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/kernel.h>
12 #include <linux/sched.h>
13 #include <linux/smp.h>
14 #include <linux/interrupt.h>
15 #include <linux/kernel_stat.h>
16 #include <linux/delay.h>
17 #include <linux/init.h>
18 #include <linux/spinlock.h>
19
20 #include <asm/ptrace.h>
21 #include <asm/atomic.h>
22 #include <asm/irq.h>
23 #include <asm/page.h>
24 #include <asm/pgtable.h>
25 #include <asm/sections.h>
26 #include <asm/io.h>
27 #include <asm/prom.h>
28 #include <asm/smp.h>
29 #include <asm/time.h>
30 #include <asm/machdep.h>
31 #include <asm/mpic.h>
32 #include <asm/rtas.h>
33
smp_chrp_kick_cpu(int nr)34 static void __devinit smp_chrp_kick_cpu(int nr)
35 {
36 *(unsigned long *)KERNELBASE = nr;
37 asm volatile("dcbf 0,%0"::"r"(KERNELBASE):"memory");
38 }
39
smp_chrp_setup_cpu(int cpu_nr)40 static void __devinit smp_chrp_setup_cpu(int cpu_nr)
41 {
42 mpic_setup_this_cpu();
43 }
44
45 static DEFINE_SPINLOCK(timebase_lock);
46 static unsigned int timebase_upper = 0, timebase_lower = 0;
47
smp_chrp_give_timebase(void)48 void __devinit smp_chrp_give_timebase(void)
49 {
50 spin_lock(&timebase_lock);
51 rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL);
52 timebase_upper = get_tbu();
53 timebase_lower = get_tbl();
54 spin_unlock(&timebase_lock);
55
56 while (timebase_upper || timebase_lower)
57 barrier();
58 rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL);
59 }
60
smp_chrp_take_timebase(void)61 void __devinit smp_chrp_take_timebase(void)
62 {
63 while (!(timebase_upper || timebase_lower))
64 barrier();
65 spin_lock(&timebase_lock);
66 set_tb(timebase_upper, timebase_lower);
67 timebase_upper = 0;
68 timebase_lower = 0;
69 spin_unlock(&timebase_lock);
70 printk("CPU %i taken timebase\n", smp_processor_id());
71 }
72
73 /* CHRP with openpic */
74 struct smp_ops_t chrp_smp_ops = {
75 .message_pass = smp_mpic_message_pass,
76 .probe = smp_mpic_probe,
77 .kick_cpu = smp_chrp_kick_cpu,
78 .setup_cpu = smp_chrp_setup_cpu,
79 .give_timebase = smp_chrp_give_timebase,
80 .take_timebase = smp_chrp_take_timebase,
81 };
82