linux-stable-rt/arch/mips/sibyte/bcm1480/irq_handler.S

166 lines
4.5 KiB
ArmAsm

/*
* Copyright (C) 2000,2001,2002,2003,2004 Broadcom Corporation
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that 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.
*/
/*
* bcm1480_irq_handler() is the routine that is actually called when an
* interrupt occurs. It is installed as the exception vector handler in
* init_IRQ() in arch/mips/sibyte/bcm1480/irq.c
*
* In the handle we figure out which interrupts need handling, and use that
* to call the dispatcher, which will take care of actually calling
* registered handlers
*
* Note that we take care of all raised interrupts in one go at the handler.
* This is more BSDish than the Indy code, and also, IMHO, more sane.
*/
#include <linux/config.h>
#include <asm/addrspace.h>
#include <asm/asm.h>
#include <asm/mipsregs.h>
#include <asm/regdef.h>
#include <asm/stackframe.h>
#include <asm/sibyte/sb1250_defs.h>
#include <asm/sibyte/bcm1480_regs.h>
#include <asm/sibyte/bcm1480_int.h>
/*
* What a pain. We have to be really careful saving the upper 32 bits of any
* register across function calls if we don't want them trashed--since were
* running in -o32, the calling routing never saves the full 64 bits of a
* register across a function call. Being the interrupt handler, we're
* guaranteed that interrupts are disabled during this code so we don't have
* to worry about random interrupts blasting the high 32 bits.
*/
.text
.set push
.set noreorder
.set noat
.set mips64
#.set mips4
.align 5
NESTED(bcm1480_irq_handler, PT_SIZE, sp)
SAVE_ALL
CLI
#ifdef CONFIG_SIBYTE_BCM1480_PROF
/* Set compare to count to silence count/compare timer interrupts */
mfc0 t1, CP0_COUNT
mtc0 t1, CP0_COMPARE /* pause to clear IP[7] bit of cause ? */
#endif
/* Read cause */
mfc0 s0, CP0_CAUSE
#ifdef CONFIG_SIBYTE_BCM1480_PROF
/* Cpu performance counter interrupt is routed to IP[7] */
andi t1, s0, CAUSEF_IP7
beqz t1, 0f
srl t1, s0, (CAUSEB_BD-2) /* Shift BD bit to bit 2 */
and t1, t1, 0x4 /* mask to get just BD bit */
#ifdef CONFIG_MIPS64
dmfc0 a0, CP0_EPC
daddu a0, a0, t1 /* a0 = EPC + (BD ? 4 : 0) */
#else
mfc0 a0, CP0_EPC
addu a0, a0, t1 /* a0 = EPC + (BD ? 4 : 0) */
#endif
jal sbprof_cpu_intr
nop
j ret_from_irq
nop
0:
#endif
/* Timer interrupt is routed to IP[4] */
andi t1, s0, CAUSEF_IP4
beqz t1, 1f
nop
jal bcm1480_timer_interrupt
move a0, sp /* Pass the registers along */
j ret_from_irq
nop /* delay slot */
1:
#ifdef CONFIG_SMP
/* Mailbox interrupt is routed to IP[3] */
andi t1, s0, CAUSEF_IP3
beqz t1, 2f
nop
jal bcm1480_mailbox_interrupt
move a0, sp
j ret_from_irq
nop /* delay slot */
2:
#endif
#ifdef CONFIG_KGDB
/* KGDB (uart 1) interrupt is routed to IP[6] */
andi t1, s0, CAUSEF_IP6
beqz t1, 3f
nop /* delay slot */
jal bcm1480_kgdb_interrupt
move a0, sp
j ret_from_irq
nop /* delay slot */
3:
#endif
and t1, s0, CAUSEF_IP2
beqz t1, 9f
nop
/*
* Default...we've hit an IP[2] interrupt, which means we've got
* to check the 1480 interrupt registers to figure out what to do
* Need to detect which CPU we're on, now that smp_affinity is
* supported.
*/
PTR_LA v0, CKSEG1 + A_BCM1480_IMR_CPU0_BASE
#ifdef CONFIG_SMP
lw t1, TI_CPU($28)
sll t1, t1, BCM1480_IMR_REGISTER_SPACING_SHIFT
addu v0, v0, t1
#endif
/* Read IP[2] status (get both high and low halves of status) */
ld s0, R_BCM1480_IMR_INTERRUPT_STATUS_BASE_H(v0)
ld s1, R_BCM1480_IMR_INTERRUPT_STATUS_BASE_L(v0)
move s2, zero /* intr number */
li s3, 64
beqz s0, 9f /* No interrupts. Return. */
move a1, sp
xori s4, s0, 1 /* if s0 (_H) == 1, it's a low intr, so... */
movz s2, s3, s4 /* start the intr number at 64, and */
movz s0, s1, s4 /* look at the low status value. */
dclz s1, s0 /* Find the next interrupt. */
dsubu a0, zero, s1
daddiu a0, a0, 63
jal do_IRQ
daddu a0, a0, s2
9: j ret_from_irq
nop
.set pop
END(bcm1480_irq_handler)