[GFS2] Fix up merge of Linus' kernel into GFS2
[pandora-kernel.git] / drivers / s390 / cio / device_pgid.c
index 54cb64e..8ca2d07 100644 (file)
 #include "device.h"
 #include "ioasm.h"
 
+/*
+ * Helper function called from interrupt context to decide whether an
+ * operation should be tried again.
+ */
+static int __ccw_device_should_retry(struct scsw *scsw)
+{
+       /* CC is only valid if start function bit is set. */
+       if ((scsw->fctl & SCSW_FCTL_START_FUNC) && scsw->cc == 1)
+               return 1;
+       /* No more activity. For sense and set PGID we stubbornly try again. */
+       if (!scsw->actl)
+               return 1;
+       return 0;
+}
+
 /*
  * Start Sense Path Group ID helper function. Used in ccw_device_recog
  * and ccw_device_sense_pgid.
@@ -33,12 +48,17 @@ __ccw_device_sense_pgid_start(struct ccw_device *cdev)
        struct subchannel *sch;
        struct ccw1 *ccw;
        int ret;
+       int i;
 
        sch = to_subchannel(cdev->dev.parent);
+       /* Return if we already checked on all paths. */
+       if (cdev->private->imask == 0)
+               return (sch->lpm == 0) ? -ENODEV : -EACCES;
+       i = 8 - ffs(cdev->private->imask);
+
        /* Setup sense path group id channel program. */
        ccw = cdev->private->iccws;
        ccw->cmd_code = CCW_CMD_SENSE_PGID;
-       ccw->cda = (__u32) __pa (&cdev->private->pgid);
        ccw->count = sizeof (struct pgid);
        ccw->flags = CCW_FLAG_SLI;
 
@@ -48,6 +68,7 @@ __ccw_device_sense_pgid_start(struct ccw_device *cdev)
        ret = -ENODEV;
        while (cdev->private->imask != 0) {
                /* Try every path multiple times. */
+               ccw->cda = (__u32) __pa (&cdev->private->pgid[i]);
                if (cdev->private->iretry > 0) {
                        cdev->private->iretry--;
                        ret = cio_start (sch, cdev->private->iccws, 
@@ -64,7 +85,9 @@ __ccw_device_sense_pgid_start(struct ccw_device *cdev)
                }
                cdev->private->imask >>= 1;
                cdev->private->iretry = 5;
+               i++;
        }
+
        return ret;
 }
 
@@ -76,7 +99,7 @@ ccw_device_sense_pgid_start(struct ccw_device *cdev)
        cdev->private->state = DEV_STATE_SENSE_PGID;
        cdev->private->imask = 0x80;
        cdev->private->iretry = 5;
-       memset (&cdev->private->pgid, 0, sizeof (struct pgid));
+       memset (&cdev->private->pgid, 0, sizeof (cdev->private->pgid));
        ret = __ccw_device_sense_pgid_start(cdev);
        if (ret && ret != -EBUSY)
                ccw_device_sense_pgid_done(cdev, ret);
@@ -91,6 +114,7 @@ __ccw_device_check_sense_pgid(struct ccw_device *cdev)
 {
        struct subchannel *sch;
        struct irb *irb;
+       int i;
 
        sch = to_subchannel(cdev->dev.parent);
        irb = &cdev->private->irb;
@@ -124,7 +148,8 @@ __ccw_device_check_sense_pgid(struct ccw_device *cdev)
                              sch->schid.sch_no, sch->orb.lpm);
                return -EACCES;
        }
-       if (cdev->private->pgid.inf.ps.state2 == SNID_STATE2_RESVD_ELSE) {
+       i = 8 - ffs(cdev->private->imask);
+       if (cdev->private->pgid[i].inf.ps.state2 == SNID_STATE2_RESVD_ELSE) {
                CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x "
                              "is reserved by someone else\n",
                              cdev->private->devno, sch->schid.ssid,
@@ -145,10 +170,10 @@ ccw_device_sense_pgid_irq(struct ccw_device *cdev, enum dev_event dev_event)
        int ret;
 
        irb = (struct irb *) __LC_IRB;
-       /* Retry sense pgid for cc=1. */
+
        if (irb->scsw.stctl ==
            (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
-               if (irb->scsw.cc == 1) {
+               if (__ccw_device_should_retry(&irb->scsw)) {
                        ret = __ccw_device_sense_pgid_start(cdev);
                        if (ret && ret != -EBUSY)
                                ccw_device_sense_pgid_done(cdev, ret);
@@ -162,12 +187,6 @@ ccw_device_sense_pgid_irq(struct ccw_device *cdev, enum dev_event dev_event)
        memset(&cdev->private->irb, 0, sizeof(struct irb));
        switch (ret) {
        /* 0, -ETIME, -EOPNOTSUPP, -EAGAIN, -EACCES or -EUSERS */
-       case 0:                 /* Sense Path Group ID successful. */
-               if (cdev->private->pgid.inf.ps.state1 == SNID_STATE1_RESET)
-                       memcpy(&cdev->private->pgid, &css[0]->global_pgid,
-                              sizeof(struct pgid));
-               ccw_device_sense_pgid_done(cdev, 0);
-               break;
        case -EOPNOTSUPP:       /* Sense Path Group ID not supported */
                ccw_device_sense_pgid_done(cdev, -EOPNOTSUPP);
                break;
@@ -176,13 +195,15 @@ ccw_device_sense_pgid_irq(struct ccw_device *cdev, enum dev_event dev_event)
                break;
        case -EACCES:           /* channel is not operational. */
                sch->lpm &= ~cdev->private->imask;
+               /* Fall through. */
+       case 0:                 /* Sense Path Group ID successful. */
                cdev->private->imask >>= 1;
                cdev->private->iretry = 5;
                /* Fall through. */
        case -EAGAIN:           /* Try again. */
                ret = __ccw_device_sense_pgid_start(cdev);
                if (ret != 0 && ret != -EBUSY)
-                       ccw_device_sense_pgid_done(cdev, -ENODEV);
+                       ccw_device_sense_pgid_done(cdev, ret);
                break;
        case -EUSERS:           /* device is reserved for someone else. */
                ccw_device_sense_pgid_done(cdev, -EUSERS);
@@ -203,20 +224,20 @@ __ccw_device_do_pgid(struct ccw_device *cdev, __u8 func)
        sch = to_subchannel(cdev->dev.parent);
 
        /* Setup sense path group id channel program. */
-       cdev->private->pgid.inf.fc = func;
+       cdev->private->pgid[0].inf.fc = func;
        ccw = cdev->private->iccws;
        if (!cdev->private->flags.pgid_single) {
-               cdev->private->pgid.inf.fc |= SPID_FUNC_MULTI_PATH;
+               cdev->private->pgid[0].inf.fc |= SPID_FUNC_MULTI_PATH;
                ccw->cmd_code = CCW_CMD_SUSPEND_RECONN;
                ccw->cda = 0;
                ccw->count = 0;
                ccw->flags = CCW_FLAG_SLI | CCW_FLAG_CC;
                ccw++;
        } else
-               cdev->private->pgid.inf.fc |= SPID_FUNC_SINGLE_PATH;
+               cdev->private->pgid[0].inf.fc |= SPID_FUNC_SINGLE_PATH;
 
        ccw->cmd_code = CCW_CMD_SET_PGID;
-       ccw->cda = (__u32) __pa (&cdev->private->pgid);
+       ccw->cda = (__u32) __pa (&cdev->private->pgid[0]);
        ccw->count = sizeof (struct pgid);
        ccw->flags = CCW_FLAG_SLI;
 
@@ -224,18 +245,17 @@ __ccw_device_do_pgid(struct ccw_device *cdev, __u8 func)
        memset(&cdev->private->irb, 0, sizeof(struct irb));
 
        /* Try multiple times. */
-       ret = -ENODEV;
+       ret = -EACCES;
        if (cdev->private->iretry > 0) {
                cdev->private->iretry--;
                ret = cio_start (sch, cdev->private->iccws,
                                 cdev->private->imask);
-               /* ret is 0, -EBUSY, -EACCES or -ENODEV */
-               if ((ret != -EACCES) && (ret != -ENODEV))
+               /* We expect an interrupt in case of success or busy
+                * indication. */
+               if ((ret == 0) || (ret == -EBUSY))
                        return ret;
        }
-       /* PGID command failed on this path. Switch it off. */
-       sch->lpm &= ~cdev->private->imask;
-       sch->vpm &= ~cdev->private->imask;
+       /* PGID command failed on this path. */
        CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel "
                      "0.%x.%04x, lpm %02X, became 'not operational'\n",
                      cdev->private->devno, sch->schid.ssid,
@@ -243,6 +263,47 @@ __ccw_device_do_pgid(struct ccw_device *cdev, __u8 func)
        return ret;
 }
 
+/*
+ * Helper function to send a nop ccw down a path.
+ */
+static int __ccw_device_do_nop(struct ccw_device *cdev)
+{
+       struct subchannel *sch;
+       struct ccw1 *ccw;
+       int ret;
+
+       sch = to_subchannel(cdev->dev.parent);
+
+       /* Setup nop channel program. */
+       ccw = cdev->private->iccws;
+       ccw->cmd_code = CCW_CMD_NOOP;
+       ccw->cda = 0;
+       ccw->count = 0;
+       ccw->flags = CCW_FLAG_SLI;
+
+       /* Reset device status. */
+       memset(&cdev->private->irb, 0, sizeof(struct irb));
+
+       /* Try multiple times. */
+       ret = -EACCES;
+       if (cdev->private->iretry > 0) {
+               cdev->private->iretry--;
+               ret = cio_start (sch, cdev->private->iccws,
+                                cdev->private->imask);
+               /* We expect an interrupt in case of success or busy
+                * indication. */
+               if ((ret == 0) || (ret == -EBUSY))
+                       return ret;
+       }
+       /* nop command failed on this path. */
+       CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel "
+                     "0.%x.%04x, lpm %02X, became 'not operational'\n",
+                     cdev->private->devno, sch->schid.ssid,
+                     sch->schid.sch_no, cdev->private->imask);
+       return ret;
+}
+
+
 /*
  * Called from interrupt context to check if a valid answer
  * to Set Path Group ID was received.
@@ -282,28 +343,59 @@ __ccw_device_check_pgid(struct ccw_device *cdev)
        return 0;
 }
 
+/*
+ * Called from interrupt context to check the path status after a nop has
+ * been send.
+ */
+static int __ccw_device_check_nop(struct ccw_device *cdev)
+{
+       struct subchannel *sch;
+       struct irb *irb;
+
+       sch = to_subchannel(cdev->dev.parent);
+       irb = &cdev->private->irb;
+       if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC))
+               return -ETIME;
+       if (irb->scsw.cc == 3) {
+               CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel 0.%x.%04x,"
+                             " lpm %02X, became 'not operational'\n",
+                             cdev->private->devno, sch->schid.ssid,
+                             sch->schid.sch_no, cdev->private->imask);
+               return -EACCES;
+       }
+       return 0;
+}
+
 static void
 __ccw_device_verify_start(struct ccw_device *cdev)
 {
        struct subchannel *sch;
-       __u8 imask, func;
+       __u8 func;
        int ret;
 
        sch = to_subchannel(cdev->dev.parent);
-       while (sch->vpm != sch->lpm) {
-               /* Find first unequal bit in vpm vs. lpm */
-               for (imask = 0x80; imask != 0; imask >>= 1)
-                       if ((sch->vpm & imask) != (sch->lpm & imask))
-                               break;
-               cdev->private->imask = imask;
-               func = (sch->vpm & imask) ?
-                       SPID_FUNC_RESIGN : SPID_FUNC_ESTABLISH;
-               ret = __ccw_device_do_pgid(cdev, func);
+       /* Repeat for all paths. */
+       for (; cdev->private->imask; cdev->private->imask >>= 1,
+                                    cdev->private->iretry = 5) {
+               if ((cdev->private->imask & sch->schib.pmcw.pam) == 0)
+                       /* Path not available, try next. */
+                       continue;
+               if (cdev->private->options.pgroup) {
+                       if (sch->opm & cdev->private->imask)
+                               func = SPID_FUNC_ESTABLISH;
+                       else
+                               func = SPID_FUNC_RESIGN;
+                       ret = __ccw_device_do_pgid(cdev, func);
+               } else
+                       ret = __ccw_device_do_nop(cdev);
+               /* We expect an interrupt in case of success or busy
+                * indication. */
                if (ret == 0 || ret == -EBUSY)
                        return;
-               cdev->private->iretry = 5;
+               /* Permanent path failure, try next. */
        }
-       ccw_device_verify_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
+       /* Done with all paths. */
+       ccw_device_verify_done(cdev, (sch->vpm != 0) ? 0 : -ENODEV);
 }
                
 /*
@@ -317,26 +409,29 @@ ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
        int ret;
 
        irb = (struct irb *) __LC_IRB;
-       /* Retry set pgid for cc=1. */
+
        if (irb->scsw.stctl ==
            (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
-               if (irb->scsw.cc == 1)
+               if (__ccw_device_should_retry(&irb->scsw))
                        __ccw_device_verify_start(cdev);
                return;
        }
        if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
                return;
        sch = to_subchannel(cdev->dev.parent);
-       ret = __ccw_device_check_pgid(cdev);
+       if (cdev->private->options.pgroup)
+               ret = __ccw_device_check_pgid(cdev);
+       else
+               ret = __ccw_device_check_nop(cdev);
        memset(&cdev->private->irb, 0, sizeof(struct irb));
+
        switch (ret) {
        /* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
        case 0:
-               /* Establish or Resign Path Group done. Update vpm. */
-               if ((sch->lpm & cdev->private->imask) != 0)
-                       sch->vpm |= cdev->private->imask;
-               else
-                       sch->vpm &= ~cdev->private->imask;
+               /* Path verification ccw finished successfully, update lpm. */
+               sch->vpm |= sch->opm & cdev->private->imask;
+               /* Go on with next path. */
+               cdev->private->imask >>= 1;
                cdev->private->iretry = 5;
                __ccw_device_verify_start(cdev);
                break;
@@ -345,11 +440,14 @@ ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
                 * One of those strange devices which claim to be able
                 * to do multipathing but not for Set Path Group ID.
                 */
-               if (cdev->private->flags.pgid_single) {
-                       ccw_device_verify_done(cdev, -EOPNOTSUPP);
-                       break;
-               }
-               cdev->private->flags.pgid_single = 1;
+               if (cdev->private->flags.pgid_single)
+                       cdev->private->options.pgroup = 0;
+               else
+                       cdev->private->flags.pgid_single = 1;
+               /* Retry */
+               sch->vpm = 0;
+               cdev->private->imask = 0x80;
+               cdev->private->iretry = 5;
                /* fall through. */
        case -EAGAIN:           /* Try again. */
                __ccw_device_verify_start(cdev);
@@ -358,8 +456,7 @@ ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
                ccw_device_verify_done(cdev, -ETIME);
                break;
        case -EACCES:           /* channel is not operational. */
-               sch->lpm &= ~cdev->private->imask;
-               sch->vpm &= ~cdev->private->imask;
+               cdev->private->imask >>= 1;
                cdev->private->iretry = 5;
                __ccw_device_verify_start(cdev);
                break;
@@ -372,19 +469,17 @@ ccw_device_verify_start(struct ccw_device *cdev)
        struct subchannel *sch = to_subchannel(cdev->dev.parent);
 
        cdev->private->flags.pgid_single = 0;
+       cdev->private->imask = 0x80;
        cdev->private->iretry = 5;
-       /*
-        * Update sch->lpm with current values to catch paths becoming
-        * available again.
-        */
+
+       /* Start with empty vpm. */
+       sch->vpm = 0;
+
+       /* Get current pam. */
        if (stsch(sch->schid, &sch->schib)) {
                ccw_device_verify_done(cdev, -ENODEV);
                return;
        }
-       sch->lpm = sch->schib.pmcw.pim &
-               sch->schib.pmcw.pam &
-               sch->schib.pmcw.pom &
-               sch->opm;
        __ccw_device_verify_start(cdev);
 }
 
@@ -418,10 +513,10 @@ ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event)
        int ret;
 
        irb = (struct irb *) __LC_IRB;
-       /* Retry set pgid for cc=1. */
+
        if (irb->scsw.stctl ==
            (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
-               if (irb->scsw.cc == 1)
+               if (__ccw_device_should_retry(&irb->scsw))
                        __ccw_device_disband_start(cdev);
                return;
        }
@@ -433,7 +528,6 @@ ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event)
        switch (ret) {
        /* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
        case 0:                 /* disband successful. */
-               sch->vpm = 0;
                ccw_device_disband_done(cdev, ret);
                break;
        case -EOPNOTSUPP: