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Commit c820de39 authored by Cornelia Huck's avatar Cornelia Huck Committed by Heiko Carstens
Browse files

[S390] cio: Rework css driver. 



Rework the css driver methods to provide sane callbacks for
subchannels of all types.

As a bonus, this cleans up and simplyfies the machine check
handling for I/O subchannels a lot.

Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
parent 7e9db9ea

drivers/s390/cio/chp.c

+20 −0
Original line number Diff line number Diff line
@@ -496,6 +496,26 @@ void chp_process_crw(int id, int status) 
		chsc_chp_offline(chpid);

}



int chp_ssd_get_mask(struct chsc_ssd_info *ssd, struct res_acc_data *data)

{

	int i;

	int mask;



	for (i = 0; i < 8; i++) {

		mask = 0x80 >> i;

		if (!(ssd->path_mask & mask))

			continue;

		if (!chp_id_is_equal(&ssd->chpid[i], &data->chpid))

			continue;

		if ((ssd->fla_valid_mask & mask) &&

		    ((ssd->fla[i] & data->fla_mask) != data->fla))

			continue;

		return mask;

	}

	return 0;

}

EXPORT_SYMBOL_GPL(chp_ssd_get_mask);



static inline int info_bit_num(struct chp_id id)

{

	return id.id + id.cssid * (__MAX_CHPID + 1);

drivers/s390/cio/chp.h

+12 −1
Original line number Diff line number Diff line
@@ -19,6 +19,17 @@ 
#define CHP_STATUS_RESERVED		2

#define CHP_STATUS_NOT_RECOGNIZED	3



#define CHP_ONLINE 0

#define CHP_OFFLINE 1

#define CHP_VARY_ON 2

#define CHP_VARY_OFF 3



struct res_acc_data {

	struct chp_id chpid;

	u32 fla_mask;

	u16 fla;

};



static inline int chp_test_bit(u8 *bitmap, int num)

{

	int byte = num >> 3;
@@ -50,5 +61,5 @@ int chp_new(struct chp_id chpid); 
void chp_cfg_schedule(struct chp_id chpid, int configure);

void chp_cfg_cancel_deconfigure(struct chp_id chpid);

int chp_info_get_status(struct chp_id chpid);



int chp_ssd_get_mask(struct chsc_ssd_info *, struct res_acc_data *);

#endif /* S390_CHP_H */

drivers/s390/cio/chsc.c

+16 −202
Original line number Diff line number Diff line
@@ -2,8 +2,7 @@ 
 *  drivers/s390/cio/chsc.c

 *   S/390 common I/O routines -- channel subsystem call

 *

 *    Copyright (C) 1999-2002 IBM Deutschland Entwicklung GmbH,

 *			      IBM Corporation

 *    Copyright IBM Corp. 1999,2008

 *    Author(s): Ingo Adlung (adlung@de.ibm.com)

 *		 Cornelia Huck (cornelia.huck@de.ibm.com)

 *		 Arnd Bergmann (arndb@de.ibm.com)
@@ -127,77 +126,12 @@ int chsc_get_ssd_info(struct subchannel_id schid, struct chsc_ssd_info *ssd) 
	return ret;

}



static int check_for_io_on_path(struct subchannel *sch, int mask)

{

	int cc;



	cc = stsch(sch->schid, &sch->schib);

	if (cc)

		return 0;

	if (sch->schib.scsw.actl && sch->schib.pmcw.lpum == mask)

		return 1;

	return 0;

}



static void terminate_internal_io(struct subchannel *sch)

{

	if (cio_clear(sch)) {

		/* Recheck device in case clear failed. */

		sch->lpm = 0;

		if (device_trigger_verify(sch) != 0)

			css_schedule_eval(sch->schid);

		return;

	}

	/* Request retry of internal operation. */

	device_set_intretry(sch);

	/* Call handler. */

	if (sch->driver && sch->driver->termination)

		sch->driver->termination(sch);

}



static int s390_subchannel_remove_chpid(struct subchannel *sch, void *data)

{

	int j;

	int mask;

	struct chp_id *chpid = data;

	struct schib schib;



	for (j = 0; j < 8; j++) {

		mask = 0x80 >> j;

		if ((sch->schib.pmcw.pim & mask) &&

		    (sch->schib.pmcw.chpid[j] == chpid->id))

			break;

	}

	if (j >= 8)

		return 0;



	spin_lock_irq(sch->lock);



	stsch(sch->schid, &schib);

	if (!css_sch_is_valid(&schib))

		goto out_unreg;

	memcpy(&sch->schib, &schib, sizeof(struct schib));

	/* Check for single path devices. */

	if (sch->schib.pmcw.pim == 0x80)

	if (sch->driver && sch->driver->chp_event)

		if (sch->driver->chp_event(sch, data, CHP_OFFLINE) != 0)

			goto out_unreg;



	if (check_for_io_on_path(sch, mask)) {

		if (device_is_online(sch))

			device_kill_io(sch);

		else {

			terminate_internal_io(sch);

			/* Re-start path verification. */

			if (sch->driver && sch->driver->verify)

				sch->driver->verify(sch);

		}

	} else {

		/* trigger path verification. */

		if (sch->driver && sch->driver->verify)

			sch->driver->verify(sch);

		else if (sch->lpm == mask)

			goto out_unreg;

	}



	spin_unlock_irq(sch->lock);

	return 0;
@@ -242,53 +176,11 @@ static int s390_process_res_acc_new_sch(struct subchannel_id schid, void *data) 
	return 0;

}



struct res_acc_data {

	struct chp_id chpid;

	u32 fla_mask;

	u16 fla;

};



static int get_res_chpid_mask(struct chsc_ssd_info *ssd,

			      struct res_acc_data *data)

{

	int i;

	int mask;



	for (i = 0; i < 8; i++) {

		mask = 0x80 >> i;

		if (!(ssd->path_mask & mask))

			continue;

		if (!chp_id_is_equal(&ssd->chpid[i], &data->chpid))

			continue;

		if ((ssd->fla_valid_mask & mask) &&

		    ((ssd->fla[i] & data->fla_mask) != data->fla))

			continue;

		return mask;

	}

	return 0;

}



static int __s390_process_res_acc(struct subchannel *sch, void *data)

{

	int chp_mask, old_lpm;

	struct res_acc_data *res_data = data;



	spin_lock_irq(sch->lock);

	chp_mask = get_res_chpid_mask(&sch->ssd_info, res_data);

	if (chp_mask == 0)

		goto out;

	if (stsch(sch->schid, &sch->schib))

		goto out;

	old_lpm = sch->lpm;

	sch->lpm = ((sch->schib.pmcw.pim &

		     sch->schib.pmcw.pam &

		     sch->schib.pmcw.pom)

		    | chp_mask) & sch->opm;

	if (!old_lpm && sch->lpm)

		device_trigger_reprobe(sch);

	else if (sch->driver && sch->driver->verify)

		sch->driver->verify(sch);

out:

	if (sch->driver && sch->driver->chp_event)

		sch->driver->chp_event(sch, data, CHP_ONLINE);

	spin_unlock_irq(sch->lock);



	return 0;
@@ -509,114 +401,36 @@ void chsc_process_crw(void) 
	} while (sei_area->flags & 0x80);

}



static int __chp_add_new_sch(struct subchannel_id schid, void *data)

{

	struct schib schib;



	if (stsch_err(schid, &schib))

		/* We're through */

		return -ENXIO;



	/* Put it on the slow path. */

	css_schedule_eval(schid);

	return 0;

}





static int __chp_add(struct subchannel *sch, void *data)

{

	int i, mask;

	struct chp_id *chpid = data;



	spin_lock_irq(sch->lock);

	for (i=0; i<8; i++) {

		mask = 0x80 >> i;

		if ((sch->schib.pmcw.pim & mask) &&

		    (sch->schib.pmcw.chpid[i] == chpid->id))

			break;

	}

	if (i==8) {

		spin_unlock_irq(sch->lock);

		return 0;

	}

	if (stsch(sch->schid, &sch->schib)) {

		spin_unlock_irq(sch->lock);

		css_schedule_eval(sch->schid);

		return 0;

	}

	sch->lpm = ((sch->schib.pmcw.pim &

		     sch->schib.pmcw.pam &

		     sch->schib.pmcw.pom)

		    | mask) & sch->opm;



	if (sch->driver && sch->driver->verify)

		sch->driver->verify(sch);



	spin_unlock_irq(sch->lock);



	return 0;

}



void chsc_chp_online(struct chp_id chpid)

{

	char dbf_txt[15];

	struct res_acc_data res_data;



	sprintf(dbf_txt, "cadd%x.%02x", chpid.cssid, chpid.id);

	CIO_TRACE_EVENT(2, dbf_txt);



	if (chp_get_status(chpid) != 0) {

		memset(&res_data, 0, sizeof(struct res_acc_data));

		res_data.chpid = chpid;

		/* Wait until previous actions have settled. */

		css_wait_for_slow_path();

		for_each_subchannel_staged(__chp_add, __chp_add_new_sch,

					   &chpid);

		for_each_subchannel_staged(__s390_process_res_acc, NULL,

					   &res_data);

	}

}



static void __s390_subchannel_vary_chpid(struct subchannel *sch,

					 struct chp_id chpid, int on)

{

	int chp, old_lpm;

	int mask;

	unsigned long flags;

	struct res_acc_data res_data;



	memset(&res_data, 0, sizeof(struct res_acc_data));

	res_data.chpid = chpid;

	spin_lock_irqsave(sch->lock, flags);

	old_lpm = sch->lpm;

	for (chp = 0; chp < 8; chp++) {

		mask = 0x80 >> chp;

		if (!(sch->ssd_info.path_mask & mask))

			continue;

		if (!chp_id_is_equal(&sch->ssd_info.chpid[chp], &chpid))

			continue;



		if (on) {

			sch->opm |= mask;

			sch->lpm |= mask;

			if (!old_lpm)

				device_trigger_reprobe(sch);

			else if (sch->driver && sch->driver->verify)

				sch->driver->verify(sch);

			break;

		}

		sch->opm &= ~mask;

		sch->lpm &= ~mask;

		if (check_for_io_on_path(sch, mask)) {

			if (device_is_online(sch))

				/* Path verification is done after killing. */

				device_kill_io(sch);

			else {

				/* Kill and retry internal I/O. */

				terminate_internal_io(sch);

				/* Re-start path verification. */

				if (sch->driver && sch->driver->verify)

					sch->driver->verify(sch);

			}

		} else if (!sch->lpm) {

			if (device_trigger_verify(sch) != 0)

				css_schedule_eval(sch->schid);

		} else if (sch->driver && sch->driver->verify)

			sch->driver->verify(sch);

		break;

	}

	if (sch->driver && sch->driver->chp_event)

		sch->driver->chp_event(sch, &res_data,

				       on ? CHP_VARY_ON : CHP_VARY_OFF);

	spin_unlock_irqrestore(sch->lock, flags);

}

drivers/s390/cio/cio.c

+1 −0
Original line number Diff line number Diff line
@@ -564,6 +564,7 @@ int cio_validate_subchannel(struct subchannel *sch, struct subchannel_id schid) 
	}

	/* Copy subchannel type from path management control word. */

	sch->st = sch->schib.pmcw.st;



	switch (sch->st) {

	case SUBCHANNEL_TYPE_IO:

		err = cio_validate_io_subchannel(sch);

drivers/s390/cio/css.c

+16 −107
Original line number Diff line number Diff line
@@ -283,7 +283,7 @@ static int css_register_subchannel(struct subchannel *sch) 
	return ret;

}



static int css_probe_device(struct subchannel_id schid)

int css_probe_device(struct subchannel_id schid)

{

	int ret;

	struct subchannel *sch;
@@ -330,112 +330,6 @@ int css_sch_is_valid(struct schib *schib) 
}

EXPORT_SYMBOL_GPL(css_sch_is_valid);



static int css_get_subchannel_status(struct subchannel *sch)

{

	struct schib schib;



	if (stsch(sch->schid, &schib))

		return CIO_GONE;

	if (!css_sch_is_valid(&schib))

		return CIO_GONE;

	if (sch->schib.pmcw.dnv && (schib.pmcw.dev != sch->schib.pmcw.dev))

		return CIO_REVALIDATE;

	if (!sch->lpm)

		return CIO_NO_PATH;

	return CIO_OPER;

}



static int css_evaluate_known_subchannel(struct subchannel *sch, int slow)

{

	int event, ret, disc;

	unsigned long flags;

	enum { NONE, UNREGISTER, UNREGISTER_PROBE, REPROBE } action;



	spin_lock_irqsave(sch->lock, flags);

	disc = device_is_disconnected(sch);

	if (disc && slow) {

		/* Disconnected devices are evaluated directly only.*/

		spin_unlock_irqrestore(sch->lock, flags);

		return 0;

	}

	/* No interrupt after machine check - kill pending timers. */

	device_kill_pending_timer(sch);

	if (!disc && !slow) {

		/* Non-disconnected devices are evaluated on the slow path. */

		spin_unlock_irqrestore(sch->lock, flags);

		return -EAGAIN;

	}

	event = css_get_subchannel_status(sch);

	CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, %s, %s path.\n",

		      sch->schid.ssid, sch->schid.sch_no, event,

		      disc ? "disconnected" : "normal",

		      slow ? "slow" : "fast");

	/* Analyze subchannel status. */

	action = NONE;

	switch (event) {

	case CIO_NO_PATH:

		if (disc) {

			/* Check if paths have become available. */

			action = REPROBE;

			break;

		}

		/* fall through */

	case CIO_GONE:

		/* Prevent unwanted effects when opening lock. */

		cio_disable_subchannel(sch);

		device_set_disconnected(sch);

		/* Ask driver what to do with device. */

		action = UNREGISTER;

		if (sch->driver && sch->driver->notify) {

			spin_unlock_irqrestore(sch->lock, flags);

			ret = sch->driver->notify(sch, event);

			spin_lock_irqsave(sch->lock, flags);

			if (ret)

				action = NONE;

		}

		break;

	case CIO_REVALIDATE:

		/* Device will be removed, so no notify necessary. */

		if (disc)

			/* Reprobe because immediate unregister might block. */

			action = REPROBE;

		else

			action = UNREGISTER_PROBE;

		break;

	case CIO_OPER:

		if (disc)

			/* Get device operational again. */

			action = REPROBE;

		break;

	}

	/* Perform action. */

	ret = 0;

	switch (action) {

	case UNREGISTER:

	case UNREGISTER_PROBE:

		/* Unregister device (will use subchannel lock). */

		spin_unlock_irqrestore(sch->lock, flags);

		css_sch_device_unregister(sch);

		spin_lock_irqsave(sch->lock, flags);



		/* Reset intparm to zeroes. */

		sch->schib.pmcw.intparm = 0;

		cio_modify(sch);

		break;

	case REPROBE:

		device_trigger_reprobe(sch);

		break;

	default:

		break;

	}

	spin_unlock_irqrestore(sch->lock, flags);

	/* Probe if necessary. */

	if (action == UNREGISTER_PROBE)

		ret = css_probe_device(sch->schid);



	return ret;

}



static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)

{

	struct schib schib;
@@ -454,6 +348,21 @@ static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow) 
	return css_probe_device(schid);

}



static int css_evaluate_known_subchannel(struct subchannel *sch, int slow)

{

	int ret = 0;



	if (sch->driver) {

		if (sch->driver->sch_event)

			ret = sch->driver->sch_event(sch, slow);

		else

			dev_dbg(&sch->dev,

				"Got subchannel machine check but "

				"no sch_event handler provided.\n");

	}

	return ret;

}



static void css_evaluate_subchannel(struct subchannel_id schid, int slow)

{

	struct subchannel *sch;