[S390] cio: Allow adapter interrupt handlers per isc.

Enhance the adapter interruption API so that device drivers can
register a handler for a specific interruption subclass. This
will allow different device drivers to move to differently
prioritized subclasses in order to avoid congestion.

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>

1 files changed, 25 insertions, 20 deletions

diff --git a/drivers/s390/cio/airq.c b/drivers/s390/cio/airq.c
index b7a07a866291..fe6cea15bbaf 100644
--- a/drivers/s390/cio/airq.c
+++ b/drivers/s390/cio/airq.c
@@ -15,6 +15,7 @@
 #include <linux/rcupdate.h>
 
 #include <asm/airq.h>
+#include <asm/isc.h>
 
 #include "cio.h"
 #include "cio_debug.h"
@@ -33,15 +34,15 @@ struct airq_t {
         void *drv_data;
 };
 
-static union indicator_t indicators;
-static struct airq_t *airqs[NR_AIRQS];
+static union indicator_t indicators[MAX_ISC];
+static struct airq_t *airqs[MAX_ISC][NR_AIRQS];
 
-static int register_airq(struct airq_t *airq)
+static int register_airq(struct airq_t *airq, u8 isc)
 {
         int i;
 
         for (i = 0; i < NR_AIRQS; i++)
-                if (!cmpxchg(&airqs[i], NULL, airq))
+                if (!cmpxchg(&airqs[isc][i], NULL, airq))
                         return i;
         return -ENOMEM;
 }
@@ -50,18 +51,21 @@ static int register_airq(struct airq_t *airq)
  * s390_register_adapter_interrupt() - register adapter interrupt handler
  * @handler: adapter handler to be registered
  * @drv_data: driver data passed with each call to the handler
+ * @isc: isc for which the handler should be called
  *
  * Returns:
  *  Pointer to the indicator to be used on success
  *  ERR_PTR() if registration failed
  */
 void *s390_register_adapter_interrupt(adapter_int_handler_t handler,
-                                      void *drv_data)
+                                      void *drv_data, u8 isc)
 {
         struct airq_t *airq;
         char dbf_txt[16];
         int ret;
 
+        if (isc > MAX_ISC)
+                return ERR_PTR(-EINVAL);
         airq = kmalloc(sizeof(struct airq_t), GFP_KERNEL);
         if (!airq) {
                 ret = -ENOMEM;
@@ -69,34 +73,35 @@ void *s390_register_adapter_interrupt(adapter_int_handler_t handler,
         }
         airq->handler = handler;
         airq->drv_data = drv_data;
-        ret = register_airq(airq);
-        if (ret < 0)
-                kfree(airq);
+
+        ret = register_airq(airq, isc);
 out:
         snprintf(dbf_txt, sizeof(dbf_txt), "rairq:%d", ret);
         CIO_TRACE_EVENT(4, dbf_txt);
-        if (ret < 0)
+        if (ret < 0) {
+                kfree(airq);
                 return ERR_PTR(ret);
-        else
-                return &indicators.byte[ret];
+        } else
+                return &indicators[isc].byte[ret];
 }
 EXPORT_SYMBOL(s390_register_adapter_interrupt);
 
 /**
  * s390_unregister_adapter_interrupt - unregister adapter interrupt handler
  * @ind: indicator for which the handler is to be unregistered
+ * @isc: interruption subclass
  */
-void s390_unregister_adapter_interrupt(void *ind)
+void s390_unregister_adapter_interrupt(void *ind, u8 isc)
 {
         struct airq_t *airq;
         char dbf_txt[16];
         int i;
 
-        i = (int) ((addr_t) ind) - ((addr_t) &indicators.byte[0]);
+        i = (int) ((addr_t) ind) - ((addr_t) &indicators[isc].byte[0]);
         snprintf(dbf_txt, sizeof(dbf_txt), "urairq:%d", i);
         CIO_TRACE_EVENT(4, dbf_txt);
-        indicators.byte[i] = 0;
-        airq = xchg(&airqs[i], NULL);
+        indicators[isc].byte[i] = 0;
+        airq = xchg(&airqs[isc][i], NULL);
         /*
          * Allow interrupts to complete. This will ensure that the airq handle
          * is no longer referenced by any interrupt handler.
@@ -108,7 +113,7 @@ EXPORT_SYMBOL(s390_unregister_adapter_interrupt);
 
 #define INDICATOR_MASK  (0xffUL << ((NR_AIRQS_PER_WORD - 1) * 8))
 
-void do_adapter_IO(void)
+void do_adapter_IO(u8 isc)
 {
         int w;
         int i;
@@ -120,22 +125,22 @@ void do_adapter_IO(void)
          * fetch operations.
          */
         for (w = 0; w < NR_AIRQ_WORDS; w++) {
-                word = indicators.word[w];
+                word = indicators[isc].word[w];
                 i = w * NR_AIRQS_PER_WORD;
                 /*
                  * Check bytes within word for active indicators.
                  */
                 while (word) {
                         if (word & INDICATOR_MASK) {
-                                airq = airqs[i];
+                                airq = airqs[isc][i];
                                 if (likely(airq))
-                                        airq->handler(&indicators.byte[i],
+                                        airq->handler(&indicators[isc].byte[i],
                                                       airq->drv_data);
                                 else
                                         /*
                                          * Reset ill-behaved indicator.
                                          */
-                                        indicators.byte[i] = 0;
+                                        indicators[isc].byte[i] = 0;
                         }
                         word <<= 8;
                         i++;