1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_SPINLOCK_H
3 #define _ASM_X86_SPINLOCK_H
4 
5 #include <linux/jump_label.h>
6 #include <linux/atomic.h>
7 #include <asm/page.h>
8 #include <asm/processor.h>
9 #include <linux/compiler.h>
10 #include <asm/paravirt.h>
11 #include <asm/bitops.h>
12 
13 /*
14  * Your basic SMP spinlocks, allowing only a single CPU anywhere
15  *
16  * Simple spin lock operations.  There are two variants, one clears IRQ's
17  * on the local processor, one does not.
18  *
19  * These are fair FIFO ticket locks, which support up to 2^16 CPUs.
20  *
21  * (the type definitions are in asm/spinlock_types.h)
22  */
23 
24 /* How long a lock should spin before we consider blocking */
25 #define SPIN_THRESHOLD	(1 << 15)
26 
27 #include <asm/qspinlock.h>
28 
29 /*
30  * Read-write spinlocks, allowing multiple readers
31  * but only one writer.
32  *
33  * NOTE! it is quite common to have readers in interrupts
34  * but no interrupt writers. For those circumstances we
35  * can "mix" irq-safe locks - any writer needs to get a
36  * irq-safe write-lock, but readers can get non-irqsafe
37  * read-locks.
38  *
39  * On x86, we implement read-write locks using the generic qrwlock with
40  * x86 specific optimization.
41  */
42 
43 #include <asm/qrwlock.h>
44 
45 #endif /* _ASM_X86_SPINLOCK_H */
46