[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;