Import of Linux/MIPS 2.1.14

1 files changed, 273 insertions, 0 deletions

diff --git a/arch/mips/dec/int-handler.S b/arch/mips/dec/int-handler.S
new file mode 100644
index 000000000..6692d657b
--- /dev/null
+++ b/arch/mips/dec/int-handler.S
@@ -0,0 +1,273 @@
+/*
+ * arch/mips/dec/int-handler.S
+ *
+ * Copyright (C) 1995, 1996 Paul M. Antoine
+ *
+ * Written by Ralf Baechle and Andreas Busse, modified for DECStation
+ * support by Paul Antoine.
+ *
+ * NOTE: There are references to R4X00 code in here, because there is an
+ *	 upgrade module for Personal DECStations with such a CPU!
+ *
+ * FIXME: still plenty to do in this file, as much of the code hasn't been
+ *	  modified to suit the DECStation's interrupts.
+ */
+#include <asm/asm.h>
+#include <asm/regdef.h>
+#include <asm/fpregdef.h>
+#include <asm/mipsconfig.h>
+#include <asm/mipsregs.h>
+#include <asm/stackframe.h>
+#include <asm/bootinfo.h>
+
+		.text
+		.set	noreorder
+/*
+ * decstation_handle_int: Interrupt handler for Personal DECStation 5000/2x
+ *
+ * FIXME: this is *extremely* experimental, though it is probably o.k. for
+ *	  most DECStation models.
+ */
+		NESTED(decstation_handle_int, FR_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
+/*
+ * FIXME: The following branch was:
+ *					beqz	t0,spurious_interrupt
+ *
+ *	  ...but the wonders of ecoff cause the gas assembler (ver 2.5.1 )
+ *	  to complain:
+ *
+ *		  "Can not represent relocation in this object file format"...
+ *
+ *	  hence this hack to branch foward a bit, and then jump <sigh>
+ *	  Perhaps a later version of gas will cope? - Paul
+ */
+		beqz	t0,3f;
+		sll	t0,16			# delay slot
+
+		/*
+		 * Find irq with highest priority
+		 * FIXME: This is slow
+		 */
+		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(decstation_handle_int)
+
+/*
+ * FIXME: The hack mentioned above.
+ */
+3:		j	spurious_interrupt
+		nop
+
+/*
+ * FIXME: the rest of this is pretty suspect, as it's straight from
+ * 	  jazz.S... and I really haven't altered it at all - Paul
+ */
+
+/*
+ * Used for keyboard driver's fake_keyboard_interrupt()
+ * (Paul, even for i386 this is no longer being used -- Ralf)
+ */
+ll_sw0:		li	s1,~IE_SW0
+		mfc0	t0,CP0_CAUSE
+		and	t0,s1
+		mtc0	t0,CP0_CAUSE
+	PRINT("sw0 received...\n")
+		li	t1,1
+		b	call_real
+		li	t3,PTRSIZE	# delay slot, re-map to irq level 1
+
+ll_sw1:		li	s1,~IE_SW1
+		PANIC("Unimplemented sw1 handler")
+
+loc_no_irq:	PANIC("Unimplemented loc_no_irq handler")
+loc_sound:	PANIC("Unimplemented loc_sound handler")
+loc_video:	PANIC("Unimplemented loc_video handler")
+loc_scsi:	PANIC("Unimplemented loc_scsi handler")
+
+/*
+ * Ethernet interrupt, remapped to level 15
+ * NOTE: Due to a bug somewhere in the kernel I was not able
+ * to figure out, the PRINT() is necessary. Without this,
+ * I get a "gfp called nonatomically from interrupt 00000000".
+ * Only god knows why... Tell me if you find the reason!
+ * Andy, 6/16/95
+ */
+loc_ethernet:	PANIC("Unimplemented loc_ethernet\n")
+
+/*
+ * Keyboard interrupt, remapped to level 1
+ */
+loc_keyboard:	PANIC("Unimplemented loc_keyboard\n")
+
+loc_mouse:	PANIC("Unimplemented loc_mouse handler")
+
+/*
+ * Serial port 1 IRQ, remapped to level 3
+ */
+loc_serial1:	PANIC("Unimplemented loc_serial handler")
+
+/*
+ * Serial port 2 IRQ, remapped to level 4
+ */
+loc_serial2:	PANIC("Unimplemented loc_serial handler")
+
+/*
+ * Parallel port IRQ, remapped to level 5
+ */
+loc_parallel:	PANIC("Unimplemented loc_parallel handler")
+
+/*
+ * Floppy IRQ, remapped to level 6
+ */
+loc_floppy:	PANIC("Unimplemented loc_floppy handler")
+  
+/*
+ * Now call the real handler
+ */
+loc_call:	lui	s3,%hi(intr_count)
+		lw	t2,%lo(intr_count)(s3)
+		la	t0,IRQ_vectors			# delay slot
+		addiu	t2,1
+		sw	t2,%lo(intr_count)(s3)
+
+		/*
+		 * Temporarily disable interrupt source
+		 */
+/*		lhu	t2,JAZZ_IO_IRQ_ENABLE
+*/
+		addu	t0,t3			# make ptr to IRQ handler
+		lw	t0,(t0)
+		and	t2,s1			# delay slot
+/*		sh	t2,JAZZ_IO_IRQ_ENABLE */
+		jalr	t0			# call IRQ handler
+		nor	s1,zero,s1		# delay slot
+
+		/*
+		 * Reenable interrupt
+		 */
+/*		lhu	t2,JAZZ_IO_IRQ_ENABLE */
+		lw	t1,%lo(intr_count)(s3) # delay slot
+		or	t2,s1
+/*		sh	t2,JAZZ_IO_IRQ_ENABLE */
+
+		subu	t1,1
+		jr	v0
+		sw	t1,%lo(intr_count)(s3)
+
+ll_tc3:		PANIC("Unimplemented tc3 interrupt handler")
+
+ll_fpu:		PANIC("Unimplemented fpu interrupt handler")
+
+ll_io_error:	PANIC("Unimplemented I/O write timeout interrupt handler")
+
+ll_rtc:		PANIC("Unimplemented RTC interrupt handler")
+
+/*
+ * Timer IRQ
+ * We remap the timer irq to be more similar to a IBM compatible
+ */
+ll_timer:	PANIC("Timer interrupt!\n");
+/*
+ * CPU count/compare IRQ (unused)
+ */
+ll_reset:	li	a0,0
+		jal	pmax_halt
+		li	a1,0			# delay slot
+
+/*
+ * Now call the real handler
+ */
+call_real:	lui	s3,%hi(intr_count)
+		lw	t2,%lo(intr_count)(s3)
+		la	t0,IRQ_vectors			# delay slot
+		addiu	t2,1
+		sw	t2,%lo(intr_count)(s3)
+
+		/*
+		 * temporarily disable interrupt
+		 */
+		mfc0	t2,CP0_STATUS
+		and	t2,s1
+
+		addu	t0,t3
+		lw	t0,(t0)
+		mtc0	t2,CP0_STATUS		# delay slot
+		jalr	t0
+		nor	s1,zero,s1		# delay slot
+
+		/*
+		 * reenable interrupt
+		 */
+		mfc0	t2,CP0_STATUS
+		or	t2,s1
+		mtc0	t2,CP0_STATUS
+
+		lw	t2,%lo(intr_count)(s3)
+		subu	t2,1
+
+		jr	v0
+		sw	t2,%lo(intr_count)(s3)	# delay slot
+
+/*
+ * Just for debugging... load a0 with address of the point inside the
+ * framebuffer at which you want to draw a line of 16x32 pixels.
+ * Maxine's framebuffer starts at 0xaa000000.
+ */
+		.set	reorder
+		LEAF(drawline)
+		li	t1,0xffffffff		# set all pixels on
+		li	t2,0x10			# we will write 16 words
+1:		sw	t1,(a0)			# write the first word
+		addiu	a0,a0,4			# move our framebuffer pointer
+		addiu	t2,t2,-1		# one less to do
+		bnez	t2,1b			# finished?
+		jr 	ra
+		END(drawline)
+
+/*
+ * FIXME: I have begun to alter this table to reflect Personal DECStation
+ *	  (i.e. Maxine) interrupts... Paul.
+ */
+		.data
+		PTR	ll_sw0			# SW0
+		PTR	ll_sw1			# SW1
+		PTR	ll_timer		# Periodic interrupt
+		PTR	ll_rtc			# RTC periodic interrupt
+		PTR	ll_io_error		# Timeout on I/O writes
+		PTR	ll_tc3			# TC slot 3, motherboard
+		PTR	ll_reset		# Halt keycode (CTRL+ALT+ENTER)
+ll_vectors:	PTR	ll_fpu			# FPU
+
+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