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/* $Id: int-handler.S,v 1.14 1999/05/01 22:40:34 ralf Exp $
*
* 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 i8259_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 return
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: j spurious_interrupt
/*
* 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
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