[S390] dasd: re-initialize read_conf buffer for retries

The buffer for read configuration data has to be initialized with an
EBCDIC string to show support for extended UIDs to z/VM.
If this read configuration data CQR needs to be retried, the buffer
may have changed in between. So re-initialize the buffer to get a
correct extended UID under z/VM.

Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

3 files changed, 32 insertions, 2 deletions

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 3b94b6542fc..ce2a780a9ea 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -2059,13 +2059,14 @@ void dasd_add_request_tail(struct dasd_ccw_req *cqr)
 /*
  * Wakeup helper for the 'sleep_on' functions.
  */
-static void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
+void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
 {
         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
         cqr->callback_data = DASD_SLEEPON_END_TAG;
         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
         wake_up(&generic_waitq);
 }
+EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
 
 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
 {
@@ -2165,7 +2166,9 @@ static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
                 } else
                         wait_event(generic_waitq, !(device->stopped));
 
-                cqr->callback = dasd_wakeup_cb;
+                if (!cqr->callback)
+                        cqr->callback = dasd_wakeup_cb;
+
                 cqr->callback_data = DASD_SLEEPON_START_TAG;
                 dasd_add_request_tail(cqr);
                 if (interruptible) {
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index 0e9c4dcf145..cb1bbc2947e 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -844,6 +844,30 @@ static void dasd_eckd_fill_rcd_cqr(struct dasd_device *device,
         set_bit(DASD_CQR_VERIFY_PATH, &cqr->flags);
 }
 
+/*
+ * Wakeup helper for read_conf
+ * if the cqr is not done and needs some error recovery
+ * the buffer has to be re-initialized with the EBCDIC "V1.0"
+ * to show support for virtual device SNEQ
+ */
+static void read_conf_cb(struct dasd_ccw_req *cqr, void *data)
+{
+        struct ccw1 *ccw;
+        __u8 *rcd_buffer;
+
+        if (cqr->status !=  DASD_CQR_DONE) {
+                ccw = cqr->cpaddr;
+                rcd_buffer = (__u8 *)((addr_t) ccw->cda);
+                memset(rcd_buffer, 0, sizeof(*rcd_buffer));
+
+                rcd_buffer[0] = 0xE5;
+                rcd_buffer[1] = 0xF1;
+                rcd_buffer[2] = 0x4B;
+                rcd_buffer[3] = 0xF0;
+        }
+        dasd_wakeup_cb(cqr, data);
+}
+
 static int dasd_eckd_read_conf_immediately(struct dasd_device *device,
                                            struct dasd_ccw_req *cqr,
                                            __u8 *rcd_buffer,
@@ -863,6 +887,7 @@ static int dasd_eckd_read_conf_immediately(struct dasd_device *device,
         clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
         set_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags);
         cqr->retries = 5;
+        cqr->callback = read_conf_cb;
         rc = dasd_sleep_on_immediatly(cqr);
         return rc;
 }
@@ -900,6 +925,7 @@ static int dasd_eckd_read_conf_lpm(struct dasd_device *device,
                 goto out_error;
         }
         dasd_eckd_fill_rcd_cqr(device, cqr, rcd_buf, lpm);
+        cqr->callback = read_conf_cb;
         ret = dasd_sleep_on(cqr);
         /*
          * on success we update the user input parms
diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h
index 1dd12bd85a6..563bf8a25dc 100644
--- a/drivers/s390/block/dasd_int.h
+++ b/drivers/s390/block/dasd_int.h
@@ -643,6 +643,7 @@ struct dasd_ccw_req *
 dasd_smalloc_request(int , int, int, struct dasd_device *);
 void dasd_kfree_request(struct dasd_ccw_req *, struct dasd_device *);
 void dasd_sfree_request(struct dasd_ccw_req *, struct dasd_device *);
+void dasd_wakeup_cb(struct dasd_ccw_req *, void *);
 
 static inline int
 dasd_kmalloc_set_cda(struct ccw1 *ccw, void *cda, struct dasd_device *device)