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powerpc/pasemi: Use raw spinlock in SMP TB sync

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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: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Benjamin Herrenschmidt 2009-06-16 16:42:51 +00:00
parent c4007a2fbf
commit 6893ce6c1c
1 changed files with 10 additions and 5 deletions
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15
arch/powerpc/platforms/pasemi/setup.c
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@ -71,20 +71,25 @@ static void pas_restart(char *cmd)
} }
#ifdef CONFIG_SMP #ifdef CONFIG_SMP
static DEFINE_SPINLOCK(timebase_lock); static raw_spinlock_t timebase_lock;
static unsigned long timebase; static unsigned long timebase;
static void __devinit pas_give_timebase(void) 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); mtspr(SPRN_TBCTL, TBCTL_FREEZE);
isync(); isync();
timebase = get_tb(); timebase = get_tb();
spin_unlock(&timebase_lock); __raw_spin_unlock(&timebase_lock);
while (timebase) while (timebase)
barrier(); barrier();
mtspr(SPRN_TBCTL, TBCTL_RESTART); mtspr(SPRN_TBCTL, TBCTL_RESTART);
local_irq_restore(flags);
} }
static void __devinit pas_take_timebase(void) static void __devinit pas_take_timebase(void)
@ -92,10 +97,10 @@ static void __devinit pas_take_timebase(void)
while (!timebase) while (!timebase)
smp_rmb(); smp_rmb();
spin_lock(&timebase_lock); __raw_spin_lock(&timebase_lock);
set_tb(timebase >> 32, timebase & 0xffffffff); set_tb(timebase >> 32, timebase & 0xffffffff);
timebase = 0; timebase = 0;
spin_unlock(&timebase_lock); __raw_spin_unlock(&timebase_lock);
} }
struct smp_ops_t pas_smp_ops = { struct smp_ops_t pas_smp_ops = {