Merge /spare/repo/linux-2.6/
[linux-2.6] / arch / ppc / platforms / chrp_smp.c
1 /*
2  * Smp support for CHRP machines.
3  *
4  * Written by Cort Dougan (cort@cs.nmt.edu) borrowing a great
5  * deal of code from the sparc and intel versions.
6  *
7  * Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
8  *
9  */
10
11 #include <linux/config.h>
12 #include <linux/kernel.h>
13 #include <linux/sched.h>
14 #include <linux/smp.h>
15 #include <linux/smp_lock.h>
16 #include <linux/interrupt.h>
17 #include <linux/kernel_stat.h>
18 #include <linux/delay.h>
19 #include <linux/init.h>
20 #include <linux/spinlock.h>
21
22 #include <asm/ptrace.h>
23 #include <asm/atomic.h>
24 #include <asm/irq.h>
25 #include <asm/page.h>
26 #include <asm/pgtable.h>
27 #include <asm/sections.h>
28 #include <asm/io.h>
29 #include <asm/prom.h>
30 #include <asm/smp.h>
31 #include <asm/residual.h>
32 #include <asm/time.h>
33 #include <asm/open_pic.h>
34
35 extern unsigned long smp_chrp_cpu_nr;
36
37 static int __init
38 smp_chrp_probe(void)
39 {
40         if (smp_chrp_cpu_nr > 1)
41                 openpic_request_IPIs();
42
43         return smp_chrp_cpu_nr;
44 }
45
46 static void __devinit
47 smp_chrp_kick_cpu(int nr)
48 {
49         *(unsigned long *)KERNELBASE = nr;
50         asm volatile("dcbf 0,%0"::"r"(KERNELBASE):"memory");
51 }
52
53 static void __devinit
54 smp_chrp_setup_cpu(int cpu_nr)
55 {
56         if (OpenPIC_Addr)
57                 do_openpic_setup_cpu();
58 }
59
60 static DEFINE_SPINLOCK(timebase_lock);
61 static unsigned int timebase_upper = 0, timebase_lower = 0;
62
63 void __devinit
64 smp_chrp_give_timebase(void)
65 {
66         spin_lock(&timebase_lock);
67         call_rtas("freeze-time-base", 0, 1, NULL);
68         timebase_upper = get_tbu();
69         timebase_lower = get_tbl();
70         spin_unlock(&timebase_lock);
71
72         while (timebase_upper || timebase_lower)
73                 barrier();
74         call_rtas("thaw-time-base", 0, 1, NULL);
75 }
76
77 void __devinit
78 smp_chrp_take_timebase(void)
79 {
80         while (!(timebase_upper || timebase_lower))
81                 barrier();
82         spin_lock(&timebase_lock);
83         set_tb(timebase_upper, timebase_lower);
84         timebase_upper = 0;
85         timebase_lower = 0;
86         spin_unlock(&timebase_lock);
87         printk("CPU %i taken timebase\n", smp_processor_id());
88 }
89
90 /* CHRP with openpic */
91 struct smp_ops_t chrp_smp_ops __chrpdata = {
92         .message_pass = smp_openpic_message_pass,
93         .probe = smp_chrp_probe,
94         .kick_cpu = smp_chrp_kick_cpu,
95         .setup_cpu = smp_chrp_setup_cpu,
96         .give_timebase = smp_chrp_give_timebase,
97         .take_timebase = smp_chrp_take_timebase,
98 };