diff options
Diffstat (limited to 'arch/mips/kernel/irq_cpu.c')
| -rw-r--r-- | arch/mips/kernel/irq_cpu.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/arch/mips/kernel/irq_cpu.c b/arch/mips/kernel/irq_cpu.c new file mode 100644 index 00000000000..2b936cf1ef7 --- /dev/null +++ b/arch/mips/kernel/irq_cpu.c @@ -0,0 +1,118 @@ +/* + * Copyright 2001 MontaVista Software Inc. + * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net + * + * Copyright (C) 2001 Ralf Baechle + * + * This file define the irq handler for MIPS CPU interrupts. + * + * 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. + */ + +/* + * Almost all MIPS CPUs define 8 interrupt sources. They are typically + * level triggered (i.e., cannot be cleared from CPU; must be cleared from + * device). The first two are software interrupts which we don't really + * use or support. The last one is usually the CPU timer interrupt if + * counter register is present or, for CPUs with an external FPU, by + * convention it's the FPU exception interrupt. + * + * Don't even think about using this on SMP. You have been warned. + * + * This file exports one global function: + * void mips_cpu_irq_init(int irq_base); + */ +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> + +#include <asm/irq_cpu.h> +#include <asm/mipsregs.h> +#include <asm/system.h> + +static int mips_cpu_irq_base; + +static inline void unmask_mips_irq(unsigned int irq) +{ + clear_c0_cause(0x100 << (irq - mips_cpu_irq_base)); + set_c0_status(0x100 << (irq - mips_cpu_irq_base)); +} + +static inline void mask_mips_irq(unsigned int irq) +{ + clear_c0_status(0x100 << (irq - mips_cpu_irq_base)); +} + +static inline void mips_cpu_irq_enable(unsigned int irq) +{ + unsigned long flags; + + local_irq_save(flags); + unmask_mips_irq(irq); + local_irq_restore(flags); +} + +static void mips_cpu_irq_disable(unsigned int irq) +{ + unsigned long flags; + + local_irq_save(flags); + mask_mips_irq(irq); + local_irq_restore(flags); +} + +static unsigned int mips_cpu_irq_startup(unsigned int irq) +{ + mips_cpu_irq_enable(irq); + + return 0; +} + +#define mips_cpu_irq_shutdown mips_cpu_irq_disable + +/* + * While we ack the interrupt interrupts are disabled and thus we don't need + * to deal with concurrency issues. Same for mips_cpu_irq_end. + */ +static void mips_cpu_irq_ack(unsigned int irq) +{ + /* Only necessary for soft interrupts */ + clear_c0_cause(0x100 << (irq - mips_cpu_irq_base)); + + mask_mips_irq(irq); +} + +static void mips_cpu_irq_end(unsigned int irq) +{ + if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS))) + unmask_mips_irq(irq); +} + +static hw_irq_controller mips_cpu_irq_controller = { + "MIPS", + mips_cpu_irq_startup, + mips_cpu_irq_shutdown, + mips_cpu_irq_enable, + mips_cpu_irq_disable, + mips_cpu_irq_ack, + mips_cpu_irq_end, + NULL /* no affinity stuff for UP */ +}; + + +void __init mips_cpu_irq_init(int irq_base) +{ + int i; + + for (i = irq_base; i < irq_base + 8; i++) { + irq_desc[i].status = IRQ_DISABLED; + irq_desc[i].action = NULL; + irq_desc[i].depth = 1; + irq_desc[i].handler = &mips_cpu_irq_controller; + } + + mips_cpu_irq_base = irq_base; +} |