x86, irq: Split out alloc_ioapic_save_registers()

Split out alloc_ioapic_save_registers() from early_irq_init(),
so it could be used for ioapic hotplug later.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1414387308-27148-10-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 15 insertions, 7 deletions

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index a157b666ac36..654b69b836b6 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -237,6 +237,19 @@ static struct irq_pin_list *alloc_irq_pin_list(int node)
         return kzalloc_node(sizeof(struct irq_pin_list), GFP_KERNEL, node);
 }
 
+static void alloc_ioapic_saved_registers(int idx)
+{
+        size_t size;
+
+        if (ioapics[idx].saved_registers)
+                return;
+
+        size = sizeof(struct IO_APIC_route_entry) * ioapics[idx].nr_registers;
+        ioapics[idx].saved_registers = kzalloc(size, GFP_KERNEL);
+        if (!ioapics[idx].saved_registers)
+                pr_err("IOAPIC %d: suspend/resume impossible!\n", idx);
+}
+
 int __init arch_early_irq_init(void)
 {
         struct irq_cfg *cfg;
@@ -245,13 +258,8 @@ int __init arch_early_irq_init(void)
         if (!nr_legacy_irqs())
                 io_apic_irqs = ~0UL;
 
-        for_each_ioapic(i) {
-                ioapics[i].saved_registers =
-                        kzalloc(sizeof(struct IO_APIC_route_entry) *
-                                ioapics[i].nr_registers, GFP_KERNEL);
-                if (!ioapics[i].saved_registers)
-                        pr_err("IOAPIC %d: suspend/resume impossible!\n", i);
-        }
+        for_each_ioapic(i)
+                alloc_ioapic_saved_registers(i);
 
         /*
          * For legacy IRQ's, start with assigning irq0 to irq15 to