[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, 75 insertions, 288 deletions

diff --git a/arch/mips/jazz/Makefile b/arch/mips/jazz/Makefile
index 85749246a671..02bd39add891 100644
--- a/arch/mips/jazz/Makefile
+++ b/arch/mips/jazz/Makefile
@@ -2,6 +2,6 @@
 # Makefile for the Jazz family specific parts of the kernel
 #
 
-obj-y	 	:= int-handler.o irq.o jazzdma.o reset.o setup.o
+obj-y	 	:= irq.o jazzdma.o reset.o setup.o
 
 EXTRA_AFLAGS := $(CFLAGS)
diff --git a/arch/mips/jazz/int-handler.S b/arch/mips/jazz/int-handler.S
deleted file mode 100644
index e35f5fcd3f90..000000000000
--- a/arch/mips/jazz/int-handler.S
+++ /dev/null
@@ -1,283 +0,0 @@
-/*
- * This file is subject to the terms and conditions of the GNU General Public
- * License.  See the file "COPYING" in the main directory of this archive
- * for more details.
- *
- * Copyright (C) 1995, 1996, 1997, 1998 by Ralf Baechle and Andreas Busse
- *
- * Jazz family specific interrupt stuff
- *
- * To do: On Jazz machines we remap some non-ISA interrupts to ISA
- *        interrupts.  These interrupts should use their own vectors.
- *        Squeeze the last cycles out of the handlers.  Only a dead
- *        cycle is a good cycle.
- */
-#include <asm/asm.h>
-#include <asm/mipsregs.h>
-#include <asm/jazz.h>
-#include <asm/regdef.h>
-#include <asm/stackframe.h>
-
-/*
- * jazz_handle_int: Interrupt handler for the ACER Pica-61 boards
- */
-		.set	noreorder
-
-		NESTED(jazz_handle_int, PT_SIZE, ra)
-		.set	noat
-		SAVE_ALL
-		CLI
-		.set	at
-
-		/*
-		 * Get pending interrupts
-		 */
-		mfc0	t0,CP0_CAUSE		# get pending interrupts
-		mfc0	t1,CP0_STATUS		# get enabled interrupts
-		and	t0,t1			# isolate allowed ones
-		andi	t0,0xff00		# isolate pending bits
-		beqz	t0,3f
-		sll	t0,16			# delay slot
-
-		/*
-		 * Find irq with highest priority
-		 * FIXME: This is slow - use binary search
-		 */
-		la	t1,ll_vectors
-1:		bltz	t0,2f			# found pending irq
-		sll	t0,1
-		b	1b
-		subu	t1,PTRSIZE		# delay slot
-
-		/*
-		 * Do the low-level stuff
-		 */
-2:		lw	t0,(t1)
-		jr	t0
-		nop				# delay slot
-		END(jazz_handle_int)
-
-ll_sw0:		li	s1,~IE_SW0
-		mfc0	t0,CP0_CAUSE
-		and	t0,s1
-		mtc0	t0,CP0_CAUSE
-		PANIC("Unimplemented sw0 handler")
-
-ll_sw1:		li	s1,~IE_SW1
-		mfc0	t0,CP0_CAUSE
-		and	t0,s1
-		mtc0	t0,CP0_CAUSE
-		PANIC("Unimplemented sw1 handler")
-
-ll_local_dma:	li	s1,~IE_IRQ0
-		PANIC("Unimplemented local_dma handler")
-
-ll_local_dev:	lbu	t0,JAZZ_IO_IRQ_SOURCE
-#if PTRSIZE == 8	/* True 64 bit kernel */
-		dsll	t0,1
-#endif
-		.set	reorder
-		LONG_L	t0,local_vector(t0)
-		jr	t0
-		.set	noreorder
-
-/*
- * The braindead PICA hardware gives us no way to distinguish if we really
- * received interrupt 7 from the (E)ISA bus or if we just received an
- * interrupt with no findable cause.  This sometimes happens with braindead
- * cards.  Oh well - for all the Jazz boxes slots are more or less just
- * whistles and bells and we're aware of the problem.
- */
-ll_isa_irq:	lw	a0, JAZZ_EISA_IRQ_ACK
-
-		jal	do_IRQ
-		 move	a1,sp
-
-		j	ret_from_irq
-		nop
-
-/*
- * Hmm...  This is not just a plain PC clone so the question is
- * which devices on Jazz machines can generate an (E)ISA NMI?
- * (Writing to nonexistent memory?)
- */
-ll_isa_nmi:	li	s1,~IE_IRQ3
-		PANIC("Unimplemented isa_nmi handler")
-
-/*
- * Timer IRQ - remapped to be more similar to an IBM compatible.
- *
- * The timer interrupt is handled specially to ensure that the jiffies
- * variable is updated at all times.  Specifically, the timer interrupt is
- * just like the complete handlers except that it is invoked with interrupts
- * disabled and should never re-enable them.  If other interrupts were
- * allowed to be processed while the timer interrupt is active, then the
- * other interrupts would have to avoid using the jiffies variable for delay
- * and interval timing operations to avoid hanging the system.
- */
-ll_timer:	lw	zero,JAZZ_TIMER_REGISTER # timer irq cleared on read
-		li	s1,~IE_IRQ4
-
-		li	a0, JAZZ_TIMER_IRQ
-		jal	do_IRQ
-		 move	a1,sp
-
-		mfc0	t0,CP0_STATUS		# disable interrupts again
-		ori	t0,1
-		xori	t0,1
-		mtc0	t0,CP0_STATUS
-
-		j	ret_from_irq
-		 nop
-
-/*
- * CPU count/compare IRQ (unused)
- */
-ll_count:	j	ret_from_irq
-		 mtc0	zero,CP0_COMPARE
-
-#if 0
-/*
- * Call the handler for the interrupt
- * (Currently unused)
- */
-call_real:	/*
-		 * temporarily disable interrupt
-		 */
-		mfc0	t2,CP0_STATUS
-		and	t2,s1
-		mtc0	t2,CP0_STATUS
-		nor	s1,zero,s1
-		jal	do_IRQ
-
-		/*
-		 * reenable interrupt
-		 */
-		mfc0	t2,CP0_STATUS
-		or	t2,s1
-		mtc0	t2,CP0_STATUS
-		j	ret_from_irq
-#endif
-
-		.data
-		PTR	ll_sw0			# SW0
-		PTR	ll_sw1			# SW1
-		PTR	ll_local_dma		# Local DMA
-		PTR	ll_local_dev		# Local devices
-		PTR	ll_isa_irq		# ISA IRQ
-		PTR	ll_isa_nmi		# ISA NMI
-		PTR	ll_timer		# Timer
-ll_vectors:	PTR	ll_count		# Count/Compare IRQ
-
-		/*
-		 * Interrupt handlers for local devices.
-		 */
-		.text
-		.set	reorder
-loc_no_irq:	PANIC("Unimplemented loc_no_irq handler")
-/*
- * Parallel port IRQ
- */
-loc_parallel:	li	s1,~JAZZ_IE_PARALLEL
-		li	a0,JAZZ_PARALLEL_IRQ
-		b	loc_call
-
-/*
- * Floppy IRQ
- */
-loc_floppy:	li	s1,~JAZZ_IE_FLOPPY
-		li	a0,JAZZ_FLOPPY_IRQ
-		b	loc_call
-
-/*
- * Sound IRQ
- */
-loc_sound:	PANIC("Unimplemented loc_sound handler")
-loc_video:	PANIC("Unimplemented loc_video handler")
-
-/*
- * Ethernet interrupt handler
- */
-loc_ethernet: 	li	s1,~JAZZ_IE_ETHERNET
-		li	a0,JAZZ_ETHERNET_IRQ
-		b	loc_call
-
-/*
- * SCSI interrupt handler
- */
-loc_scsi:	li	s1,~JAZZ_IE_SCSI
-		li	a0,JAZZ_SCSI_IRQ
-		b	loc_call
-
-/*
- * Keyboard interrupt handler
- */
-loc_keyboard:	li	s1,~JAZZ_IE_KEYBOARD
-		li	a0,JAZZ_KEYBOARD_IRQ
-		b	loc_call
-
-/*
- * Mouse interrupt handler
- */
-loc_mouse:	li	s1,~JAZZ_IE_MOUSE
-		li	a0,JAZZ_MOUSE_IRQ
-		b	loc_call
-
-/*
- * Serial port 1 IRQ
- */
-loc_serial1:	li	s1,~JAZZ_IE_SERIAL1
-		li	a0,JAZZ_SERIAL1_IRQ
-		b	loc_call
-
-/*
- * Serial port 2 IRQ
- */
-loc_serial2:	li	s1,~JAZZ_IE_SERIAL2
-		li	a0,JAZZ_SERIAL2_IRQ
-		b	loc_call
-
-/*
- * Call the interrupt handler for an interrupt generated by a
- * local device.
- */
-loc_call:	/*
-		 * Temporarily disable interrupt source
-		 */
-		lhu	t2,JAZZ_IO_IRQ_ENABLE
-		and	t2,s1
-		sh	t2,JAZZ_IO_IRQ_ENABLE
-
-		nor	s1,zero,s1
-		jal	do_IRQ
-
-		/*
-		 * Reenable interrupt
-		 */
-		lhu	t2,JAZZ_IO_IRQ_ENABLE
-		or	t2,s1
-		sh	t2,JAZZ_IO_IRQ_ENABLE
-
-		j	ret_from_irq
-
-/*
- * "Jump extender" to reach spurious_interrupt
- */
-3:		jal	spurious_interrupt
-		j	ret_from_irq
-
-/*
- * Vectors for interrupts generated by local devices
- */
-		.data
-local_vector:	PTR	loc_no_irq
-		PTR	loc_parallel
-		PTR	loc_floppy
-		PTR	loc_sound
-		PTR	loc_video
-		PTR	loc_ethernet
-		PTR	loc_scsi
-		PTR	loc_keyboard
-		PTR	loc_mouse
-		PTR	loc_serial1
-		PTR	loc_serial2
diff --git a/arch/mips/jazz/irq.c b/arch/mips/jazz/irq.c
index b309b1bcf2e8..becc9accd495 100644
--- a/arch/mips/jazz/irq.c
+++ b/arch/mips/jazz/irq.c
@@ -15,8 +15,6 @@
 #include <asm/io.h>
 #include <asm/jazz.h>
 
-extern asmlinkage void jazz_handle_int(void);
-
 static DEFINE_SPINLOCK(r4030_lock);
 
 static void enable_r4030_irq(unsigned int irq)
@@ -90,10 +88,82 @@ void __init init_r4030_ints(void)
  */
 void __init arch_init_irq(void)
 {
-	set_except_vector(0, jazz_handle_int);
-
 	init_i8259_irqs();			/* Integrated i8259  */
 	init_r4030_ints();
 
 	change_c0_status(ST0_IM, IE_IRQ4 | IE_IRQ3 | IE_IRQ2 | IE_IRQ1);
 }
+
+static void loc_call(unsigned int irq, struct pt_regs *regs, unsigned int mask)
+{
+	r4030_write_reg16(JAZZ_IO_IRQ_ENABLE,
+	                  r4030_read_reg16(JAZZ_IO_IRQ_ENABLE) & mask);
+	do_IRQ(irq, regs);
+	r4030_write_reg16(JAZZ_IO_IRQ_ENABLE,
+	                  r4030_read_reg16(JAZZ_IO_IRQ_ENABLE) | mask);
+}
+
+static void ll_local_dev(struct pt_regs *regs)
+{
+	switch (r4030_read_reg32(JAZZ_IO_IRQ_SOURCE)) {
+	case 0:
+		panic("Unimplemented loc_no_irq handler");
+		break;
+	case 4:
+		loc_call(JAZZ_PARALLEL_IRQ, regs, JAZZ_IE_PARALLEL);
+		break;
+	case 8:
+		loc_call(JAZZ_PARALLEL_IRQ, regs, JAZZ_IE_FLOPPY);
+		break;
+	case 12:
+		panic("Unimplemented loc_sound handler");
+		break;
+	case 16:
+		panic("Unimplemented loc_video handler");
+		break;
+	case 20:
+		loc_call(JAZZ_ETHERNET_IRQ, regs, JAZZ_IE_ETHERNET);
+		break;
+	case 24:
+		loc_call(JAZZ_SCSI_IRQ, regs, JAZZ_IE_SCSI);
+		break;
+	case 28:
+		loc_call(JAZZ_KEYBOARD_IRQ, regs, JAZZ_IE_KEYBOARD);
+		break;
+	case 32:
+		loc_call(JAZZ_MOUSE_IRQ, regs, JAZZ_IE_MOUSE);
+		break;
+	case 36:
+		loc_call(JAZZ_SERIAL1_IRQ, regs, JAZZ_IE_SERIAL1);
+		break;
+	case 40:
+		loc_call(JAZZ_SERIAL2_IRQ, regs, JAZZ_IE_SERIAL2);
+		break;
+	}
+}
+
+asmlinkage void plat_irq_dispatch(struct pt_regs *regs)
+{
+	unsigned int pending = read_c0_cause() & read_c0_status() & ST0_IM;
+
+	if (pending & IE_IRQ5)
+		write_c0_compare(0);
+	else if (pending & IE_IRQ4) {
+		r4030_read_reg32(JAZZ_TIMER_REGISTER);
+		do_IRQ(JAZZ_TIMER_IRQ, regs);
+	} else if (pending & IE_IRQ3)
+		panic("Unimplemented ISA NMI handler");
+	else if (pending & IE_IRQ2)
+		do_IRQ(r4030_read_reg32(JAZZ_EISA_IRQ_ACK), regs);
+	else if (pending & IE_IRQ1) {
+		ll_local_dev(regs);
+	} else if (unlikely(pending & IE_IRQ0))
+		panic("Unimplemented local_dma handler");
+	else if (pending & IE_SW1) {
+		clear_c0_cause(IE_SW1);
+		panic("Unimplemented sw1 handler");
+	} else if (pending & IE_SW0) {
+		clear_c0_cause(IE_SW0);
+		panic("Unimplemented sw0 handler");
+	}
+}