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 
18 #define JUMP_ENTRY_TYPE		stringify_in_c(FTR_ENTRY_LONG)
19 #define JUMP_LABEL_NOP_SIZE	4
20 
21 static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
22 {
23 	asm_volatile_goto("1:\n\t"
24 		 "nop\n\t"
25 		 ".pushsection __jump_table,  \"aw\"\n\t"
26 		 JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t"
27 		 ".popsection \n\t"
28 		 : :  "i" (&((char *)key)[branch]) : : l_yes);
29 
30 	return false;
31 l_yes:
32 	return true;
33 }
34 
35 static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
36 {
37 	asm_volatile_goto("1:\n\t"
38 		 "b %l[l_yes]\n\t"
39 		 ".pushsection __jump_table,  \"aw\"\n\t"
40 		 JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t"
41 		 ".popsection \n\t"
42 		 : :  "i" (&((char *)key)[branch]) : : l_yes);
43 
44 	return false;
45 l_yes:
46 	return true;
47 }
48 
49 #ifdef CONFIG_PPC64
50 typedef u64 jump_label_t;
51 #else
52 typedef u32 jump_label_t;
53 #endif
54 
55 struct jump_entry {
56 	jump_label_t code;
57 	jump_label_t target;
58 	jump_label_t key;
59 };
60 
61 #else
62 #define ARCH_STATIC_BRANCH(LABEL, KEY)		\
63 1098:	nop;					\
64 	.pushsection __jump_table, "aw";	\
65 	FTR_ENTRY_LONG 1098b, LABEL, KEY;	\
66 	.popsection
67 #endif
68 
69 #endif /* _ASM_POWERPC_JUMP_LABEL_H */
70