1 /*
2 * SMP support for iSeries machines.
3 *
4 * Dave Engebretsen, Peter Bergner, and
5 * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com
6 *
7 * Plus various changes from other IBM teams...
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 */
14
15 #undef DEBUG
16
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/sched.h>
20 #include <linux/smp.h>
21 #include <linux/interrupt.h>
22 #include <linux/kernel_stat.h>
23 #include <linux/delay.h>
24 #include <linux/init.h>
25 #include <linux/spinlock.h>
26 #include <linux/cache.h>
27 #include <linux/err.h>
28 #include <linux/sysdev.h>
29 #include <linux/cpu.h>
30
31 #include <asm/ptrace.h>
32 #include <asm/atomic.h>
33 #include <asm/irq.h>
34 #include <asm/page.h>
35 #include <asm/pgtable.h>
36 #include <asm/io.h>
37 #include <asm/smp.h>
38 #include <asm/paca.h>
39 #include <asm/iseries/hv_call.h>
40 #include <asm/time.h>
41 #include <asm/machdep.h>
42 #include <asm/cputable.h>
43 #include <asm/system.h>
44
45 #include "smp.h"
46
47 static unsigned long iSeries_smp_message[NR_CPUS];
48
iSeries_smp_message_recv(void)49 void iSeries_smp_message_recv(void)
50 {
51 int cpu = smp_processor_id();
52 int msg;
53
54 if (num_online_cpus() < 2)
55 return;
56
57 for (msg = 0; msg < 4; msg++)
58 if (test_and_clear_bit(msg, &iSeries_smp_message[cpu]))
59 smp_message_recv(msg);
60 }
61
smp_iSeries_do_message(int cpu,int msg)62 static inline void smp_iSeries_do_message(int cpu, int msg)
63 {
64 set_bit(msg, &iSeries_smp_message[cpu]);
65 HvCall_sendIPI(&(paca[cpu]));
66 }
67
smp_iSeries_message_pass(int target,int msg)68 static void smp_iSeries_message_pass(int target, int msg)
69 {
70 int i;
71
72 if (target < NR_CPUS)
73 smp_iSeries_do_message(target, msg);
74 else {
75 for_each_online_cpu(i) {
76 if ((target == MSG_ALL_BUT_SELF) &&
77 (i == smp_processor_id()))
78 continue;
79 smp_iSeries_do_message(i, msg);
80 }
81 }
82 }
83
smp_iSeries_probe(void)84 static int smp_iSeries_probe(void)
85 {
86 return cpumask_weight(cpu_possible_mask);
87 }
88
smp_iSeries_kick_cpu(int nr)89 static void smp_iSeries_kick_cpu(int nr)
90 {
91 BUG_ON((nr < 0) || (nr >= NR_CPUS));
92
93 /* Verify that our partition has a processor nr */
94 if (lppaca_of(nr).dyn_proc_status >= 2)
95 return;
96
97 /* The processor is currently spinning, waiting
98 * for the cpu_start field to become non-zero
99 * After we set cpu_start, the processor will
100 * continue on to secondary_start in iSeries_head.S
101 */
102 paca[nr].cpu_start = 1;
103 }
104
smp_iSeries_setup_cpu(int nr)105 static void __devinit smp_iSeries_setup_cpu(int nr)
106 {
107 }
108
109 static struct smp_ops_t iSeries_smp_ops = {
110 .message_pass = smp_iSeries_message_pass,
111 .probe = smp_iSeries_probe,
112 .kick_cpu = smp_iSeries_kick_cpu,
113 .setup_cpu = smp_iSeries_setup_cpu,
114 };
115
116 /* This is called very early. */
smp_init_iSeries(void)117 void __init smp_init_iSeries(void)
118 {
119 smp_ops = &iSeries_smp_ops;
120 }
121