xref: /openbmc/u-boot/arch/arm/include/asm/barriers.h (revision 00caae6d)
1 /*
2  * Copyright (C) 2016 ARM Ltd.
3  *
4  * ARM and ARM64 barrier instructions
5  * split from armv7.h to allow sharing between ARM and ARM64
6  *
7  * Original copyright in armv7.h was:
8  * (C) Copyright 2010 Texas Instruments, <www.ti.com> Aneesh V <aneesh@ti.com>
9  *
10  * Much of the original barrier code was contributed by:
11  *   Valentine Barshak <valentine.barshak@cogentembedded.com>
12  *
13  * SPDX-License-Identifier:	GPL-2.0+
14  */
15 #ifndef __BARRIERS_H__
16 #define __BARRIERS_H__
17 
18 #ifndef __ASSEMBLY__
19 
20 #ifndef CONFIG_ARM64
21 /*
22  * CP15 Barrier instructions
23  * Please note that we have separate barrier instructions in ARMv7
24  * However, we use the CP15 based instructtions because we use
25  * -march=armv5 in U-Boot
26  */
27 #define CP15ISB	asm volatile ("mcr     p15, 0, %0, c7, c5, 4" : : "r" (0))
28 #define CP15DSB	asm volatile ("mcr     p15, 0, %0, c7, c10, 4" : : "r" (0))
29 #define CP15DMB	asm volatile ("mcr     p15, 0, %0, c7, c10, 5" : : "r" (0))
30 
31 #endif /* !CONFIG_ARM64 */
32 
33 #if __LINUX_ARM_ARCH__ >= 7
34 #define ISB	asm volatile ("isb sy" : : : "memory")
35 #define DSB	asm volatile ("dsb sy" : : : "memory")
36 #define DMB	asm volatile ("dmb sy" : : : "memory")
37 #elif __LINUX_ARM_ARCH__ == 6
38 #define ISB	CP15ISB
39 #define DSB	CP15DSB
40 #define DMB	CP15DMB
41 #else
42 #define ISB	asm volatile ("" : : : "memory")
43 #define DSB	CP15DSB
44 #define DMB	asm volatile ("" : : : "memory")
45 #endif
46 
47 #define isb()	ISB
48 #define dsb()	DSB
49 #define dmb()	DMB
50 #endif	/* __ASSEMBLY__ */
51 #endif	/* __BARRIERS_H__ */
52