linux_dsm_epyc7002/arch/powerpc/include/asm/spinlock.h
Nicholas Piggin 20c0e8269e powerpc/pseries: Implement paravirt qspinlocks for SPLPAR
This implements the generic paravirt qspinlocks using H_PROD and
H_CONFER to kick and wait.

This uses an un-directed yield to any CPU rather than the directed
yield to a pre-empted lock holder that paravirtualised simple
spinlocks use, that requires no kick hcall. This is something that
could be investigated and improved in future.

Performance results can be found in the commit which added queued
spinlocks.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200724131423.1362108-5-npiggin@gmail.com
2020-07-27 00:01:29 +10:00

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C

/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef __ASM_SPINLOCK_H
#define __ASM_SPINLOCK_H
#ifdef __KERNEL__
#ifdef CONFIG_PPC_QUEUED_SPINLOCKS
#include <asm/qspinlock.h>
#include <asm/qrwlock.h>
#else
#include <asm/simple_spinlock.h>
#endif
#ifndef CONFIG_PARAVIRT_SPINLOCKS
static inline void pv_spinlocks_init(void) { }
#endif
#endif /* __KERNEL__ */
#endif /* __ASM_SPINLOCK_H */