1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copied from the kernel sources:
4  *
5  * Copyright IBM Corp. 1999, 2009
6  *
7  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
8  */
9 
10 #ifndef __TOOLS_LINUX_ASM_BARRIER_H
11 #define __TOOLS_LINUX_ASM_BARRIER_H
12 
13 /*
14  * Force strict CPU ordering.
15  * And yes, this is required on UP too when we're talking
16  * to devices.
17  */
18 
19 #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
20 /* Fast-BCR without checkpoint synchronization */
21 #define __ASM_BARRIER "bcr 14,0\n"
22 #else
23 #define __ASM_BARRIER "bcr 15,0\n"
24 #endif
25 
26 #define mb() do {  asm volatile(__ASM_BARRIER : : : "memory"); } while (0)
27 
28 #define rmb()				mb()
29 #define wmb()				mb()
30 
31 #define smp_store_release(p, v)			\
32 do {						\
33 	barrier();				\
34 	WRITE_ONCE(*p, v);			\
35 } while (0)
36 
37 #define smp_load_acquire(p)			\
38 ({						\
39 	typeof(*p) ___p1 = READ_ONCE(*p);	\
40 	barrier();				\
41 	___p1;					\
42 })
43 
44 #endif /* __TOOLS_LIB_ASM_BARRIER_H */
45