[deliverable/linux.git] / drivers / s390 / cio / crw.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);
Commit	Line	Data
f5daba1d HC	1	/*
	2	* Channel report handling code
	3	*
a53c8fab	4	* Copyright IBM Corp. 2000, 2009
f5daba1d HC	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
98c1c682	11	#include <linux/mutex.h>
f5daba1d HC	12	#include <linux/kthread.h>
f5daba1d HC	13	#include <linux/init.h>
b4563e89	14	#include <linux/wait.h>
f5daba1d	15	#include <asm/crw.h>
a0616cde	16	#include <asm/ctl_reg.h>
f5daba1d	17
98c1c682	18	static DEFINE_MUTEX(crw_handler_mutex);
f5daba1d	19	static crw_handler_t crw_handlers[NR_RSCS];
b4563e89 SO	20	static atomic_t crw_nr_req = ATOMIC_INIT(0);
b4563e89 SO	21	static DECLARE_WAIT_QUEUE_HEAD(crw_handler_wait_q);
f5daba1d HC	22
	23	/**
	24	* crw_register_handler() - register a channel report word handler
	25	* @rsc: reporting source code to handle
	26	* @handler: handler to be registered
	27	*
	28	* Returns %0 on success and a negative error value otherwise.
	29	*/
	30	int crw_register_handler(int rsc, crw_handler_t handler)
	31	{
98c1c682 HC	32	int rc = 0;
98c1c682 HC	33
f5daba1d HC	34	if ((rsc < 0) \|\| (rsc >= NR_RSCS))
f5daba1d HC	35	return -EINVAL;
98c1c682 HC	36	mutex_lock(&crw_handler_mutex);
	37	if (crw_handlers[rsc])
	38	rc = -EBUSY;
	39	else
	40	crw_handlers[rsc] = handler;
	41	mutex_unlock(&crw_handler_mutex);
	42	return rc;
f5daba1d HC	43	}
	44
	45	/**
	46	* crw_unregister_handler() - unregister a channel report word handler
	47	* @rsc: reporting source code to handle
	48	*/
	49	void crw_unregister_handler(int rsc)
	50	{
	51	if ((rsc < 0) \|\| (rsc >= NR_RSCS))
	52	return;
98c1c682 HC	53	mutex_lock(&crw_handler_mutex);
	54	crw_handlers[rsc] = NULL;
	55	mutex_unlock(&crw_handler_mutex);
f5daba1d HC	56	}
	57
	58	/*
	59	* Retrieve CRWs and call function to handle event.
	60	*/
	61	static int crw_collect_info(void *unused)
	62	{
	63	struct crw crw[2];
b4563e89	64	int ccode, signal;
f5daba1d	65	unsigned int chain;
f5daba1d HC	66
f5daba1d HC	67	repeat:
b4563e89 SO	68	signal = wait_event_interruptible(crw_handler_wait_q,
	69	atomic_read(&crw_nr_req) > 0);
	70	if (unlikely(signal))
	71	atomic_inc(&crw_nr_req);
f5daba1d HC	72	chain = 0;
f5daba1d HC	73	while (1) {
98c1c682 HC	74	crw_handler_t handler;
98c1c682 HC	75
f5daba1d HC	76	if (unlikely(chain > 1)) {
	77	struct crw tmp_crw;
	78
	79	printk(KERN_WARNING"%s: Code does not support more "
	80	"than two chained crws; please report to "
	81	"linux390@de.ibm.com!\n", __func__);
	82	ccode = stcrw(&tmp_crw);
	83	printk(KERN_WARNING"%s: crw reports slct=%d, oflw=%d, "
	84	"chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
	85	__func__, tmp_crw.slct, tmp_crw.oflw,
	86	tmp_crw.chn, tmp_crw.rsc, tmp_crw.anc,
	87	tmp_crw.erc, tmp_crw.rsid);
	88	printk(KERN_WARNING"%s: This was crw number %x in the "
	89	"chain\n", __func__, chain);
	90	if (ccode != 0)
	91	break;
	92	chain = tmp_crw.chn ? chain + 1 : 0;
	93	continue;
	94	}
	95	ccode = stcrw(&crw[chain]);
	96	if (ccode != 0)
	97	break;
	98	printk(KERN_DEBUG "crw_info : CRW reports slct=%d, oflw=%d, "
	99	"chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
	100	crw[chain].slct, crw[chain].oflw, crw[chain].chn,
	101	crw[chain].rsc, crw[chain].anc, crw[chain].erc,
	102	crw[chain].rsid);
	103	/* Check for overflows. */
	104	if (crw[chain].oflw) {
	105	int i;
	106
	107	pr_debug("%s: crw overflow detected!\n", __func__);
98c1c682	108	mutex_lock(&crw_handler_mutex);
f5daba1d HC	109	for (i = 0; i < NR_RSCS; i++) {
	110	if (crw_handlers[i])
	111	crw_handlers[i](NULL, NULL, 1);
	112	}
98c1c682	113	mutex_unlock(&crw_handler_mutex);
f5daba1d HC	114	chain = 0;
	115	continue;
	116	}
	117	if (crw[0].chn && !chain) {
	118	chain++;
	119	continue;
	120	}
98c1c682 HC	121	mutex_lock(&crw_handler_mutex);
	122	handler = crw_handlers[crw[chain].rsc];
	123	if (handler)
	124	handler(&crw[0], chain ? &crw[1] : NULL, 0);
	125	mutex_unlock(&crw_handler_mutex);
f5daba1d HC	126	/* chain is always 0 or 1 here. */
	127	chain = crw[chain].chn ? chain + 1 : 0;
	128	}
b4563e89 SO	129	if (atomic_dec_and_test(&crw_nr_req))
b4563e89 SO	130	wake_up(&crw_handler_wait_q);
f5daba1d HC	131	goto repeat;
	132	return 0;
	133	}
	134
	135	void crw_handle_channel_report(void)
	136	{
b4563e89 SO	137	atomic_inc(&crw_nr_req);
b4563e89 SO	138	wake_up(&crw_handler_wait_q);
f5daba1d HC	139	}
f5daba1d HC	140
b4563e89	141	void crw_wait_for_channel_report(void)
f5daba1d	142	{
b4563e89 SO	143	crw_handle_channel_report();
b4563e89 SO	144	wait_event(crw_handler_wait_q, atomic_read(&crw_nr_req) == 0);
f5daba1d	145	}
f5daba1d HC	146
	147	/*
	148	* Machine checks for the channel subsystem must be enabled
	149	* after the channel subsystem is initialized
	150	*/
	151	static int __init crw_machine_check_init(void)
	152	{
	153	struct task_struct *task;
	154
	155	task = kthread_run(crw_collect_info, NULL, "kmcheck");
	156	if (IS_ERR(task))
	157	return PTR_ERR(task);
	158	ctl_set_bit(14, 28); /* enable channel report MCH */
	159	return 0;
	160	}
	161	device_initcall(crw_machine_check_init);