summaryrefslogtreecommitdiffstats
path: root/arch/s390/kernel/s390_ext.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/s390/kernel/s390_ext.c')
-rw-r--r--arch/s390/kernel/s390_ext.c135
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 000000000000..3bdd38ec71da
--- /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);
+