arm: Tell irq work about self IPI support

ARM irq work IPI support depends on SMP support. That information is
partly known at early boottime. Lets implement
arch_irq_work_has_interrupt() accordingly.
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>

arch/arm/include/asm/Kbuild

@@ -11,7 +11,6 @@ generic-y += hash.h
 generic-y += ioctl.h
 generic-y += ipcbuf.h
 generic-y += irq_regs.h
-generic-y += irq_work.h
 generic-y += kdebug.h
 generic-y += local.h
 generic-y += local64.h

arch/arm/include/asm/irq_work.h

+#ifndef __ASM_ARM_IRQ_WORK_H
+#define __ASM_ARM_IRQ_WORK_H
+
+#include <asm/smp_plat.h>
+
+static inline bool arch_irq_work_has_interrupt(void)
+{
+	return is_smp();
+}
+
+#endif /* _ASM_ARM_IRQ_WORK_H */

arch/arm/kernel/smp.c

@@ -503,7 +503,7 @@ void arch_send_call_function_single_ipi(int cpu)
 #ifdef CONFIG_IRQ_WORK
 void arch_irq_work_raise(void)
 {
-	if (is_smp())
+	if (arch_irq_work_has_interrupt())
 		smp_cross_call(cpumask_of(smp_processor_id()), IPI_IRQ_WORK);
 }
 #endif