[PATCH] genirq: add IRQ_NOREQUEST support

Enable platforms to disable request_irq() for certain interrupts.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 4 insertions, 1 deletions

diff --git a/include/linux/irq.h b/include/linux/irq.h
index b2fcf330cf2e..1df49ec7f820 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -41,6 +41,7 @@
 #endif
 
 #define IRQ_NOPROBE     512     /* IRQ is not valid for probing */
+#define IRQ_NOREQUEST   1024    /* IRQ cannot be requested */
 /**
  * struct hw_interrupt_type - hardware interrupt type descriptor
  *
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 90a944a7fadc..cae900a849c4 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -141,7 +141,7 @@ int can_request_irq(unsigned int irq, unsigned long irqflags)
 {
         struct irqaction *action;
 
-        if (irq >= NR_IRQS)
+        if (irq >= NR_IRQS || irq_desc[irq].status & IRQ_NOREQUEST)
                 return 0;
 
         action = irq_desc[irq].action;
@@ -356,6 +356,8 @@ int request_irq(unsigned int irq,
                 return -EINVAL;
         if (irq >= NR_IRQS)
                 return -EINVAL;
+        if (irq_desc[irq].status & IRQ_NOREQUEST)
+                return -EINVAL;
         if (!handler)
                 return -EINVAL;