linux/arch/powerpc/lib/qspinlock.c
Nicholas Piggin 9f61521c7a powerpc/qspinlock: powerpc qspinlock implementation
Add a powerpc specific implementation of queued spinlocks. This is the
build framework with a very simple (non-queued) spinlock implementation
to begin with. Later changes add queueing, and other features and
optimisations one-at-a-time. It is done this way to more easily see how
the queued spinlocks are built, and to make performance and correctness
bisects more useful.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Drop paravirt.h & processor.h changes to fix 32-bit build]
[mpe: Fix 32-bit build of qspinlock.o & disallow GENERIC_LOCKBREAK per Nick]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/CONLLQB6DCJU.2ZPOS7T6S5GRR@bobo
2022-12-02 17:48:02 +11:00

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C

// SPDX-License-Identifier: GPL-2.0-or-later
#include <linux/export.h>
#include <linux/processor.h>
#include <asm/qspinlock.h>
void queued_spin_lock_slowpath(struct qspinlock *lock)
{
while (!queued_spin_trylock(lock))
cpu_relax();
}
EXPORT_SYMBOL(queued_spin_lock_slowpath);
#ifdef CONFIG_PARAVIRT_SPINLOCKS
void pv_spinlocks_init(void)
{
}
#endif