x86/lguest: Clean up lguest_setup_irq

We make it static and hoist it higher in the file for the next patch.
We also give a nice panic if it fails during boot.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Link: http://lkml.kernel.org/r/1438662776-4823-1-git-send-email-rusty@rustcorp.com.au
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c
index f2dc08c003eb0b4c6c9f691a1c4b9e8f556eaaac..d933a11ceba62d5214ffc9a139265d37e563917a 100644 (file)
--- a/arch/x86/lguest/boot.c
+++ b/arch/x86/lguest/boot.c
@@ -835,6 +835,26 @@ static struct irq_chip lguest_irq_controller = {
        .irq_unmask     = enable_lguest_irq,
 };
 
+/*
+ * Interrupt descriptors are allocated as-needed, but low-numbered ones are
+ * reserved by the generic x86 code.  So we ignore irq_alloc_desc_at if it
+ * tells us the irq is already used: other errors (ie. ENOMEM) we take
+ * seriously.
+ */
+static int lguest_setup_irq(unsigned int irq)
+{
+       int err;
+
+       /* Returns -ve error or vector number. */
+       err = irq_alloc_desc_at(irq, 0);
+       if (err < 0 && err != -EEXIST)
+               return err;
+
+       irq_set_chip_and_handler_name(irq, &lguest_irq_controller,
+                                     handle_level_irq, "level");
+       return 0;
+}
+
 static int lguest_enable_irq(struct pci_dev *dev)
 {
        u8 line = 0;
@@ -878,26 +898,6 @@ static void __init lguest_init_IRQ(void)
        irq_ctx_init(smp_processor_id());
 }
 
-/*
- * Interrupt descriptors are allocated as-needed, but low-numbered ones are
- * reserved by the generic x86 code.  So we ignore irq_alloc_desc_at if it
- * tells us the irq is already used: other errors (ie. ENOMEM) we take
- * seriously.
- */
-int lguest_setup_irq(unsigned int irq)
-{
-       int err;
-
-       /* Returns -ve error or vector number. */
-       err = irq_alloc_desc_at(irq, 0);
-       if (err < 0 && err != -EEXIST)
-               return err;
-
-       irq_set_chip_and_handler_name(irq, &lguest_irq_controller,
-                                     handle_level_irq, "level");
-       return 0;
-}
-
 /*
  * Time.
  *
@@ -1040,7 +1040,8 @@ static void lguest_time_irq(unsigned int irq, struct irq_desc *desc)
 static void lguest_time_init(void)
 {
        /* Set up the timer interrupt (0) to go to our simple timer routine */
-       lguest_setup_irq(0);
+       if (lguest_setup_irq(0) != 0)
+               panic("Could not set up timer irq");
        irq_set_handler(0, lguest_time_irq);
 
        clocksource_register_hz(&lguest_clock, NSEC_PER_SEC);