s390/cio: dont abort verification after missing irq

Do not abort path verification when waiting for an interrupt timed out.
Use path_noirq_mask to keep track of the paths used for this (also
maintain a path_notoper_mask for debugging purposes). If the timeout
happend to be during an operation where we query or alter the state of
path groups set the pgid_unknown flag.

With this change we allow usage of devices which have such ill-behaved
paths (if at least one path is operational).

Reviewed-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 43 insertions, 10 deletions

diff --git a/drivers/s390/cio/device_pgid.c b/drivers/s390/cio/device_pgid.c
index 908d287f66c1..6f2987d8da99 100644
--- a/drivers/s390/cio/device_pgid.c
+++ b/drivers/s390/cio/device_pgid.c
@@ -102,10 +102,20 @@ static void nop_callback(struct ccw_device *cdev, void *data, int rc)
         struct subchannel *sch = to_subchannel(cdev->dev.parent);
         struct ccw_request *req = &cdev->private->req;
 
-        if (rc == 0)
+        switch (rc) {
+        case 0:
                 sch->vpm |= req->lpm;
-        else if (rc != -EACCES)
+                break;
+        case -ETIME:
+                cdev->private->path_noirq_mask |= req->lpm;
+                break;
+        case -EACCES:
+                cdev->private->path_notoper_mask |= req->lpm;
+                break;
+        default:
                 goto err;
+        }
+        /* Continue on the next path. */
         req->lpm >>= 1;
         nop_do(cdev);
         return;
@@ -174,7 +184,12 @@ static void spid_callback(struct ccw_device *cdev, void *data, int rc)
         case 0:
                 sch->vpm |= req->lpm & sch->opm;
                 break;
+        case -ETIME:
+                cdev->private->flags.pgid_unknown = 1;
+                cdev->private->path_noirq_mask |= req->lpm;
+                break;
         case -EACCES:
+                cdev->private->path_notoper_mask |= req->lpm;
                 break;
         case -EOPNOTSUPP:
                 if (cdev->private->flags.mpath) {
@@ -404,10 +419,21 @@ static void snid_callback(struct ccw_device *cdev, void *data, int rc)
 {
         struct ccw_request *req = &cdev->private->req;
 
-        if (rc == 0)
+        switch (rc) {
+        case 0:
                 cdev->private->pgid_valid_mask |= req->lpm;
-        else if (rc != -EACCES)
+                break;
+        case -ETIME:
+                cdev->private->flags.pgid_unknown = 1;
+                cdev->private->path_noirq_mask |= req->lpm;
+                break;
+        case -EACCES:
+                cdev->private->path_notoper_mask |= req->lpm;
+                break;
+        default:
                 goto err;
+        }
+        /* Continue on the next path. */
         req->lpm >>= 1;
         snid_do(cdev);
         return;
@@ -427,6 +453,13 @@ static void verify_start(struct ccw_device *cdev)
 
         sch->vpm = 0;
         sch->lpm = sch->schib.pmcw.pam;
+
+        /* Initialize PGID data. */
+        memset(cdev->private->pgid, 0, sizeof(cdev->private->pgid));
+        cdev->private->pgid_valid_mask = 0;
+        cdev->private->pgid_todo_mask = sch->schib.pmcw.pam;
+        cdev->private->path_notoper_mask = 0;
+
         /* Initialize request data. */
         memset(req, 0, sizeof(*req));
         req->timeout    = PGID_TIMEOUT;
@@ -459,14 +492,8 @@ static void verify_start(struct ccw_device *cdev)
  */
 void ccw_device_verify_start(struct ccw_device *cdev)
 {
-        struct subchannel *sch = to_subchannel(cdev->dev.parent);
-
         CIO_TRACE_EVENT(4, "vrfy");
         CIO_HEX_EVENT(4, &cdev->private->dev_id, sizeof(cdev->private->dev_id));
-        /* Initialize PGID data. */
-        memset(cdev->private->pgid, 0, sizeof(cdev->private->pgid));
-        cdev->private->pgid_valid_mask = 0;
-        cdev->private->pgid_todo_mask = sch->schib.pmcw.pam;
         /*
          * Initialize pathgroup and multipath state with target values.
          * They may change in the course of path verification.
@@ -474,6 +501,7 @@ void ccw_device_verify_start(struct ccw_device *cdev)
         cdev->private->flags.pgroup = cdev->private->options.pgroup;
         cdev->private->flags.mpath = cdev->private->options.mpath;
         cdev->private->flags.doverify = 0;
+        cdev->private->path_noirq_mask = 0;
         verify_start(cdev);
 }
 
diff --git a/drivers/s390/cio/io_sch.h b/drivers/s390/cio/io_sch.h
index 76253dfcc1be..b108f4a5c7dd 100644
--- a/drivers/s390/cio/io_sch.h
+++ b/drivers/s390/cio/io_sch.h
@@ -126,6 +126,10 @@ struct ccw_device_private {
         u8 pgid_valid_mask;     /* mask of valid PGIDs */
         u8 pgid_todo_mask;      /* mask of PGIDs to be adjusted */
         u8 pgid_reset_mask;     /* mask of PGIDs which were reset */
+        u8 path_noirq_mask;     /* mask of paths for which no irq was
+                                   received */
+        u8 path_notoper_mask;   /* mask of paths which were found
+                                   not operable */
         u8 path_gone_mask;      /* mask of paths, that became unavailable */
         u8 path_new_mask;       /* mask of paths, that became available */
         struct {
@@ -145,6 +149,7 @@ struct ccw_device_private {
                 unsigned int resuming:1;    /* recognition while resume */
                 unsigned int pgroup:1;      /* pathgroup is set up */
                 unsigned int mpath:1;       /* multipathing is set up */
+                unsigned int pgid_unknown:1;/* unknown pgid state */
                 unsigned int initialized:1; /* set if initial reference held */
         } __attribute__((packed)) flags;
         unsigned long intparm;  /* user interruption parameter */