2 * SMP Support for A2 platforms
4 * Copyright 2007 Benjamin Herrenschmidt, IBM Corp.
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.
13 #include <linux/cpumask.h>
14 #include <linux/init.h>
15 #include <linux/kernel.h>
17 #include <linux/smp.h>
19 #include <asm/dbell.h>
20 #include <asm/machdep.h>
26 static void smp_a2_setup_cpu(int cpu)
28 doorbell_setup_this_cpu();
30 if (cpu != boot_cpuid)
34 int smp_a2_kick_cpu(int nr)
36 const char *enable_method;
37 struct device_node *np;
40 if (nr < 0 || nr >= NR_CPUS)
43 np = of_get_cpu_node(nr, &thr_idx);
47 enable_method = of_get_property(np, "enable-method", NULL);
48 pr_devel("CPU%d has enable-method: \"%s\"\n", nr, enable_method);
51 printk(KERN_ERR "CPU%d has no enable-method\n", nr);
53 } else if (strcmp(enable_method, "ibm,a2-scom") == 0) {
54 if (a2_scom_startup_cpu(nr, thr_idx, np))
57 printk(KERN_ERR "CPU%d: Don't understand enable-method \"%s\"\n",
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
67 paca[nr].cpu_start = 1;
72 static int __init smp_a2_probe(void)
74 return num_possible_cpus();
77 static 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,
85 void __init a2_setup_smp(void)
87 smp_ops = &a2_smp_ops;