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1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 #ifndef _ASM_POWERPC_JUMP_LABEL_H
3 #define _ASM_POWERPC_JUMP_LABEL_H
4 
5 /*
6  * Copyright 2010 Michael Ellerman, IBM Corp.
7  */
8 
9 #ifndef __ASSEMBLY__
10 #include <linux/types.h>
11 
12 #include <asm/feature-fixups.h>
13 #include <asm/asm-const.h>
14 
15 #define JUMP_ENTRY_TYPE		stringify_in_c(FTR_ENTRY_LONG)
16 #define JUMP_LABEL_NOP_SIZE	4
17 
arch_static_branch(struct static_key * key,bool branch)18 static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
19 {
20 	asm_volatile_goto("1:\n\t"
21 		 "nop # arch_static_branch\n\t"
22 		 ".pushsection __jump_table,  \"aw\"\n\t"
23 		 JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t"
24 		 ".popsection \n\t"
25 		 : :  "i" (&((char *)key)[branch]) : : l_yes);
26 
27 	return false;
28 l_yes:
29 	return true;
30 }
31 
arch_static_branch_jump(struct static_key * key,bool branch)32 static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
33 {
34 	asm_volatile_goto("1:\n\t"
35 		 "b %l[l_yes] # arch_static_branch_jump\n\t"
36 		 ".pushsection __jump_table,  \"aw\"\n\t"
37 		 JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t"
38 		 ".popsection \n\t"
39 		 : :  "i" (&((char *)key)[branch]) : : l_yes);
40 
41 	return false;
42 l_yes:
43 	return true;
44 }
45 
46 #ifdef CONFIG_PPC64
47 typedef u64 jump_label_t;
48 #else
49 typedef u32 jump_label_t;
50 #endif
51 
52 struct jump_entry {
53 	jump_label_t code;
54 	jump_label_t target;
55 	jump_label_t key;
56 };
57 
58 #else
59 #define ARCH_STATIC_BRANCH(LABEL, KEY)		\
60 1098:	nop;					\
61 	.pushsection __jump_table, "aw";	\
62 	FTR_ENTRY_LONG 1098b, LABEL, KEY;	\
63 	.popsection
64 #endif
65 
66 #endif /* _ASM_POWERPC_JUMP_LABEL_H */
67