xref: /openbmc/linux/arch/powerpc/include/asm/jump_label.h (revision 2874c5fd284268364ece81a7bd936f3c8168e567)
1*2874c5fdSThomas Gleixner /* SPDX-License-Identifier: GPL-2.0-or-later */
2ac5f89c7SMichael Ellerman #ifndef _ASM_POWERPC_JUMP_LABEL_H
3ac5f89c7SMichael Ellerman #define _ASM_POWERPC_JUMP_LABEL_H
4ac5f89c7SMichael Ellerman 
5ac5f89c7SMichael Ellerman /*
6ac5f89c7SMichael Ellerman  * Copyright 2010 Michael Ellerman, IBM Corp.
7ac5f89c7SMichael Ellerman  */
8ac5f89c7SMichael Ellerman 
9cc1adb5fSAnton Blanchard #ifndef __ASSEMBLY__
10ac5f89c7SMichael Ellerman #include <linux/types.h>
11ac5f89c7SMichael Ellerman 
12ac5f89c7SMichael Ellerman #include <asm/feature-fixups.h>
13ec0c464cSChristophe Leroy #include <asm/asm-const.h>
14ac5f89c7SMichael Ellerman 
15ac5f89c7SMichael Ellerman #define JUMP_ENTRY_TYPE		stringify_in_c(FTR_ENTRY_LONG)
16ac5f89c7SMichael Ellerman #define JUMP_LABEL_NOP_SIZE	4
17ac5f89c7SMichael Ellerman 
1811276d53SPeter Zijlstra static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
19ac5f89c7SMichael Ellerman {
203f0116c3SIngo Molnar 	asm_volatile_goto("1:\n\t"
21e2985fd9SMichael Ellerman 		 "nop # arch_static_branch\n\t"
22ac5f89c7SMichael Ellerman 		 ".pushsection __jump_table,  \"aw\"\n\t"
23ac5f89c7SMichael Ellerman 		 JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t"
24ac5f89c7SMichael Ellerman 		 ".popsection \n\t"
2511276d53SPeter Zijlstra 		 : :  "i" (&((char *)key)[branch]) : : l_yes);
2611276d53SPeter Zijlstra 
2711276d53SPeter Zijlstra 	return false;
2811276d53SPeter Zijlstra l_yes:
2911276d53SPeter Zijlstra 	return true;
3011276d53SPeter Zijlstra }
3111276d53SPeter Zijlstra 
3211276d53SPeter Zijlstra static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
3311276d53SPeter Zijlstra {
3411276d53SPeter Zijlstra 	asm_volatile_goto("1:\n\t"
35e2985fd9SMichael Ellerman 		 "b %l[l_yes] # arch_static_branch_jump\n\t"
3611276d53SPeter Zijlstra 		 ".pushsection __jump_table,  \"aw\"\n\t"
3711276d53SPeter Zijlstra 		 JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t"
3811276d53SPeter Zijlstra 		 ".popsection \n\t"
3911276d53SPeter Zijlstra 		 : :  "i" (&((char *)key)[branch]) : : l_yes);
4011276d53SPeter Zijlstra 
41ac5f89c7SMichael Ellerman 	return false;
42ac5f89c7SMichael Ellerman l_yes:
43ac5f89c7SMichael Ellerman 	return true;
44ac5f89c7SMichael Ellerman }
45ac5f89c7SMichael Ellerman 
46ac5f89c7SMichael Ellerman #ifdef CONFIG_PPC64
47ac5f89c7SMichael Ellerman typedef u64 jump_label_t;
48ac5f89c7SMichael Ellerman #else
49ac5f89c7SMichael Ellerman typedef u32 jump_label_t;
50ac5f89c7SMichael Ellerman #endif
51ac5f89c7SMichael Ellerman 
52ac5f89c7SMichael Ellerman struct jump_entry {
53ac5f89c7SMichael Ellerman 	jump_label_t code;
54ac5f89c7SMichael Ellerman 	jump_label_t target;
55ac5f89c7SMichael Ellerman 	jump_label_t key;
56ac5f89c7SMichael Ellerman };
57ac5f89c7SMichael Ellerman 
58cc1adb5fSAnton Blanchard #else
59cc1adb5fSAnton Blanchard #define ARCH_STATIC_BRANCH(LABEL, KEY)		\
60cc1adb5fSAnton Blanchard 1098:	nop;					\
61cc1adb5fSAnton Blanchard 	.pushsection __jump_table, "aw";	\
62cc1adb5fSAnton Blanchard 	FTR_ENTRY_LONG 1098b, LABEL, KEY;	\
63cc1adb5fSAnton Blanchard 	.popsection
64cc1adb5fSAnton Blanchard #endif
65cc1adb5fSAnton Blanchard 
66ac5f89c7SMichael Ellerman #endif /* _ASM_POWERPC_JUMP_LABEL_H */
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