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Commit 6893ce6c authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt
Browse files

powerpc/pasemi: Use raw spinlock in SMP TB sync 



spin_lock() can hang if called while the timebase is frozen,
so use a raw lock instead, also disable interrupts while
at it.

Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent c4007a2f

arch/powerpc/platforms/pasemi/setup.c

+10 −5
Original line number Diff line number Diff line
@@ -71,20 +71,25 @@ static void pas_restart(char *cmd) 
}



#ifdef CONFIG_SMP

static DEFINE_SPINLOCK(timebase_lock);

static raw_spinlock_t timebase_lock;

static unsigned long timebase;



static void __devinit pas_give_timebase(void)

{

	spin_lock(&timebase_lock);

	unsigned long flags;



	local_irq_save(flags);

	hard_irq_disable();

	__raw_spin_lock(&timebase_lock);

	mtspr(SPRN_TBCTL, TBCTL_FREEZE);

	isync();

	timebase = get_tb();

	spin_unlock(&timebase_lock);

	__raw_spin_unlock(&timebase_lock);



	while (timebase)

		barrier();

	mtspr(SPRN_TBCTL, TBCTL_RESTART);

	local_irq_restore(flags);

}



static void __devinit pas_take_timebase(void)
@@ -92,10 +97,10 @@ static void __devinit pas_take_timebase(void) 
	while (!timebase)

		smp_rmb();



	spin_lock(&timebase_lock);

	__raw_spin_lock(&timebase_lock);

	set_tb(timebase >> 32, timebase & 0xffffffff);

	timebase = 0;

	spin_unlock(&timebase_lock);

	__raw_spin_unlock(&timebase_lock);

}



struct smp_ops_t pas_smp_ops = {