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/*
* 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.
*
* $Id: int-handler.S,v 1.3 1997/09/20 19:20:07 root Exp $
*/
#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
nop
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")
loc_ethernet: PANIC("Unimplemented loc_ethernet")
/*
* Keyboard interrupt, remapped to level 1
*/
loc_keyboard: PANIC("Unimplemented loc_keyboard")
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: /*
* Temporarily disable interrupt source
*/
/* lhu t2,JAZZ_IO_IRQ_ENABLE
*/
and t2,s1
/* sh t2,JAZZ_IO_IRQ_ENABLE */
jal do_IRQ # call IRQ handler
nor s1,zero,s1
/*
* Reenable interrupt
*/
/* lhu t2,JAZZ_IO_IRQ_ENABLE */
or t2,s1
/* sh t2,JAZZ_IO_IRQ_ENABLE */
j ret_from_irq
nop # delay slot
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!");
/*
* 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: /*
* temporarily disable interrupt
*/
mfc0 t2,CP0_STATUS
and t2,s1
mtc0 t2,CP0_STATUS
jal do_IRQ
nor s1,zero,s1
/*
* reenable interrupt
*/
mfc0 t2,CP0_STATUS
or t2,s1
mtc0 t2,CP0_STATUS
j ret_from_irq
nop # 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
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