xen: events: dynamically allocate irq info structures

Removes nr_irq sized array allocation at start of day.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 16 insertions, 15 deletions

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index e119989ec15b..002283e01749 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -107,7 +107,6 @@ struct irq_info
 #define PIRQ_NEEDS_EOI  (1 << 0)
 #define PIRQ_SHAREABLE  (1 << 1)
 
-static struct irq_info *irq_info;
 static int *pirq_to_irq;
 
 static int *evtchn_to_irq;
@@ -125,7 +124,7 @@ static struct irq_chip xen_pirq_chip;
 /* Get info for IRQ */
 static struct irq_info *info_for_irq(unsigned irq)
 {
-        return &irq_info[irq];
+        return get_irq_data(irq);
 }
 
 /* Constructors for packed IRQ information. */
@@ -309,7 +308,7 @@ static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
         clear_bit(chn, per_cpu(cpu_evtchn_mask, cpu_from_irq(irq)));
         set_bit(chn, per_cpu(cpu_evtchn_mask, cpu));
 
-        irq_info[irq].cpu = cpu;
+        info_for_irq(irq)->cpu = cpu;
 }
 
 static void init_evtchn_cpu_bindings(void)
@@ -328,7 +327,6 @@ static void init_evtchn_cpu_bindings(void)
         for_each_possible_cpu(i)
                 memset(per_cpu(cpu_evtchn_mask, i),
                        (i == 0) ? ~0 : 0, sizeof(*per_cpu(cpu_evtchn_mask, i)));
-
 }
 
 static inline void clear_evtchn(int port)
@@ -411,10 +409,14 @@ static void xen_irq_init(unsigned irq)
         /* By default all event channels notify CPU#0. */
         cpumask_copy(desc->irq_data.affinity, cpumask_of(0));
 
-        info = &irq_info[irq];
+        info = kzalloc(sizeof(*info), GFP_KERNEL);
+        if (info == NULL)
+                panic("Unable to allocate metadata for IRQ%d\n", irq);
 
         info->type = IRQT_UNBOUND;
 
+        set_irq_data(irq, info);
+
         list_add_tail(&info->list, &xen_irq_list_head);
 }
 
@@ -481,12 +483,14 @@ static int xen_allocate_irq_gsi(unsigned gsi)
 
 static void xen_free_irq(unsigned irq)
 {
-        struct irq_info *info = &irq_info[irq];
-
-        info->type = IRQT_UNBOUND;
+        struct irq_info *info = get_irq_data(irq);
 
         list_del(&info->list);
 
+        set_irq_data(irq, NULL);
+
+        kfree(info);
+
         /* Legacy IRQ descriptors are managed by the arch. */
         if (irq < NR_IRQS_LEGACY)
                 return;
@@ -649,10 +653,9 @@ int xen_bind_pirq_gsi_to_irq(unsigned gsi,
 
         spin_lock(&irq_mapping_update_lock);
 
-        if ((pirq > nr_irqs) || (gsi > nr_irqs)) {
-                printk(KERN_WARNING "xen_map_pirq_gsi: %s %s is incorrect!\n",
-                        pirq > nr_irqs ? "pirq" :"",
-                        gsi > nr_irqs ? "gsi" : "");
+        if (pirq > nr_irqs) {
+                printk(KERN_WARNING "xen_map_pirq_gsi: pirq %d > nr_irqs %d!\n",
+                       pirq, nr_irqs);
                 goto out;
         }
 
@@ -889,7 +892,7 @@ static void unbind_from_irq(unsigned int irq)
                 evtchn_to_irq[evtchn] = -1;
         }
 
-        BUG_ON(irq_info[irq].type == IRQT_UNBOUND);
+        BUG_ON(info_for_irq(irq)->type == IRQT_UNBOUND);
 
         xen_free_irq(irq);
 
@@ -1509,8 +1512,6 @@ void __init xen_init_IRQ(void)
 {
         int i;
 
-        irq_info = kcalloc(nr_irqs, sizeof(*irq_info), GFP_KERNEL);
-
         /* We are using nr_irqs as the maximum number of pirq available but
          * that number is actually chosen by Xen and we don't know exactly
          * what it is. Be careful choosing high pirq numbers. */