LXR linux/arch/sh/kernel/cpu/irq/imask.c

   1/*
   2 * arch/sh/kernel/cpu/irq/imask.c
   3 *
   4 * Copyright (C) 1999, 2000  Niibe Yutaka
   5 *
   6 * Simple interrupt handling using IMASK of SR register.
   7 *
   8 */
   9/* NOTE: Will not work on level 15 */
  10#include <linux/ptrace.h>
  11#include <linux/errno.h>
  12#include <linux/kernel_stat.h>
  13#include <linux/signal.h>
  14#include <linux/sched.h>
  15#include <linux/interrupt.h>
  16#include <linux/init.h>
  17#include <linux/bitops.h>
  18#include <linux/spinlock.h>
  19#include <linux/cache.h>
  20#include <linux/irq.h>
  21#include <linux/bitmap.h>
  22#include <asm/irq.h>
  23
  24/* Bitmap of IRQ masked */
  25#define IMASK_PRIORITY  15
  26
  27static DECLARE_BITMAP(imask_mask, IMASK_PRIORITY);
  28static int interrupt_priority;
  29
  30static inline void set_interrupt_registers(int ip)
  31{
  32        unsigned long __dummy;
  33
  34        asm volatile(
  35#ifdef CONFIG_CPU_HAS_SR_RB
  36                     "ldc       %2, r6_bank\n\t"
  37#endif
  38                     "stc       sr, %0\n\t"
  39                     "and       #0xf0, %0\n\t"
  40                     "shlr2     %0\n\t"
  41                     "cmp/eq    #0x3c, %0\n\t"
  42                     "bt/s      1f      ! CLI-ed\n\t"
  43                     " stc      sr, %0\n\t"
  44                     "and       %1, %0\n\t"
  45                     "or        %2, %0\n\t"
  46                     "ldc       %0, sr\n"
  47                     "1:"
  48                     : "=&z" (__dummy)
  49                     : "r" (~0xf0), "r" (ip << 4)
  50                     : "t");
  51}
  52
  53static void mask_imask_irq(struct irq_data *data)
  54{
  55        unsigned int irq = data->irq;
  56
  57        clear_bit(irq, imask_mask);
  58        if (interrupt_priority < IMASK_PRIORITY - irq)
  59                interrupt_priority = IMASK_PRIORITY - irq;
  60        set_interrupt_registers(interrupt_priority);
  61}
  62
  63static void unmask_imask_irq(struct irq_data *data)
  64{
  65        unsigned int irq = data->irq;
  66
  67        set_bit(irq, imask_mask);
  68        interrupt_priority = IMASK_PRIORITY -
  69                find_first_zero_bit(imask_mask, IMASK_PRIORITY);
  70        set_interrupt_registers(interrupt_priority);
  71}
  72
  73static struct irq_chip imask_irq_chip = {
  74        .name           = "SR.IMASK",
  75        .irq_mask       = mask_imask_irq,
  76        .irq_unmask     = unmask_imask_irq,
  77        .irq_mask_ack   = mask_imask_irq,
  78};
  79
  80void make_imask_irq(unsigned int irq)
  81{
  82        irq_set_chip_and_handler_name(irq, &imask_irq_chip, handle_level_irq,
  83                                      "level");
  84}
  85