xen: dynamically allocate irq & event structures

Dynamically allocate the irq_info and evtchn_to_irq arrays, so that
1) the irq_info array scales to the actual number of possible irqs,
and 2) we don't needlessly increase the static size of the kernel
when we aren't running under Xen.

Derived on patch from Mike Travis <travis@sgi.com>.

[Impact: reduce memory usage ]
[v2: Conflict in drivers/xen/events.c: Replaced alloc_bootmen with kcalloc ]

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 1bb51e459ab27018345f745eb645c906579d409f..19a93297e8902e7731d7c1e077ae58891da4ba1b 100644 (file)
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -28,6 +28,7 @@
 #include <linux/string.h>
 #include <linux/bootmem.h>
 #include <linux/slab.h>
+#include <linux/irqnr.h>
 
 #include <asm/desc.h>
 #include <asm/ptrace.h>
@@ -97,11 +98,9 @@ struct irq_info
 };
 #define PIRQ_NEEDS_EOI (1 << 0)
 
-static struct irq_info irq_info[NR_IRQS];
+static struct irq_info *irq_info;
 
-static int evtchn_to_irq[NR_EVENT_CHANNELS] = {
-       [0 ... NR_EVENT_CHANNELS-1] = -1
-};
+static int *evtchn_to_irq;
 struct cpu_evtchn_s {
        unsigned long bits[NR_EVENT_CHANNELS/BITS_PER_LONG];
 };
@@ -527,7 +526,7 @@ static int find_irq_by_gsi(unsigned gsi)
 {
        int irq;
 
-       for (irq = 0; irq < NR_IRQS; irq++) {
+       for (irq = 0; irq < nr_irqs; irq++) {
                struct irq_info *info = info_for_irq(irq);
 
                if (info == NULL || info->type != IRQT_PIRQ)
@@ -1267,7 +1266,12 @@ void __init xen_init_IRQ(void)
 
        cpu_evtchn_mask_p = kcalloc(nr_cpu_ids, sizeof(struct cpu_evtchn_s),
                                    GFP_KERNEL);
-       BUG_ON(cpu_evtchn_mask_p == NULL);
+       irq_info = kcalloc(nr_irqs, sizeof(*irq_info), GFP_KERNEL);
+
+       evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq),
+                                   GFP_KERNEL);
+       for (i = 0; i < NR_EVENT_CHANNELS; i++)
+               evtchn_to_irq[i] = -1;
 
        init_evtchn_cpu_bindings();