1 files changed, 120 insertions, 29 deletions

diff --git a/drivers/s390/cio/device_pgid.c b/drivers/s390/cio/device_pgid.c
index 54cb64ed0786..1693a102dcfe 100644
--- a/drivers/s390/cio/device_pgid.c
+++ b/drivers/s390/cio/device_pgid.c
@@ -24,6 +24,21 @@
 #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;
 
@@ -244,6 +265,48 @@ __ccw_device_do_pgid(struct ccw_device *cdev, __u8 func)
 }
 
 /*
+ * 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 = -ENODEV;
+        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))
+                        return ret;
+        }
+        /* nop command failed on this path. Switch it off. */
+        sch->lpm &= ~cdev->private->imask;
+        sch->vpm &= ~cdev->private->imask;
+        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.
  */
@@ -282,6 +345,29 @@ __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)
 {
@@ -296,9 +382,12 @@ __ccw_device_verify_start(struct ccw_device *cdev)
                         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);
+                if (cdev->private->options.pgroup) {
+                        func = (sch->vpm & imask) ?
+                                SPID_FUNC_RESIGN : SPID_FUNC_ESTABLISH;
+                        ret = __ccw_device_do_pgid(cdev, func);
+                } else
+                        ret = __ccw_device_do_nop(cdev);
                 if (ret == 0 || ret == -EBUSY)
                         return;
                 cdev->private->iretry = 5;
@@ -317,17 +406,20 @@ 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 */
@@ -345,11 +437,10 @@ 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;
                 /* fall through. */
         case -EAGAIN:           /* Try again. */
                 __ccw_device_verify_start(cdev);
@@ -418,10 +509,10 @@ 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;
         }