1/*
 2 *  SMP Support for A2 platforms
 3 *
 4 *  Copyright 2007 Benjamin Herrenschmidt, IBM Corp.
 5 *
 6 *  This program is free software; you can redistribute it and/or
 7 *  modify it under the terms of the GNU General Public License
 8 *  as published by the Free Software Foundation; either version
 9 *  2 of the License, or (at your option) any later version.
10 *
11 */
12
13#include <linux/cpumask.h>
14#include <linux/init.h>
15#include <linux/kernel.h>
16#include <linux/of.h>
17#include <linux/smp.h>
18
19#include <asm/dbell.h>
20#include <asm/machdep.h>
21#include <asm/xics.h>
22
23#include "ics.h"
24#include "wsp.h"
25
26static void __devinit smp_a2_setup_cpu(int cpu)
27{
28	doorbell_setup_this_cpu();
29
30	if (cpu != boot_cpuid)
31		xics_setup_cpu();
32}
33
34int __devinit smp_a2_kick_cpu(int nr)
35{
36	const char *enable_method;
37	struct device_node *np;
38	int thr_idx;
39
40	if (nr < 0 || nr >= NR_CPUS)
41		return -ENOENT;
42
43	np = of_get_cpu_node(nr, &thr_idx);
44	if (!np)
45		return -ENODEV;
46
47	enable_method = of_get_property(np, "enable-method", NULL);
48	pr_devel("CPU%d has enable-method: \"%s\"\n", nr, enable_method);
49
50	if (!enable_method) {
51                printk(KERN_ERR "CPU%d has no enable-method\n", nr);
52		return -ENOENT;
53	} else if (strcmp(enable_method, "ibm,a2-scom") == 0) {
54		if (a2_scom_startup_cpu(nr, thr_idx, np))
55			return -1;
56	} else {
57		printk(KERN_ERR "CPU%d: Don't understand enable-method \"%s\"\n",
58                       nr, enable_method);
59		return -EINVAL;
60	}
61
62	/*
63	 * The processor is currently spinning, waiting for the
64	 * cpu_start field to become non-zero After we set cpu_start,
65	 * the processor will continue on to secondary_start
66	 */
67	paca[nr].cpu_start = 1;
68
69	return 0;
70}
71
72static int __init smp_a2_probe(void)
73{
74	return num_possible_cpus();
75}
76
77static struct smp_ops_t a2_smp_ops = {
78	.message_pass	= NULL,	/* Use smp_muxed_ipi_message_pass */
79	.cause_ipi	= doorbell_cause_ipi,
80	.probe		= smp_a2_probe,
81	.kick_cpu	= smp_a2_kick_cpu,
82	.setup_cpu	= smp_a2_setup_cpu,
83};
84
85void __init a2_setup_smp(void)
86{
87	smp_ops = &a2_smp_ops;
88}