arch/mips/kernel/irq-rm9000.c

   1 /*
   2  * Copyright (C) 2003 Ralf Baechle
   3  *
   4  * This program is free software; you can redistribute  it and/or modify it
   5  * under  the terms of  the GNU General  Public License as published by the
   6  * Free Software Foundation;  either version 2 of the  License, or (at your
   7  * option) any later version.
   8  *
   9  * Handler for RM9000 extended interrupts.  These are a non-standard
  10  * feature so we handle them separately from standard interrupts.
  11  */
  12 #include <linux/init.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16
  17 #include <asm/irq_cpu.h>
  18 #include <asm/mipsregs.h>
  19 #include <asm/system.h>
  20
  21 static int irq_base;
  22
  23 static inline void unmask_rm9k_irq(unsigned int irq)
  24 {
  25         set_c0_intcontrol(0x1000 << (irq - irq_base));
  26 }
  27
  28 static inline void mask_rm9k_irq(unsigned int irq)
  29 {
  30         clear_c0_intcontrol(0x1000 << (irq - irq_base));
  31 }
  32
  33 static inline void rm9k_cpu_irq_enable(unsigned int irq)
  34 {
  35         unsigned long flags;
  36
  37         local_irq_save(flags);
  38         unmask_rm9k_irq(irq);
  39         local_irq_restore(flags);
  40 }
  41
  42 static void rm9k_cpu_irq_disable(unsigned int irq)
  43 {
  44         unsigned long flags;
  45
  46         local_irq_save(flags);
  47         mask_rm9k_irq(irq);
  48         local_irq_restore(flags);
  49 }
  50
  51 static unsigned int rm9k_cpu_irq_startup(unsigned int irq)
  52 {
  53         rm9k_cpu_irq_enable(irq);
  54
  55         return 0;
  56 }
  57
  58 #define rm9k_cpu_irq_shutdown   rm9k_cpu_irq_disable
  59
  60 /*
  61  * Performance counter interrupts are global on all processors.
  62  */
  63 static void local_rm9k_perfcounter_irq_startup(void *args)
  64 {
  65         unsigned int irq = (unsigned int) args;
  66
  67         rm9k_cpu_irq_enable(irq);
  68 }
  69
  70 static unsigned int rm9k_perfcounter_irq_startup(unsigned int irq)
  71 {
  72         on_each_cpu(local_rm9k_perfcounter_irq_startup, (void *) irq, 0, 1);
  73
  74         return 0;
  75 }
  76
  77 static void local_rm9k_perfcounter_irq_shutdown(void *args)
  78 {
  79         unsigned int irq = (unsigned int) args;
  80         unsigned long flags;
  81
  82         local_irq_save(flags);
  83         mask_rm9k_irq(irq);
  84         local_irq_restore(flags);
  85 }
  86
  87 static void rm9k_perfcounter_irq_shutdown(unsigned int irq)
  88 {
  89         on_each_cpu(local_rm9k_perfcounter_irq_shutdown, (void *) irq, 0, 1);
  90 }
  91
  92
  93 /*
  94  * While we ack the interrupt interrupts are disabled and thus we don't need
  95  * to deal with concurrency issues.  Same for rm9k_cpu_irq_end.
  96  */
  97 static void rm9k_cpu_irq_ack(unsigned int irq)
  98 {
  99         mask_rm9k_irq(irq);
 100 }
 101
 102 static void rm9k_cpu_irq_end(unsigned int irq)
 103 {
 104         if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS)))
 105                 unmask_rm9k_irq(irq);
 106 }
 107
 108 static struct irq_chip rm9k_irq_controller = {
 109         .typename = "RM9000",
 110         .startup = rm9k_cpu_irq_startup,
 111         .shutdown = rm9k_cpu_irq_shutdown,
 112         .enable = rm9k_cpu_irq_enable,
 113         .disable = rm9k_cpu_irq_disable,
 114         .ack = rm9k_cpu_irq_ack,
 115         .end = rm9k_cpu_irq_end,
 116 };
 117
 118 static struct irq_chip rm9k_perfcounter_irq = {
 119         .typename = "RM9000",
 120         .startup = rm9k_perfcounter_irq_startup,
 121         .shutdown = rm9k_perfcounter_irq_shutdown,
 122         .enable = rm9k_cpu_irq_enable,
 123         .disable = rm9k_cpu_irq_disable,
 124         .ack = rm9k_cpu_irq_ack,
 125         .end = rm9k_cpu_irq_end,
 126 };
 127
 128 unsigned int rm9000_perfcount_irq;
 129
 130 EXPORT_SYMBOL(rm9000_perfcount_irq);
 131
 132 void __init rm9k_cpu_irq_init(int base)
 133 {
 134         int i;
 135
 136         clear_c0_intcontrol(0x0000f000);                /* Mask all */
 137
 138         for (i = base; i < base + 4; i++) {
 139                 irq_desc[i].status = IRQ_DISABLED;
 140                 irq_desc[i].action = NULL;
 141                 irq_desc[i].depth = 1;
 142                 irq_desc[i].chip = &rm9k_irq_controller;
 143         }
 144
 145         rm9000_perfcount_irq = base + 1;
 146         irq_desc[rm9000_perfcount_irq].chip = &rm9k_perfcounter_irq;
 147
 148         irq_base = base;
 149 }