mirror of
https://github.com/openwrt/openwrt.git
synced 2024-12-27 09:12:39 +00:00
136 lines
3.4 KiB
ArmAsm
136 lines
3.4 KiB
ArmAsm
/*
|
|
* Carsten Langgaard, carstenl@mips.com
|
|
* Copyright (C) 1999, 2000 MIPS Technologies, Inc. All rights reserved.
|
|
*
|
|
* ########################################################################
|
|
*
|
|
* This program is free software; you can distribute it and/or modify it
|
|
* under the terms of the GNU General Public License (Version 2) as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope it will be useful, but WITHOUT
|
|
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
|
* for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with this program; if not, write to the Free Software Foundation, Inc.,
|
|
* 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
|
|
*
|
|
* ########################################################################
|
|
*
|
|
* Interrupt exception dispatch code.
|
|
*
|
|
*/
|
|
#include <linux/autoconf.h>
|
|
|
|
#include <asm/asm.h>
|
|
#include <asm/mipsregs.h>
|
|
#include <asm/regdef.h>
|
|
#include <asm/stackframe.h>
|
|
|
|
#define STATUS_IE 0x00000001
|
|
|
|
/* 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 MIPS board look basically (barring software
|
|
* IRQs which we don't use at all and all external interrupt sources are
|
|
* combined together on hardware interrupt 0 (MIPS IRQ 2)) like:
|
|
*
|
|
* MIPS IRQ Source
|
|
* -------- ------
|
|
* 0 Software (ignored)
|
|
* 1 Software (ignored)
|
|
* 2 Combined hardware interrupt (hw0)
|
|
* 3 Hardware (ignored)
|
|
* 4 Hardware (ignored)
|
|
* 5 Hardware (ignored)
|
|
* 6 Hardware (ignored)
|
|
* 7 R4k timer (what we use)
|
|
*
|
|
* Note: On the SEAD board thing are a little bit different.
|
|
* Here IRQ 2 (hw0) is wired to the UART0 and IRQ 3 (hw1) is wired
|
|
* wired to UART1.
|
|
*
|
|
* We handle the IRQ according to _our_ priority which is:
|
|
*
|
|
* Highest ---- R4k Timer
|
|
* Lowest ---- Combined hardware interrupt
|
|
*
|
|
* 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(mipsIRQ, PT_SIZE, sp)
|
|
SAVE_ALL
|
|
CLI
|
|
.set at
|
|
|
|
mfc0 s0, CP0_CAUSE
|
|
mfc0 s1, CP0_STATUS
|
|
and s0, s0, s1
|
|
|
|
/* First we check for r4k counter/timer IRQ. */
|
|
andi a0, s0, CAUSEF_IP7
|
|
beq a0, zero, 1f
|
|
nop
|
|
|
|
move a0, sp
|
|
jal mips_timer_interrupt
|
|
nop
|
|
|
|
j ret_from_irq
|
|
nop
|
|
|
|
1:
|
|
andi a0, s0, CAUSEF_IP2
|
|
beq a0, zero, 1f
|
|
nop
|
|
|
|
move a0, sp
|
|
jal adm5120_hw0_irqdispatch
|
|
nop
|
|
1:
|
|
j ret_from_irq
|
|
nop
|
|
|
|
END(mipsIRQ)
|
|
|
|
|
|
LEAF(mips_int_lock)
|
|
.set noreorder
|
|
mfc0 v0, CP0_STATUS
|
|
li v1, ~STATUS_IE
|
|
and v1, v1, v0
|
|
mtc0 v1, CP0_STATUS
|
|
j ra
|
|
and v0, v0, STATUS_IE
|
|
.set reorder
|
|
END(mips_int_lock)
|
|
|
|
|
|
LEAF(mips_int_unlock)
|
|
mfc0 v0, CP0_STATUS
|
|
and a0, a0, STATUS_IE
|
|
or v0, v0, a0
|
|
mtc0 v0, CP0_STATUS
|
|
j ra
|
|
nop
|
|
END(mips_int_unlock)
|
|
|