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 <[email protected]>
   6  */
   7
   8 #include <linux/init.h>
   9 #include <linux/interrupt.h>
  10 #include <linux/irq.h>
  11 #include <linux/irqchip.h>
  12 #include <linux/irqdomain.h>
  13 #include <linux/of_irq.h>
  14 #include <asm/traps.h>
  15
  16 #ifdef CONFIG_RAMKERNEL
  17 typedef void (*h8300_vector)(void);
  18
  19 static const h8300_vector __initconst trap_table[] = {
  20         0, 0, 0, 0,
  21         _trace_break,
  22         0, 0,
  23         _nmi,
  24         _system_call,
  25         0, 0,
  26         _trace_break,
  27 };
  28
  29 static unsigned long __init *get_vector_address(void)
  30 {
  31         unsigned long *rom_vector = CPU_VECTOR;
  32         unsigned long base, tmp;
  33         int vec_no;
  34
  35         base = rom_vector[EXT_IRQ0] & ADDR_MASK;
  36
  37         /* check romvector format */
  38         for (vec_no = EXT_IRQ0 + 1; vec_no <= EXT_IRQ0+EXT_IRQS; vec_no++) {
  39                 if ((base+(vec_no - EXT_IRQ0)*4) !=
  40                     (rom_vector[vec_no] & ADDR_MASK))
  41                         return NULL;
  42         }
  43
  44         /* ramvector base address */
  45         base -= EXT_IRQ0*4;
  46
  47         /* writerble? */
  48         tmp = ~(*(volatile unsigned long *)base);
  49         (*(volatile unsigned long *)base) = tmp;
  50         if ((*(volatile unsigned long *)base) != tmp)
  51                 return NULL;
  52         return (unsigned long *)base;
  53 }
  54
  55 static void __init setup_vector(void)
  56 {
  57         int i;
  58         unsigned long *ramvec, *ramvec_p;
  59         const h8300_vector *trap_entry;
  60
  61         ramvec = get_vector_address();
  62         if (ramvec == NULL)
  63                 panic("interrupt vector serup failed.");
  64         else
  65                 pr_debug("virtual vector at 0x%p\n", ramvec);
  66
  67         /* create redirect table */
  68         ramvec_p = ramvec;
  69         trap_entry = trap_table;
  70         for (i = 0; i < NR_IRQS; i++) {
  71                 if (i < 12) {
  72                         if (*trap_entry)
  73                                 *ramvec_p = VECTOR(*trap_entry);
  74                         ramvec_p++;
  75                         trap_entry++;
  76                 } else
  77                         *ramvec_p++ = REDIRECT(_interrupt_entry);
  78         }
  79         _interrupt_redirect_table = ramvec;
  80 }
  81 #else
  82 void setup_vector(void)
  83 {
  84         /* noting do */
  85 }
  86 #endif
  87
  88 void __init init_IRQ(void)
  89 {
  90         setup_vector();
  91         irqchip_init();
  92 }
  93
  94 asmlinkage void do_IRQ(int irq)
  95 {
  96         irq_enter();
  97         generic_handle_irq(irq);
  98         irq_exit();
  99 }