[S390] cio: Introduce abstract isc definitions.

Replace the numeric values for I/O interruption subclass usage
with abstract definitions and collect them all in asm/isc.h.
This gives us a better overview of which iscs are actually used
and makes it possible to better spread out isc usage in the
future.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

5 files changed, 32 insertions, 9 deletions

diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index c24dfcd858da..a4f9130910d6 100644
--- a/drivers/s390/cio/cio.c
+++ b/drivers/s390/cio/cio.c
@@ -24,6 +24,7 @@
 #include <asm/ipl.h>
 #include <asm/chpid.h>
 #include <asm/airq.h>
+#include <asm/isc.h>
 #include <asm/cpu.h>
 #include <asm/fcx.h>
 #include "cio.h"
@@ -699,9 +700,9 @@ void wait_cons_dev(void)
         if (!console_subchannel_in_use)
                 return;
 
-        /* disable all but isc 1 (console device) */
+        /* disable all but the console isc */
         __ctl_store (save_cr6, 6, 6);
-        cr6 = 0x40000000;
+        cr6 = 1UL << (31 - CONSOLE_ISC);
         __ctl_load (cr6, 6, 6);
 
         do {
@@ -783,10 +784,10 @@ cio_probe_console(void)
         }
 
         /*
-         * enable console I/O-interrupt subclass 1
+         * enable console I/O-interrupt subclass
          */
-        ctl_set_bit(6, 30);
-        console_subchannel.schib.pmcw.isc = 1;
+        ctl_set_bit(6, 31 - CONSOLE_ISC);
+        console_subchannel.schib.pmcw.isc = CONSOLE_ISC;
         console_subchannel.schib.pmcw.intparm =
                 (u32)(addr_t)&console_subchannel;
         ret = cio_modify(&console_subchannel);
@@ -802,7 +803,7 @@ cio_release_console(void)
 {
         console_subchannel.schib.pmcw.intparm = 0;
         cio_modify(&console_subchannel);
-        ctl_clear_bit(6, 30);
+        ctl_clear_bit(6, 31 - CONSOLE_ISC);
         console_subchannel_in_use = 0;
 }
 
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index ebed2212778d..b24618b5362e 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -13,6 +13,7 @@
 #include <linux/errno.h>
 #include <linux/list.h>
 #include <linux/reboot.h>
+#include <asm/isc.h>
 
 #include "../s390mach.h"
 #include "css.h"
@@ -804,7 +805,8 @@ init_channel_subsystem (void)
                 goto out_pseudo;
         css_init_done = 1;
 
-        ctl_set_bit(6, 28);
+        /* Enable default isc for I/O subchannels. */
+        ctl_set_bit(6, 31 - IO_SCH_ISC);
 
         for_each_subchannel(__init_channel_subsystem, NULL);
         return 0;
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 215d27dba9e2..67e7a3123954 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -22,6 +22,7 @@
 #include <asm/cio.h>
 #include <asm/param.h>          /* HZ */
 #include <asm/cmb.h>
+#include <asm/isc.h>
 
 #include "chp.h"
 #include "cio.h"
@@ -1121,7 +1122,7 @@ static void io_subchannel_init_fields(struct subchannel *sch)
         else
                 sch->opm = chp_get_sch_opm(sch);
         sch->lpm = sch->schib.pmcw.pam & sch->opm;
-        sch->isc = cio_is_console(sch->schid) ? 1 : 3;
+        sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
 
         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
                       " - PIM = %02X, PAM = %02X, POM = %02X\n",
diff --git a/drivers/s390/cio/qdio.h b/drivers/s390/cio/qdio.h
index c3df6b2c38b7..733934a166b1 100644
--- a/drivers/s390/cio/qdio.h
+++ b/drivers/s390/cio/qdio.h
@@ -2,6 +2,7 @@
 #define _CIO_QDIO_H
 
 #include <asm/page.h>
+#include <asm/isc.h>
 
 #include "schid.h"
 
@@ -26,7 +27,7 @@
  */
 #define IQDIO_FILL_LEVEL_TO_POLL 4
 
-#define TIQDIO_THININT_ISC 3
+#define TIQDIO_THININT_ISC QDIO_AIRQ_ISC
 #define TIQDIO_DELAY_TARGET 0
 #define QDIO_BUSY_BIT_PATIENCE 100 /* in microsecs */
 #define QDIO_BUSY_BIT_GIVE_UP 10000000 /* 10 seconds */
diff --git a/include/asm-s390/isc.h b/include/asm-s390/isc.h
new file mode 100644
index 000000000000..533a1372234a
--- /dev/null
+++ b/include/asm-s390/isc.h
@@ -0,0 +1,18 @@
+#ifndef _ASM_S390_ISC_H
+#define _ASM_S390_ISC_H
+
+/*
+ * I/O interruption subclasses used by drivers.
+ * Please add all used iscs here so that it is possible to distribute
+ * isc usage between drivers.
+ * Reminder: 0 is highest priority, 7 lowest.
+ */
+#define MAX_ISC 7
+
+/* Regular I/O interrupts. */
+#define IO_SCH_ISC 3                    /* regular I/O subchannels */
+#define CONSOLE_ISC 1                   /* console I/O subchannel */
+/* Adapter interrupts. */
+#define QDIO_AIRQ_ISC IO_SCH_ISC        /* I/O subchannel in qdio mode */
+
+#endif /* _ASM_S390_ISC_H */