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 <mach/common.h>
27 #include <asm/smp_plat.h>
28 #include <mach/sh73a0.h>
29 #include <asm/smp_scu.h>
30 #include <asm/smp_twd.h>
31 #include <asm/hardware/gic.h>
32 
33 #define WUPCR		IOMEM(0xe6151010)
34 #define SRESCR		IOMEM(0xe6151018)
35 #define PSTR		IOMEM(0xe6151040)
36 #define SBAR		IOMEM(0xe6180020)
37 #define APARMBAREA	IOMEM(0xe6f10020)
38 
39 static void __iomem *scu_base_addr(void)
40 {
41 	return (void __iomem *)0xf0000000;
42 }
43 
44 static DEFINE_SPINLOCK(scu_lock);
45 static unsigned long tmp;
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 void modify_scu_cpu_psr(unsigned long set, unsigned long clr)
56 {
57 	void __iomem *scu_base = scu_base_addr();
58 
59 	spin_lock(&scu_lock);
60 	tmp = __raw_readl(scu_base + 8);
61 	tmp &= ~clr;
62 	tmp |= set;
63 	spin_unlock(&scu_lock);
64 
65 	/* disable cache coherency after releasing the lock */
66 	__raw_writel(tmp, scu_base + 8);
67 }
68 
69 static unsigned int __init sh73a0_get_core_count(void)
70 {
71 	void __iomem *scu_base = scu_base_addr();
72 
73 	return scu_get_core_count(scu_base);
74 }
75 
76 static void __cpuinit sh73a0_secondary_init(unsigned int cpu)
77 {
78 	gic_secondary_init(0);
79 }
80 
81 static int __cpuinit sh73a0_boot_secondary(unsigned int cpu, struct task_struct *idle)
82 {
83 	cpu = cpu_logical_map(cpu);
84 
85 	/* enable cache coherency */
86 	modify_scu_cpu_psr(0, 3 << (cpu * 8));
87 
88 	if (((__raw_readl(PSTR) >> (4 * cpu)) & 3) == 3)
89 		__raw_writel(1 << cpu, WUPCR);	/* wake up */
90 	else
91 		__raw_writel(1 << cpu, SRESCR);	/* reset */
92 
93 	return 0;
94 }
95 
96 static void __init sh73a0_smp_prepare_cpus(unsigned int max_cpus)
97 {
98 	int cpu = cpu_logical_map(0);
99 
100 	scu_enable(scu_base_addr());
101 
102 	/* Map the reset vector (in headsmp.S) */
103 	__raw_writel(0, APARMBAREA);      /* 4k */
104 	__raw_writel(__pa(shmobile_secondary_vector), SBAR);
105 
106 	/* enable cache coherency on CPU0 */
107 	modify_scu_cpu_psr(0, 3 << (cpu * 8));
108 }
109 
110 static void __init sh73a0_smp_init_cpus(void)
111 {
112 	unsigned int ncores = sh73a0_get_core_count();
113 
114 	shmobile_smp_init_cpus(ncores);
115 }
116 
117 static int __maybe_unused sh73a0_cpu_kill(unsigned int cpu)
118 {
119 	int k;
120 
121 	/* this function is running on another CPU than the offline target,
122 	 * here we need wait for shutdown code in platform_cpu_die() to
123 	 * finish before asking SoC-specific code to power off the CPU core.
124 	 */
125 	for (k = 0; k < 1000; k++) {
126 		if (shmobile_cpu_is_dead(cpu))
127 			return 1;
128 
129 		mdelay(1);
130 	}
131 
132 	return 0;
133 }
134 
135 
136 struct smp_operations sh73a0_smp_ops __initdata = {
137 	.smp_init_cpus		= sh73a0_smp_init_cpus,
138 	.smp_prepare_cpus	= sh73a0_smp_prepare_cpus,
139 	.smp_secondary_init	= sh73a0_secondary_init,
140 	.smp_boot_secondary	= sh73a0_boot_secondary,
141 #ifdef CONFIG_HOTPLUG_CPU
142 	.cpu_kill		= sh73a0_cpu_kill,
143 	.cpu_die		= shmobile_cpu_die,
144 	.cpu_disable		= shmobile_cpu_disable,
145 #endif
146 };
147