xref: /linux/arch/sh/kernel/cpu/sh4a/smp-shx3.c (revision 367b8112fe2ea5c39a7bb4d263dcdd9b612fae18)
1 /*
2  * SH-X3 SMP
3  *
4  *  Copyright (C) 2007 - 2008  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 static irqreturn_t ipi_interrupt_handler(int irq, void *arg)
18 {
19 	unsigned int message = (unsigned int)(long)arg;
20 	unsigned int cpu = hard_smp_processor_id();
21 	unsigned int offs = 4 * cpu;
22 	unsigned int x;
23 
24 	x = ctrl_inl(0xfe410070 + offs); /* C0INITICI..CnINTICI */
25 	x &= (1 << (message << 2));
26 	ctrl_outl(x, 0xfe410080 + offs); /* C0INTICICLR..CnINTICICLR */
27 
28 	smp_message_recv(message);
29 
30 	return IRQ_HANDLED;
31 }
32 
33 void __init plat_smp_setup(void)
34 {
35 	unsigned int cpu = 0;
36 	int i, num;
37 
38 	cpus_clear(cpu_possible_map);
39 	cpu_set(cpu, cpu_possible_map);
40 
41 	__cpu_number_map[0] = 0;
42 	__cpu_logical_map[0] = 0;
43 
44 	/*
45 	 * Do this stupidly for now.. we don't have an easy way to probe
46 	 * for the total number of cores.
47 	 */
48 	for (i = 1, num = 0; i < NR_CPUS; i++) {
49 		cpu_set(i, cpu_possible_map);
50 		__cpu_number_map[i] = ++num;
51 		__cpu_logical_map[num] = i;
52 	}
53 
54         printk(KERN_INFO "Detected %i available secondary CPU(s)\n", num);
55 }
56 
57 void __init plat_prepare_cpus(unsigned int max_cpus)
58 {
59 	int i;
60 
61 	BUILD_BUG_ON(SMP_MSG_NR >= 8);
62 
63 	for (i = 0; i < SMP_MSG_NR; i++)
64 		request_irq(104 + i, ipi_interrupt_handler, IRQF_DISABLED,
65 			    "IPI", (void *)(long)i);
66 }
67 
68 #define STBCR_REG(phys_id) (0xfe400004 | (phys_id << 12))
69 #define RESET_REG(phys_id) (0xfe400008 | (phys_id << 12))
70 
71 #define STBCR_MSTP	0x00000001
72 #define STBCR_RESET	0x00000002
73 #define STBCR_LTSLP	0x80000000
74 
75 #define STBCR_AP_VAL	(STBCR_RESET | STBCR_LTSLP)
76 
77 void plat_start_cpu(unsigned int cpu, unsigned long entry_point)
78 {
79 	ctrl_outl(entry_point, RESET_REG(cpu));
80 
81 	if (!(ctrl_inl(STBCR_REG(cpu)) & STBCR_MSTP))
82 		ctrl_outl(STBCR_MSTP, STBCR_REG(cpu));
83 
84 	while (!(ctrl_inl(STBCR_REG(cpu)) & STBCR_MSTP))
85 		cpu_relax();
86 
87 	/* Start up secondary processor by sending a reset */
88 	ctrl_outl(STBCR_AP_VAL, STBCR_REG(cpu));
89 }
90 
91 int plat_smp_processor_id(void)
92 {
93 	return ctrl_inl(0xff000048); /* CPIDR */
94 }
95 
96 void plat_send_ipi(unsigned int cpu, unsigned int message)
97 {
98 	unsigned long addr = 0xfe410070 + (cpu * 4);
99 
100 	BUG_ON(cpu >= 4);
101 
102 	ctrl_outl(1 << (message << 2), addr); /* C0INTICI..CnINTICI */
103 }
104