arch/mips/vr41xx/common/irq.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Interrupt handing routines for NEC VR4100 series.
   4  *
   5  *  Copyright (C) 2005-2007  Yoichi Yuasa <yuasa@linux-mips.org>
   6  */
   7 #include <linux/export.h>
   8 #include <linux/interrupt.h>
   9 #include <linux/irq.h>
  10
  11 #include <asm/irq_cpu.h>
  12 #include <asm/vr41xx/irq.h>
  13
  14 typedef struct irq_cascade {
  15         int (*get_irq)(unsigned int);
  16 } irq_cascade_t;
  17
  18 static irq_cascade_t irq_cascade[NR_IRQS] __cacheline_aligned;
  19
  20 static struct irqaction cascade_irqaction = {
  21         .handler        = no_action,
  22         .name           = "cascade",
  23         .flags          = IRQF_NO_THREAD,
  24 };
  25
  26 int cascade_irq(unsigned int irq, int (*get_irq)(unsigned int))
  27 {
  28         int retval = 0;
  29
  30         if (irq >= NR_IRQS)
  31                 return -EINVAL;
  32
  33         if (irq_cascade[irq].get_irq != NULL)
  34                 free_irq(irq, NULL);
  35
  36         irq_cascade[irq].get_irq = get_irq;
  37
  38         if (get_irq != NULL) {
  39                 retval = setup_irq(irq, &cascade_irqaction);
  40                 if (retval < 0)
  41                         irq_cascade[irq].get_irq = NULL;
  42         }
  43
  44         return retval;
  45 }
  46
  47 EXPORT_SYMBOL_GPL(cascade_irq);
  48
  49 static void irq_dispatch(unsigned int irq)
  50 {
  51         irq_cascade_t *cascade;
  52
  53         if (irq >= NR_IRQS) {
  54                 atomic_inc(&irq_err_count);
  55                 return;
  56         }
  57
  58         cascade = irq_cascade + irq;
  59         if (cascade->get_irq != NULL) {
  60                 struct irq_desc *desc = irq_to_desc(irq);
  61                 struct irq_data *idata = irq_desc_get_irq_data(desc);
  62                 struct irq_chip *chip = irq_desc_get_chip(desc);
  63                 int ret;
  64
  65                 if (chip->irq_mask_ack)
  66                         chip->irq_mask_ack(idata);
  67                 else {
  68                         chip->irq_mask(idata);
  69                         chip->irq_ack(idata);
  70                 }
  71                 ret = cascade->get_irq(irq);
  72                 irq = ret;
  73                 if (ret < 0)
  74                         atomic_inc(&irq_err_count);
  75                 else
  76                         irq_dispatch(irq);
  77                 if (!irqd_irq_disabled(idata) && chip->irq_unmask)
  78                         chip->irq_unmask(idata);
  79         } else
  80                 do_IRQ(irq);
  81 }
  82
  83 asmlinkage void plat_irq_dispatch(void)
  84 {
  85         unsigned int pending = read_c0_cause() & read_c0_status() & ST0_IM;
  86
  87         if (pending & CAUSEF_IP7)
  88                 do_IRQ(TIMER_IRQ);
  89         else if (pending & 0x7800) {
  90                 if (pending & CAUSEF_IP3)
  91                         irq_dispatch(INT1_IRQ);
  92                 else if (pending & CAUSEF_IP4)
  93                         irq_dispatch(INT2_IRQ);
  94                 else if (pending & CAUSEF_IP5)
  95                         irq_dispatch(INT3_IRQ);
  96                 else if (pending & CAUSEF_IP6)
  97                         irq_dispatch(INT4_IRQ);
  98         } else if (pending & CAUSEF_IP2)
  99                 irq_dispatch(INT0_IRQ);
 100         else if (pending & CAUSEF_IP0)
 101                 do_IRQ(MIPS_SOFTINT0_IRQ);
 102         else if (pending & CAUSEF_IP1)
 103                 do_IRQ(MIPS_SOFTINT1_IRQ);
 104         else
 105                 spurious_interrupt();
 106 }
 107
 108 void __init arch_init_irq(void)
 109 {
 110         mips_cpu_irq_init();
 111 }