xref: /OK3568_Linux_fs/kernel/arch/powerpc/include/asm/jump_label.h (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0-or-later */
2*4882a593Smuzhiyun #ifndef _ASM_POWERPC_JUMP_LABEL_H
3*4882a593Smuzhiyun #define _ASM_POWERPC_JUMP_LABEL_H
4*4882a593Smuzhiyun 
5*4882a593Smuzhiyun /*
6*4882a593Smuzhiyun  * Copyright 2010 Michael Ellerman, IBM Corp.
7*4882a593Smuzhiyun  */
8*4882a593Smuzhiyun 
9*4882a593Smuzhiyun #ifndef __ASSEMBLY__
10*4882a593Smuzhiyun #include <linux/types.h>
11*4882a593Smuzhiyun 
12*4882a593Smuzhiyun #include <asm/feature-fixups.h>
13*4882a593Smuzhiyun #include <asm/asm-const.h>
14*4882a593Smuzhiyun 
15*4882a593Smuzhiyun #define JUMP_ENTRY_TYPE		stringify_in_c(FTR_ENTRY_LONG)
16*4882a593Smuzhiyun #define JUMP_LABEL_NOP_SIZE	4
17*4882a593Smuzhiyun 
arch_static_branch(struct static_key * key,bool branch)18*4882a593Smuzhiyun static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
19*4882a593Smuzhiyun {
20*4882a593Smuzhiyun 	asm_volatile_goto("1:\n\t"
21*4882a593Smuzhiyun 		 "nop # arch_static_branch\n\t"
22*4882a593Smuzhiyun 		 ".pushsection __jump_table,  \"aw\"\n\t"
23*4882a593Smuzhiyun 		 JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t"
24*4882a593Smuzhiyun 		 ".popsection \n\t"
25*4882a593Smuzhiyun 		 : :  "i" (&((char *)key)[branch]) : : l_yes);
26*4882a593Smuzhiyun 
27*4882a593Smuzhiyun 	return false;
28*4882a593Smuzhiyun l_yes:
29*4882a593Smuzhiyun 	return true;
30*4882a593Smuzhiyun }
31*4882a593Smuzhiyun 
arch_static_branch_jump(struct static_key * key,bool branch)32*4882a593Smuzhiyun static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
33*4882a593Smuzhiyun {
34*4882a593Smuzhiyun 	asm_volatile_goto("1:\n\t"
35*4882a593Smuzhiyun 		 "b %l[l_yes] # arch_static_branch_jump\n\t"
36*4882a593Smuzhiyun 		 ".pushsection __jump_table,  \"aw\"\n\t"
37*4882a593Smuzhiyun 		 JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t"
38*4882a593Smuzhiyun 		 ".popsection \n\t"
39*4882a593Smuzhiyun 		 : :  "i" (&((char *)key)[branch]) : : l_yes);
40*4882a593Smuzhiyun 
41*4882a593Smuzhiyun 	return false;
42*4882a593Smuzhiyun l_yes:
43*4882a593Smuzhiyun 	return true;
44*4882a593Smuzhiyun }
45*4882a593Smuzhiyun 
46*4882a593Smuzhiyun #ifdef CONFIG_PPC64
47*4882a593Smuzhiyun typedef u64 jump_label_t;
48*4882a593Smuzhiyun #else
49*4882a593Smuzhiyun typedef u32 jump_label_t;
50*4882a593Smuzhiyun #endif
51*4882a593Smuzhiyun 
52*4882a593Smuzhiyun struct jump_entry {
53*4882a593Smuzhiyun 	jump_label_t code;
54*4882a593Smuzhiyun 	jump_label_t target;
55*4882a593Smuzhiyun 	jump_label_t key;
56*4882a593Smuzhiyun };
57*4882a593Smuzhiyun 
58*4882a593Smuzhiyun #else
59*4882a593Smuzhiyun #define ARCH_STATIC_BRANCH(LABEL, KEY)		\
60*4882a593Smuzhiyun 1098:	nop;					\
61*4882a593Smuzhiyun 	.pushsection __jump_table, "aw";	\
62*4882a593Smuzhiyun 	FTR_ENTRY_LONG 1098b, LABEL, KEY;	\
63*4882a593Smuzhiyun 	.popsection
64*4882a593Smuzhiyun #endif
65*4882a593Smuzhiyun 
66*4882a593Smuzhiyun #endif /* _ASM_POWERPC_JUMP_LABEL_H */
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