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

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * arch/sh/kernel/cpu/irq/imask.c
   4 *
   5 * Copyright (C) 1999, 2000  Niibe Yutaka
   6 *
   7 * Simple interrupt handling using IMASK of SR register.
   8 *
   9 */
  10/* NOTE: Will not work on level 15 */
  11#include <linux/ptrace.h>
  12#include <linux/errno.h>
  13#include <linux/kernel_stat.h>
  14#include <linux/signal.h>
  15#include <linux/sched.h>
  16#include <linux/interrupt.h>
  17#include <linux/init.h>
  18#include <linux/bitops.h>
  19#include <linux/spinlock.h>
  20#include <linux/cache.h>
  21#include <linux/irq.h>
  22#include <linux/bitmap.h>
  23#include <asm/irq.h>
  24
  25/* Bitmap of IRQ masked */
  26#define IMASK_PRIORITY  15
  27
  28static DECLARE_BITMAP(imask_mask, IMASK_PRIORITY);
  29static int interrupt_priority;
  30
  31static inline void set_interrupt_registers(int ip)
  32{
  33        unsigned long __dummy;
  34
  35        asm volatile(
  36#ifdef CONFIG_CPU_HAS_SR_RB
  37                     "ldc       %2, r6_bank\n\t"
  38#endif
  39                     "stc       sr, %0\n\t"
  40                     "and       #0xf0, %0\n\t"
  41                     "shlr2     %0\n\t"
  42                     "cmp/eq    #0x3c, %0\n\t"
  43                     "bt/s      1f      ! CLI-ed\n\t"
  44                     " stc      sr, %0\n\t"
  45                     "and       %1, %0\n\t"
  46                     "or        %2, %0\n\t"
  47                     "ldc       %0, sr\n"
  48                     "1:"
  49                     : "=&z" (__dummy)
  50                     : "r" (~0xf0), "r" (ip << 4)
  51                     : "t");
  52}
  53
  54static void mask_imask_irq(struct irq_data *data)
  55{
  56        unsigned int irq = data->irq;
  57
  58        clear_bit(irq, imask_mask);
  59        if (interrupt_priority < IMASK_PRIORITY - irq)
  60                interrupt_priority = IMASK_PRIORITY - irq;
  61        set_interrupt_registers(interrupt_priority);
  62}
  63
  64static void unmask_imask_irq(struct irq_data *data)
  65{
  66        unsigned int irq = data->irq;
  67
  68        set_bit(irq, imask_mask);
  69        interrupt_priority = IMASK_PRIORITY -
  70                find_first_zero_bit(imask_mask, IMASK_PRIORITY);
  71        set_interrupt_registers(interrupt_priority);
  72}
  73
  74static struct irq_chip imask_irq_chip = {
  75        .name           = "SR.IMASK",
  76        .irq_mask       = mask_imask_irq,
  77        .irq_unmask     = unmask_imask_irq,
  78        .irq_mask_ack   = mask_imask_irq,
  79};
  80
  81void make_imask_irq(unsigned int irq)
  82{
  83        irq_set_chip_and_handler_name(irq, &imask_irq_chip, handle_level_irq,
  84                                      "level");
  85}
  86