xref: /openbmc/u-boot/arch/arm/include/asm/barriers.h (revision 88dc4099)
1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * Copyright (C) 2016 ARM Ltd.
4  *
5  * ARM and ARM64 barrier instructions
6  * split from armv7.h to allow sharing between ARM and ARM64
7  *
8  * Original copyright in armv7.h was:
9  * (C) Copyright 2010 Texas Instruments, <www.ti.com> Aneesh V <aneesh@ti.com>
10  *
11  * Much of the original barrier code was contributed by:
12  *   Valentine Barshak <valentine.barshak@cogentembedded.com>
13  */
14 #ifndef __BARRIERS_H__
15 #define __BARRIERS_H__
16 
17 #ifndef __ASSEMBLY__
18 
19 #ifndef CONFIG_ARM64
20 /*
21  * CP15 Barrier instructions
22  * Please note that we have separate barrier instructions in ARMv7
23  * However, we use the CP15 based instructtions because we use
24  * -march=armv5 in U-Boot
25  */
26 #define CP15ISB	asm volatile ("mcr     p15, 0, %0, c7, c5, 4" : : "r" (0))
27 #define CP15DSB	asm volatile ("mcr     p15, 0, %0, c7, c10, 4" : : "r" (0))
28 #define CP15DMB	asm volatile ("mcr     p15, 0, %0, c7, c10, 5" : : "r" (0))
29 
30 #endif /* !CONFIG_ARM64 */
31 
32 #if __LINUX_ARM_ARCH__ >= 7
33 #define ISB	asm volatile ("isb sy" : : : "memory")
34 #define DSB	asm volatile ("dsb sy" : : : "memory")
35 #define DMB	asm volatile ("dmb sy" : : : "memory")
36 #elif __LINUX_ARM_ARCH__ == 6
37 #define ISB	CP15ISB
38 #define DSB	CP15DSB
39 #define DMB	CP15DMB
40 #else
41 #define ISB	asm volatile ("" : : : "memory")
42 #define DSB	CP15DSB
43 #define DMB	asm volatile ("" : : : "memory")
44 #endif
45 
46 #define isb()	ISB
47 #define dsb()	DSB
48 #define dmb()	DMB
49 #endif	/* __ASSEMBLY__ */
50 #endif	/* __BARRIERS_H__ */
51