+ struct irq_host *host;
+ unsigned int size = sizeof(struct irq_host);
+ unsigned int i;
+ unsigned int *rmap;
+ unsigned long flags;
+
+ /* Allocate structure and revmap table if using linear mapping */
+ if (revmap_type == IRQ_HOST_MAP_LINEAR)
+ size += revmap_arg * sizeof(unsigned int);
+ if (mem_init_done)
+ host = kzalloc(size, GFP_KERNEL);
+ else {
+ host = alloc_bootmem(size);
+ if (host)
+ memset(host, 0, size);
+ }
+ if (host == NULL)
+ return NULL;
+
+ /* Fill structure */
+ host->revmap_type = revmap_type;
+ host->inval_irq = inval_irq;
+ host->ops = ops;
+
+ spin_lock_irqsave(&irq_big_lock, flags);
+
+ /* If it's a legacy controller, check for duplicates and
+ * mark it as allocated (we use irq 0 host pointer for that
+ */
+ if (revmap_type == IRQ_HOST_MAP_LEGACY) {
+ if (irq_map[0].host != NULL) {
+ spin_unlock_irqrestore(&irq_big_lock, flags);
+ /* If we are early boot, we can't free the structure,
+ * too bad...
+ * this will be fixed once slab is made available early
+ * instead of the current cruft
+ */
+ if (mem_init_done)
+ kfree(host);
+ return NULL;
+ }
+ irq_map[0].host = host;
+ }
+
+ list_add(&host->link, &irq_hosts);
+ spin_unlock_irqrestore(&irq_big_lock, flags);
+
+ /* Additional setups per revmap type */
+ switch(revmap_type) {
+ case IRQ_HOST_MAP_LEGACY:
+ /* 0 is always the invalid number for legacy */
+ host->inval_irq = 0;
+ /* setup us as the host for all legacy interrupts */
+ for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
+ irq_map[i].hwirq = 0;
+ smp_wmb();
+ irq_map[i].host = host;
+ smp_wmb();
+
+ /* Clear norequest flags */
+ get_irq_desc(i)->status &= ~IRQ_NOREQUEST;
+
+ /* Legacy flags are left to default at this point,
+ * one can then use irq_create_mapping() to
+ * explicitely change them
+ */
+ ops->map(host, i, i);
+ }
+ break;
+ case IRQ_HOST_MAP_LINEAR:
+ rmap = (unsigned int *)(host + 1);
+ for (i = 0; i < revmap_arg; i++)
+ rmap[i] = IRQ_NONE;
+ host->revmap_data.linear.size = revmap_arg;
+ smp_wmb();
+ host->revmap_data.linear.revmap = rmap;
+ break;
+ default:
+ break;
+ }
+
+ pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
+
+ return host;
+}
+
+struct irq_host *irq_find_host(struct device_node *node)
+{
+ struct irq_host *h, *found = NULL;
+ unsigned long flags;
+
+ /* We might want to match the legacy controller last since
+ * it might potentially be set to match all interrupts in
+ * the absence of a device node. This isn't a problem so far
+ * yet though...
+ */
+ spin_lock_irqsave(&irq_big_lock, flags);
+ list_for_each_entry(h, &irq_hosts, link)
+ if (h->ops->match == NULL || h->ops->match(h, node)) {
+ found = h;
+ break;
+ }
+ spin_unlock_irqrestore(&irq_big_lock, flags);
+ return found;
+}
+EXPORT_SYMBOL_GPL(irq_find_host);
+
+void irq_set_default_host(struct irq_host *host)
+{
+ pr_debug("irq: Default host set to @0x%p\n", host);
+
+ irq_default_host = host;
+}
+
+void irq_set_virq_count(unsigned int count)
+{
+ pr_debug("irq: Trying to set virq count to %d\n", count);
+
+ BUG_ON(count < NUM_ISA_INTERRUPTS);
+ if (count < NR_IRQS)
+ irq_virq_count = count;