blob: 425f741a280c4668ba17befa8762b4bd227fcb24 [file] [log] [blame]
Heiko Carstensf5daba12009-03-26 15:24:01 +01001/*
2 * Channel report handling code
3 *
4 * Copyright IBM Corp. 2000,2009
5 * Author(s): Ingo Adlung <adlung@de.ibm.com>,
6 * Martin Schwidefsky <schwidefsky@de.ibm.com>,
7 * Cornelia Huck <cornelia.huck@de.ibm.com>,
8 * Heiko Carstens <heiko.carstens@de.ibm.com>,
9 */
10
Heiko Carstens98c1c682009-03-26 15:24:09 +010011#include <linux/mutex.h>
Heiko Carstensf5daba12009-03-26 15:24:01 +010012#include <linux/kthread.h>
13#include <linux/init.h>
Sebastian Ottb4563e82010-02-26 22:37:26 +010014#include <linux/wait.h>
Heiko Carstensf5daba12009-03-26 15:24:01 +010015#include <asm/crw.h>
16
Heiko Carstens98c1c682009-03-26 15:24:09 +010017static DEFINE_MUTEX(crw_handler_mutex);
Heiko Carstensf5daba12009-03-26 15:24:01 +010018static crw_handler_t crw_handlers[NR_RSCS];
Sebastian Ottb4563e82010-02-26 22:37:26 +010019static atomic_t crw_nr_req = ATOMIC_INIT(0);
20static DECLARE_WAIT_QUEUE_HEAD(crw_handler_wait_q);
Heiko Carstensf5daba12009-03-26 15:24:01 +010021
22/**
23 * crw_register_handler() - register a channel report word handler
24 * @rsc: reporting source code to handle
25 * @handler: handler to be registered
26 *
27 * Returns %0 on success and a negative error value otherwise.
28 */
29int crw_register_handler(int rsc, crw_handler_t handler)
30{
Heiko Carstens98c1c682009-03-26 15:24:09 +010031 int rc = 0;
32
Heiko Carstensf5daba12009-03-26 15:24:01 +010033 if ((rsc < 0) || (rsc >= NR_RSCS))
34 return -EINVAL;
Heiko Carstens98c1c682009-03-26 15:24:09 +010035 mutex_lock(&crw_handler_mutex);
36 if (crw_handlers[rsc])
37 rc = -EBUSY;
38 else
39 crw_handlers[rsc] = handler;
40 mutex_unlock(&crw_handler_mutex);
41 return rc;
Heiko Carstensf5daba12009-03-26 15:24:01 +010042}
43
44/**
45 * crw_unregister_handler() - unregister a channel report word handler
46 * @rsc: reporting source code to handle
47 */
48void crw_unregister_handler(int rsc)
49{
50 if ((rsc < 0) || (rsc >= NR_RSCS))
51 return;
Heiko Carstens98c1c682009-03-26 15:24:09 +010052 mutex_lock(&crw_handler_mutex);
53 crw_handlers[rsc] = NULL;
54 mutex_unlock(&crw_handler_mutex);
Heiko Carstensf5daba12009-03-26 15:24:01 +010055}
56
57/*
58 * Retrieve CRWs and call function to handle event.
59 */
60static int crw_collect_info(void *unused)
61{
62 struct crw crw[2];
Sebastian Ottb4563e82010-02-26 22:37:26 +010063 int ccode, signal;
Heiko Carstensf5daba12009-03-26 15:24:01 +010064 unsigned int chain;
Heiko Carstensf5daba12009-03-26 15:24:01 +010065
66repeat:
Sebastian Ottb4563e82010-02-26 22:37:26 +010067 signal = wait_event_interruptible(crw_handler_wait_q,
68 atomic_read(&crw_nr_req) > 0);
69 if (unlikely(signal))
70 atomic_inc(&crw_nr_req);
Heiko Carstensf5daba12009-03-26 15:24:01 +010071 chain = 0;
72 while (1) {
Heiko Carstens98c1c682009-03-26 15:24:09 +010073 crw_handler_t handler;
74
Heiko Carstensf5daba12009-03-26 15:24:01 +010075 if (unlikely(chain > 1)) {
76 struct crw tmp_crw;
77
78 printk(KERN_WARNING"%s: Code does not support more "
79 "than two chained crws; please report to "
80 "linux390@de.ibm.com!\n", __func__);
81 ccode = stcrw(&tmp_crw);
82 printk(KERN_WARNING"%s: crw reports slct=%d, oflw=%d, "
83 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
84 __func__, tmp_crw.slct, tmp_crw.oflw,
85 tmp_crw.chn, tmp_crw.rsc, tmp_crw.anc,
86 tmp_crw.erc, tmp_crw.rsid);
87 printk(KERN_WARNING"%s: This was crw number %x in the "
88 "chain\n", __func__, chain);
89 if (ccode != 0)
90 break;
91 chain = tmp_crw.chn ? chain + 1 : 0;
92 continue;
93 }
94 ccode = stcrw(&crw[chain]);
95 if (ccode != 0)
96 break;
97 printk(KERN_DEBUG "crw_info : CRW reports slct=%d, oflw=%d, "
98 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
99 crw[chain].slct, crw[chain].oflw, crw[chain].chn,
100 crw[chain].rsc, crw[chain].anc, crw[chain].erc,
101 crw[chain].rsid);
102 /* Check for overflows. */
103 if (crw[chain].oflw) {
104 int i;
105
106 pr_debug("%s: crw overflow detected!\n", __func__);
Heiko Carstens98c1c682009-03-26 15:24:09 +0100107 mutex_lock(&crw_handler_mutex);
Heiko Carstensf5daba12009-03-26 15:24:01 +0100108 for (i = 0; i < NR_RSCS; i++) {
109 if (crw_handlers[i])
110 crw_handlers[i](NULL, NULL, 1);
111 }
Heiko Carstens98c1c682009-03-26 15:24:09 +0100112 mutex_unlock(&crw_handler_mutex);
Heiko Carstensf5daba12009-03-26 15:24:01 +0100113 chain = 0;
114 continue;
115 }
116 if (crw[0].chn && !chain) {
117 chain++;
118 continue;
119 }
Heiko Carstens98c1c682009-03-26 15:24:09 +0100120 mutex_lock(&crw_handler_mutex);
121 handler = crw_handlers[crw[chain].rsc];
122 if (handler)
123 handler(&crw[0], chain ? &crw[1] : NULL, 0);
124 mutex_unlock(&crw_handler_mutex);
Heiko Carstensf5daba12009-03-26 15:24:01 +0100125 /* chain is always 0 or 1 here. */
126 chain = crw[chain].chn ? chain + 1 : 0;
127 }
Sebastian Ottb4563e82010-02-26 22:37:26 +0100128 if (atomic_dec_and_test(&crw_nr_req))
129 wake_up(&crw_handler_wait_q);
Heiko Carstensf5daba12009-03-26 15:24:01 +0100130 goto repeat;
131 return 0;
132}
133
134void crw_handle_channel_report(void)
135{
Sebastian Ottb4563e82010-02-26 22:37:26 +0100136 atomic_inc(&crw_nr_req);
137 wake_up(&crw_handler_wait_q);
Heiko Carstensf5daba12009-03-26 15:24:01 +0100138}
139
Sebastian Ottb4563e82010-02-26 22:37:26 +0100140void crw_wait_for_channel_report(void)
Heiko Carstensf5daba12009-03-26 15:24:01 +0100141{
Sebastian Ottb4563e82010-02-26 22:37:26 +0100142 crw_handle_channel_report();
143 wait_event(crw_handler_wait_q, atomic_read(&crw_nr_req) == 0);
Heiko Carstensf5daba12009-03-26 15:24:01 +0100144}
Heiko Carstensf5daba12009-03-26 15:24:01 +0100145
146/*
147 * Machine checks for the channel subsystem must be enabled
148 * after the channel subsystem is initialized
149 */
150static int __init crw_machine_check_init(void)
151{
152 struct task_struct *task;
153
154 task = kthread_run(crw_collect_info, NULL, "kmcheck");
155 if (IS_ERR(task))
156 return PTR_ERR(task);
157 ctl_set_bit(14, 28); /* enable channel report MCH */
158 return 0;
159}
160device_initcall(crw_machine_check_init);