linux/arch/x86/kernel/paravirt-spinlocks.c
Jeremy Fitzhardinge 63d3a75d6f x86/paravirt: add spin_lock_flags lock op
It is useful for a pv_lock_ops backend to know whether interrupts are
enabled or not in the context a spin_lock is being called.  This
allows it to enable interrupts while spinning, which could be
particularly helpful when spinning becomes blocking.

The default implementation just calls the normal spin_lock op,
ignoring the flags.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-20 12:40:07 +02:00

37 lines
980 B
C

/*
* Split spinlock implementation out into its own file, so it can be
* compiled in a FTRACE-compatible way.
*/
#include <linux/spinlock.h>
#include <linux/module.h>
#include <asm/paravirt.h>
static void default_spin_lock_flags(struct raw_spinlock *lock, unsigned long flags)
{
__raw_spin_lock(lock);
}
struct pv_lock_ops pv_lock_ops = {
#ifdef CONFIG_SMP
.spin_is_locked = __ticket_spin_is_locked,
.spin_is_contended = __ticket_spin_is_contended,
.spin_lock = __ticket_spin_lock,
.spin_lock_flags = default_spin_lock_flags,
.spin_trylock = __ticket_spin_trylock,
.spin_unlock = __ticket_spin_unlock,
#endif
};
EXPORT_SYMBOL_GPL(pv_lock_ops);
void __init paravirt_use_bytelocks(void)
{
#ifdef CONFIG_SMP
pv_lock_ops.spin_is_locked = __byte_spin_is_locked;
pv_lock_ops.spin_is_contended = __byte_spin_is_contended;
pv_lock_ops.spin_lock = __byte_spin_lock;
pv_lock_ops.spin_trylock = __byte_spin_trylock;
pv_lock_ops.spin_unlock = __byte_spin_unlock;
#endif
}