diff options
Diffstat (limited to 'drivers/s390/cio/crw.c')
| -rw-r--r-- | drivers/s390/cio/crw.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/drivers/s390/cio/crw.c b/drivers/s390/cio/crw.c new file mode 100644 index 000000000000..508f88f6420c --- /dev/null +++ b/drivers/s390/cio/crw.c @@ -0,0 +1,145 @@ +/* + * Channel report handling code + * + * Copyright IBM Corp. 2000,2009 + * Author(s): Ingo Adlung <adlung@de.ibm.com>, + * Martin Schwidefsky <schwidefsky@de.ibm.com>, + * Cornelia Huck <cornelia.huck@de.ibm.com>, + * Heiko Carstens <heiko.carstens@de.ibm.com>, + */ + +#include <linux/semaphore.h> +#include <linux/kthread.h> +#include <linux/init.h> +#include <asm/crw.h> + +static struct semaphore crw_semaphore; +static crw_handler_t crw_handlers[NR_RSCS]; + +/** + * crw_register_handler() - register a channel report word handler + * @rsc: reporting source code to handle + * @handler: handler to be registered + * + * Returns %0 on success and a negative error value otherwise. + */ +int crw_register_handler(int rsc, crw_handler_t handler) +{ + if ((rsc < 0) || (rsc >= NR_RSCS)) + return -EINVAL; + if (!cmpxchg(&crw_handlers[rsc], NULL, handler)) + return 0; + return -EBUSY; +} + +/** + * crw_unregister_handler() - unregister a channel report word handler + * @rsc: reporting source code to handle + */ +void crw_unregister_handler(int rsc) +{ + if ((rsc < 0) || (rsc >= NR_RSCS)) + return; + xchg(&crw_handlers[rsc], NULL); + synchronize_sched(); +} + +/* + * Retrieve CRWs and call function to handle event. + */ +static int crw_collect_info(void *unused) +{ + struct crw crw[2]; + int ccode; + unsigned int chain; + int ignore; + +repeat: + ignore = down_interruptible(&crw_semaphore); + chain = 0; + while (1) { + if (unlikely(chain > 1)) { + struct crw tmp_crw; + + printk(KERN_WARNING"%s: Code does not support more " + "than two chained crws; please report to " + "linux390@de.ibm.com!\n", __func__); + ccode = stcrw(&tmp_crw); + printk(KERN_WARNING"%s: crw reports slct=%d, oflw=%d, " + "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n", + __func__, tmp_crw.slct, tmp_crw.oflw, + tmp_crw.chn, tmp_crw.rsc, tmp_crw.anc, + tmp_crw.erc, tmp_crw.rsid); + printk(KERN_WARNING"%s: This was crw number %x in the " + "chain\n", __func__, chain); + if (ccode != 0) + break; + chain = tmp_crw.chn ? chain + 1 : 0; + continue; + } + ccode = stcrw(&crw[chain]); + if (ccode != 0) + break; + printk(KERN_DEBUG "crw_info : CRW reports slct=%d, oflw=%d, " + "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n", + crw[chain].slct, crw[chain].oflw, crw[chain].chn, + crw[chain].rsc, crw[chain].anc, crw[chain].erc, + crw[chain].rsid); + /* Check for overflows. */ + if (crw[chain].oflw) { + int i; + + pr_debug("%s: crw overflow detected!\n", __func__); + for (i = 0; i < NR_RSCS; i++) { + if (crw_handlers[i]) + crw_handlers[i](NULL, NULL, 1); + } + chain = 0; + continue; + } + if (crw[0].chn && !chain) { + chain++; + continue; + } + if (crw_handlers[crw[chain].rsc]) + crw_handlers[crw[chain].rsc](&crw[0], + chain ? &crw[1] : NULL, + 0); + /* chain is always 0 or 1 here. */ + chain = crw[chain].chn ? chain + 1 : 0; + } + goto repeat; + return 0; +} + +void crw_handle_channel_report(void) +{ + up(&crw_semaphore); +} + +/* + * Separate initcall needed for semaphore initialization since + * crw_handle_channel_report might be called before crw_machine_check_init. + */ +static int __init crw_init_semaphore(void) +{ + init_MUTEX_LOCKED(&crw_semaphore); + return 0; +} +pure_initcall(crw_init_semaphore); + +/* + * Machine checks for the channel subsystem must be enabled + * after the channel subsystem is initialized + */ +static int __init crw_machine_check_init(void) +{ + struct task_struct *task; + + task = kthread_run(crw_collect_info, NULL, "kmcheck"); + if (IS_ERR(task)) + return PTR_ERR(task); + ctl_set_bit(14, 28); /* enable channel report MCH */ + return 0; +} +device_initcall(crw_machine_check_init); |