patch-2.3.9 linux/arch/mips/dec/irq.c

• Lines: 270
• Date: Fri Jun 25 17:40:12 1999
• Orig file: v2.3.8/linux/arch/mips/dec/irq.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.8/linux/arch/mips/dec/irq.c linux/arch/mips/dec/irq.c
@@ -0,0 +1,269 @@
+/*
+ * 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 1.3 1999/04/11 17:06:16 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/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();
+}