1 files changed, 135 insertions, 0 deletions
diff --git a/arch/s390/kernel/s390_ext.c b/arch/s390/kernel/s390_ext.c
new file mode 100644
index 0000000..3bdd38e
--- /dev/null
+++ b/arch/s390/kernel/s390_ext.c
@@ -0,0 +1,135 @@
+/*
+ *  arch/s390/kernel/s390_ext.c
+ *
+ *  S390 version
+ *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Holger Smolinski (Holger.Smolinski@de.ibm.com),
+ *               Martin Schwidefsky (schwidefsky@de.ibm.com)
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/kernel_stat.h>
+#include <linux/interrupt.h>
+
+#include <asm/lowcore.h>
+#include <asm/s390_ext.h>
+#include <asm/irq.h>
+
+/*
+ * Simple hash strategy: index = code & 0xff;
+ * ext_int_hash[index] is the start of the list for all external interrupts
+ * that hash to this index. With the current set of external interrupts 
+ * (0x1202 external call, 0x1004 cpu timer, 0x2401 hwc console, 0x4000
+ * iucv and 0x2603 pfault) this is always the first element. 
+ */
+ext_int_info_t *ext_int_hash[256] = { 0, };
+
+int register_external_interrupt(__u16 code, ext_int_handler_t handler)
+{
+        ext_int_info_t *p;
+        int index;
+
+	p = (ext_int_info_t *) kmalloc(sizeof(ext_int_info_t), GFP_ATOMIC);
+        if (p == NULL)
+                return -ENOMEM;
+        p->code = code;
+        p->handler = handler;
+        index = code & 0xff;
+        p->next = ext_int_hash[index];
+        ext_int_hash[index] = p;
+        return 0;
+}
+
+int register_early_external_interrupt(__u16 code, ext_int_handler_t handler,
+				      ext_int_info_t *p)
+{
+        int index;
+
+        if (p == NULL)
+                return -EINVAL;
+        p->code = code;
+        p->handler = handler;
+        index = code & 0xff;
+        p->next = ext_int_hash[index];
+        ext_int_hash[index] = p;
+        return 0;
+}
+
+int unregister_external_interrupt(__u16 code, ext_int_handler_t handler)
+{
+        ext_int_info_t *p, *q;
+        int index;
+
+        index = code & 0xff;
+        q = NULL;
+        p = ext_int_hash[index];
+        while (p != NULL) {
+                if (p->code == code && p->handler == handler)
+                        break;
+                q = p;
+                p = p->next;
+        }
+        if (p == NULL)
+                return -ENOENT;
+        if (q != NULL)
+                q->next = p->next;
+        else
+                ext_int_hash[index] = p->next;
+	kfree(p);
+        return 0;
+}
+
+int unregister_early_external_interrupt(__u16 code, ext_int_handler_t handler,
+					ext_int_info_t *p)
+{
+	ext_int_info_t *q;
+	int index;
+
+	if (p == NULL || p->code != code || p->handler != handler)
+		return -EINVAL;
+	index = code & 0xff;
+	q = ext_int_hash[index];
+	if (p != q) {
+		while (q != NULL) {
+			if (q->next == p)
+				break;
+			q = q->next;
+		}
+		if (q == NULL)
+			return -ENOENT;
+		q->next = p->next;
+	} else
+		ext_int_hash[index] = p->next;
+	return 0;
+}
+
+void do_extint(struct pt_regs *regs, unsigned short code)
+{
+        ext_int_info_t *p;
+        int index;
+
+	irq_enter();
+	asm volatile ("mc 0,0");
+	if (S390_lowcore.int_clock >= S390_lowcore.jiffy_timer)
+		/**
+		 * Make sure that the i/o interrupt did not "overtake"
+		 * the last HZ timer interrupt.
+		 */
+		account_ticks(regs);
+	kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++;
+        index = code & 0xff;
+	for (p = ext_int_hash[index]; p; p = p->next) {
+		if (likely(p->code == code)) {
+			if (likely(p->handler))
+				p->handler(regs, code);
+		}
+	}
+	irq_exit();
+}
+
+EXPORT_SYMBOL(register_external_interrupt);
+EXPORT_SYMBOL(unregister_external_interrupt);
+