142 	.smp_boot_secondary	= sh73a0_boot_secondary,
143 #ifdef CONFIG_HOTPLUG_CPU
144 	.cpu_kill		= sh73a0_cpu_kill,
145 	.cpu_die		= sh73a0_cpu_die,
146 	.cpu_disable		= shmobile_cpu_disable_any,
147 #endif
148 };
149