[PATCH] m68k: introduce irq controller

Introduce irq controller and use it to manage auto vector interrupts.
Introduce setup_irq() which can be used for irq setup.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 123 insertions, 48 deletions

diff --git a/arch/m68k/kernel/ints.c b/arch/m68k/kernel/ints.c
index 3ce7c6166bb9..c7f6ee67fd5a 100644
--- a/arch/m68k/kernel/ints.c
+++ b/arch/m68k/kernel/ints.c
@@ -45,7 +45,15 @@
 #endif
 
 /* table for system interrupt handlers */
-static irq_handler_t irq_list[SYS_IRQS];
+static struct irq_node *irq_list[SYS_IRQS];
+static struct irq_controller *irq_controller[SYS_IRQS];
+
+static struct irq_controller auto_irq_controller = {
+	.name		= "auto",
+	.lock		= SPIN_LOCK_UNLOCKED,
+	.startup	= m68k_irq_startup,
+	.shutdown	= m68k_irq_shutdown,
+};
 
 static const char *default_names[SYS_IRQS] = {
 	[0] = "spurious int",
@@ -101,17 +109,13 @@ void __init init_IRQ(void)
 		hardirq_mask_is_broken();
 	}
 
-	for (i = 0; i < SYS_IRQS; i++) {
-		if (mach_default_handler)
-			irq_list[i].handler = (*mach_default_handler)[i];
-		irq_list[i].flags   = 0;
-		irq_list[i].dev_id  = NULL;
-		irq_list[i].devname = default_names[i];
+	for (i = IRQ_AUTO_1; i <= IRQ_AUTO_7; i++) {
+		irq_controller[i] = &auto_irq_controller;
+		if (mach_default_handler && (*mach_default_handler)[i])
+			cpu_request_irq(i, (*mach_default_handler)[i],
+					0, default_names[i], NULL);
 	}
 
-	for (i = 0; i < NUM_IRQ_NODES; i++)
-		nodes[i].handler = NULL;
-
 	mach_init_IRQ ();
 }
 
@@ -120,9 +124,12 @@ irq_node_t *new_irq_node(void)
 	irq_node_t *node;
 	short i;
 
-	for (node = nodes, i = NUM_IRQ_NODES-1; i >= 0; node++, i--)
-		if (!node->handler)
+	for (node = nodes, i = NUM_IRQ_NODES-1; i >= 0; node++, i--) {
+		if (!node->handler) {
+			memset(node, 0, sizeof(*node));
 			return node;
+		}
+	}
 
 	printk ("new_irq_node: out of nodes\n");
 	return NULL;
@@ -149,55 +156,115 @@ void free_irq(unsigned int irq, void *dev_id)
 
 EXPORT_SYMBOL(free_irq);
 
-int cpu_request_irq(unsigned int irq,
-                    irqreturn_t (*handler)(int, void *, struct pt_regs *),
-                    unsigned long flags, const char *devname, void *dev_id)
+int setup_irq(unsigned int irq, struct irq_node *node)
 {
-	if (irq < IRQ_AUTO_1 || irq > IRQ_AUTO_7) {
+	struct irq_controller *contr;
+	struct irq_node **prev;
+	unsigned long flags;
+
+	if (irq >= SYS_IRQS || !(contr = irq_controller[irq])) {
 		printk("%s: Incorrect IRQ %d from %s\n",
-		       __FUNCTION__, irq, devname);
+		       __FUNCTION__, irq, node->devname);
 		return -ENXIO;
 	}
 
-#if 0
-	if (!(irq_list[irq].flags & IRQ_FLG_STD)) {
-		if (irq_list[irq].flags & IRQ_FLG_LOCK) {
-			printk("%s: IRQ %d from %s is not replaceable\n",
-			       __FUNCTION__, irq, irq_list[irq].devname);
-			return -EBUSY;
-		}
-		if (!(flags & IRQ_FLG_REPLACE)) {
-			printk("%s: %s can't replace IRQ %d from %s\n",
-			       __FUNCTION__, devname, irq, irq_list[irq].devname);
+	spin_lock_irqsave(&contr->lock, flags);
+
+	prev = irq_list + irq;
+	if (*prev) {
+		/* Can't share interrupts unless both agree to */
+		if (!((*prev)->flags & node->flags & SA_SHIRQ)) {
+			spin_unlock_irqrestore(&contr->lock, flags);
 			return -EBUSY;
 		}
+		while (*prev)
+			prev = &(*prev)->next;
 	}
-#endif
 
-	irq_list[irq].handler = handler;
-	irq_list[irq].flags   = flags;
-	irq_list[irq].dev_id  = dev_id;
-	irq_list[irq].devname = devname;
+	if (!irq_list[irq]) {
+		if (contr->startup)
+			contr->startup(irq);
+		else
+			contr->enable(irq);
+	}
+	node->next = NULL;
+	*prev = node;
+
+	spin_unlock_irqrestore(&contr->lock, flags);
+
 	return 0;
 }
 
+int cpu_request_irq(unsigned int irq,
+                    irqreturn_t (*handler)(int, void *, struct pt_regs *),
+                    unsigned long flags, const char *devname, void *dev_id)
+{
+	struct irq_node *node;
+	int res;
+
+	node = new_irq_node();
+	if (!node)
+		return -ENOMEM;
+
+	node->handler = handler;
+	node->flags   = flags;
+	node->dev_id  = dev_id;
+	node->devname = devname;
+
+	res = setup_irq(irq, node);
+	if (res)
+		node->handler = NULL;
+
+	return res;
+}
+
 void cpu_free_irq(unsigned int irq, void *dev_id)
 {
-	if (irq < IRQ_AUTO_1 || irq > IRQ_AUTO_7) {
+	struct irq_controller *contr;
+	struct irq_node **p, *node;
+	unsigned long flags;
+
+	if (irq >= SYS_IRQS || !(contr = irq_controller[irq])) {
 		printk("%s: Incorrect IRQ %d\n", __FUNCTION__, irq);
 		return;
 	}
 
-	if (irq_list[irq].dev_id != dev_id)
-		printk("%s: Removing probably wrong IRQ %d from %s\n",
-		       __FUNCTION__, irq, irq_list[irq].devname);
+	spin_lock_irqsave(&contr->lock, flags);
+
+	p = irq_list + irq;
+	while ((node = *p)) {
+		if (node->dev_id == dev_id)
+			break;
+		p = &node->next;
+	}
+
+	if (node) {
+		*p = node->next;
+		node->handler = NULL;
+	} else
+		printk("%s: Removing probably wrong IRQ %d\n",
+		       __FUNCTION__, irq);
+
+	if (!irq_list[irq])
+		contr->shutdown(irq);
 
-	irq_list[irq].handler = (*mach_default_handler)[irq];
-	irq_list[irq].flags   = 0;
-	irq_list[irq].dev_id  = NULL;
-	irq_list[irq].devname = default_names[irq];
+	spin_unlock_irqrestore(&contr->lock, flags);
 }
 
+int m68k_irq_startup(unsigned int irq)
+{
+	if (irq <= IRQ_AUTO_7)
+		vectors[VEC_SPUR + irq] = auto_inthandler;
+	return 0;
+}
+
+void m68k_irq_shutdown(unsigned int irq)
+{
+	if (irq <= IRQ_AUTO_7)
+		vectors[VEC_SPUR + irq] = bad_inthandler;
+}
+
+
 /*
  * Do we need these probe functions on the m68k?
  *
@@ -250,8 +317,14 @@ static void dummy_free_irq(unsigned int irq, void *dev_id)
 
 asmlinkage void m68k_handle_int(unsigned int irq, struct pt_regs *regs)
 {
+	struct irq_node *node;
+
 	kstat_cpu(0).irqs[irq]++;
-	irq_list[irq].handler(irq, irq_list[irq].dev_id, regs);
+	node = irq_list[irq];
+	do {
+		node->handler(irq, node->dev_id, regs);
+		node = node->next;
+	} while (node);
 }
 
 asmlinkage void handle_badint(struct pt_regs *regs)
@@ -262,16 +335,18 @@ asmlinkage void handle_badint(struct pt_regs *regs)
 
 int show_interrupts(struct seq_file *p, void *v)
 {
+	struct irq_controller *contr;
+	struct irq_node *node;
 	int i = *(loff_t *) v;
 
 	/* autovector interrupts */
-	if (i < SYS_IRQS) {
-		if (mach_default_handler) {
-			seq_printf(p, "auto %2d: %10u ", i,
-			               i ? kstat_cpu(0).irqs[i] : num_spurious);
-			seq_puts(p, "  ");
-			seq_printf(p, "%s\n", irq_list[i].devname);
-		}
+	if (i < SYS_IRQS && irq_list[i]) {
+		contr = irq_controller[i];
+		node = irq_list[i];
+		seq_printf(p, "%s %u: %10u %s", contr->name, i, kstat_cpu(0).irqs[i], node->devname);
+		while ((node = node->next))
+			seq_printf(p, ", %s", node->devname);
+		seq_puts(p, "\n");
 	} else if (i == SYS_IRQS)
 		mach_get_irq_list(p, v);
 	return 0;