[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: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

1 files changed, 16 insertions, 202 deletions

diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index 5de86908b0d0..1c0f5db94c7b 100644
--- a/drivers/s390/cio/chsc.c
+++ b/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@de.ibm.com)
  *               Cornelia Huck (cornelia.huck@de.ibm.com)
  *               Arnd Bergmann (arndb@de.ibm.com)
@@ -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(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);
 }