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Diffstat (limited to 'arch/mips/mips-boards/malta/malta-irq.S')
| -rw-r--r-- | arch/mips/mips-boards/malta/malta-irq.S | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/arch/mips/mips-boards/malta/malta-irq.S b/arch/mips/mips-boards/malta/malta-irq.S new file mode 100644 index 000000000000..6217aff3be03 --- /dev/null +++ b/arch/mips/mips-boards/malta/malta-irq.S @@ -0,0 +1,122 @@ +/* + * 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/config.h> + +#include <asm/asm.h> +#include <asm/mipsregs.h> +#include <asm/regdef.h> +#include <asm/stackframe.h> +#include <asm/mips-boards/maltaint.h> + +/* + * IRQs on the Malta 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) + * + * 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 # get irq bits + mfc0 s1, CP0_STATUS # get irq mask + andi s0, ST0_IM # CAUSE.CE may be non-zero! + and s0, s1 + +#if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64) + .set mips32 + clz a0, s0 + .set mips0 + negu a0 + addu a0, 31-CAUSEB_IP + bltz a0, spurious +#else + beqz s0, spurious + li a0, 7 + + and t0, s0, 0xf000 + sltiu t0, t0, 1 + sll t0, 2 + subu a0, t0 + sll s0, t0 + + and t0, s0, 0xc000 + sltiu t0, t0, 1 + sll t0, 1 + subu a0, t0 + sll s0, t0 + + and t0, s0, 0x8000 + sltiu t0, t0, 1 + # sll t0, 0 + subu a0, t0 + # sll s0, t0 +#endif + + li a1, MIPSCPU_INT_I8259A + bne a0, a1, 1f + addu a0, MIPSCPU_INT_BASE + + jal malta_hw0_irqdispatch + move a0, sp + + j ret_from_irq + nop +1: + + jal do_IRQ + move a1, sp + + j ret_from_irq + nop + +spurious: + j spurious_interrupt + nop + END(mipsIRQ) |