powerpc: Merge 32-bit CHRP support.
[linux-2.6.git] / arch / powerpc / 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 #include <asm/machdep.h>
35
36 extern unsigned long smp_chrp_cpu_nr;
37
38 static int __init 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 smp_chrp_kick_cpu(int nr)
47 {
48         *(unsigned long *)KERNELBASE = nr;
49         asm volatile("dcbf 0,%0"::"r"(KERNELBASE):"memory");
50 }
51
52 static void __devinit smp_chrp_setup_cpu(int cpu_nr)
53 {
54         if (OpenPIC_Addr)
55                 do_openpic_setup_cpu();
56 }
57
58 static DEFINE_SPINLOCK(timebase_lock);
59 static unsigned int timebase_upper = 0, timebase_lower = 0;
60
61 void __devinit smp_chrp_give_timebase(void)
62 {
63         spin_lock(&timebase_lock);
64         rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL);
65         timebase_upper = get_tbu();
66         timebase_lower = get_tbl();
67         spin_unlock(&timebase_lock);
68
69         while (timebase_upper || timebase_lower)
70                 barrier();
71         rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL);
72 }
73
74 void __devinit smp_chrp_take_timebase(void)
75 {
76         while (!(timebase_upper || timebase_lower))
77                 barrier();
78         spin_lock(&timebase_lock);
79         set_tb(timebase_upper, timebase_lower);
80         timebase_upper = 0;
81         timebase_lower = 0;
82         spin_unlock(&timebase_lock);
83         printk("CPU %i taken timebase\n", smp_processor_id());
84 }
85
86 /* CHRP with openpic */
87 struct smp_ops_t chrp_smp_ops = {
88         .message_pass = smp_openpic_message_pass,
89         .probe = smp_chrp_probe,
90         .kick_cpu = smp_chrp_kick_cpu,
91         .setup_cpu = smp_chrp_setup_cpu,
92         .give_timebase = smp_chrp_give_timebase,
93         .take_timebase = smp_chrp_take_timebase,
94 };