include/asm/spinlock.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #ifndef _ASM_X86_SPINLOCK_H
0003 #define _ASM_X86_SPINLOCK_H
0004
0005 #include <linux/jump_label.h>
0006 #include <linux/atomic.h>
0007 #include <asm/page.h>
0008 #include <asm/processor.h>
0009 #include <linux/compiler.h>
0010 #include <asm/paravirt.h>
0011 #include <asm/bitops.h>
0012
0013 /*
0014  * Your basic SMP spinlocks, allowing only a single CPU anywhere
0015  *
0016  * Simple spin lock operations.  There are two variants, one clears IRQ's
0017  * on the local processor, one does not.
0018  *
0019  * These are fair FIFO ticket locks, which support up to 2^16 CPUs.
0020  *
0021  * (the type definitions are in asm/spinlock_types.h)
0022  */
0023
0024 /* How long a lock should spin before we consider blocking */
0025 #define SPIN_THRESHOLD  (1 << 15)
0026
0027 #include <asm/qspinlock.h>
0028
0029 /*
0030  * Read-write spinlocks, allowing multiple readers
0031  * but only one writer.
0032  *
0033  * NOTE! it is quite common to have readers in interrupts
0034  * but no interrupt writers. For those circumstances we
0035  * can "mix" irq-safe locks - any writer needs to get a
0036  * irq-safe write-lock, but readers can get non-irqsafe
0037  * read-locks.
0038  *
0039  * On x86, we implement read-write locks using the generic qrwlock with
0040  * x86 specific optimization.
0041  */
0042
0043 #include <asm/qrwlock.h>
0044
0045 #endif /* _ASM_X86_SPINLOCK_H */