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Commit 13952ec1 authored by Sebastian Ott's avatar Sebastian Ott Committed by Martin Schwidefsky
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[S390] cio: introduce cio_commit_config 



To change the configuration of a subchannel we alter the modifiable
bits of the subchannel's schib field and issue a modify subchannel.
There can be the case that not all changes were applied -or worse-
quietly overwritten by the hardware. With the next store subchannel
we obtain the current state of the hardware but lose our target
configuration.

With this patch we introduce a subchannel_config structure which
contains the target subchannel configuration. Additionally the msch
wrapper cio_modify is replaced with cio_commit_config which
copies the desired changes to a temporary schib. msch is then
called with the temporary schib. This schib is only written back
to the subchannel if all changes were applied.

Signed-off-by: default avatarSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent cdb912a4

drivers/s390/cio/cio.c

+73 −61
Original line number Diff line number Diff line
@@ -330,23 +330,63 @@ cio_cancel (struct subchannel *sch) 
	}

}





static void cio_apply_config(struct subchannel *sch, struct schib *schib)

{

	schib->pmcw.intparm = sch->config.intparm;

	schib->pmcw.mbi = sch->config.mbi;

	schib->pmcw.isc = sch->config.isc;

	schib->pmcw.ena = sch->config.ena;

	schib->pmcw.mme = sch->config.mme;

	schib->pmcw.mp = sch->config.mp;

	schib->pmcw.csense = sch->config.csense;

	schib->pmcw.mbfc = sch->config.mbfc;

	if (sch->config.mbfc)

		schib->mba = sch->config.mba;

}



static int cio_check_config(struct subchannel *sch, struct schib *schib)

{

	return (schib->pmcw.intparm == sch->config.intparm) &&

		(schib->pmcw.mbi == sch->config.mbi) &&

		(schib->pmcw.isc == sch->config.isc) &&

		(schib->pmcw.ena == sch->config.ena) &&

		(schib->pmcw.mme == sch->config.mme) &&

		(schib->pmcw.mp == sch->config.mp) &&

		(schib->pmcw.csense == sch->config.csense) &&

		(schib->pmcw.mbfc == sch->config.mbfc) &&

		(!sch->config.mbfc || (schib->mba == sch->config.mba));

}



/*

 * Function: cio_modify

 * Issues a "Modify Subchannel" on the specified subchannel

 * cio_commit_config - apply configuration to the subchannel

 */

int

cio_modify (struct subchannel *sch)

int cio_commit_config(struct subchannel *sch)

{

	int ccode, retry, ret;

	struct schib schib;

	int ccode, retry, ret = 0;



	if (stsch(sch->schid, &schib) || !css_sch_is_valid(&schib))

		return -ENODEV;



	ret = 0;

	for (retry = 0; retry < 5; retry++) {

		ccode = msch_err (sch->schid, &sch->schib);

		/* copy desired changes to local schib */

		cio_apply_config(sch, &schib);

		ccode = msch_err(sch->schid, &schib);

		if (ccode < 0) /* -EIO if msch gets a program check. */

			return ccode;

		switch (ccode) {

		case 0: /* successfull */

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

			    !css_sch_is_valid(&schib))

				return -ENODEV;

			if (cio_check_config(sch, &schib)) {

				/* commit changes from local schib */

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

				return 0;

			}

			ret = -EAGAIN;

			break;

		case 1: /* status pending */

			return -EBUSY;

		case 2: /* busy */
@@ -396,32 +436,24 @@ int cio_enable_subchannel(struct subchannel *sch, u32 intparm) 
	if (cio_update_schib(sch))

		return -ENODEV;



	for (retry = 5, ret = 0; retry > 0; retry--) {

		sch->schib.pmcw.ena = 1;

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

		sch->schib.pmcw.intparm = intparm;

		ret = cio_modify(sch);

		if (ret == -ENODEV)

			break;

		if (ret == -EIO)

	sch->config.ena = 1;

	sch->config.isc = sch->isc;

	sch->config.intparm = intparm;



	for (retry = 0; retry < 3; retry++) {

		ret = cio_commit_config(sch);

		if (ret == -EIO) {

			/*

			 * Got a program check in cio_modify. Try without

			 * Got a program check in msch. Try without

			 * the concurrent sense bit the next time.

			 */

			sch->schib.pmcw.csense = 0;

		if (ret == 0) {

			if (cio_update_schib(sch)) {

				ret = -ENODEV;

				break;

			}

			if (sch->schib.pmcw.ena)

				break;

		}

		if (ret == -EBUSY) {

			sch->config.csense = 0;

		} else if (ret == -EBUSY) {

			struct irb irb;

			if (tsch(sch->schid, &irb) != 0)

				break;

		}

		} else

			break;

	}

	sprintf (dbf_txt, "ret:%d", ret);

	CIO_TRACE_EVENT (2, dbf_txt);
@@ -436,7 +468,6 @@ EXPORT_SYMBOL_GPL(cio_enable_subchannel); 
int cio_disable_subchannel(struct subchannel *sch)

{

	char dbf_txt[15];

	int retry;

	int ret;



	CIO_TRACE_EVENT (2, "dissch");
@@ -454,27 +485,9 @@ int cio_disable_subchannel(struct subchannel *sch) 
		 */

		return -EBUSY;



	for (retry = 5, ret = 0; retry > 0; retry--) {

		sch->schib.pmcw.ena = 0;

		ret = cio_modify(sch);

		if (ret == -ENODEV)

			break;

		if (ret == -EBUSY)

			/*

			 * The subchannel is busy or status pending.

			 * We'll disable when the next interrupt was delivered

			 * via the state machine.

			 */

			break;

		if (ret == 0) {

			if (cio_update_schib(sch)) {

				ret = -ENODEV;

				break;

			}

			if (!sch->schib.pmcw.ena)

				break;

		}

	}

	sch->config.ena = 0;

	ret = cio_commit_config(sch);



	sprintf (dbf_txt, "ret:%d", ret);

	CIO_TRACE_EVENT (2, dbf_txt);

	return ret;
@@ -817,10 +830,9 @@ cio_probe_console(void) 
	 * enable console I/O-interrupt subclass

	 */

	isc_register(CONSOLE_ISC);

	console_subchannel.schib.pmcw.isc = CONSOLE_ISC;

	console_subchannel.schib.pmcw.intparm =

		(u32)(addr_t)&console_subchannel;

	ret = cio_modify(&console_subchannel);

	console_subchannel.config.isc = CONSOLE_ISC;

	console_subchannel.config.intparm = (u32)(addr_t)&console_subchannel;

	ret = cio_commit_config(&console_subchannel);

	if (ret) {

		isc_unregister(CONSOLE_ISC);

		console_subchannel_in_use = 0;
@@ -832,8 +844,8 @@ cio_probe_console(void) 
void

cio_release_console(void)

{

	console_subchannel.schib.pmcw.intparm = 0;

	cio_modify(&console_subchannel);

	console_subchannel.config.intparm = 0;

	cio_commit_config(&console_subchannel);

	isc_unregister(CONSOLE_ISC);

	console_subchannel_in_use = 0;

}

drivers/s390/cio/cio.h

+15 −1
Original line number Diff line number Diff line
@@ -45,6 +45,19 @@ struct pmcw { 
				/*  ... in an operand exception.       */

} __attribute__ ((packed));



/* Target SCHIB configuration. */

struct schib_config {

	u64 mba;

	u32 intparm;

	u16 mbi;

	u32 isc:3;

	u32 ena:1;

	u32 mme:2;

	u32 mp:1;

	u32 csense:1;

	u32 mbfc:1;

} __attribute__ ((packed));



/*

 * subchannel information block

 */
@@ -83,6 +96,7 @@ struct subchannel { 
	struct css_driver *driver;

	void *private; /* private per subchannel type data */

	struct work_struct work;

	struct schib_config config;

} __attribute__ ((aligned(8)));



#define IO_INTERRUPT_TYPE	   0 /* I/O interrupt type */
@@ -101,8 +115,8 @@ extern int cio_start_key (struct subchannel *, struct ccw1 *, __u8, __u8); 
extern int cio_cancel (struct subchannel *);

extern int cio_set_options (struct subchannel *, int);

extern int cio_get_options (struct subchannel *);

extern int cio_modify (struct subchannel *);

extern int cio_update_schib(struct subchannel *sch);

extern int cio_commit_config(struct subchannel *sch);



int cio_tm_start_key(struct subchannel *sch, struct tcw *tcw, u8 lpm, u8 key);

int cio_tm_intrg(struct subchannel *sch);

drivers/s390/cio/cmf.c

+8 −47
Original line number Diff line number Diff line
@@ -185,58 +185,19 @@ static inline void cmf_activate(void *area, unsigned int onoff) 
static int set_schib(struct ccw_device *cdev, u32 mme, int mbfc,

		     unsigned long address)

{

	int ret;

	int retry;

	struct subchannel *sch;

	struct schib *schib;



	sch = to_subchannel(cdev->dev.parent);

	schib = &sch->schib;

	/* msch can silently fail, so do it again if necessary */

	for (retry = 0; retry < 3; retry++) {

		/* prepare schib */

		if (cio_update_schib(sch))

			return -ENODEV;

		schib->pmcw.mme  = mme;

		schib->pmcw.mbfc = mbfc;



	sch->config.mme = mme;

	sch->config.mbfc = mbfc;

	/* address can be either a block address or a block index */

	if (mbfc)

			schib->mba = address;

		sch->config.mba = address;

	else

			schib->pmcw.mbi = address;



		/* try to submit it */

		switch(ret = msch_err(sch->schid, schib)) {

			case 0:

				break;

			case 1:

			case 2: /* in I/O or status pending */

				ret = -EBUSY;

				break;

			case 3: /* subchannel is no longer valid */

				ret = -ENODEV;

				break;

			default: /* msch caught an exception */

				ret = -EINVAL;

				break;

		}

		if (cio_update_schib(sch))

			return -ENODEV;



		if (ret)

			break;



		/* check if it worked */

		if (schib->pmcw.mme  == mme &&

		    schib->pmcw.mbfc == mbfc &&

		    (mbfc ? (schib->mba == address)

			  : (schib->pmcw.mbi == address)))

			return 0;

		sch->config.mbi = address;



		ret = -EINVAL;

	}



	return ret;

	return cio_commit_config(sch);

}



struct set_schib_struct {

drivers/s390/cio/css.c

+2 −2
Original line number Diff line number Diff line
@@ -128,8 +128,8 @@ css_free_subchannel(struct subchannel *sch) 
{

	if (sch) {

		/* Reset intparm to zeroes. */

		sch->schib.pmcw.intparm = 0;

		cio_modify(sch);

		sch->config.intparm = 0;

		cio_commit_config(sch);

		kfree(sch->lock);

		kfree(sch);

	}

drivers/s390/cio/device.c

+18 −18
Original line number Diff line number Diff line
@@ -1020,8 +1020,8 @@ static void ccw_device_call_sch_unregister(struct work_struct *work) 
	sch = to_subchannel(cdev->dev.parent);

	css_sch_device_unregister(sch);

	/* Reset intparm to zeroes. */

	sch->schib.pmcw.intparm = 0;

	cio_modify(sch);

	sch->config.intparm = 0;

	cio_commit_config(sch);

	/* Release cdev reference for workqueue processing.*/

	put_device(&cdev->dev);

	/* Release subchannel reference for local processing. */
@@ -1148,8 +1148,8 @@ static void ccw_device_move_to_sch(struct work_struct *work) 
		spin_unlock_irq(former_parent->lock);

		css_sch_device_unregister(former_parent);

		/* Reset intparm to zeroes. */

		former_parent->schib.pmcw.intparm = 0;

		cio_modify(former_parent);

		former_parent->config.intparm = 0;

		cio_commit_config(former_parent);

	}

	sch_attach_device(sch, cdev);

out:
@@ -1170,6 +1170,14 @@ static void io_subchannel_irq(struct subchannel *sch) 
		dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);

}



void io_subchannel_init_config(struct subchannel *sch)

{

	memset(&sch->config, 0, sizeof(sch->config));

	sch->config.csense = 1;

	if ((sch->lpm & (sch->lpm - 1)) != 0)

		sch->config.mp = 1;

}



static void io_subchannel_init_fields(struct subchannel *sch)

{

	if (cio_is_console(sch->schid))
@@ -1184,16 +1192,8 @@ static void io_subchannel_init_fields(struct subchannel *sch) 
		      sch->schib.pmcw.dev, sch->schid.ssid,

		      sch->schid.sch_no, sch->schib.pmcw.pim,

		      sch->schib.pmcw.pam, sch->schib.pmcw.pom);

	/* Initially set up some fields in the pmcw. */

	sch->schib.pmcw.ena = 0;

	sch->schib.pmcw.csense = 1;	/* concurrent sense */

	if ((sch->lpm & (sch->lpm - 1)) != 0)

		sch->schib.pmcw.mp = 1; /* multipath mode */

	/* clean up possible residual cmf stuff */

	sch->schib.pmcw.mme = 0;

	sch->schib.pmcw.mbfc = 0;

	sch->schib.pmcw.mbi = 0;

	sch->schib.mba = 0;



	io_subchannel_init_config(sch);

}



static void io_subchannel_do_unreg(struct work_struct *work)
@@ -1203,8 +1203,8 @@ static void io_subchannel_do_unreg(struct work_struct *work) 
	sch = container_of(work, struct subchannel, work);

	css_sch_device_unregister(sch);

	/* Reset intparm to zeroes. */

	sch->schib.pmcw.intparm = 0;

	cio_modify(sch);

	sch->config.intparm = 0;

	cio_commit_config(sch);

	put_device(&sch->dev);

}
@@ -1680,8 +1680,8 @@ static int io_subchannel_sch_event(struct subchannel *sch, int slow) 
		spin_lock_irqsave(sch->lock, flags);



		/* Reset intparm to zeroes. */

		sch->schib.pmcw.intparm = 0;

		cio_modify(sch);

		sch->config.intparm = 0;

		cio_commit_config(sch);

		break;

	case REPROBE:

		ccw_device_trigger_reprobe(cdev);