1 files changed, 129 insertions, 8 deletions

diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
index e204f9597aaf..e3264f6a9720 100644
--- a/arch/s390/kernel/irq.c
+++ b/arch/s390/kernel/irq.c
@@ -1,19 +1,28 @@
 /*
- *    Copyright IBM Corp. 2004,2010
- *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
- *               Thomas Spatzier (tspat@de.ibm.com)
+ *    Copyright IBM Corp. 2004,2011
+ *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
+ *               Holger Smolinski <Holger.Smolinski@de.ibm.com>,
+ *               Thomas Spatzier <tspat@de.ibm.com>,
  *
  * This file contains interrupt related functions.
  */
 
-#include <linux/module.h>
-#include <linux/kernel.h>
 #include <linux/kernel_stat.h>
 #include <linux/interrupt.h>
 #include <linux/seq_file.h>
-#include <linux/cpu.h>
 #include <linux/proc_fs.h>
 #include <linux/profile.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/ftrace.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/cpu.h>
+#include <asm/irq_regs.h>
+#include <asm/cputime.h>
+#include <asm/lowcore.h>
+#include <asm/irq.h>
+#include "entry.h"
 
 struct irq_class {
         char *name;
@@ -82,8 +91,7 @@ int show_interrupts(struct seq_file *p, void *v)
  * For compatibilty only. S/390 specific setup of interrupts et al. is done
  * much later in init_channel_subsystem().
  */
-void __init
-init_IRQ(void)
+void __init init_IRQ(void)
 {
         /* nothing... */
 }
@@ -134,3 +142,116 @@ void init_irq_proc(void)
         create_prof_cpu_mask(root_irq_dir);
 }
 #endif
+
+/*
+ * 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.
+ */
+
+struct ext_int_info {
+        struct ext_int_info *next;
+        ext_int_handler_t handler;
+        u16 code;
+};
+
+static struct ext_int_info *ext_int_hash[256];
+
+static inline int ext_hash(u16 code)
+{
+        return (code + (code >> 9)) & 0xff;
+}
+
+int register_external_interrupt(u16 code, ext_int_handler_t handler)
+{
+        struct ext_int_info *p;
+        int index;
+
+        p = kmalloc(sizeof(*p), GFP_ATOMIC);
+        if (!p)
+                return -ENOMEM;
+        p->code = code;
+        p->handler = handler;
+        index = ext_hash(code);
+        p->next = ext_int_hash[index];
+        ext_int_hash[index] = p;
+        return 0;
+}
+EXPORT_SYMBOL(register_external_interrupt);
+
+int unregister_external_interrupt(u16 code, ext_int_handler_t handler)
+{
+        struct ext_int_info *p, *q;
+        int index;
+
+        index = ext_hash(code);
+        q = NULL;
+        p = ext_int_hash[index];
+        while (p) {
+                if (p->code == code && p->handler == handler)
+                        break;
+                q = p;
+                p = p->next;
+        }
+        if (!p)
+                return -ENOENT;
+        if (q)
+                q->next = p->next;
+        else
+                ext_int_hash[index] = p->next;
+        kfree(p);
+        return 0;
+}
+EXPORT_SYMBOL(unregister_external_interrupt);
+
+void __irq_entry do_extint(struct pt_regs *regs, unsigned int ext_int_code,
+                           unsigned int param32, unsigned long param64)
+{
+        struct pt_regs *old_regs;
+        unsigned short code;
+        struct ext_int_info *p;
+        int index;
+
+        code = (unsigned short) ext_int_code;
+        old_regs = set_irq_regs(regs);
+        s390_idle_check(regs, S390_lowcore.int_clock,
+                        S390_lowcore.async_enter_timer);
+        irq_enter();
+        if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator)
+                /* Serve timer interrupts first. */
+                clock_comparator_work();
+        kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++;
+        if (code != 0x1004)
+                __get_cpu_var(s390_idle).nohz_delay = 1;
+        index = ext_hash(code);
+        for (p = ext_int_hash[index]; p; p = p->next) {
+                if (likely(p->code == code))
+                        p->handler(ext_int_code, param32, param64);
+        }
+        irq_exit();
+        set_irq_regs(old_regs);
+}
+
+static DEFINE_SPINLOCK(sc_irq_lock);
+static int sc_irq_refcount;
+
+void service_subclass_irq_register(void)
+{
+        spin_lock(&sc_irq_lock);
+        if (!sc_irq_refcount)
+                ctl_set_bit(0, 9);
+        sc_irq_refcount++;
+        spin_unlock(&sc_irq_lock);
+}
+EXPORT_SYMBOL(service_subclass_irq_register);
+
+void service_subclass_irq_unregister(void)
+{
+        spin_lock(&sc_irq_lock);
+        sc_irq_refcount--;
+        if (!sc_irq_refcount)
+                ctl_clear_bit(0, 9);
+        spin_unlock(&sc_irq_lock);
+}
+EXPORT_SYMBOL(service_subclass_irq_unregister);