[S390] cio async subchannel reprobe.

Changes in the DASD driver require an asynchronous implementation of the
subchannel reprobe loop. This loop was so far only used by the blacklisting
mechanism but is now available to all CCW device drivers.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/drivers/s390/cio/blacklist.c b/drivers/s390/cio/blacklist.c
index 0960bef7b199ca6c45868f6e746dee1a862550ac..15b895496a45025038559b18eb874d1b6b6cfc50 100644 (file)
--- a/drivers/s390/cio/blacklist.c
+++ b/drivers/s390/cio/blacklist.c
@@ -224,39 +224,6 @@ is_blacklisted (int ssid, int devno)
 }
 
 #ifdef CONFIG_PROC_FS
-static int
-__s390_redo_validation(struct subchannel_id schid, void *data)
-{
-       int ret;
-       struct subchannel *sch;
-
-       sch = get_subchannel_by_schid(schid);
-       if (sch) {
-               /* Already known. */
-               put_device(&sch->dev);
-               return 0;
-       }
-       ret = css_probe_device(schid);
-       if (ret == -ENXIO)
-               return ret; /* We're through. */
-       if (ret == -ENOMEM)
-               /* Stop validation for now. Bad, but no need for a panic. */
-               return ret;
-       return 0;
-}
-
-/*
- * Function: s390_redo_validation
- * Look for no longer blacklisted devices
- * FIXME: there must be a better way to do this */
-static inline void
-s390_redo_validation (void)
-{
-       CIO_TRACE_EVENT (0, "redoval");
-
-       for_each_subchannel(__s390_redo_validation, NULL);
-}
-
 /*
  * Function: blacklist_parse_proc_parameters
  * parse the stuff which is piped to /proc/cio_ignore
@@ -281,7 +248,7 @@ blacklist_parse_proc_parameters (char *buf)
                return;
        }
 
-       s390_redo_validation ();
+       css_schedule_reprobe();
 }
 
 /* Iterator struct for all devices. */

diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 74ea8aac4b7d9683c37ce79e79a41edf673b9d07..1d3be80797f81e1ed119a08394f872cc20700236 100644 (file)
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -19,9 +19,11 @@
 #include "cio_debug.h"
 #include "ioasm.h"
 #include "chsc.h"
+#include "device.h"
 
 int need_rescan = 0;
 int css_init_done = 0;
+static int need_reprobe = 0;
 static int max_ssid = 0;
 
 struct channel_subsystem *css[__MAX_CSSID + 1];
@@ -339,6 +341,67 @@ typedef void (*workfunc)(void *);
 DECLARE_WORK(slow_path_work, (workfunc)css_trigger_slow_path, NULL);
 struct workqueue_struct *slow_path_wq;
 
+/* Reprobe subchannel if unregistered. */
+static int reprobe_subchannel(struct subchannel_id schid, void *data)
+{
+       struct subchannel *sch;
+       int ret;
+
+       CIO_DEBUG(KERN_INFO, 6, "cio: reprobe 0.%x.%04x\n",
+                 schid.ssid, schid.sch_no);
+       if (need_reprobe)
+               return -EAGAIN;
+
+       sch = get_subchannel_by_schid(schid);
+       if (sch) {
+               /* Already known. */
+               put_device(&sch->dev);
+               return 0;
+       }
+
+       ret = css_probe_device(schid);
+       switch (ret) {
+       case 0:
+               break;
+       case -ENXIO:
+       case -ENOMEM:
+               /* These should abort looping */
+               break;
+       default:
+               ret = 0;
+       }
+
+       return ret;
+}
+
+/* Work function used to reprobe all unregistered subchannels. */
+static void reprobe_all(void *data)
+{
+       int ret;
+
+       CIO_MSG_EVENT(2, "reprobe start\n");
+
+       need_reprobe = 0;
+       /* Make sure initial subchannel scan is done. */
+       wait_event(ccw_device_init_wq,
+                  atomic_read(&ccw_device_init_count) == 0);
+       ret = for_each_subchannel(reprobe_subchannel, NULL);
+
+       CIO_MSG_EVENT(2, "reprobe done (rc=%d, need_reprobe=%d)\n", ret,
+                     need_reprobe);
+}
+
+DECLARE_WORK(css_reprobe_work, reprobe_all, NULL);
+
+/* Schedule reprobing of all unregistered subchannels. */
+void css_schedule_reprobe(void)
+{
+       need_reprobe = 1;
+       queue_work(ccw_device_work, &css_reprobe_work);
+}
+
+EXPORT_SYMBOL_GPL(css_schedule_reprobe);
+
 /*
  * Rescan for new devices. FIXME: This is slow.
  * This function is called when we have lost CRWs due to overflows and we have

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 8e3053c2a451b4f5dc84d5b7fb77df52119d124c..eafde43e8410cd3e1f041343f86dad2bd543d8c6 100644 (file)
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -133,8 +133,8 @@ struct css_driver io_subchannel_driver = {
 
 struct workqueue_struct *ccw_device_work;
 struct workqueue_struct *ccw_device_notify_work;
-static wait_queue_head_t ccw_device_init_wq;
-static atomic_t ccw_device_init_count;
+wait_queue_head_t ccw_device_init_wq;
+atomic_t ccw_device_init_count;
 
 static int __init
 init_ccw_bus_type (void)

diff --git a/drivers/s390/cio/device.h b/drivers/s390/cio/device.h
index 11587ebb72897dcd68d04dc8d26df767e01af52f..8e0d1db3dd4ea53df3b8dbe8e92bc44793cefb22 100644 (file)
--- a/drivers/s390/cio/device.h
+++ b/drivers/s390/cio/device.h
@@ -1,6 +1,10 @@
 #ifndef S390_DEVICE_H
 #define S390_DEVICE_H
 
+#include <asm/ccwdev.h>
+#include <asm/atomic.h>
+#include <linux/wait.h>
+
 /*
  * states of the device statemachine
  */
@@ -67,6 +71,8 @@ dev_fsm_final_state(struct ccw_device *cdev)
 
 extern struct workqueue_struct *ccw_device_work;
 extern struct workqueue_struct *ccw_device_notify_work;
+extern wait_queue_head_t ccw_device_init_wq;
+extern atomic_t ccw_device_init_count;
 
 void io_subchannel_recog_done(struct ccw_device *cdev);
 

diff --git a/include/asm-s390/cio.h b/include/asm-s390/cio.h
index 089cf567c317b48f09501a377e73b320a59192d0..2b16193063513003e49e7327e8e5add0690f48a9 100644 (file)
--- a/include/asm-s390/cio.h
+++ b/include/asm-s390/cio.h
@@ -276,6 +276,8 @@ extern void wait_cons_dev(void);
 
 extern void clear_all_subchannels(void);
 
+extern void css_schedule_reprobe(void);
+
 #endif
 
 #endif