[PATCH] s390: introduce for_each_subchannel

for_each_subchannel() is an iterator calling a function for every possible
subchannel id until non-zero is returned.  Convert the current iterating
functions to it.

Signed-off-by: Cornelia Huck <cohuck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 43 insertions, 36 deletions

diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index 396bada65f86..3eb6cb608fc9 100644
--- a/drivers/s390/cio/cio.c
+++ b/drivers/s390/cio/cio.c
@@ -691,7 +691,22 @@ wait_cons_dev (void)
 }
 
 static int
-cio_console_irq(void)
+cio_test_for_console(struct subchannel_id schid, void *data)
+{
+        if (stsch(schid, &console_subchannel.schib) != 0)
+                return -ENXIO;
+        if (console_subchannel.schib.pmcw.dnv &&
+            console_subchannel.schib.pmcw.dev ==
+            console_devno) {
+                console_irq = schid.sch_no;
+                return 1; /* found */
+        }
+        return 0;
+}
+
+
+static int
+cio_get_console_sch_no(void)
 {
         struct subchannel_id schid;
         
@@ -705,16 +720,7 @@ cio_console_irq(void)
                 console_devno = console_subchannel.schib.pmcw.dev;
         } else if (console_devno != -1) {
                 /* At least the console device number is known. */
-                do {
-                        if (stsch(schid, &console_subchannel.schib) != 0)
-                                break;
-                        if (console_subchannel.schib.pmcw.dnv &&
-                            console_subchannel.schib.pmcw.dev ==
-                            console_devno) {
-                                console_irq = schid.sch_no;
-                                break;
-                        }
-                } while (schid.sch_no++ < __MAX_SUBCHANNEL);
+                for_each_subchannel(cio_test_for_console, NULL);
                 if (console_irq == -1)
                         return -1;
         } else {
@@ -730,19 +736,19 @@ cio_console_irq(void)
 struct subchannel *
 cio_probe_console(void)
 {
-        int irq, ret;
+        int sch_no, ret;
         struct subchannel_id schid;
 
         if (xchg(&console_subchannel_in_use, 1) != 0)
                 return ERR_PTR(-EBUSY);
-        irq = cio_console_irq();
-        if (irq == -1) {
+        sch_no = cio_get_console_sch_no();
+        if (sch_no == -1) {
                 console_subchannel_in_use = 0;
                 return ERR_PTR(-ENODEV);
         }
         memset(&console_subchannel, 0, sizeof(struct subchannel));
         init_subchannel_id(&schid);
-        schid.sch_no = irq;
+        schid.sch_no = sch_no;
         ret = cio_validate_subchannel(&console_subchannel, schid);
         if (ret) {
                 console_subchannel_in_use = 0;
@@ -830,32 +836,33 @@ __clear_subchannel_easy(struct subchannel_id schid)
 }
 
 extern void do_reipl(unsigned long devno);
+static int
+__shutdown_subchannel_easy(struct subchannel_id schid, void *data)
+{
+        struct schib schib;
+
+        if (stsch(schid, &schib))
+                return -ENXIO;
+        if (!schib.pmcw.ena)
+                return 0;
+        switch(__disable_subchannel_easy(schid, &schib)) {
+        case 0:
+        case -ENODEV:
+                break;
+        default: /* -EBUSY */
+                if (__clear_subchannel_easy(schid))
+                        break; /* give up... */
+                stsch(schid, &schib);
+                __disable_subchannel_easy(schid, &schib);
+        }
+        return 0;
+}
 
-/* Clear all subchannels. */
 void
 clear_all_subchannels(void)
 {
-        struct subchannel_id schid;
-
         local_irq_disable();
-        init_subchannel_id(&schid);
-        do {
-                struct schib schib;
-                if (stsch(schid, &schib))
-                        break; /* break out of the loop */
-                if (!schib.pmcw.ena)
-                        continue;
-                switch(__disable_subchannel_easy(schid, &schib)) {
-                case 0:
-                case -ENODEV:
-                        break;
-                default: /* -EBUSY */
-                        if (__clear_subchannel_easy(schid))
-                                break; /* give up... jump out of switch */
-                        stsch(schid, &schib);
-                        __disable_subchannel_easy(schid, &schib);
-                }
-        } while (schid.sch_no++ < __MAX_SUBCHANNEL);
+        for_each_subchannel(__shutdown_subchannel_easy, NULL);
 }
 
 /* Make sure all subchannels are quiet before we re-ipl an lpar. */