1 files changed, 115 insertions, 56 deletions

diff --git a/drivers/s390/cio/airq.c b/drivers/s390/cio/airq.c
index 5287631fbfc8..b7a07a866291 100644
--- a/drivers/s390/cio/airq.c
+++ b/drivers/s390/cio/airq.c
@@ -1,12 +1,12 @@
 /*
  *  drivers/s390/cio/airq.c
- *   S/390 common I/O routines -- support for adapter interruptions
+ *    Support for adapter interruptions
  *
- *    Copyright (C) 1999-2002 IBM Deutschland Entwicklung GmbH,
- *                            IBM Corporation
- *    Author(s): Ingo Adlung (adlung@de.ibm.com)
- *               Cornelia Huck (cornelia.huck@de.ibm.com)
- *               Arnd Bergmann (arndb@de.ibm.com)
+ *    Copyright IBM Corp. 1999,2007
+ *    Author(s): Ingo Adlung <adlung@de.ibm.com>
+ *               Cornelia Huck <cornelia.huck@de.ibm.com>
+ *               Arnd Bergmann <arndb@de.ibm.com>
+ *               Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
  */
 
 #include <linux/init.h>
@@ -14,72 +14,131 @@
 #include <linux/slab.h>
 #include <linux/rcupdate.h>
 
+#include <asm/airq.h>
+
+#include "cio.h"
 #include "cio_debug.h"
-#include "airq.h"
 
-static adapter_int_handler_t adapter_handler;
+#define NR_AIRQS                32
+#define NR_AIRQS_PER_WORD       sizeof(unsigned long)
+#define NR_AIRQ_WORDS           (NR_AIRQS / NR_AIRQS_PER_WORD)
 
-/*
- * register for adapter interrupts
- *
- * With HiperSockets the zSeries architecture provides for
- *  means of adapter interrups, pseudo I/O interrupts that are
- *  not tied to an I/O subchannel, but to an adapter. However,
- *  it doesn't disclose the info how to enable/disable them, but
- *  to recognize them only. Perhaps we should consider them
- *  being shared interrupts, and thus build a linked list
- *  of adapter handlers ... to be evaluated ...
- */
-int
-s390_register_adapter_interrupt (adapter_int_handler_t handler)
-{
-        int ret;
-        char dbf_txt[15];
+union indicator_t {
+        unsigned long word[NR_AIRQ_WORDS];
+        unsigned char byte[NR_AIRQS];
+} __attribute__((packed));
 
-        CIO_TRACE_EVENT (4, "rgaint");
+struct airq_t {
+        adapter_int_handler_t handler;
+        void *drv_data;
+};
 
-        if (handler == NULL)
-                ret = -EINVAL;
-        else
-                ret = (cmpxchg(&adapter_handler, NULL, handler) ? -EBUSY : 0);
-        if (!ret)
-                synchronize_sched();  /* Allow interrupts to complete. */
+static union indicator_t indicators;
+static struct airq_t *airqs[NR_AIRQS];
 
-        sprintf (dbf_txt, "ret:%d", ret);
-        CIO_TRACE_EVENT (4, dbf_txt);
+static int register_airq(struct airq_t *airq)
+{
+        int i;
 
-        return ret;
+        for (i = 0; i < NR_AIRQS; i++)
+                if (!cmpxchg(&airqs[i], NULL, airq))
+                        return i;
+        return -ENOMEM;
 }
 
-int
-s390_unregister_adapter_interrupt (adapter_int_handler_t handler)
+/**
+ * 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
+ *
+ * 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)
 {
+        struct airq_t *airq;
+        char dbf_txt[16];
         int ret;
-        char dbf_txt[15];
 
-        CIO_TRACE_EVENT (4, "urgaint");
-
-        if (handler == NULL)
-                ret = -EINVAL;
-        else {
-                adapter_handler = NULL;
-                synchronize_sched();  /* Allow interrupts to complete. */
-                ret = 0;
+        airq = kmalloc(sizeof(struct airq_t), GFP_KERNEL);
+        if (!airq) {
+                ret = -ENOMEM;
+                goto out;
         }
-        sprintf (dbf_txt, "ret:%d", ret);
-        CIO_TRACE_EVENT (4, dbf_txt);
-
-        return ret;
+        airq->handler = handler;
+        airq->drv_data = drv_data;
+        ret = register_airq(airq);
+        if (ret < 0)
+                kfree(airq);
+out:
+        snprintf(dbf_txt, sizeof(dbf_txt), "rairq:%d", ret);
+        CIO_TRACE_EVENT(4, dbf_txt);
+        if (ret < 0)
+                return ERR_PTR(ret);
+        else
+                return &indicators.byte[ret];
 }
+EXPORT_SYMBOL(s390_register_adapter_interrupt);
 
-void
-do_adapter_IO (void)
+/**
+ * s390_unregister_adapter_interrupt - unregister adapter interrupt handler
+ * @ind: indicator for which the handler is to be unregistered
+ */
+void s390_unregister_adapter_interrupt(void *ind)
 {
-        CIO_TRACE_EVENT (6, "doaio");
+        struct airq_t *airq;
+        char dbf_txt[16];
+        int i;
 
-        if (adapter_handler)
-                (*adapter_handler) ();
+        i = (int) ((addr_t) ind) - ((addr_t) &indicators.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);
+        /*
+         * Allow interrupts to complete. This will ensure that the airq handle
+         * is no longer referenced by any interrupt handler.
+         */
+        synchronize_sched();
+        kfree(airq);
 }
+EXPORT_SYMBOL(s390_unregister_adapter_interrupt);
+
+#define INDICATOR_MASK  (0xffUL << ((NR_AIRQS_PER_WORD - 1) * 8))
 
-EXPORT_SYMBOL (s390_register_adapter_interrupt);
-EXPORT_SYMBOL (s390_unregister_adapter_interrupt);
+void do_adapter_IO(void)
+{
+        int w;
+        int i;
+        unsigned long word;
+        struct airq_t *airq;
+
+        /*
+         * Access indicator array in word-sized chunks to minimize storage
+         * fetch operations.
+         */
+        for (w = 0; w < NR_AIRQ_WORDS; w++) {
+                word = indicators.word[w];
+                i = w * NR_AIRQS_PER_WORD;
+                /*
+                 * Check bytes within word for active indicators.
+                 */
+                while (word) {
+                        if (word & INDICATOR_MASK) {
+                                airq = airqs[i];
+                                if (likely(airq))
+                                        airq->handler(&indicators.byte[i],
+                                                      airq->drv_data);
+                                else
+                                        /*
+                                         * Reset ill-behaved indicator.
+                                         */
+                                        indicators.byte[i] = 0;
+                        }
+                        word <<= 8;
+                        i++;
+                }
+        }
+}