diff options
Diffstat (limited to 'kernel/drivers/irqchip/irq-mips-cpu.c')
| -rw-r--r-- | kernel/drivers/irqchip/irq-mips-cpu.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/kernel/drivers/irqchip/irq-mips-cpu.c b/kernel/drivers/irqchip/irq-mips-cpu.c new file mode 100644 index 000000000..8c504f562 --- /dev/null +++ b/kernel/drivers/irqchip/irq-mips-cpu.c @@ -0,0 +1,171 @@ +/* + * 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 <linux/irqchip.h> +#include <linux/irqdomain.h> + +#include <asm/irq_cpu.h> +#include <asm/mipsregs.h> +#include <asm/mipsmtregs.h> +#include <asm/setup.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, + .irq_disable = mask_mips_irq, + .irq_enable = 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, + .irq_disable = mask_mips_irq, + .irq_enable = unmask_mips_irq, +}; + +asmlinkage void __weak plat_irq_dispatch(void) +{ + unsigned long pending = read_c0_cause() & read_c0_status() & ST0_IM; + int irq; + + if (!pending) { + spurious_interrupt(); + return; + } + + pending >>= CAUSEB_IP; + while (pending) { + irq = fls(pending) - 1; + do_IRQ(MIPS_CPU_IRQ_BASE + irq); + pending &= ~BIT(irq); + } +} + +static int mips_cpu_intc_map(struct irq_domain *d, unsigned int irq, + irq_hw_number_t hw) +{ + static struct irq_chip *chip; + + if (hw < 2 && cpu_has_mipsmt) { + /* Software interrupts are used for MT/CMT IPI */ + chip = &mips_mt_cpu_irq_controller; + } else { + chip = &mips_cpu_irq_controller; + } + + if (cpu_has_vint) + set_vi_handler(hw, plat_irq_dispatch); + + irq_set_chip_and_handler(irq, chip, handle_percpu_irq); + + return 0; +} + +static const struct irq_domain_ops mips_cpu_intc_irq_domain_ops = { + .map = mips_cpu_intc_map, + .xlate = irq_domain_xlate_onecell, +}; + +static void __init __mips_cpu_irq_init(struct device_node *of_node) +{ + struct irq_domain *domain; + + /* Mask interrupts. */ + clear_c0_status(ST0_IM); + clear_c0_cause(CAUSEF_IP); + + domain = irq_domain_add_legacy(of_node, 8, MIPS_CPU_IRQ_BASE, 0, + &mips_cpu_intc_irq_domain_ops, NULL); + if (!domain) + panic("Failed to add irqdomain for MIPS CPU"); +} + +void __init mips_cpu_irq_init(void) +{ + __mips_cpu_irq_init(NULL); +} + +int __init mips_cpu_irq_of_init(struct device_node *of_node, + struct device_node *parent) +{ + __mips_cpu_irq_init(of_node); + return 0; +} +IRQCHIP_DECLARE(cpu_intc, "mti,cpu-interrupt-controller", mips_cpu_irq_of_init); |