linux/drivers/s390/cio/crw.c
Heiko Carstens a53c8fab3f s390/comments: unify copyright messages and remove file names
Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.

Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2012-07-20 11:15:04 +02:00

162 lines
4.0 KiB
C

/*
* 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/mutex.h>
#include <linux/kthread.h>
#include <linux/init.h>
#include <linux/wait.h>
#include <asm/crw.h>
#include <asm/ctl_reg.h>
static DEFINE_MUTEX(crw_handler_mutex);
static crw_handler_t crw_handlers[NR_RSCS];
static atomic_t crw_nr_req = ATOMIC_INIT(0);
static DECLARE_WAIT_QUEUE_HEAD(crw_handler_wait_q);
/**
* 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)
{
int rc = 0;
if ((rsc < 0) || (rsc >= NR_RSCS))
return -EINVAL;
mutex_lock(&crw_handler_mutex);
if (crw_handlers[rsc])
rc = -EBUSY;
else
crw_handlers[rsc] = handler;
mutex_unlock(&crw_handler_mutex);
return rc;
}
/**
* 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;
mutex_lock(&crw_handler_mutex);
crw_handlers[rsc] = NULL;
mutex_unlock(&crw_handler_mutex);
}
/*
* Retrieve CRWs and call function to handle event.
*/
static int crw_collect_info(void *unused)
{
struct crw crw[2];
int ccode, signal;
unsigned int chain;
repeat:
signal = wait_event_interruptible(crw_handler_wait_q,
atomic_read(&crw_nr_req) > 0);
if (unlikely(signal))
atomic_inc(&crw_nr_req);
chain = 0;
while (1) {
crw_handler_t handler;
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__);
mutex_lock(&crw_handler_mutex);
for (i = 0; i < NR_RSCS; i++) {
if (crw_handlers[i])
crw_handlers[i](NULL, NULL, 1);
}
mutex_unlock(&crw_handler_mutex);
chain = 0;
continue;
}
if (crw[0].chn && !chain) {
chain++;
continue;
}
mutex_lock(&crw_handler_mutex);
handler = crw_handlers[crw[chain].rsc];
if (handler)
handler(&crw[0], chain ? &crw[1] : NULL, 0);
mutex_unlock(&crw_handler_mutex);
/* chain is always 0 or 1 here. */
chain = crw[chain].chn ? chain + 1 : 0;
}
if (atomic_dec_and_test(&crw_nr_req))
wake_up(&crw_handler_wait_q);
goto repeat;
return 0;
}
void crw_handle_channel_report(void)
{
atomic_inc(&crw_nr_req);
wake_up(&crw_handler_wait_q);
}
void crw_wait_for_channel_report(void)
{
crw_handle_channel_report();
wait_event(crw_handler_wait_q, atomic_read(&crw_nr_req) == 0);
}
/*
* 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);