arch/h8300/kernel/irq.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * linux/arch/h8300/kernel/irq.c
   4  *
   5  * Copyright 2014-2015 Yoshinori Sato <ysato@users.sourceforge.jp>
   6  */
   7
   8 #include <linux/init.h>
   9 #include <linux/interrupt.h>
  10 #include <linux/irq.h>
  11 #include <linux/irqdomain.h>
  12 #include <linux/of_irq.h>
  13 #include <asm/traps.h>
  14
  15 #ifdef CONFIG_RAMKERNEL
  16 typedef void (*h8300_vector)(void);
  17
  18 static const h8300_vector __initconst trap_table[] = {
  19         0, 0, 0, 0,
  20         _trace_break,
  21         0, 0,
  22         _nmi,
  23         _system_call,
  24         0, 0,
  25         _trace_break,
  26 };
  27
  28 static unsigned long __init *get_vector_address(void)
  29 {
  30         unsigned long *rom_vector = CPU_VECTOR;
  31         unsigned long base, tmp;
  32         int vec_no;
  33
  34         base = rom_vector[EXT_IRQ0] & ADDR_MASK;
  35
  36         /* check romvector format */
  37         for (vec_no = EXT_IRQ0 + 1; vec_no <= EXT_IRQ0+EXT_IRQS; vec_no++) {
  38                 if ((base+(vec_no - EXT_IRQ0)*4) !=
  39                     (rom_vector[vec_no] & ADDR_MASK))
  40                         return NULL;
  41         }
  42
  43         /* ramvector base address */
  44         base -= EXT_IRQ0*4;
  45
  46         /* writerble? */
  47         tmp = ~(*(volatile unsigned long *)base);
  48         (*(volatile unsigned long *)base) = tmp;
  49         if ((*(volatile unsigned long *)base) != tmp)
  50                 return NULL;
  51         return (unsigned long *)base;
  52 }
  53
  54 static void __init setup_vector(void)
  55 {
  56         int i;
  57         unsigned long *ramvec, *ramvec_p;
  58         const h8300_vector *trap_entry;
  59
  60         ramvec = get_vector_address();
  61         if (ramvec == NULL)
  62                 panic("interrupt vector serup failed.");
  63         else
  64                 pr_debug("virtual vector at 0x%p\n", ramvec);
  65
  66         /* create redirect table */
  67         ramvec_p = ramvec;
  68         trap_entry = trap_table;
  69         for (i = 0; i < NR_IRQS; i++) {
  70                 if (i < 12) {
  71                         if (*trap_entry)
  72                                 *ramvec_p = VECTOR(*trap_entry);
  73                         ramvec_p++;
  74                         trap_entry++;
  75                 } else
  76                         *ramvec_p++ = REDIRECT(_interrupt_entry);
  77         }
  78         _interrupt_redirect_table = ramvec;
  79 }
  80 #else
  81 void setup_vector(void)
  82 {
  83         /* noting do */
  84 }
  85 #endif
  86
  87 void __init init_IRQ(void)
  88 {
  89         setup_vector();
  90         irqchip_init();
  91 }
  92
  93 asmlinkage void do_IRQ(int irq)
  94 {
  95         irq_enter();
  96         generic_handle_irq(irq);
  97         irq_exit();
  98 }