xref: /openbmc/linux/arch/sh/kernel/cpu/sh4a/smp-shx3.c (revision a1e58bbd)
1 /*
2  * SH-X3 SMP
3  *
4  *  Copyright (C) 2007  Paul Mundt
5  *  Copyright (C) 2007  Magnus Damm
6  *
7  * This file is subject to the terms and conditions of the GNU General Public
8  * License.  See the file "COPYING" in the main directory of this archive
9  * for more details.
10  */
11 #include <linux/init.h>
12 #include <linux/cpumask.h>
13 #include <linux/smp.h>
14 #include <linux/interrupt.h>
15 #include <linux/io.h>
16 
17 void __init plat_smp_setup(void)
18 {
19 	unsigned int cpu = 0;
20 	int i, num;
21 
22 	cpus_clear(cpu_possible_map);
23 	cpu_set(cpu, cpu_possible_map);
24 
25 	__cpu_number_map[0] = 0;
26 	__cpu_logical_map[0] = 0;
27 
28 	/*
29 	 * Do this stupidly for now.. we don't have an easy way to probe
30 	 * for the total number of cores.
31 	 */
32 	for (i = 1, num = 0; i < NR_CPUS; i++) {
33 		cpu_set(i, cpu_possible_map);
34 		__cpu_number_map[i] = ++num;
35 		__cpu_logical_map[num] = i;
36 	}
37 
38         printk(KERN_INFO "Detected %i available secondary CPU(s)\n", num);
39 }
40 
41 void __init plat_prepare_cpus(unsigned int max_cpus)
42 {
43 }
44 
45 #define STBCR_REG(phys_id) (0xfe400004 | (phys_id << 12))
46 #define RESET_REG(phys_id) (0xfe400008 | (phys_id << 12))
47 
48 #define STBCR_MSTP	0x00000001
49 #define STBCR_RESET	0x00000002
50 #define STBCR_LTSLP	0x80000000
51 
52 #define STBCR_AP_VAL	(STBCR_RESET | STBCR_LTSLP)
53 
54 void plat_start_cpu(unsigned int cpu, unsigned long entry_point)
55 {
56 	ctrl_outl(entry_point, RESET_REG(cpu));
57 
58 	if (!(ctrl_inl(STBCR_REG(cpu)) & STBCR_MSTP))
59 		ctrl_outl(STBCR_MSTP, STBCR_REG(cpu));
60 
61 	while (!(ctrl_inl(STBCR_REG(cpu)) & STBCR_MSTP))
62 		;
63 
64 	/* Start up secondary processor by sending a reset */
65 	ctrl_outl(STBCR_AP_VAL, STBCR_REG(cpu));
66 }
67 
68 int plat_smp_processor_id(void)
69 {
70 	return ctrl_inl(0xff000048); /* CPIDR */
71 }
72 
73 void plat_send_ipi(unsigned int cpu, unsigned int message)
74 {
75 	unsigned long addr = 0xfe410070 + (cpu * 4);
76 
77 	BUG_ON(cpu >= 4);
78 	BUG_ON(message >= SMP_MSG_NR);
79 
80 	ctrl_outl(1 << (message << 2), addr); /* C0INTICI..CnINTICI */
81 }
82 
83 struct ipi_data {
84 	void (*handler)(void *);
85 	void *arg;
86 	unsigned int message;
87 };
88 
89 static irqreturn_t ipi_interrupt_handler(int irq, void *arg)
90 {
91 	struct ipi_data *id = arg;
92 	unsigned int cpu = hard_smp_processor_id();
93 	unsigned int offs = 4 * cpu;
94 	unsigned int x;
95 
96 	x = ctrl_inl(0xfe410070 + offs); /* C0INITICI..CnINTICI */
97 	x &= (1 << (id->message << 2));
98 	ctrl_outl(x, 0xfe410080 + offs); /* C0INTICICLR..CnINTICICLR */
99 
100 	id->handler(id->arg);
101 
102 	return IRQ_HANDLED;
103 }
104 
105 static struct ipi_data ipi_handlers[SMP_MSG_NR];
106 
107 int plat_register_ipi_handler(unsigned int message,
108 			      void (*handler)(void *), void *arg)
109 {
110 	struct ipi_data *id = &ipi_handlers[message];
111 
112 	BUG_ON(SMP_MSG_NR >= 8);
113 	BUG_ON(message >= SMP_MSG_NR);
114 
115 	id->handler = handler;
116 	id->arg = arg;
117 	id->message = message;
118 
119 	return request_irq(104 + message, ipi_interrupt_handler, 0, "IPI", id);
120 }
121