blob: fda6a4d3bf23381be7dc24d77d7ca1c40ad60efc [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001
2/*
3 * IBM ASM Service Processor Device Driver
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 *
19 * Copyright (C) IBM Corporation, 2004
20 *
Dmitry Torokhov3110dc72007-07-17 04:03:58 -070021 * Author: Max Asböck <amax@us.ibm.com>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022 *
23 */
24
25#include "ibmasm.h"
Max Asbockb8acb802005-06-21 17:16:33 -070026#include "lowlevel.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
28/*
29 * ASM service processor event handling routines.
30 *
31 * Events are signalled to the device drivers through interrupts.
32 * They have the format of dot commands, with the type field set to
33 * sp_event.
34 * The driver does not interpret the events, it simply stores them in a
35 * circular buffer.
36 */
37
Linus Torvalds1da177e2005-04-16 15:20:36 -070038static void wake_up_event_readers(struct service_processor *sp)
39{
40 struct event_reader *reader;
41
42 list_for_each_entry(reader, &sp->event_buffer->readers, node)
43 wake_up_interruptible(&reader->wait);
44}
45
46/**
47 * receive_event
48 * Called by the interrupt handler when a dot command of type sp_event is
49 * received.
50 * Store the event in the circular event buffer, wake up any sleeping
51 * event readers.
52 * There is no reader marker in the buffer, therefore readers are
53 * responsible for keeping up with the writer, or they will loose events.
Dmitry Torokhov3110dc72007-07-17 04:03:58 -070054 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070055void ibmasm_receive_event(struct service_processor *sp, void *data, unsigned int data_size)
56{
57 struct event_buffer *buffer = sp->event_buffer;
58 struct ibmasm_event *event;
59 unsigned long flags;
60
61 data_size = min(data_size, IBMASM_EVENT_MAX_SIZE);
62
63 spin_lock_irqsave(&sp->lock, flags);
64 /* copy the event into the next slot in the circular buffer */
65 event = &buffer->events[buffer->next_index];
Max Asbockb8acb802005-06-21 17:16:33 -070066 memcpy_fromio(event->data, data, data_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 event->data_size = data_size;
68 event->serial_number = buffer->next_serial_number;
69
70 /* advance indices in the buffer */
71 buffer->next_index = (buffer->next_index + 1) % IBMASM_NUM_EVENTS;
72 buffer->next_serial_number++;
73 spin_unlock_irqrestore(&sp->lock, flags);
74
75 wake_up_event_readers(sp);
76}
77
78static inline int event_available(struct event_buffer *b, struct event_reader *r)
79{
Dmitry Torokhov3110dc72007-07-17 04:03:58 -070080 return (r->next_serial_number < b->next_serial_number);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081}
82
83/**
84 * get_next_event
85 * Called by event readers (initiated from user space through the file
Dmitry Torokhov3110dc72007-07-17 04:03:58 -070086 * system).
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 * Sleeps until a new event is available.
88 */
89int ibmasm_get_next_event(struct service_processor *sp, struct event_reader *reader)
90{
91 struct event_buffer *buffer = sp->event_buffer;
92 struct ibmasm_event *event;
93 unsigned int index;
94 unsigned long flags;
95
Max Asbockb8acb802005-06-21 17:16:33 -070096 reader->cancelled = 0;
97
98 if (wait_event_interruptible(reader->wait,
99 event_available(buffer, reader) || reader->cancelled))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 return -ERESTARTSYS;
101
102 if (!event_available(buffer, reader))
103 return 0;
104
105 spin_lock_irqsave(&sp->lock, flags);
106
107 index = buffer->next_index;
108 event = &buffer->events[index];
109 while (event->serial_number < reader->next_serial_number) {
110 index = (index + 1) % IBMASM_NUM_EVENTS;
111 event = &buffer->events[index];
112 }
113 memcpy(reader->data, event->data, event->data_size);
114 reader->data_size = event->data_size;
115 reader->next_serial_number = event->serial_number + 1;
116
117 spin_unlock_irqrestore(&sp->lock, flags);
118
119 return event->data_size;
120}
121
Max Asbockb8acb802005-06-21 17:16:33 -0700122void ibmasm_cancel_next_event(struct event_reader *reader)
123{
124 reader->cancelled = 1;
125 wake_up_interruptible(&reader->wait);
126}
127
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128void ibmasm_event_reader_register(struct service_processor *sp, struct event_reader *reader)
129{
130 unsigned long flags;
131
132 reader->next_serial_number = sp->event_buffer->next_serial_number;
133 init_waitqueue_head(&reader->wait);
134 spin_lock_irqsave(&sp->lock, flags);
135 list_add(&reader->node, &sp->event_buffer->readers);
136 spin_unlock_irqrestore(&sp->lock, flags);
137}
138
139void ibmasm_event_reader_unregister(struct service_processor *sp, struct event_reader *reader)
140{
141 unsigned long flags;
142
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 spin_lock_irqsave(&sp->lock, flags);
144 list_del(&reader->node);
145 spin_unlock_irqrestore(&sp->lock, flags);
146}
147
148int ibmasm_event_buffer_init(struct service_processor *sp)
149{
150 struct event_buffer *buffer;
151 struct ibmasm_event *event;
152 int i;
153
154 buffer = kmalloc(sizeof(struct event_buffer), GFP_KERNEL);
155 if (!buffer)
156 return 1;
157
158 buffer->next_index = 0;
159 buffer->next_serial_number = 1;
160
161 event = buffer->events;
162 for (i=0; i<IBMASM_NUM_EVENTS; i++, event++)
163 event->serial_number = 0;
164
165 INIT_LIST_HEAD(&buffer->readers);
166
167 sp->event_buffer = buffer;
168
169 return 0;
170}
171
172void ibmasm_event_buffer_exit(struct service_processor *sp)
173{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 kfree(sp->event_buffer);
175}