xref: /linux/arch/powerpc/include/asm/jump_label.h (revision e9f0878c4b2004ac19581274c1ae4c61ae3ca70e)
1 #ifndef _ASM_POWERPC_JUMP_LABEL_H
2 #define _ASM_POWERPC_JUMP_LABEL_H
3 
4 /*
5  * Copyright 2010 Michael Ellerman, IBM Corp.
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * as published by the Free Software Foundation; either version
10  * 2 of the License, or (at your option) any later version.
11  */
12 
13 #ifndef __ASSEMBLY__
14 #include <linux/types.h>
15 
16 #include <asm/feature-fixups.h>
17 #include <asm/asm-const.h>
18 
19 #define JUMP_ENTRY_TYPE		stringify_in_c(FTR_ENTRY_LONG)
20 #define JUMP_LABEL_NOP_SIZE	4
21 
22 static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
23 {
24 	asm_volatile_goto("1:\n\t"
25 		 "nop # arch_static_branch\n\t"
26 		 ".pushsection __jump_table,  \"aw\"\n\t"
27 		 JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t"
28 		 ".popsection \n\t"
29 		 : :  "i" (&((char *)key)[branch]) : : l_yes);
30 
31 	return false;
32 l_yes:
33 	return true;
34 }
35 
36 static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
37 {
38 	asm_volatile_goto("1:\n\t"
39 		 "b %l[l_yes] # arch_static_branch_jump\n\t"
40 		 ".pushsection __jump_table,  \"aw\"\n\t"
41 		 JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t"
42 		 ".popsection \n\t"
43 		 : :  "i" (&((char *)key)[branch]) : : l_yes);
44 
45 	return false;
46 l_yes:
47 	return true;
48 }
49 
50 #ifdef CONFIG_PPC64
51 typedef u64 jump_label_t;
52 #else
53 typedef u32 jump_label_t;
54 #endif
55 
56 struct jump_entry {
57 	jump_label_t code;
58 	jump_label_t target;
59 	jump_label_t key;
60 };
61 
62 #else
63 #define ARCH_STATIC_BRANCH(LABEL, KEY)		\
64 1098:	nop;					\
65 	.pushsection __jump_table, "aw";	\
66 	FTR_ENTRY_LONG 1098b, LABEL, KEY;	\
67 	.popsection
68 #endif
69 
70 #endif /* _ASM_POWERPC_JUMP_LABEL_H */
71