patch-2.4.6 linux/arch/mips/kernel/old-irq.c

• Lines: 406
• Date: Mon Jul 2 13:56:40 2001
• Orig file: v2.4.5/linux/arch/mips/kernel/old-irq.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.5/linux/arch/mips/kernel/old-irq.c linux/arch/mips/kernel/old-irq.c
@@ -0,0 +1,405 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Code to handle x86 style IRQs plus some generic interrupt stuff.
+ *
+ * Copyright (C) 1992 Linus Torvalds
+ * Copyright (C) 1994 - 2001 Ralf Baechle
+ *
+ * Old rotten IRQ code.  To be killed as soon as everybody had converted or
+ * in 2.5.0, whatever comes first.
+ */
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/kernel_stat.h>
+#include <linux/module.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/slab.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/nile4.h>
+
+/*
+ * The board specific setup routine sets irq_setup to point to a board
+ * specific setup routine.
+ */
+void (*irq_setup)(void);
+
+/*
+ * Linux has a controller-independent x86 interrupt architecture.
+ * every controller has a 'controller-template', that is used
+ * by the main code to do the right thing. Each driver-visible
+ * interrupt source is transparently wired to the apropriate
+ * controller. Thus drivers need not be aware of the
+ * interrupt-controller.
+ *
+ * Various interrupt controllers we handle: 8259 PIC, SMP IO-APIC,
+ * PIIX4's internal 8259 PIC and SGI's Visual Workstation Cobalt (IO-)APIC.
+ * (IO-APICs assumed to be messaging to Pentium local-APICs)
+ *
+ * the code is designed to be easily extended with new/different
+ * interrupt controllers, without having to do assembly magic.
+ */
+
+/*
+ * This contains the irq mask for both 8259A irq controllers, it's an
+ * int so we can deal with the third PIC in some systems like the RM300.
+ * (XXX This is broken for big endian.)
+ */
+static unsigned int cached_irq_mask = 0xffff;
+
+#define __byte(x,y) (((unsigned char *)&(y))[x])
+#define __word(x,y) (((unsigned short *)&(y))[x])
+#define __long(x,y) (((unsigned int *)&(y))[x])
+
+#define cached_21       (__byte(0,cached_irq_mask))
+#define cached_A1       (__byte(1,cached_irq_mask))
+
+unsigned long spurious_count = 0;
+
+/*
+ * (un)mask_irq, disable_irq() and enable_irq() only handle (E)ISA and
+ * PCI devices.  Other onboard hardware needs specific routines.
+ */
+static inline void mask_irq(unsigned int irq)
+{
+	cached_irq_mask |= 1 << irq;
+	if (irq & 8) {
+		outb(cached_A1, 0xa1);
+	} else {
+		outb(cached_21, 0x21);
+	}
+}
+
+static inline void unmask_irq(unsigned int irq)
+{
+	cached_irq_mask &= ~(1 << irq);
+	if (irq & 8) {
+		outb(cached_A1, 0xa1);
+	} else {
+		outb(cached_21, 0x21);
+	}
+}
+
+void i8259_disable_irq(unsigned int irq_nr)
+{
+	unsigned long flags;
+
+	save_and_cli(flags);
+	mask_irq(irq_nr);
+	restore_flags(flags);
+}
+
+void i8259_enable_irq(unsigned int irq_nr)
+{
+	unsigned long flags;
+	save_and_cli(flags);
+	unmask_irq(irq_nr);
+	restore_flags(flags);
+}
+
+static struct irqaction *irq_action[NR_IRQS] = {
+	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,
+	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;
+}
+
+static inline void i8259_mask_and_ack_irq(int irq)
+{
+	cached_irq_mask |= 1 << irq;
+
+	if (irq & 8) {
+		inb(0xa1);
+		outb(cached_A1, 0xa1);
+		outb(0x62, 0x20);		/* Specific EOI to cascade */
+                outb(0x20, 0xa0);
+        } else {
+		inb(0x21);
+		outb(cached_21, 0x21);
+		outb(0x20, 0x20);
+        }
+}
+
+asmlinkage void i8259_do_irq(int irq, struct pt_regs *regs)
+{
+	struct irqaction *action;
+	int do_random, cpu;
+
+	cpu = smp_processor_id();
+	irq_enter(cpu, irq);
+
+	if (irq >= 16)
+		goto out;
+
+	i8259_mask_and_ack_irq(irq);
+
+	kstat.irqs[cpu][irq]++;
+
+	action = *(irq + irq_action);
+	if (!action)
+		goto out;
+
+	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);
+	__cli();
+	unmask_irq (irq);
+
+out:
+	irq_exit(cpu, irq);
+}
+
+/*
+ * 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();
+	irq_enter(cpu, irq);
+	kstat.irqs[cpu][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);
+		__cli();
+	}
+	irq_exit(cpu, irq);
+
+	if (softirq_active(cpu)&softirq_mask(cpu))
+		do_softirq();
+
+	/* unmasking and bottom half handling is done magically for us. */
+}
+
+int i8259_setup_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) {
+		if (is_i8259_irq(irq))
+		    unmask_irq(irq);
+#if (defined(CONFIG_DDB5074) || defined(CONFIG_DDB5476))
+		else
+		    nile4_enable_irq(irq_to_nile4(irq));
+#endif
+	}
+	restore_flags(flags);
+	return 0;
+}
+
+/*
+ * Request_interrupt and free_interrupt ``sort of'' handle interrupts of
+ * non i8259 devices.  They will have to be replaced by architecture
+ * specific variants.  For now we still use this as broken as it is because
+ * it used to work ...
+ */
+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 = i8259_setup_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 > 31) {
+		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)
+{
+	unsigned int i, irqs = 0;
+	unsigned long delay;
+
+	/* first, enable any unassigned (E)ISA irqs */
+	for (i = 15; i > 0; i--) {
+		if (!irq_action[i]) {
+			i8259_enable_irq(i);
+			irqs |= (1 << i);
+		}
+	}
+
+	/* wait for spurious interrupts to mask themselves out again */
+	for (delay = jiffies + HZ/10; time_before(jiffies, delay); )
+		/* about 100ms delay */;
+
+	/* now filter out any obviously spurious interrupts */
+	return irqs & ~cached_irq_mask;
+}
+
+int probe_irq_off (unsigned long irqs)
+{
+	unsigned int i;
+
+#ifdef DEBUG
+	printk("probe_irq_off: irqs=0x%04x irqmask=0x%04x\n", irqs, irqmask);
+#endif
+	irqs &= cached_irq_mask;
+	if (!irqs)
+		return 0;
+	i = ffz(~irqs);
+	if (irqs != (irqs & (1 << i)))
+		i = -i;
+	return i;
+}
+
+void __init i8259_init(void)
+{
+	/* Init master interrupt controller */
+	outb(0x11, 0x20); /* Start init sequence */
+	outb(0x00, 0x21); /* Vector base */
+	outb(0x04, 0x21); /* edge tiggered, Cascade (slave) on IRQ2 */
+	outb(0x01, 0x21); /* Select 8086 mode */
+	outb(0xff, 0x21); /* Mask all */
+        
+	/* Init slave interrupt controller */
+	outb(0x11, 0xa0); /* Start init sequence */
+	outb(0x08, 0xa1); /* Vector base */
+	outb(0x02, 0xa1); /* edge triggered, Cascade (slave) on IRQ2 */
+	outb(0x01, 0xa1); /* Select 8086 mode */
+	outb(0xff, 0xa1); /* Mask all */
+
+	outb(cached_A1, 0xa1);
+	outb(cached_21, 0x21);
+}
+
+void __init init_IRQ(void)
+{
+	/* i8259_init(); */
+	irq_setup();
+}