diff options
Diffstat (limited to 'arch/mips/sibyte/sb1250/irq_handler.S')
| -rw-r--r-- | arch/mips/sibyte/sb1250/irq_handler.S | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/arch/mips/sibyte/sb1250/irq_handler.S b/arch/mips/sibyte/sb1250/irq_handler.S new file mode 100644 index 00000000000..60edc8fb302 --- /dev/null +++ b/arch/mips/sibyte/sb1250/irq_handler.S @@ -0,0 +1,147 @@ +/* + * Copyright (C) 2000, 2001, 2002, 2003 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. + */ + +/* + * sb1250_handle_int() is the routine that is actually called when an interrupt + * occurs. It is installed as the exception vector handler in arch_init_irq() + * in arch/mips/sibyte/sb1250/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/sb1250_regs.h> +#include <asm/sibyte/sb1250_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 + .align 5 + NESTED(sb1250_irq_handler, PT_SIZE, sp) + SAVE_ALL + CLI + +#ifdef CONFIG_SIBYTE_SB1250_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_SB1250_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 */ + mfc0 a0, CP0_EPC + jal sbprof_cpu_intr + addu a0, a0, t1 /* a0 = EPC + (BD ? 4 : 0) */ + j ret_from_irq + nop +0: +#endif + + /* Timer interrupt is routed to IP[4] */ + andi t1, s0, CAUSEF_IP4 + beqz t1, 1f + nop + jal sb1250_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 sb1250_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, 1f + nop # delay slot + jal sb1250_kgdb_interrupt + move a0, sp + j ret_from_irq + nop # delay slot +1: +#endif + + and t1, s0, CAUSEF_IP2 + beqz t1, 4f + nop + + /* + * Default...we've hit an IP[2] interrupt, which means we've got to + * check the 1250 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_IMR_CPU0_BASE +#ifdef CONFIG_SMP + lw t1, TI_CPU($28) + sll t1, IMR_REGISTER_SPACING_SHIFT + addu v0, t1 +#endif + ld s0, R_IMR_INTERRUPT_STATUS_BASE(v0) /* read IP[2] status */ + + beqz s0, 4f /* No interrupts. Return */ + move a1, sp + +3: dclz s1, s0 /* Find the next interrupt */ + dsubu a0, zero, s1 + daddiu a0, a0, 63 + jal do_IRQ + nop + +4: j ret_from_irq + nop + + .set pop + END(sb1250_irq_handler) |