ARM: 7133/1: SMP: fix per cpu timer setup before the cpu is marked online

The problem is related to the early enabling of interrupts and the
per cpu timer setup before the cpu is marked online. This doesn't
need to be done in order to call calibrate_delay().

calibrate_delay() monitors jiffies, which are updated from the CPU
which is waiting for the new CPU to set the online bit.

So simply calibrate_delay() can be called on the new CPU just from
the interrupt disabled region and move the local timer setup after
stored the cpu data and before enabling interrupts.

This solves both the cpu_online vs. cpu_active problem and the
affinity setting of the per cpu timers.

Signed-off-by: Thomas Gleinxer <tglx@linutronix.de>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index d88ff0230e826f8ea15a60560668dcf81ef80373..697e9a8cbdd84aa22fe573ff2218ce10fcd2d46e 100644 (file)
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -301,17 +301,7 @@ asmlinkage void __cpuinit secondary_start_kernel(void)
         */
        platform_secondary_init(cpu);
 
-       /*
-        * Enable local interrupts.
-        */
        notify_cpu_starting(cpu);
-       local_irq_enable();
-       local_fiq_enable();
-
-       /*
-        * Setup the percpu timer for this CPU.
-        */
-       percpu_timer_setup();
 
        calibrate_delay();
 
@@ -323,9 +313,22 @@ asmlinkage void __cpuinit secondary_start_kernel(void)
         * before we continue.
         */
        set_cpu_online(cpu, true);
+
+       /*
+        * Setup the percpu timer for this CPU.
+        */
+       percpu_timer_setup();
+
        while (!cpu_active(cpu))
                cpu_relax();
 
+       /*
+        * cpu_active bit is set, so it's safe to enalbe interrupts
+        * now.
+        */
+       local_irq_enable();
+       local_fiq_enable();
+
        /*
         * OK, it's off to the idle thread for us
         */