Merge branch 'core/softlockup-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6] / arch / powerpc / platforms / ps3 / smp.c
1 /*
2  *  PS3 SMP routines.
3  *
4  *  Copyright (C) 2006 Sony Computer Entertainment Inc.
5  *  Copyright 2006 Sony Corp.
6  *
7  *  This program is free software; you can redistribute it and/or modify
8  *  it under the terms of the GNU General Public License as published by
9  *  the Free Software Foundation; version 2 of the License.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, write to the Free Software
18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19  */
20
21 #include <linux/kernel.h>
22 #include <linux/smp.h>
23
24 #include <asm/machdep.h>
25 #include <asm/udbg.h>
26
27 #include "platform.h"
28
29 #if defined(DEBUG)
30 #define DBG udbg_printf
31 #else
32 #define DBG pr_debug
33 #endif
34
35 static irqreturn_t ipi_function_handler(int irq, void *msg)
36 {
37         smp_message_recv((int)(long)msg);
38         return IRQ_HANDLED;
39 }
40
41 /**
42   * ps3_ipi_virqs - a per cpu array of virqs for ipi use
43   */
44
45 #define MSG_COUNT 4
46 static DEFINE_PER_CPU(unsigned int, ps3_ipi_virqs[MSG_COUNT]);
47
48 static const char *names[MSG_COUNT] = {
49         "ipi call",
50         "ipi reschedule",
51         "ipi migrate",
52         "ipi debug brk"
53 };
54
55 static void do_message_pass(int target, int msg)
56 {
57         int result;
58         unsigned int virq;
59
60         if (msg >= MSG_COUNT) {
61                 DBG("%s:%d: bad msg: %d\n", __func__, __LINE__, msg);
62                 return;
63         }
64
65         virq = per_cpu(ps3_ipi_virqs, target)[msg];
66         result = ps3_send_event_locally(virq);
67
68         if (result)
69                 DBG("%s:%d: ps3_send_event_locally(%d, %d) failed"
70                         " (%d)\n", __func__, __LINE__, target, msg, result);
71 }
72
73 static void ps3_smp_message_pass(int target, int msg)
74 {
75         int cpu;
76
77         if (target < NR_CPUS)
78                 do_message_pass(target, msg);
79         else if (target == MSG_ALL_BUT_SELF) {
80                 for_each_online_cpu(cpu)
81                         if (cpu != smp_processor_id())
82                                 do_message_pass(cpu, msg);
83         } else {
84                 for_each_online_cpu(cpu)
85                         do_message_pass(cpu, msg);
86         }
87 }
88
89 static int ps3_smp_probe(void)
90 {
91         return 2;
92 }
93
94 static void __init ps3_smp_setup_cpu(int cpu)
95 {
96         int result;
97         unsigned int *virqs = per_cpu(ps3_ipi_virqs, cpu);
98         int i;
99
100         DBG(" -> %s:%d: (%d)\n", __func__, __LINE__, cpu);
101
102         /*
103          * Check assumptions on ps3_ipi_virqs[] indexing. If this
104          * check fails, then a different mapping of PPC_MSG_
105          * to index needs to be setup.
106          */
107
108         BUILD_BUG_ON(PPC_MSG_CALL_FUNCTION    != 0);
109         BUILD_BUG_ON(PPC_MSG_RESCHEDULE       != 1);
110         BUILD_BUG_ON(PPC_MSG_CALL_FUNC_SINGLE != 2);
111         BUILD_BUG_ON(PPC_MSG_DEBUGGER_BREAK   != 3);
112
113         for (i = 0; i < MSG_COUNT; i++) {
114                 result = ps3_event_receive_port_setup(cpu, &virqs[i]);
115
116                 if (result)
117                         continue;
118
119                 DBG("%s:%d: (%d, %d) => virq %u\n",
120                         __func__, __LINE__, cpu, i, virqs[i]);
121
122                 result = request_irq(virqs[i], ipi_function_handler,
123                         IRQF_DISABLED, names[i], (void*)(long)i);
124
125                 if (result)
126                         virqs[i] = NO_IRQ;
127         }
128
129         ps3_register_ipi_debug_brk(cpu, virqs[PPC_MSG_DEBUGGER_BREAK]);
130
131         DBG(" <- %s:%d: (%d)\n", __func__, __LINE__, cpu);
132 }
133
134 void ps3_smp_cleanup_cpu(int cpu)
135 {
136         unsigned int *virqs = per_cpu(ps3_ipi_virqs, cpu);
137         int i;
138
139         DBG(" -> %s:%d: (%d)\n", __func__, __LINE__, cpu);
140
141         for (i = 0; i < MSG_COUNT; i++) {
142                 /* Can't call free_irq from interrupt context. */
143                 ps3_event_receive_port_destroy(virqs[i]);
144                 virqs[i] = NO_IRQ;
145         }
146
147         DBG(" <- %s:%d: (%d)\n", __func__, __LINE__, cpu);
148 }
149
150 static struct smp_ops_t ps3_smp_ops = {
151         .probe          = ps3_smp_probe,
152         .message_pass   = ps3_smp_message_pass,
153         .kick_cpu       = smp_generic_kick_cpu,
154         .setup_cpu      = ps3_smp_setup_cpu,
155 };
156
157 void smp_init_ps3(void)
158 {
159         DBG(" -> %s\n", __func__);
160         smp_ops = &ps3_smp_ops;
161         DBG(" <- %s\n", __func__);
162 }