ARM: 7536/1: smp: Formalize an IPI for wakeup

Remove the offset from ipi_msg_type and assume that SGI0 is the
wakeup interrupt now that all WFI hotplug users call
gic_raise_softirq() with 0 instead of 1. This allows us to
track how many wakeup interrupts are sent and also removes the
unknown IPI printk message for WFI hotplug based systems.
Reviewed-by: NNicolas Pitre <nico@linaro.org>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/include/asm/hardirq.h

@@ -5,7 +5,7 @@
 #include <linux/threads.h>
 #include <asm/irq.h>
 
-#define NR_IPI	5
+#define NR_IPI	6
 
 typedef struct {
 	unsigned int __softirq_pending;

arch/arm/kernel/smp.c

@@ -51,7 +51,8 @@
 struct secondary_data secondary_data;
 
 enum ipi_msg_type {
-	IPI_TIMER = 2,
+	IPI_WAKEUP,
+	IPI_TIMER,
 	IPI_RESCHEDULE,
 	IPI_CALL_FUNC,
 	IPI_CALL_FUNC_SINGLE,
@@ -347,7 +348,8 @@ void arch_send_call_function_single_ipi(int cpu)
 }
 
 static const char *ipi_types[NR_IPI] = {
-#define S(x,s)	[x - IPI_TIMER] = s
+#define S(x,s)	[x] = s
+	S(IPI_WAKEUP, "CPU wakeup interrupts"),
 	S(IPI_TIMER, "Timer broadcast interrupts"),
 	S(IPI_RESCHEDULE, "Rescheduling interrupts"),
 	S(IPI_CALL_FUNC, "Function call interrupts"),
@@ -500,10 +502,13 @@ void handle_IPI(int ipinr, struct pt_regs *regs)
 	unsigned int cpu = smp_processor_id();
 	struct pt_regs *old_regs = set_irq_regs(regs);
 
-	if (ipinr >= IPI_TIMER && ipinr < IPI_TIMER + NR_IPI)
-		__inc_irq_stat(cpu, ipi_irqs[ipinr - IPI_TIMER]);
+	if (ipinr < NR_IPI)
+		__inc_irq_stat(cpu, ipi_irqs[ipinr]);
 
 	switch (ipinr) {
+	case IPI_WAKEUP:
+		break;
+
 	case IPI_TIMER:
 		irq_enter();
 		ipi_timer();