[S390] cio: notify drivers of channel path events

This patch adds a notification mechanism to inform ccw drivers
about changes to channel paths, which occured while the device
is online.

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

1 files changed, 32 insertions, 0 deletions

diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c
index c9b852647f01..4395c01a9dac 100644
--- a/drivers/s390/cio/device_fsm.c
+++ b/drivers/s390/cio/device_fsm.c
@@ -349,9 +349,13 @@ out:
 
 static void ccw_device_oper_notify(struct ccw_device *cdev)
 {
+        struct subchannel *sch = to_subchannel(cdev->dev.parent);
+
         if (ccw_device_notify(cdev, CIO_OPER) == NOTIFY_OK) {
                 /* Reenable channel measurements, if needed. */
                 ccw_device_sched_todo(cdev, CDEV_TODO_ENABLE_CMF);
+                /* Save indication for new paths. */
+                cdev->private->path_new_mask = sch->vpm;
                 return;
         }
         /* Driver doesn't want device back. */
@@ -462,6 +466,32 @@ static void ccw_device_request_event(struct ccw_device *cdev, enum dev_event e)
         }
 }
 
+static void ccw_device_report_path_events(struct ccw_device *cdev)
+{
+        struct subchannel *sch = to_subchannel(cdev->dev.parent);
+        int path_event[8];
+        int chp, mask;
+
+        for (chp = 0, mask = 0x80; chp < 8; chp++, mask >>= 1) {
+                path_event[chp] = PE_NONE;
+                if (mask & cdev->private->path_gone_mask & ~(sch->vpm))
+                        path_event[chp] |= PE_PATH_GONE;
+                if (mask & cdev->private->path_new_mask & sch->vpm)
+                        path_event[chp] |= PE_PATH_AVAILABLE;
+                if (mask & cdev->private->pgid_reset_mask & sch->vpm)
+                        path_event[chp] |= PE_PATHGROUP_ESTABLISHED;
+        }
+        if (cdev->online && cdev->drv->path_event)
+                cdev->drv->path_event(cdev, path_event);
+}
+
+static void ccw_device_reset_path_events(struct ccw_device *cdev)
+{
+        cdev->private->path_gone_mask = 0;
+        cdev->private->path_new_mask = 0;
+        cdev->private->pgid_reset_mask = 0;
+}
+
 void
 ccw_device_verify_done(struct ccw_device *cdev, int err)
 {
@@ -498,6 +528,7 @@ callback:
                                               &cdev->private->irb);
                         memset(&cdev->private->irb, 0, sizeof(struct irb));
                 }
+                ccw_device_report_path_events(cdev);
                 break;
         case -ETIME:
         case -EUSERS:
@@ -516,6 +547,7 @@ callback:
                 ccw_device_done(cdev, DEV_STATE_NOT_OPER);
                 break;
         }
+        ccw_device_reset_path_events(cdev);
 }
 
 /*