diff options
Diffstat (limited to 'arch/mips/kernel/irq_cpu.c')
| -rw-r--r-- | arch/mips/kernel/irq_cpu.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/arch/mips/kernel/irq_cpu.c b/arch/mips/kernel/irq_cpu.c new file mode 100644 index 00000000..972263bc --- /dev/null +++ b/arch/mips/kernel/irq_cpu.c @@ -0,0 +1,115 @@ +/* + * Copyright 2001 MontaVista Software Inc. + * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net + * + * Copyright (C) 2001 Ralf Baechle + * Copyright (C) 2005 MIPS Technologies, Inc. All rights reserved. + * Author: Maciej W. Rozycki <macro@mips.com> + * + * 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(void); + */ +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/irq.h> + +#include <asm/irq_cpu.h> +#include <asm/mipsregs.h> +#include <asm/mipsmtregs.h> + +static inline void unmask_mips_irq(struct irq_data *d) +{ + set_c0_status(0x100 << (d->irq - MIPS_CPU_IRQ_BASE)); + irq_enable_hazard(); +} + +static inline void mask_mips_irq(struct irq_data *d) +{ + clear_c0_status(0x100 << (d->irq - MIPS_CPU_IRQ_BASE)); + irq_disable_hazard(); +} + +static struct irq_chip mips_cpu_irq_controller = { + .name = "MIPS", + .irq_ack = mask_mips_irq, + .irq_mask = mask_mips_irq, + .irq_mask_ack = mask_mips_irq, + .irq_unmask = unmask_mips_irq, + .irq_eoi = unmask_mips_irq, +}; + +/* + * Basically the same as above but taking care of all the MT stuff + */ + +static unsigned int mips_mt_cpu_irq_startup(struct irq_data *d) +{ + unsigned int vpflags = dvpe(); + + clear_c0_cause(0x100 << (d->irq - MIPS_CPU_IRQ_BASE)); + evpe(vpflags); + unmask_mips_irq(d); + return 0; +} + +/* + * 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_mt_cpu_irq_ack(struct irq_data *d) +{ + unsigned int vpflags = dvpe(); + clear_c0_cause(0x100 << (d->irq - MIPS_CPU_IRQ_BASE)); + evpe(vpflags); + mask_mips_irq(d); +} + +static struct irq_chip mips_mt_cpu_irq_controller = { + .name = "MIPS", + .irq_startup = mips_mt_cpu_irq_startup, + .irq_ack = mips_mt_cpu_irq_ack, + .irq_mask = mask_mips_irq, + .irq_mask_ack = mips_mt_cpu_irq_ack, + .irq_unmask = unmask_mips_irq, + .irq_eoi = unmask_mips_irq, +}; + +void __init mips_cpu_irq_init(void) +{ + int irq_base = MIPS_CPU_IRQ_BASE; + int i; + + /* Mask interrupts. */ + clear_c0_status(ST0_IM); + clear_c0_cause(CAUSEF_IP); + + /* Software interrupts are used for MT/CMT IPI */ + for (i = irq_base; i < irq_base + 2; i++) + irq_set_chip_and_handler(i, cpu_has_mipsmt ? + &mips_mt_cpu_irq_controller : + &mips_cpu_irq_controller, + handle_percpu_irq); + + for (i = irq_base + 2; i < irq_base + 8; i++) + irq_set_chip_and_handler(i, &mips_cpu_irq_controller, + handle_percpu_irq); +} |