projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 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); |