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[S390] cio: introduce cio_commit_config
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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: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Sebastian Ott authored and Martin Schwidefsky committed Dec 25, 2008
1 parent cdb912a commit 13952ec
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Showing 7 changed files with 123 additions and 134 deletions.
134 changes: 73 additions & 61 deletions drivers/s390/cio/cio.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -330,30 +330,70 @@ 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);
if (ccode < 0) /* -EIO if msch gets a program check. */
/* 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 */
return 0;
case 1: /* status pending */
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 */
udelay (100); /* allow for recovery */
case 2: /* busy */
udelay(100); /* allow for recovery */
ret = -EBUSY;
break;
case 3: /* not operational */
case 3: /* not operational */
return -ENODEV;
}
}
Expand Down Expand Up @@ -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);
Expand All @@ -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");
Expand All @@ -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;
Expand Down Expand Up @@ -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;
Expand All @@ -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;
}
Expand Down
16 changes: 15 additions & 1 deletion drivers/s390/cio/cio.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
*/
Expand Down Expand Up @@ -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 */
Expand All @@ -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);
Expand Down
55 changes: 8 additions & 47 deletions drivers/s390/cio/cmf.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
/* address can be either a block address or a block index */
if (mbfc)
schib->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.mme = mme;
sch->config.mbfc = mbfc;
/* address can be either a block address or a block index */
if (mbfc)
sch->config.mba = address;
else
sch->config.mbi = address;

ret = -EINVAL;
}

return ret;
return cio_commit_config(sch);
}

struct set_schib_struct {
Expand Down
4 changes: 2 additions & 2 deletions drivers/s390/cio/css.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
}
Expand Down
36 changes: 18 additions & 18 deletions drivers/s390/cio/device.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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. */
Expand Down Expand Up @@ -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:
Expand All @@ -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))
Expand All @@ -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)
Expand All @@ -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);
}

Expand Down Expand Up @@ -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);
Expand Down
1 change: 1 addition & 0 deletions drivers/s390/cio/device.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -76,6 +76,7 @@ extern wait_queue_head_t ccw_device_init_wq;
extern atomic_t ccw_device_init_count;

void io_subchannel_recog_done(struct ccw_device *cdev);
void io_subchannel_init_config(struct subchannel *sch);

int ccw_device_cancel_halt_clear(struct ccw_device *);

Expand Down
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