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f5daba1d HC |
1 | /* |
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 | ||
11 | #include <linux/semaphore.h> | |
98c1c682 | 12 | #include <linux/mutex.h> |
f5daba1d HC |
13 | #include <linux/kthread.h> |
14 | #include <linux/init.h> | |
15 | #include <asm/crw.h> | |
16 | ||
17 | static struct semaphore crw_semaphore; | |
98c1c682 | 18 | static DEFINE_MUTEX(crw_handler_mutex); |
f5daba1d HC |
19 | static crw_handler_t crw_handlers[NR_RSCS]; |
20 | ||
21 | /** | |
22 | * crw_register_handler() - register a channel report word handler | |
23 | * @rsc: reporting source code to handle | |
24 | * @handler: handler to be registered | |
25 | * | |
26 | * Returns %0 on success and a negative error value otherwise. | |
27 | */ | |
28 | int crw_register_handler(int rsc, crw_handler_t handler) | |
29 | { | |
98c1c682 HC |
30 | int rc = 0; |
31 | ||
f5daba1d HC |
32 | if ((rsc < 0) || (rsc >= NR_RSCS)) |
33 | return -EINVAL; | |
98c1c682 HC |
34 | mutex_lock(&crw_handler_mutex); |
35 | if (crw_handlers[rsc]) | |
36 | rc = -EBUSY; | |
37 | else | |
38 | crw_handlers[rsc] = handler; | |
39 | mutex_unlock(&crw_handler_mutex); | |
40 | return rc; | |
f5daba1d HC |
41 | } |
42 | ||
43 | /** | |
44 | * crw_unregister_handler() - unregister a channel report word handler | |
45 | * @rsc: reporting source code to handle | |
46 | */ | |
47 | void crw_unregister_handler(int rsc) | |
48 | { | |
49 | if ((rsc < 0) || (rsc >= NR_RSCS)) | |
50 | return; | |
98c1c682 HC |
51 | mutex_lock(&crw_handler_mutex); |
52 | crw_handlers[rsc] = NULL; | |
53 | mutex_unlock(&crw_handler_mutex); | |
f5daba1d HC |
54 | } |
55 | ||
56 | /* | |
57 | * Retrieve CRWs and call function to handle event. | |
58 | */ | |
59 | static int crw_collect_info(void *unused) | |
60 | { | |
61 | struct crw crw[2]; | |
62 | int ccode; | |
63 | unsigned int chain; | |
64 | int ignore; | |
65 | ||
66 | repeat: | |
67 | ignore = down_interruptible(&crw_semaphore); | |
68 | chain = 0; | |
69 | while (1) { | |
98c1c682 HC |
70 | crw_handler_t handler; |
71 | ||
f5daba1d HC |
72 | if (unlikely(chain > 1)) { |
73 | struct crw tmp_crw; | |
74 | ||
75 | printk(KERN_WARNING"%s: Code does not support more " | |
76 | "than two chained crws; please report to " | |
77 | "linux390@de.ibm.com!\n", __func__); | |
78 | ccode = stcrw(&tmp_crw); | |
79 | printk(KERN_WARNING"%s: crw reports slct=%d, oflw=%d, " | |
80 | "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n", | |
81 | __func__, tmp_crw.slct, tmp_crw.oflw, | |
82 | tmp_crw.chn, tmp_crw.rsc, tmp_crw.anc, | |
83 | tmp_crw.erc, tmp_crw.rsid); | |
84 | printk(KERN_WARNING"%s: This was crw number %x in the " | |
85 | "chain\n", __func__, chain); | |
86 | if (ccode != 0) | |
87 | break; | |
88 | chain = tmp_crw.chn ? chain + 1 : 0; | |
89 | continue; | |
90 | } | |
91 | ccode = stcrw(&crw[chain]); | |
92 | if (ccode != 0) | |
93 | break; | |
94 | printk(KERN_DEBUG "crw_info : CRW reports slct=%d, oflw=%d, " | |
95 | "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n", | |
96 | crw[chain].slct, crw[chain].oflw, crw[chain].chn, | |
97 | crw[chain].rsc, crw[chain].anc, crw[chain].erc, | |
98 | crw[chain].rsid); | |
99 | /* Check for overflows. */ | |
100 | if (crw[chain].oflw) { | |
101 | int i; | |
102 | ||
103 | pr_debug("%s: crw overflow detected!\n", __func__); | |
98c1c682 | 104 | mutex_lock(&crw_handler_mutex); |
f5daba1d HC |
105 | for (i = 0; i < NR_RSCS; i++) { |
106 | if (crw_handlers[i]) | |
107 | crw_handlers[i](NULL, NULL, 1); | |
108 | } | |
98c1c682 | 109 | mutex_unlock(&crw_handler_mutex); |
f5daba1d HC |
110 | chain = 0; |
111 | continue; | |
112 | } | |
113 | if (crw[0].chn && !chain) { | |
114 | chain++; | |
115 | continue; | |
116 | } | |
98c1c682 HC |
117 | mutex_lock(&crw_handler_mutex); |
118 | handler = crw_handlers[crw[chain].rsc]; | |
119 | if (handler) | |
120 | handler(&crw[0], chain ? &crw[1] : NULL, 0); | |
121 | mutex_unlock(&crw_handler_mutex); | |
f5daba1d HC |
122 | /* chain is always 0 or 1 here. */ |
123 | chain = crw[chain].chn ? chain + 1 : 0; | |
124 | } | |
125 | goto repeat; | |
126 | return 0; | |
127 | } | |
128 | ||
129 | void crw_handle_channel_report(void) | |
130 | { | |
131 | up(&crw_semaphore); | |
132 | } | |
133 | ||
134 | /* | |
135 | * Separate initcall needed for semaphore initialization since | |
136 | * crw_handle_channel_report might be called before crw_machine_check_init. | |
137 | */ | |
138 | static int __init crw_init_semaphore(void) | |
139 | { | |
140 | init_MUTEX_LOCKED(&crw_semaphore); | |
141 | return 0; | |
142 | } | |
143 | pure_initcall(crw_init_semaphore); | |
144 | ||
145 | /* | |
146 | * Machine checks for the channel subsystem must be enabled | |
147 | * after the channel subsystem is initialized | |
148 | */ | |
149 | static int __init crw_machine_check_init(void) | |
150 | { | |
151 | struct task_struct *task; | |
152 | ||
153 | task = kthread_run(crw_collect_info, NULL, "kmcheck"); | |
154 | if (IS_ERR(task)) | |
155 | return PTR_ERR(task); | |
156 | ctl_set_bit(14, 28); /* enable channel report MCH */ | |
157 | return 0; | |
158 | } | |
159 | device_initcall(crw_machine_check_init); |