[MIPS] Rewrite all the assembler interrupt handlers to C.

Saves like 1,600 lines of code, is way easier to debug, compilers
frequently do a better job than the cut and paste type of handlers many
boards had.  And finally having all the stuff done in a single place
also means alot of bug potencial for the MT ASE is gone.

The only surviving handler in assembler is the DECstation one; I hope
Maciej will rewrite it.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/dec/int-handler.S

@@ -36,7 +36,7 @@
 		.text
 		.set	noreorder
 /*
- * decstation_handle_int: Interrupt handler for DECstations
+ * plat_irq_dispatch: Interrupt handler for DECstations
  *
  * We follow the model in the Indy interrupt code by David Miller, where he
  * says: a lot of complication here is taken away because:
@@ -125,11 +125,7 @@
  * just take another exception, big deal.
  */
 		.align	5
-		NESTED(decstation_handle_int, PT_SIZE, ra)
-		.set	noat
-		SAVE_ALL
-		CLI				# TEST: interrupts should be off
-		.set	at
+		NESTED(plat_irq_dispatch, PT_SIZE, ra)
 		.set	noreorder
 
 		/*
@@ -286,7 +282,7 @@ spurious:
 		 nop
 		j	ret_from_irq
 		 nop
-		END(decstation_handle_int)
+		END(plat_irq_dispatch)
 
 /*
  * Generic unimplemented interrupt routines -- cpu_mask_nr_tbl

arch/mips/dec/setup.c

@@ -48,8 +48,6 @@ extern void dec_machine_halt(void);
 extern void dec_machine_power_off(void);
 extern irqreturn_t dec_intr_halt(int irq, void *dev_id, struct pt_regs *regs);
 
-extern asmlinkage void decstation_handle_int(void);
-
 unsigned long dec_kn_slot_base, dec_kn_slot_size;
 
 EXPORT_SYMBOL(dec_kn_slot_base);
@@ -744,7 +742,6 @@ void __init arch_init_irq(void)
 		panic("Don't know how to set this up!");
 		break;
 	}
-	set_except_vector(0, decstation_handle_int);
 
 	/* Free the FPU interrupt if the exception is present. */
 	if (!cpu_has_nofpuex) {