xref: /linux/arch/csky/include/asm/barrier.h (revision 0d3b051adbb72ed81956447d0d1e54d5943ee6f5)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
3 
4 #ifndef __ASM_CSKY_BARRIER_H
5 #define __ASM_CSKY_BARRIER_H
6 
7 #ifndef __ASSEMBLY__
8 
9 #define nop()	asm volatile ("nop\n":::"memory")
10 
11 #ifdef CONFIG_SMP
12 
13 /*
14  * bar.brwarws: ordering barrier for all load/store instructions
15  *              before/after
16  *
17  * |31|30 26|25 21|20 16|15  10|9   5|4           0|
18  *  1  10000 00000 00000 100001	00001 0 bw br aw ar
19  *
20  * b: before
21  * a: after
22  * r: read
23  * w: write
24  *
25  * Here are all combinations:
26  *
27  * bar.brw
28  * bar.br
29  * bar.bw
30  * bar.arw
31  * bar.ar
32  * bar.aw
33  * bar.brwarw
34  * bar.brarw
35  * bar.bwarw
36  * bar.brwar
37  * bar.brwaw
38  * bar.brar
39  * bar.bwaw
40  */
41 #define __bar_brw()	asm volatile (".long 0x842cc000\n":::"memory")
42 #define __bar_br()	asm volatile (".long 0x8424c000\n":::"memory")
43 #define __bar_bw()	asm volatile (".long 0x8428c000\n":::"memory")
44 #define __bar_arw()	asm volatile (".long 0x8423c000\n":::"memory")
45 #define __bar_ar()	asm volatile (".long 0x8421c000\n":::"memory")
46 #define __bar_aw()	asm volatile (".long 0x8422c000\n":::"memory")
47 #define __bar_brwarw()	asm volatile (".long 0x842fc000\n":::"memory")
48 #define __bar_brarw()	asm volatile (".long 0x8427c000\n":::"memory")
49 #define __bar_bwarw()	asm volatile (".long 0x842bc000\n":::"memory")
50 #define __bar_brwar()	asm volatile (".long 0x842dc000\n":::"memory")
51 #define __bar_brwaw()	asm volatile (".long 0x842ec000\n":::"memory")
52 #define __bar_brar()	asm volatile (".long 0x8425c000\n":::"memory")
53 #define __bar_brar()	asm volatile (".long 0x8425c000\n":::"memory")
54 #define __bar_bwaw()	asm volatile (".long 0x842ac000\n":::"memory")
55 
56 #define __smp_mb()	__bar_brwarw()
57 #define __smp_rmb()	__bar_brar()
58 #define __smp_wmb()	__bar_bwaw()
59 
60 #define ACQUIRE_FENCE		".long 0x8427c000\n"
61 #define __smp_acquire_fence()	__bar_brarw()
62 #define __smp_release_fence()	__bar_brwaw()
63 
64 #endif /* CONFIG_SMP */
65 
66 /*
67  * sync:        completion barrier, all sync.xx instructions
68  *              guarantee the last response recieved by bus transaction
69  *              made by ld/st instructions before sync.s
70  * sync.s:      inherit from sync, but also shareable to other cores
71  * sync.i:      inherit from sync, but also flush cpu pipeline
72  * sync.is:     the same with sync.i + sync.s
73  */
74 #define mb()		asm volatile ("sync\n":::"memory")
75 
76 #ifdef CONFIG_CPU_HAS_CACHEV2
77 /*
78  * Using three sync.is to prevent speculative PTW
79  */
80 #define sync_is()	asm volatile ("sync.is\nsync.is\nsync.is\n":::"memory")
81 #endif
82 
83 #include <asm-generic/barrier.h>
84 
85 #endif /* __ASSEMBLY__ */
86 #endif /* __ASM_CSKY_BARRIER_H */
87