include/asm/jump_label.h

0001 /* SPDX-License-Identifier: GPL-2.0-or-later */
0002 #ifndef _ASM_POWERPC_JUMP_LABEL_H
0003 #define _ASM_POWERPC_JUMP_LABEL_H
0004
0005 /*
0006  * Copyright 2010 Michael Ellerman, IBM Corp.
0007  */
0008
0009 #ifndef __ASSEMBLY__
0010 #include <linux/types.h>
0011
0012 #include <asm/feature-fixups.h>
0013 #include <asm/asm-const.h>
0014
0015 #define JUMP_ENTRY_TYPE     stringify_in_c(FTR_ENTRY_LONG)
0016 #define JUMP_LABEL_NOP_SIZE 4
0017
0018 static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
0019 {
0020     asm_volatile_goto("1:\n\t"
0021          "nop # arch_static_branch\n\t"
0022          ".pushsection __jump_table,  \"aw\"\n\t"
0023          ".long 1b - ., %l[l_yes] - .\n\t"
0024          JUMP_ENTRY_TYPE "%c0 - .\n\t"
0025          ".popsection \n\t"
0026          : :  "i" (&((char *)key)[branch]) : : l_yes);
0027
0028     return false;
0029 l_yes:
0030     return true;
0031 }
0032
0033 static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
0034 {
0035     asm_volatile_goto("1:\n\t"
0036          "b %l[l_yes] # arch_static_branch_jump\n\t"
0037          ".pushsection __jump_table,  \"aw\"\n\t"
0038          ".long 1b - ., %l[l_yes] - .\n\t"
0039          JUMP_ENTRY_TYPE "%c0 - .\n\t"
0040          ".popsection \n\t"
0041          : :  "i" (&((char *)key)[branch]) : : l_yes);
0042
0043     return false;
0044 l_yes:
0045     return true;
0046 }
0047
0048 #else
0049 #define ARCH_STATIC_BRANCH(LABEL, KEY)      \
0050 1098:   nop;                    \
0051     .pushsection __jump_table, "aw";    \
0052     .long 1098b - ., LABEL - .;     \
0053     FTR_ENTRY_LONG KEY - .;         \
0054     .popsection
0055 #endif
0056
0057 #endif /* _ASM_POWERPC_JUMP_LABEL_H */