ubuntu-linux-kernel/arch/x86/include/asm/spinlock.h

46 lines
1.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_SPINLOCK_H
#define _ASM_X86_SPINLOCK_H
#include <linux/jump_label.h>
#include <linux/atomic.h>
#include <asm/page.h>
#include <asm/processor.h>
#include <linux/compiler.h>
#include <asm/paravirt.h>
#include <asm/bitops.h>
/*
* Your basic SMP spinlocks, allowing only a single CPU anywhere
*
* Simple spin lock operations. There are two variants, one clears IRQ's
* on the local processor, one does not.
*
* These are fair FIFO ticket locks, which support up to 2^16 CPUs.
*
* (the type definitions are in asm/spinlock_types.h)
*/
/* How long a lock should spin before we consider blocking */
#define SPIN_THRESHOLD (1 << 15)
#include <asm/qspinlock.h>
/*
* Read-write spinlocks, allowing multiple readers
* but only one writer.
*
* NOTE! it is quite common to have readers in interrupts
* but no interrupt writers. For those circumstances we
* can "mix" irq-safe locks - any writer needs to get a
* irq-safe write-lock, but readers can get non-irqsafe
* read-locks.
*
* On x86, we implement read-write locks using the generic qrwlock with
* x86 specific optimization.
*/
#include <asm/qrwlock.h>
#endif /* _ASM_X86_SPINLOCK_H */