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

   1 /*
   2  *      linux/arch/cris/kernel/irq.c
   3  *
   4  *      Copyright (c) 2000-2002 Axis Communications AB
   5  *
   6  *      Authors: Bjorn Wesen (bjornw@axis.com)
   7  *
   8  *      This file contains the interrupt vectors and some
   9  *      helper functions
  10  *
  11  */
  12
  13 #include <asm/irq.h>
  14 #include <asm/current.h>
  15 #include <linux/irq.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/kernel.h>
  18 #include <linux/init.h>
  19
  20 #define crisv10_mask_irq(irq_nr) (*R_VECT_MASK_CLR = 1 << (irq_nr));
  21 #define crisv10_unmask_irq(irq_nr) (*R_VECT_MASK_SET = 1 << (irq_nr));
  22
  23 extern void kgdb_init(void);
  24 extern void breakpoint(void);
  25
  26 /* don't use set_int_vector, it bypasses the linux interrupt handlers. it is
  27  * global just so that the kernel gdb can use it.
  28  */
  29
  30 void
  31 set_int_vector(int n, irqvectptr addr)
  32 {
  33         etrax_irv->v[n + 0x20] = (irqvectptr)addr;
  34 }
  35
  36 /* the breakpoint vector is obviously not made just like the normal irq handlers
  37  * but needs to contain _code_ to jump to addr.
  38  *
  39  * the BREAK n instruction jumps to IBR + n * 8
  40  */
  41
  42 void
  43 set_break_vector(int n, irqvectptr addr)
  44 {
  45         unsigned short *jinstr = (unsigned short *)&etrax_irv->v[n*2];
  46         unsigned long *jaddr = (unsigned long *)(jinstr + 1);
  47
  48         /* if you don't know what this does, do not touch it! */
  49
  50         *jinstr = 0x0d3f;
  51         *jaddr = (unsigned long)addr;
  52
  53         /* 00000026 <clrlop+1a> 3f0d82000000     jump  0x82 */
  54 }
  55
  56 /*
  57  * This builds up the IRQ handler stubs using some ugly macros in irq.h
  58  *
  59  * These macros create the low-level assembly IRQ routines that do all
  60  * the operations that are needed. They are also written to be fast - and to
  61  * disable interrupts as little as humanly possible.
  62  *
  63  */
  64
  65 /* IRQ0 and 1 are special traps */
  66 void hwbreakpoint(void);
  67 void IRQ1_interrupt(void);
  68 BUILD_TIMER_IRQ(2, 0x04)       /* the timer interrupt is somewhat special */
  69 BUILD_IRQ(3, 0x08)
  70 BUILD_IRQ(4, 0x10)
  71 BUILD_IRQ(5, 0x20)
  72 BUILD_IRQ(6, 0x40)
  73 BUILD_IRQ(7, 0x80)
  74 BUILD_IRQ(8, 0x100)
  75 BUILD_IRQ(9, 0x200)
  76 BUILD_IRQ(10, 0x400)
  77 BUILD_IRQ(11, 0x800)
  78 BUILD_IRQ(12, 0x1000)
  79 BUILD_IRQ(13, 0x2000)
  80 void mmu_bus_fault(void);      /* IRQ 14 is the bus fault interrupt */
  81 void multiple_interrupt(void); /* IRQ 15 is the multiple IRQ interrupt */
  82 BUILD_IRQ(16, 0x10000 | 0x20000)  /* ethernet tx interrupt needs to block rx */
  83 BUILD_IRQ(17, 0x20000 | 0x10000)  /* ...and vice versa */
  84 BUILD_IRQ(18, 0x40000)
  85 BUILD_IRQ(19, 0x80000)
  86 BUILD_IRQ(20, 0x100000)
  87 BUILD_IRQ(21, 0x200000)
  88 BUILD_IRQ(22, 0x400000)
  89 BUILD_IRQ(23, 0x800000)
  90 BUILD_IRQ(24, 0x1000000)
  91 BUILD_IRQ(25, 0x2000000)
  92 /* IRQ 26-30 are reserved */
  93 BUILD_IRQ(31, 0x80000000)
  94
  95 /*
  96  * Pointers to the low-level handlers
  97  */
  98
  99 static void (*interrupt[NR_IRQS])(void) = {
 100         NULL, NULL, IRQ2_interrupt, IRQ3_interrupt,
 101         IRQ4_interrupt, IRQ5_interrupt, IRQ6_interrupt, IRQ7_interrupt,
 102         IRQ8_interrupt, IRQ9_interrupt, IRQ10_interrupt, IRQ11_interrupt,
 103         IRQ12_interrupt, IRQ13_interrupt, NULL, NULL,
 104         IRQ16_interrupt, IRQ17_interrupt, IRQ18_interrupt, IRQ19_interrupt,
 105         IRQ20_interrupt, IRQ21_interrupt, IRQ22_interrupt, IRQ23_interrupt,
 106         IRQ24_interrupt, IRQ25_interrupt, NULL, NULL, NULL, NULL, NULL,
 107         IRQ31_interrupt
 108 };
 109
 110 static void enable_crisv10_irq(struct irq_data *data)
 111 {
 112         crisv10_unmask_irq(data->irq);
 113 }
 114
 115 static void disable_crisv10_irq(struct irq_data *data)
 116 {
 117         crisv10_mask_irq(data->irq);
 118 }
 119
 120 static struct irq_chip crisv10_irq_type = {
 121         .name           = "CRISv10",
 122         .irq_shutdown   = disable_crisv10_irq,
 123         .irq_enable     = enable_crisv10_irq,
 124         .irq_disable    = disable_crisv10_irq,
 125 };
 126
 127 void weird_irq(void);
 128 void system_call(void);  /* from entry.S */
 129 void do_sigtrap(void); /* from entry.S */
 130 void gdb_handle_breakpoint(void); /* from entry.S */
 131
 132 extern void do_IRQ(int irq, struct pt_regs * regs);
 133
 134 /* Handle multiple IRQs */
 135 void do_multiple_IRQ(struct pt_regs* regs)
 136 {
 137         int bit;
 138         unsigned masked;
 139         unsigned mask;
 140         unsigned ethmask = 0;
 141
 142         /* Get interrupts to mask and handle */
 143         mask = masked = *R_VECT_MASK_RD;
 144
 145         /* Never mask timer IRQ */
 146         mask &= ~(IO_MASK(R_VECT_MASK_RD, timer0));
 147
 148         /*
 149          * If either ethernet interrupt (rx or tx) is active then block
 150          * the other one too. Unblock afterwards also.
 151          */
 152         if (mask &
 153             (IO_STATE(R_VECT_MASK_RD, dma0, active) |
 154              IO_STATE(R_VECT_MASK_RD, dma1, active))) {
 155                 ethmask = (IO_MASK(R_VECT_MASK_RD, dma0) |
 156                            IO_MASK(R_VECT_MASK_RD, dma1));
 157         }
 158
 159         /* Block them */
 160         *R_VECT_MASK_CLR = (mask | ethmask);
 161
 162         /* An extra irq_enter here to prevent softIRQs to run after
 163          * each do_IRQ. This will decrease the interrupt latency.
 164          */
 165         irq_enter();
 166
 167         /* Handle all IRQs */
 168         for (bit = 2; bit < 32; bit++) {
 169                 if (masked & (1 << bit)) {
 170                         do_IRQ(bit, regs);
 171                 }
 172         }
 173
 174         /* This irq_exit() will trigger the soft IRQs. */
 175         irq_exit();
 176
 177         /* Unblock the IRQs again */
 178         *R_VECT_MASK_SET = (masked | ethmask);
 179 }
 180
 181 /* init_IRQ() is called by start_kernel and is responsible for fixing IRQ masks and
 182    setting the irq vector table.
 183 */
 184
 185 void __init init_IRQ(void)
 186 {
 187         int i;
 188
 189         /* clear all interrupt masks */
 190         *R_IRQ_MASK0_CLR = 0xffffffff;
 191         *R_IRQ_MASK1_CLR = 0xffffffff;
 192         *R_IRQ_MASK2_CLR = 0xffffffff;
 193         *R_VECT_MASK_CLR = 0xffffffff;
 194
 195         for (i = 0; i < 256; i++)
 196                etrax_irv->v[i] = weird_irq;
 197
 198         /* Initialize IRQ handler descriptors. */
 199         for(i = 2; i < NR_IRQS; i++) {
 200                 irq_set_chip_and_handler(i, &crisv10_irq_type,
 201                                          handle_simple_irq);
 202                 set_int_vector(i, interrupt[i]);
 203         }
 204
 205         /* the entries in the break vector contain actual code to be
 206            executed by the associated break handler, rather than just a jump
 207            address. therefore we need to setup a default breakpoint handler
 208            for all breakpoints */
 209         for (i = 0; i < 16; i++)
 210                 set_break_vector(i, do_sigtrap);
 211
 212         /* except IRQ 15 which is the multiple-IRQ handler on Etrax100 */
 213         set_int_vector(15, multiple_interrupt);
 214
 215         /* 0 and 1 which are special breakpoint/NMI traps */
 216         set_int_vector(0, hwbreakpoint);
 217         set_int_vector(1, IRQ1_interrupt);
 218
 219         /* and irq 14 which is the mmu bus fault handler */
 220         set_int_vector(14, mmu_bus_fault);
 221
 222         /* setup the system-call trap, which is reached by BREAK 13 */
 223         set_break_vector(13, system_call);
 224
 225         /* setup a breakpoint handler for debugging used for both user and
 226            kernel mode debugging  (which is why it is not inside an ifdef
 227            CONFIG_ETRAX_KGDB) */
 228         set_break_vector(8, gdb_handle_breakpoint);
 229
 230 #ifdef CONFIG_ETRAX_KGDB
 231         /* setup kgdb if its enabled, and break into the debugger */
 232         kgdb_init();
 233         breakpoint();
 234 #endif
 235 }