1 /* $Id: irq_imask.c,v 1.1.2.1 2002/11/17 10:53:43 mrbrown Exp $
3 * linux/arch/sh/kernel/irq_imask.c
5 * Copyright (C) 1999, 2000 Niibe Yutaka
7 * Simple interrupt handling using IMASK of SR register.
11 /* NOTE: Will not work on level 15 */
14 #include <linux/ptrace.h>
15 #include <linux/errno.h>
16 #include <linux/kernel_stat.h>
17 #include <linux/signal.h>
18 #include <linux/sched.h>
19 #include <linux/interrupt.h>
20 #include <linux/init.h>
21 #include <linux/bitops.h>
23 #include <asm/system.h>
26 #include <linux/spinlock.h>
27 #include <linux/cache.h>
28 #include <linux/irq.h>
30 /* Bitmap of IRQ masked */
31 static unsigned long imask_mask = 0x7fff;
32 static int interrupt_priority = 0;
34 static void enable_imask_irq(unsigned int irq);
35 static void disable_imask_irq(unsigned int irq);
36 static void shutdown_imask_irq(unsigned int irq);
37 static void mask_and_ack_imask(unsigned int);
38 static void end_imask_irq(unsigned int irq);
40 #define IMASK_PRIORITY 15
42 static unsigned int startup_imask_irq(unsigned int irq)
45 return 0; /* never anything pending */
48 static struct hw_interrupt_type imask_irq_type = {
58 void static inline set_interrupt_registers(int ip)
60 unsigned long __dummy;
62 asm volatile("ldc %2, r6_bank\n\t"
66 "cmp/eq #0x3c, %0\n\t"
67 "bt/s 1f ! CLI-ed\n\t"
74 : "r" (~0xf0), "r" (ip << 4)
78 static void disable_imask_irq(unsigned int irq)
80 clear_bit(irq, &imask_mask);
81 if (interrupt_priority < IMASK_PRIORITY - irq)
82 interrupt_priority = IMASK_PRIORITY - irq;
84 set_interrupt_registers(interrupt_priority);
87 static void enable_imask_irq(unsigned int irq)
89 set_bit(irq, &imask_mask);
90 interrupt_priority = IMASK_PRIORITY - ffz(imask_mask);
92 set_interrupt_registers(interrupt_priority);
95 static void mask_and_ack_imask(unsigned int irq)
97 disable_imask_irq(irq);
100 static void end_imask_irq(unsigned int irq)
102 if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
103 enable_imask_irq(irq);
106 static void shutdown_imask_irq(unsigned int irq)
111 void make_imask_irq(unsigned int irq)
113 disable_irq_nosync(irq);
114 irq_desc[irq].handler = &imask_irq_type;