diff options
Diffstat (limited to 'arch/mips/dec/irq.c')
| -rw-r--r-- | arch/mips/dec/irq.c | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/arch/mips/dec/irq.c b/arch/mips/dec/irq.c new file mode 100644 index 000000000..1090470a0 --- /dev/null +++ b/arch/mips/dec/irq.c @@ -0,0 +1,270 @@ +/* + * Code to handle DECstation IRQs plus some generic interrupt stuff. + * + * Copyright (C) 1992 Linus Torvalds + * Copyright (C) 1994, 1995, 1996, 1997 Ralf Baechle + * + * $Id: irq.c,v 1.1.2.1 1998/03/18 20:51:19 harald Exp $ + */ +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/kernel_stat.h> +#include <linux/signal.h> +#include <linux/sched.h> +#include <linux/types.h> +#include <linux/interrupt.h> +#include <linux/ioport.h> +#include <linux/timex.h> +#include <linux/malloc.h> +#include <linux/random.h> + +#include <asm/bitops.h> +#include <asm/bootinfo.h> +#include <asm/io.h> +#include <asm/irq.h> +#include <asm/mipsregs.h> +#include <asm/system.h> +#include <asm/wbflush.h> + +#include <asm/dec/interrupts.h> + +extern volatile unsigned int *isr; /* address of the interrupt status register */ +extern volatile unsigned int *imr; /* address of the interrupt mask register */ +extern decint_t dec_interrupt[NR_INTS]; + +unsigned int local_bh_count[NR_CPUS]; +unsigned int local_irq_count[NR_CPUS]; +unsigned long spurious_count = 0; + +static inline void mask_irq(unsigned int irq_nr) +{ + unsigned int dummy; + + if (dec_interrupt[irq_nr].iemask) { /* This is an ASIC interrupt */ + *imr &= ~dec_interrupt[irq_nr].iemask; + dummy = *imr; + dummy = *imr; + } else /* This is a cpu interrupt */ + set_cp0_status(ST0_IM, read_32bit_cp0_register(CP0_STATUS) & ~dec_interrupt[irq_nr].cpu_mask); +} + +static inline void unmask_irq(unsigned int irq_nr) +{ + unsigned int dummy; + + if (dec_interrupt[irq_nr].iemask) { /* This is an ASIC interrupt */ + *imr |= dec_interrupt[irq_nr].iemask; + dummy = *imr; + dummy = *imr; + } + set_cp0_status(ST0_IM, read_32bit_cp0_register(CP0_STATUS) | dec_interrupt[irq_nr].cpu_mask); +} + +void disable_irq(unsigned int irq_nr) +{ + unsigned long flags; + + save_and_cli(flags); + mask_irq(irq_nr); + restore_flags(flags); +} + +void enable_irq(unsigned int irq_nr) +{ + unsigned long flags; + + save_and_cli(flags); + unmask_irq(irq_nr); + restore_flags(flags); +} + +/* + * Pointers to the low-level handlers: first the general ones, then the + * fast ones, then the bad ones. + */ +extern void interrupt(void); + +static struct irqaction *irq_action[32] = +{ + NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, + NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, + NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, + NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL +}; + +int get_irq_list(char *buf) +{ + int i, len = 0; + struct irqaction *action; + + for (i = 0; i < 32; i++) { + action = irq_action[i]; + if (!action) + continue; + len += sprintf(buf + len, "%2d: %8d %c %s", + i, kstat.irqs[0][i], + (action->flags & SA_INTERRUPT) ? '+' : ' ', + action->name); + for (action = action->next; action; action = action->next) { + len += sprintf(buf + len, ",%s %s", + (action->flags & SA_INTERRUPT) ? " +" : "", + action->name); + } + len += sprintf(buf + len, "\n"); + } + return len; +} + +atomic_t __mips_bh_counter; + +/* + * do_IRQ handles IRQ's that have been installed without the + * SA_INTERRUPT flag: it uses the full signal-handling return + * and runs with other interrupts enabled. All relatively slow + * IRQ's should use this format: notably the keyboard/timer + * routines. + */ +asmlinkage void do_IRQ(int irq, struct pt_regs *regs) +{ + struct irqaction *action; + int do_random, cpu; + + cpu = smp_processor_id(); + hardirq_enter(cpu); + kstat.irqs[cpu][irq]++; + + mask_irq(irq); + action = *(irq + irq_action); + if (action) { + if (!(action->flags & SA_INTERRUPT)) + __sti(); + action = *(irq + irq_action); + do_random = 0; + do { + do_random |= action->flags; + action->handler(irq, action->dev_id, regs); + action = action->next; + } while (action); + if (do_random & SA_SAMPLE_RANDOM) + add_interrupt_randomness(irq); + unmask_irq(irq); + __cli(); + } + hardirq_exit(cpu); + + /* unmasking and bottom half handling is done magically for us. */ +} + +/* + * Idea is to put all interrupts + * in a single table and differenciate them just by number. + */ +int setup_dec_irq(int irq, struct irqaction *new) +{ + int shared = 0; + struct irqaction *old, **p; + unsigned long flags; + + p = irq_action + irq; + if ((old = *p) != NULL) { + /* Can't share interrupts unless both agree to */ + if (!(old->flags & new->flags & SA_SHIRQ)) + return -EBUSY; + + /* Can't share interrupts unless both are same type */ + if ((old->flags ^ new->flags) & SA_INTERRUPT) + return -EBUSY; + + /* add new interrupt at end of irq queue */ + do { + p = &old->next; + old = *p; + } while (old); + shared = 1; + } + if (new->flags & SA_SAMPLE_RANDOM) + rand_initialize_irq(irq); + + save_and_cli(flags); + *p = new; + + if (!shared) { + unmask_irq(irq); + } + restore_flags(flags); + return 0; +} + +int request_irq(unsigned int irq, + void (*handler) (int, void *, struct pt_regs *), + unsigned long irqflags, + const char *devname, + void *dev_id) +{ + int retval; + struct irqaction *action; + + if (irq >= 32) + return -EINVAL; + if (!handler) + return -EINVAL; + + action = (struct irqaction *) kmalloc(sizeof(struct irqaction), GFP_KERNEL); + if (!action) + return -ENOMEM; + + action->handler = handler; + action->flags = irqflags; + action->mask = 0; + action->name = devname; + action->next = NULL; + action->dev_id = dev_id; + + retval = setup_dec_irq(irq, action); + + if (retval) + kfree(action); + return retval; +} + +void free_irq(unsigned int irq, void *dev_id) +{ + struct irqaction *action, **p; + unsigned long flags; + + if (irq > 39) { + printk("Trying to free IRQ%d\n", irq); + return; + } + for (p = irq + irq_action; (action = *p) != NULL; p = &action->next) { + if (action->dev_id != dev_id) + continue; + + /* Found it - now free it */ + save_and_cli(flags); + *p = action->next; + if (!irq[irq_action]) + mask_irq(irq); + restore_flags(flags); + kfree(action); + return; + } + printk("Trying to free free IRQ%d\n", irq); +} + +unsigned long probe_irq_on(void) +{ + /* TODO */ + return 0; +} + +int probe_irq_off(unsigned long irqs) +{ + /* TODO */ + return 0; +} + +__initfunc(void init_IRQ(void)) +{ + irq_setup(); +} |