arch/cris/arch-v10/kernel/irq.c

   1 /* $Id: irq.c,v 1.2 2004/06/09 05:30:27 starvik Exp $
   2  *
   3  *      linux/arch/cris/kernel/irq.c
   4  *
   5  *      Copyright (c) 2000-2002 Axis Communications AB
   6  *
   7  *      Authors: Bjorn Wesen (bjornw@axis.com)
   8  *
   9  *      This file contains the interrupt vectors and some
  10  *      helper functions
  11  *
  12  */
  13
  14 #include <asm/irq.h>
  15 #include <linux/kernel.h>
  16 #include <linux/init.h>
  17 #include <linux/config.h>
  18
  19 irqvectptr irq_shortcuts[NR_IRQS]; /* vector of shortcut jumps after the irq prologue */
  20
  21 /* don't use set_int_vector, it bypasses the linux interrupt handlers. it is
  22  * global just so that the kernel gdb can use it.
  23  */
  24
  25 void
  26 set_int_vector(int n, irqvectptr addr)
  27 {
  28         etrax_irv->v[n + 0x20] = (irqvectptr)addr;
  29 }
  30
  31 /* the breakpoint vector is obviously not made just like the normal irq handlers
  32  * but needs to contain _code_ to jump to addr.
  33  *
  34  * the BREAK n instruction jumps to IBR + n * 8
  35  */
  36
  37 void
  38 set_break_vector(int n, irqvectptr addr)
  39 {
  40         unsigned short *jinstr = (unsigned short *)&etrax_irv->v[n*2];
  41         unsigned long *jaddr = (unsigned long *)(jinstr + 1);
  42
  43         /* if you don't know what this does, do not touch it! */
  44
  45         *jinstr = 0x0d3f;
  46         *jaddr = (unsigned long)addr;
  47
  48         /* 00000026 <clrlop+1a> 3f0d82000000     jump  0x82 */
  49 }
  50
  51 /*
  52  * This builds up the IRQ handler stubs using some ugly macros in irq.h
  53  *
  54  * These macros create the low-level assembly IRQ routines that do all
  55  * the operations that are needed. They are also written to be fast - and to
  56  * disable interrupts as little as humanly possible.
  57  *
  58  */
  59
  60 /* IRQ0 and 1 are special traps */
  61 void hwbreakpoint(void);
  62 void IRQ1_interrupt(void);
  63 BUILD_TIMER_IRQ(2, 0x04)       /* the timer interrupt is somewhat special */
  64 BUILD_IRQ(3, 0x08)
  65 BUILD_IRQ(4, 0x10)
  66 BUILD_IRQ(5, 0x20)
  67 BUILD_IRQ(6, 0x40)
  68 BUILD_IRQ(7, 0x80)
  69 BUILD_IRQ(8, 0x100)
  70 BUILD_IRQ(9, 0x200)
  71 BUILD_IRQ(10, 0x400)
  72 BUILD_IRQ(11, 0x800)
  73 BUILD_IRQ(12, 0x1000)
  74 BUILD_IRQ(13, 0x2000)
  75 void mmu_bus_fault(void);      /* IRQ 14 is the bus fault interrupt */
  76 void multiple_interrupt(void); /* IRQ 15 is the multiple IRQ interrupt */
  77 BUILD_IRQ(16, 0x10000)
  78 BUILD_IRQ(17, 0x20000)
  79 BUILD_IRQ(18, 0x40000)
  80 BUILD_IRQ(19, 0x80000)
  81 BUILD_IRQ(20, 0x100000)
  82 BUILD_IRQ(21, 0x200000)
  83 BUILD_IRQ(22, 0x400000)
  84 BUILD_IRQ(23, 0x800000)
  85 BUILD_IRQ(24, 0x1000000)
  86 BUILD_IRQ(25, 0x2000000)
  87 /* IRQ 26-30 are reserved */
  88 BUILD_IRQ(31, 0x80000000)
  89
  90 /*
  91  * Pointers to the low-level handlers
  92  */
  93
  94 static void (*interrupt[NR_IRQS])(void) = {
  95         NULL, NULL, IRQ2_interrupt, IRQ3_interrupt,
  96         IRQ4_interrupt, IRQ5_interrupt, IRQ6_interrupt, IRQ7_interrupt,
  97         IRQ8_interrupt, IRQ9_interrupt, IRQ10_interrupt, IRQ11_interrupt,
  98         IRQ12_interrupt, IRQ13_interrupt, NULL, NULL,
  99         IRQ16_interrupt, IRQ17_interrupt, IRQ18_interrupt, IRQ19_interrupt,
 100         IRQ20_interrupt, IRQ21_interrupt, IRQ22_interrupt, IRQ23_interrupt,
 101         IRQ24_interrupt, IRQ25_interrupt, NULL, NULL, NULL, NULL, NULL,
 102         IRQ31_interrupt
 103 };
 104
 105 static void (*bad_interrupt[NR_IRQS])(void) = {
 106         NULL, NULL,
 107         NULL, bad_IRQ3_interrupt,
 108         bad_IRQ4_interrupt, bad_IRQ5_interrupt,
 109         bad_IRQ6_interrupt, bad_IRQ7_interrupt,
 110         bad_IRQ8_interrupt, bad_IRQ9_interrupt,
 111         bad_IRQ10_interrupt, bad_IRQ11_interrupt,
 112         bad_IRQ12_interrupt, bad_IRQ13_interrupt,
 113         NULL, NULL,
 114         bad_IRQ16_interrupt, bad_IRQ17_interrupt,
 115         bad_IRQ18_interrupt, bad_IRQ19_interrupt,
 116         bad_IRQ20_interrupt, bad_IRQ21_interrupt,
 117         bad_IRQ22_interrupt, bad_IRQ23_interrupt,
 118         bad_IRQ24_interrupt, bad_IRQ25_interrupt,
 119         NULL, NULL, NULL, NULL, NULL,
 120         bad_IRQ31_interrupt
 121 };
 122
 123 void arch_setup_irq(int irq)
 124 {
 125   set_int_vector(irq, interrupt[irq]);
 126 }
 127
 128 void arch_free_irq(int irq)
 129 {
 130   set_int_vector(irq, bad_interrupt[irq]);
 131 }
 132
 133 void weird_irq(void);
 134 void system_call(void);  /* from entry.S */
 135 void do_sigtrap(void); /* from entry.S */
 136 void gdb_handle_breakpoint(void); /* from entry.S */
 137
 138 /* init_IRQ() is called by start_kernel and is responsible for fixing IRQ masks and
 139    setting the irq vector table to point to bad_interrupt ptrs.
 140 */
 141
 142 void __init
 143 init_IRQ(void)
 144 {
 145         int i;
 146
 147         /* clear all interrupt masks */
 148
 149 #ifndef CONFIG_SVINTO_SIM
 150         *R_IRQ_MASK0_CLR = 0xffffffff;
 151         *R_IRQ_MASK1_CLR = 0xffffffff;
 152         *R_IRQ_MASK2_CLR = 0xffffffff;
 153 #endif
 154
 155         *R_VECT_MASK_CLR = 0xffffffff;
 156
 157         /* clear the shortcut entry points */
 158
 159         for(i = 0; i < NR_IRQS; i++)
 160                 irq_shortcuts[i] = NULL;
 161
 162         for (i = 0; i < 256; i++)
 163                etrax_irv->v[i] = weird_irq;
 164
 165         /* the entries in the break vector contain actual code to be
 166            executed by the associated break handler, rather than just a jump
 167            address. therefore we need to setup a default breakpoint handler
 168            for all breakpoints */
 169
 170         for (i = 0; i < 16; i++)
 171                 set_break_vector(i, do_sigtrap);
 172
 173         /* set all etrax irq's to the bad handlers */
 174         for (i = 2; i < NR_IRQS; i++)
 175                 set_int_vector(i, bad_interrupt[i]);
 176
 177         /* except IRQ 15 which is the multiple-IRQ handler on Etrax100 */
 178
 179         set_int_vector(15, multiple_interrupt);
 180
 181         /* 0 and 1 which are special breakpoint/NMI traps */
 182
 183         set_int_vector(0, hwbreakpoint);
 184         set_int_vector(1, IRQ1_interrupt);
 185
 186         /* and irq 14 which is the mmu bus fault handler */
 187
 188         set_int_vector(14, mmu_bus_fault);
 189
 190         /* setup the system-call trap, which is reached by BREAK 13 */
 191
 192         set_break_vector(13, system_call);
 193
 194         /* setup a breakpoint handler for debugging used for both user and
 195            kernel mode debugging  (which is why it is not inside an ifdef
 196            CONFIG_ETRAX_KGDB) */
 197         set_break_vector(8, gdb_handle_breakpoint);
 198
 199 #ifdef CONFIG_ETRAX_KGDB
 200         /* setup kgdb if its enabled, and break into the debugger */
 201         kgdb_init();
 202         breakpoint();
 203 #endif
 204 }