[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>

3 files changed, 19 insertions, 129 deletions

diff --git a/arch/mips/ddb5xxx/ddb5074/Makefile b/arch/mips/ddb5xxx/ddb5074/Makefile
index 488206b8d94e..304c02107b46 100644
--- a/arch/mips/ddb5xxx/ddb5074/Makefile
+++ b/arch/mips/ddb5xxx/ddb5074/Makefile
@@ -3,6 +3,6 @@
 # under Linux.
 #
 
-obj-y			+= setup.o irq.o int-handler.o nile4_pic.o
+obj-y			+= setup.o irq.o nile4_pic.o
 
 EXTRA_AFLAGS := $(CFLAGS)
diff --git a/arch/mips/ddb5xxx/ddb5074/int-handler.S b/arch/mips/ddb5xxx/ddb5074/int-handler.S
deleted file mode 100644
index a78644150b37..000000000000
--- a/arch/mips/ddb5xxx/ddb5074/int-handler.S
+++ /dev/null
@@ -1,120 +0,0 @@
-/*
- *  arch/mips/ddb5074/int-handler.S -- NEC DDB Vrc-5074 interrupt handler
- *
- *  Based on arch/mips/sgi/kernel/indyIRQ.S
- *
- *  Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
- *
- *  Copyright (C) 2000 Geert Uytterhoeven <geert@sonycom.com>
- *                     Sony Software Development Center Europe (SDCE), Brussels
- */
-#include <asm/asm.h>
-#include <asm/mipsregs.h>
-#include <asm/regdef.h>
-#include <asm/stackframe.h>
-
-/* A lot of complication here is taken away because:
- *
- * 1) We handle one interrupt and return, sitting in a loop and moving across
- *    all the pending IRQ bits in the cause register is _NOT_ the answer, the
- *    common case is one pending IRQ so optimize in that direction.
- *
- * 2) We need not check against bits in the status register IRQ mask, that
- *    would make this routine slow as hell.
- *
- * 3) Linux only thinks in terms of all IRQs on or all IRQs off, nothing in
- *    between like BSD spl() brain-damage.
- *
- * Furthermore, the IRQs on the INDY look basically (barring software IRQs
- * which we don't use at all) like:
- *
- *	MIPS IRQ	Source
- *      --------        ------
- *             0	Software (ignored)
- *             1        Software (ignored)
- *             2        Local IRQ level zero
- *             3        Local IRQ level one
- *             4        8254 Timer zero
- *             5        8254 Timer one
- *             6        Bus Error
- *             7        R4k timer (what we use)
- *
- * We handle the IRQ according to _our_ priority which is:
- *
- * Highest ----     R4k Timer
- *                  Local IRQ zero
- *                  Local IRQ one
- *                  Bus Error
- *                  8254 Timer zero
- * Lowest  ----     8254 Timer one
- *
- * then we just return, if multiple IRQs are pending then we will just take
- * another exception, big deal.
- */
-
-	.text
-	.set	noreorder
-	.set	noat
-	.align	5
-	NESTED(ddbIRQ, PT_SIZE, sp)
-	SAVE_ALL
-	CLI
-	.set	at
-	mfc0	s0, CP0_CAUSE		# get irq mask
-
-#if 1
-	mfc0	t2,CP0_STATUS		# get enabled interrupts
-	and	s0,t2			# isolate allowed ones
-#endif
-	/* First we check for r4k counter/timer IRQ. */
-	andi	a0, s0, CAUSEF_IP2	# delay slot, check local level zero
-	beq	a0, zero, 1f
-	 andi	a0, s0, CAUSEF_IP3	# delay slot, check local level one
-
-	/* Wheee, local level zero interrupt. */
-	jal	ddb_local0_irqdispatch
-	 move	a0, sp			# delay slot
-
-	j	ret_from_irq
-	 nop				# delay slot
-
-1:
-	beq	a0, zero, 1f
-	 andi	a0, s0, CAUSEF_IP6	# delay slot, check bus error
-
-	/* Wheee, local level one interrupt. */
-	move	a0, sp
-	jal	ddb_local1_irqdispatch
-	 nop
-
-	j	ret_from_irq
-	 nop
-
-1:
-	beq	a0, zero, 1f
-	 nop
-
-	/* Wheee, an asynchronous bus error... */
-	move	a0, sp
-	jal	ddb_buserror_irq
-	 nop
-
-	j	ret_from_irq
-	 nop
-
-1:
-	/* Here by mistake?  This is possible, what can happen
-	 * is that by the time we take the exception the IRQ
-	 * pin goes low, so just leave if this is the case.
-	 */
-	andi	a0, s0, (CAUSEF_IP4 | CAUSEF_IP5)
-	beq	a0, zero, 1f
-
-	/* Must be one of the 8254 timers... */
-	move	a0, sp
-	jal	ddb_8254timer_irq
-	 nop
-1:
-	j	ret_from_irq
-	 nop
-	END(ddbIRQ)
diff --git a/arch/mips/ddb5xxx/ddb5074/irq.c b/arch/mips/ddb5xxx/ddb5074/irq.c
index 45088a1be414..60c087b7738c 100644
--- a/arch/mips/ddb5xxx/ddb5074/irq.c
+++ b/arch/mips/ddb5xxx/ddb5074/irq.c
@@ -21,8 +21,6 @@
 #include <asm/ddb5xxx/ddb5074.h>
 
 
-extern asmlinkage void ddbIRQ(void);
-
 static struct irqaction irq_cascade = { no_action, 0, CPU_MASK_NONE, "cascade", NULL, NULL };
 
 #define M1543_PNP_CONFIG	0x03f0	/* PnP Config Port */
@@ -90,7 +88,7 @@ static void m1543_irq_setup(void)
 
 }
 
-void ddb_local0_irqdispatch(struct pt_regs *regs)
+static void ddb_local0_irqdispatch(struct pt_regs *regs)
 {
 	u32 mask;
 	int nile4_irq;
@@ -118,29 +116,41 @@ void ddb_local0_irqdispatch(struct pt_regs *regs)
 		}
 }
 
-void ddb_local1_irqdispatch(void)
+static void ddb_local1_irqdispatch(void)
 {
 	printk("ddb_local1_irqdispatch called\n");
 }
 
-void ddb_buserror_irq(void)
+static void ddb_buserror_irq(void)
 {
 	printk("ddb_buserror_irq called\n");
 }
 
-void ddb_8254timer_irq(void)
+static void ddb_8254timer_irq(void)
 {
 	printk("ddb_8254timer_irq called\n");
 }
 
+asmlinkage void plat_irq_dispatch(struct pt_regs *regs)
+{
+	unsigned int pending = read_c0_cause() & read_c0_status();
+
+	if (pending & CAUSEF_IP2)
+		ddb_local0_irqdispatch(regs);
+	else if (pending & CAUSEF_IP3)
+		ddb_local1_irqdispatch();
+	else if (pending & CAUSEF_IP6)
+		ddb_buserror_irq();
+	else if (pending & (CAUSEF_IP4 | CAUSEF_IP5))
+		ddb_8254timer_irq();
+}
+
 void __init arch_init_irq(void)
 {
 	/* setup cascade interrupts */
 	setup_irq(NILE4_IRQ_BASE  + NILE4_INT_INTE, &irq_cascade);
 	setup_irq(CPU_IRQ_BASE + CPU_NILE4_CASCADE, &irq_cascade);
 
-	set_except_vector(0, ddbIRQ);
-
 	nile4_irq_setup(NILE4_IRQ_BASE);
 	m1543_irq_setup();
 	init_i8259_irqs();