arch/h8300/kernel/irq.c

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