[patch 03/14] cio: Rework css driver.

From: Martin Schwidefsky
Date: Tue Jun 03 2008 - 13:09:39 EST


From: Cornelia Huck <cornelia.huck@xxxxxxxxxx>

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: Cornelia Huck <cornelia.huck@xxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
---

drivers/s390/cio/chp.c | 20 ++
drivers/s390/cio/chp.h | 13 +
drivers/s390/cio/chsc.c | 218 +------------------------
drivers/s390/cio/cio.c | 1
drivers/s390/cio/css.c | 123 +-------------
drivers/s390/cio/css.h | 38 +---
drivers/s390/cio/device.c | 365 ++++++++++++++++++++++++++++++++----------
drivers/s390/cio/device.h | 7
drivers/s390/cio/device_fsm.c | 106 +-----------
9 files changed, 381 insertions(+), 510 deletions(-)

Index: quilt-2.6/drivers/s390/cio/chp.c
===================================================================
--- quilt-2.6.orig/drivers/s390/cio/chp.c
+++ quilt-2.6/drivers/s390/cio/chp.c
@@ -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);
Index: quilt-2.6/drivers/s390/cio/chp.h
===================================================================
--- quilt-2.6.orig/drivers/s390/cio/chp.h
+++ quilt-2.6/drivers/s390/cio/chp.h
@@ -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 */
Index: quilt-2.6/drivers/s390/cio/chsc.c
===================================================================
--- quilt-2.6.orig/drivers/s390/cio/chsc.c
+++ quilt-2.6/drivers/s390/cio/chsc.c
@@ -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@xxxxxxxxxx)
* Cornelia Huck (cornelia.huck@xxxxxxxxxx)
* Arnd Bergmann (arndb@xxxxxxxxxx)
@@ -127,77 +126,12 @@ out_free:
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)
- 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)
+ if (sch->driver && sch->driver->chp_event)
+ if (sch->driver->chp_event(sch, data, CHP_OFFLINE) != 0)
goto out_unreg;
- }
-
spin_unlock_irq(sch->lock);
return 0;

@@ -242,53 +176,11 @@ static int s390_process_res_acc_new_sch(
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);
}

Index: quilt-2.6/drivers/s390/cio/cio.c
===================================================================
--- quilt-2.6.orig/drivers/s390/cio/cio.c
+++ quilt-2.6/drivers/s390/cio/cio.c
@@ -564,6 +564,7 @@ int cio_validate_subchannel(struct subch
}
/* 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);
Index: quilt-2.6/drivers/s390/cio/css.c
===================================================================
--- quilt-2.6.orig/drivers/s390/cio/css.c
+++ quilt-2.6/drivers/s390/cio/css.c
@@ -283,7 +283,7 @@ static int css_register_subchannel(struc
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(s
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;
Index: quilt-2.6/drivers/s390/cio/css.h
===================================================================
--- quilt-2.6.orig/drivers/s390/cio/css.h
+++ quilt-2.6/drivers/s390/cio/css.h
@@ -58,18 +58,27 @@ struct pgid {
__u32 tod_high; /* high word TOD clock */
} __attribute__ ((packed));

-/*
- * A css driver handles all subchannels of one type.
- */
struct subchannel;
+/**
+ * struct css_driver - device driver for subchannels
+ * @owner: owning module
+ * @subchannel_type: subchannel type supported by this driver
+ * @drv: embedded device driver structure
+ * @irq: called on interrupts
+ * @chp_event: called for events affecting a channel path
+ * @sch_event: called for events affecting the subchannel
+ * @probe: function called on probe
+ * @remove: function called on remove
+ * @shutdown: called at device shutdown
+ * @name: name of the device driver
+ */
struct css_driver {
struct module *owner;
unsigned int subchannel_type;
struct device_driver drv;
void (*irq)(struct subchannel *);
- int (*notify)(struct subchannel *, int);
- void (*verify)(struct subchannel *);
- void (*termination)(struct subchannel *);
+ int (*chp_event)(struct subchannel *, void *, int);
+ int (*sch_event)(struct subchannel *, int);
int (*probe)(struct subchannel *);
int (*remove)(struct subchannel *);
void (*shutdown)(struct subchannel *);
@@ -87,7 +96,8 @@ extern int css_driver_register(struct cs
extern void css_driver_unregister(struct css_driver *);

extern void css_sch_device_unregister(struct subchannel *);
-extern struct subchannel * get_subchannel_by_schid(struct subchannel_id);
+extern int css_probe_device(struct subchannel_id);
+extern struct subchannel *get_subchannel_by_schid(struct subchannel_id);
extern int css_init_done;
int for_each_subchannel_staged(int (*fn_known)(struct subchannel *, void *),
int (*fn_unknown)(struct subchannel_id,
@@ -119,20 +129,6 @@ struct channel_subsystem {
extern struct bus_type css_bus_type;
extern struct channel_subsystem *channel_subsystems[];

-/* Some helper functions for disconnected state. */
-int device_is_disconnected(struct subchannel *);
-void device_set_disconnected(struct subchannel *);
-void device_trigger_reprobe(struct subchannel *);
-
-/* Helper functions for vary on/off. */
-int device_is_online(struct subchannel *);
-void device_kill_io(struct subchannel *);
-void device_set_intretry(struct subchannel *sch);
-int device_trigger_verify(struct subchannel *sch);
-
-/* Machine check helper function. */
-void device_kill_pending_timer(struct subchannel *);
-
/* Helper functions to build lists for the slow path. */
void css_schedule_eval(struct subchannel_id schid);
void css_schedule_eval_all(void);
Index: quilt-2.6/drivers/s390/cio/device.c
===================================================================
--- quilt-2.6.orig/drivers/s390/cio/device.c
+++ quilt-2.6/drivers/s390/cio/device.c
@@ -2,8 +2,7 @@
* drivers/s390/cio/device.c
* bus driver for ccw devices
*
- * Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
- * IBM Corporation
+ * Copyright IBM Corp. 2002,2008
* Author(s): Arnd Bergmann (arndb@xxxxxxxxxx)
* Cornelia Huck (cornelia.huck@xxxxxxxxxx)
* Martin Schwidefsky (schwidefsky@xxxxxxxxxx)
@@ -126,19 +125,17 @@ struct bus_type ccw_bus_type;
static void io_subchannel_irq(struct subchannel *);
static int io_subchannel_probe(struct subchannel *);
static int io_subchannel_remove(struct subchannel *);
-static int io_subchannel_notify(struct subchannel *, int);
-static void io_subchannel_verify(struct subchannel *);
-static void io_subchannel_ioterm(struct subchannel *);
static void io_subchannel_shutdown(struct subchannel *);
+static int io_subchannel_sch_event(struct subchannel *, int);
+static int io_subchannel_chp_event(struct subchannel *, void *, int);

static struct css_driver io_subchannel_driver = {
.owner = THIS_MODULE,
.subchannel_type = SUBCHANNEL_TYPE_IO,
.name = "io_subchannel",
.irq = io_subchannel_irq,
- .notify = io_subchannel_notify,
- .verify = io_subchannel_verify,
- .termination = io_subchannel_ioterm,
+ .sch_event = io_subchannel_sch_event,
+ .chp_event = io_subchannel_chp_event,
.probe = io_subchannel_probe,
.remove = io_subchannel_remove,
.shutdown = io_subchannel_shutdown,
@@ -786,7 +783,7 @@ static void sch_attach_device(struct sub
sch_set_cdev(sch, cdev);
cdev->private->schid = sch->schid;
cdev->ccwlock = sch->lock;
- device_trigger_reprobe(sch);
+ ccw_device_trigger_reprobe(cdev);
spin_unlock_irq(sch->lock);
}

@@ -1265,11 +1262,7 @@ static int io_subchannel_notify(struct s
cdev = sch_get_cdev(sch);
if (!cdev)
return 0;
- if (!cdev->drv)
- return 0;
- if (!cdev->online)
- return 0;
- return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
+ return ccw_device_notify(cdev, event);
}

static void io_subchannel_verify(struct subchannel *sch)
@@ -1281,22 +1274,98 @@ static void io_subchannel_verify(struct
dev_fsm_event(cdev, DEV_EVENT_VERIFY);
}

-static void io_subchannel_ioterm(struct subchannel *sch)
+static int check_for_io_on_path(struct subchannel *sch, int mask)
{
- struct ccw_device *cdev;
+ int cc;

- cdev = sch_get_cdev(sch);
- if (!cdev)
- return;
- /* Internal I/O will be retried by the interrupt handler. */
- if (cdev->private->flags.intretry)
+ 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,
+ struct ccw_device *cdev)
+{
+ if (cio_clear(sch)) {
+ /* Recheck device in case clear failed. */
+ sch->lpm = 0;
+ if (cdev->online)
+ dev_fsm_event(cdev, DEV_EVENT_VERIFY);
+ else
+ css_schedule_eval(sch->schid);
return;
+ }
cdev->private->state = DEV_STATE_CLEAR_VERIFY;
+ /* Request retry of internal operation. */
+ cdev->private->flags.intretry = 1;
+ /* Call handler. */
if (cdev->handler)
cdev->handler(cdev, cdev->private->intparm,
ERR_PTR(-EIO));
}

+static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
+{
+ struct ccw_device *cdev;
+
+ cdev = sch_get_cdev(sch);
+ if (!cdev)
+ return;
+ if (check_for_io_on_path(sch, mask)) {
+ if (cdev->private->state == DEV_STATE_ONLINE)
+ ccw_device_kill_io(cdev);
+ else {
+ terminate_internal_io(sch, cdev);
+ /* Re-start path verification. */
+ dev_fsm_event(cdev, DEV_EVENT_VERIFY);
+ }
+ } else
+ /* trigger path verification. */
+ dev_fsm_event(cdev, DEV_EVENT_VERIFY);
+
+}
+
+static int io_subchannel_chp_event(struct subchannel *sch, void *data,
+ int event)
+{
+ int mask;
+ struct res_acc_data *res_data;
+
+ res_data = data;
+ mask = chp_ssd_get_mask(&sch->ssd_info, res_data);
+ if (!mask)
+ return 0;
+ switch (event) {
+ case CHP_VARY_OFF:
+ sch->opm &= ~mask;
+ sch->lpm &= ~mask;
+ io_subchannel_terminate_path(sch, mask);
+ break;
+ case CHP_VARY_ON:
+ sch->opm |= mask;
+ sch->lpm |= mask;
+ io_subchannel_verify(sch);
+ break;
+ case CHP_OFFLINE:
+ if (stsch(sch->schid, &sch->schib))
+ return -ENXIO;
+ if (!css_sch_is_valid(&sch->schib))
+ return -ENODEV;
+ io_subchannel_terminate_path(sch, mask);
+ break;
+ case CHP_ONLINE:
+ if (stsch(sch->schid, &sch->schib))
+ return -ENXIO;
+ sch->lpm |= mask & sch->opm;
+ io_subchannel_verify(sch);
+ break;
+ }
+ return 0;
+}
+
static void
io_subchannel_shutdown(struct subchannel *sch)
{
@@ -1326,6 +1395,195 @@ io_subchannel_shutdown(struct subchannel
cio_disable_subchannel(sch);
}

+static int io_subchannel_get_status(struct subchannel *sch)
+{
+ struct schib schib;
+
+ if (stsch(sch->schid, &schib) || !schib.pmcw.dnv)
+ 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 device_is_disconnected(struct ccw_device *cdev)
+{
+ if (!cdev)
+ return 0;
+ return (cdev->private->state == DEV_STATE_DISCONNECTED ||
+ cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
+}
+
+static int recovery_check(struct device *dev, void *data)
+{
+ struct ccw_device *cdev = to_ccwdev(dev);
+ int *redo = data;
+
+ spin_lock_irq(cdev->ccwlock);
+ switch (cdev->private->state) {
+ case DEV_STATE_DISCONNECTED:
+ CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
+ cdev->private->dev_id.ssid,
+ cdev->private->dev_id.devno);
+ dev_fsm_event(cdev, DEV_EVENT_VERIFY);
+ *redo = 1;
+ break;
+ case DEV_STATE_DISCONNECTED_SENSE_ID:
+ *redo = 1;
+ break;
+ }
+ spin_unlock_irq(cdev->ccwlock);
+
+ return 0;
+}
+
+static void recovery_work_func(struct work_struct *unused)
+{
+ int redo = 0;
+
+ bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
+ if (redo) {
+ spin_lock_irq(&recovery_lock);
+ if (!timer_pending(&recovery_timer)) {
+ if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
+ recovery_phase++;
+ mod_timer(&recovery_timer, jiffies +
+ recovery_delay[recovery_phase] * HZ);
+ }
+ spin_unlock_irq(&recovery_lock);
+ } else
+ CIO_MSG_EVENT(4, "recovery: end\n");
+}
+
+static DECLARE_WORK(recovery_work, recovery_work_func);
+
+static void recovery_func(unsigned long data)
+{
+ /*
+ * We can't do our recovery in softirq context and it's not
+ * performance critical, so we schedule it.
+ */
+ schedule_work(&recovery_work);
+}
+
+static void ccw_device_schedule_recovery(void)
+{
+ unsigned long flags;
+
+ CIO_MSG_EVENT(4, "recovery: schedule\n");
+ spin_lock_irqsave(&recovery_lock, flags);
+ if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
+ recovery_phase = 0;
+ mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
+ }
+ spin_unlock_irqrestore(&recovery_lock, flags);
+}
+
+static void device_set_disconnected(struct ccw_device *cdev)
+{
+ if (!cdev)
+ return;
+ ccw_device_set_timeout(cdev, 0);
+ cdev->private->flags.fake_irb = 0;
+ cdev->private->state = DEV_STATE_DISCONNECTED;
+ if (cdev->online)
+ ccw_device_schedule_recovery();
+}
+
+static int io_subchannel_sch_event(struct subchannel *sch, int slow)
+{
+ int event, ret, disc;
+ unsigned long flags;
+ enum { NONE, UNREGISTER, UNREGISTER_PROBE, REPROBE } action;
+ struct ccw_device *cdev;
+
+ spin_lock_irqsave(sch->lock, flags);
+ cdev = sch_get_cdev(sch);
+ disc = device_is_disconnected(cdev);
+ 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. */
+ if (cdev)
+ ccw_device_set_timeout(cdev, 0);
+ if (!disc && !slow) {
+ /* Non-disconnected devices are evaluated on the slow path. */
+ spin_unlock_irqrestore(sch->lock, flags);
+ return -EAGAIN;
+ }
+ event = io_subchannel_get_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(cdev);
+ /* Ask driver what to do with device. */
+ action = UNREGISTER;
+ spin_unlock_irqrestore(sch->lock, flags);
+ ret = io_subchannel_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:
+ ccw_device_trigger_reprobe(cdev);
+ break;
+ default:
+ break;
+ }
+ spin_unlock_irqrestore(sch->lock, flags);
+ /* Probe if necessary. */
+ if (action == UNREGISTER_PROBE)
+ ret = css_probe_device(sch->schid);
+
+ return ret;
+}
+
#ifdef CONFIG_CCW_CONSOLE
static struct ccw_device console_cdev;
static struct ccw_device_private console_private;
@@ -1558,71 +1816,6 @@ ccw_device_get_subchannel_id(struct ccw_
return sch->schid;
}

-static int recovery_check(struct device *dev, void *data)
-{
- struct ccw_device *cdev = to_ccwdev(dev);
- int *redo = data;
-
- spin_lock_irq(cdev->ccwlock);
- switch (cdev->private->state) {
- case DEV_STATE_DISCONNECTED:
- CIO_MSG_EVENT(4, "recovery: trigger 0.%x.%04x\n",
- cdev->private->dev_id.ssid,
- cdev->private->dev_id.devno);
- dev_fsm_event(cdev, DEV_EVENT_VERIFY);
- *redo = 1;
- break;
- case DEV_STATE_DISCONNECTED_SENSE_ID:
- *redo = 1;
- break;
- }
- spin_unlock_irq(cdev->ccwlock);
-
- return 0;
-}
-
-static void recovery_work_func(struct work_struct *unused)
-{
- int redo = 0;
-
- bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
- if (redo) {
- spin_lock_irq(&recovery_lock);
- if (!timer_pending(&recovery_timer)) {
- if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
- recovery_phase++;
- mod_timer(&recovery_timer, jiffies +
- recovery_delay[recovery_phase] * HZ);
- }
- spin_unlock_irq(&recovery_lock);
- } else
- CIO_MSG_EVENT(4, "recovery: end\n");
-}
-
-static DECLARE_WORK(recovery_work, recovery_work_func);
-
-static void recovery_func(unsigned long data)
-{
- /*
- * We can't do our recovery in softirq context and it's not
- * performance critical, so we schedule it.
- */
- schedule_work(&recovery_work);
-}
-
-void ccw_device_schedule_recovery(void)
-{
- unsigned long flags;
-
- CIO_MSG_EVENT(4, "recovery: schedule\n");
- spin_lock_irqsave(&recovery_lock, flags);
- if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
- recovery_phase = 0;
- mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
- }
- spin_unlock_irqrestore(&recovery_lock, flags);
-}
-
MODULE_LICENSE("GPL");
EXPORT_SYMBOL(ccw_device_set_online);
EXPORT_SYMBOL(ccw_device_set_offline);
Index: quilt-2.6/drivers/s390/cio/device_fsm.c
===================================================================
--- quilt-2.6.orig/drivers/s390/cio/device_fsm.c
+++ quilt-2.6/drivers/s390/cio/device_fsm.c
@@ -2,8 +2,7 @@
* drivers/s390/cio/device_fsm.c
* finite state machine for device handling
*
- * Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
- * IBM Corporation
+ * Copyright IBM Corp. 2002,2008
* Author(s): Cornelia Huck (cornelia.huck@xxxxxxxxxx)
* Martin Schwidefsky (schwidefsky@xxxxxxxxxx)
*/
@@ -27,65 +26,6 @@

static int timeout_log_enabled;

-int
-device_is_online(struct subchannel *sch)
-{
- struct ccw_device *cdev;
-
- cdev = sch_get_cdev(sch);
- if (!cdev)
- return 0;
- return (cdev->private->state == DEV_STATE_ONLINE);
-}
-
-int
-device_is_disconnected(struct subchannel *sch)
-{
- struct ccw_device *cdev;
-
- cdev = sch_get_cdev(sch);
- if (!cdev)
- return 0;
- return (cdev->private->state == DEV_STATE_DISCONNECTED ||
- cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
-}
-
-void
-device_set_disconnected(struct subchannel *sch)
-{
- struct ccw_device *cdev;
-
- cdev = sch_get_cdev(sch);
- if (!cdev)
- return;
- ccw_device_set_timeout(cdev, 0);
- cdev->private->flags.fake_irb = 0;
- cdev->private->state = DEV_STATE_DISCONNECTED;
- if (cdev->online)
- ccw_device_schedule_recovery();
-}
-
-void device_set_intretry(struct subchannel *sch)
-{
- struct ccw_device *cdev;
-
- cdev = sch_get_cdev(sch);
- if (!cdev)
- return;
- cdev->private->flags.intretry = 1;
-}
-
-int device_trigger_verify(struct subchannel *sch)
-{
- struct ccw_device *cdev;
-
- cdev = sch_get_cdev(sch);
- if (!cdev || !cdev->online)
- return -EINVAL;
- dev_fsm_event(cdev, DEV_EVENT_VERIFY);
- return 0;
-}
-
static int __init ccw_timeout_log_setup(char *unused)
{
timeout_log_enabled = 1;
@@ -171,18 +111,6 @@ ccw_device_set_timeout(struct ccw_device
add_timer(&cdev->private->timer);
}

-/* Kill any pending timers after machine check. */
-void
-device_kill_pending_timer(struct subchannel *sch)
-{
- struct ccw_device *cdev;
-
- cdev = sch_get_cdev(sch);
- if (!cdev)
- return;
- ccw_device_set_timeout(cdev, 0);
-}
-
/*
* Cancel running i/o. This is called repeatedly since halt/clear are
* asynchronous operations. We do one try with cio_cancel, two tries
@@ -388,25 +316,27 @@ ccw_device_sense_id_done(struct ccw_devi
}
}

+int ccw_device_notify(struct ccw_device *cdev, int event)
+{
+ if (!cdev->drv)
+ return 0;
+ if (!cdev->online)
+ return 0;
+ return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
+}
+
static void
ccw_device_oper_notify(struct work_struct *work)
{
struct ccw_device_private *priv;
struct ccw_device *cdev;
- struct subchannel *sch;
int ret;
unsigned long flags;

priv = container_of(work, struct ccw_device_private, kick_work);
cdev = priv->cdev;
+ ret = ccw_device_notify(cdev, CIO_OPER);
spin_lock_irqsave(cdev->ccwlock, flags);
- sch = to_subchannel(cdev->dev.parent);
- if (sch->driver && sch->driver->notify) {
- spin_unlock_irqrestore(cdev->ccwlock, flags);
- ret = sch->driver->notify(sch, CIO_OPER);
- spin_lock_irqsave(cdev->ccwlock, flags);
- } else
- ret = 0;
if (ret) {
/* Reenable channel measurements, if needed. */
spin_unlock_irqrestore(cdev->ccwlock, flags);
@@ -986,12 +916,10 @@ ccw_device_killing_timeout(struct ccw_de
ERR_PTR(-EIO));
}

-void device_kill_io(struct subchannel *sch)
+void ccw_device_kill_io(struct ccw_device *cdev)
{
int ret;
- struct ccw_device *cdev;

- cdev = sch_get_cdev(sch);
ret = ccw_device_cancel_halt_clear(cdev);
if (ret == -EBUSY) {
ccw_device_set_timeout(cdev, 3*HZ);
@@ -1055,17 +983,14 @@ ccw_device_start_id(struct ccw_device *c
ccw_device_sense_id_start(cdev);
}

-void
-device_trigger_reprobe(struct subchannel *sch)
+void ccw_device_trigger_reprobe(struct ccw_device *cdev)
{
- struct ccw_device *cdev;
+ struct subchannel *sch;

- cdev = sch_get_cdev(sch);
- if (!cdev)
- return;
if (cdev->private->state != DEV_STATE_DISCONNECTED)
return;

+ sch = to_subchannel(cdev->dev.parent);
/* Update some values. */
if (stsch(sch->schid, &sch->schib))
return;
@@ -1081,7 +1006,6 @@ device_trigger_reprobe(struct subchannel
sch->schib.pmcw.ena = 0;
if ((sch->lpm & (sch->lpm - 1)) != 0)
sch->schib.pmcw.mp = 1;
- sch->schib.pmcw.intparm = (u32)(addr_t)sch;
/* We should also udate ssd info, but this has to wait. */
/* Check if this is another device which appeared on the same sch. */
if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
Index: quilt-2.6/drivers/s390/cio/device.h
===================================================================
--- quilt-2.6.orig/drivers/s390/cio/device.h
+++ quilt-2.6/drivers/s390/cio/device.h
@@ -88,8 +88,6 @@ int ccw_device_recognition(struct ccw_de
int ccw_device_online(struct ccw_device *);
int ccw_device_offline(struct ccw_device *);

-void ccw_device_schedule_recovery(void);
-
/* Function prototypes for device status and basic sense stuff. */
void ccw_device_accumulate_irb(struct ccw_device *, struct irb *);
void ccw_device_accumulate_basic_sense(struct ccw_device *, struct irb *);
@@ -118,6 +116,11 @@ int ccw_device_call_handler(struct ccw_d

int ccw_device_stlck(struct ccw_device *);

+/* Helper function for machine check handling. */
+void ccw_device_trigger_reprobe(struct ccw_device *);
+void ccw_device_kill_io(struct ccw_device *);
+int ccw_device_notify(struct ccw_device *, int);
+
/* qdio needs this. */
void ccw_device_set_timeout(struct ccw_device *, int);
extern struct subchannel_id ccw_device_get_subchannel_id(struct ccw_device *);

--
blue skies,
Martin.

"Reality continues to ruin my life." - Calvin.

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