include/asm/jump_label.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #ifndef _ASM_X86_JUMP_LABEL_H
0003 #define _ASM_X86_JUMP_LABEL_H
0004
0005 #define HAVE_JUMP_LABEL_BATCH
0006
0007 #include <asm/asm.h>
0008 #include <asm/nops.h>
0009
0010 #ifndef __ASSEMBLY__
0011
0012 #include <linux/stringify.h>
0013 #include <linux/types.h>
0014
0015 #define JUMP_TABLE_ENTRY                \
0016     ".pushsection __jump_table,  \"aw\" \n\t"   \
0017     _ASM_ALIGN "\n\t"               \
0018     ".long 1b - . \n\t"             \
0019     ".long %l[l_yes] - . \n\t"          \
0020     _ASM_PTR "%c0 + %c1 - .\n\t"            \
0021     ".popsection \n\t"
0022
0023 #ifdef CONFIG_HAVE_JUMP_LABEL_HACK
0024
0025 static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
0026 {
0027     asm_volatile_goto("1:"
0028         "jmp %l[l_yes] # objtool NOPs this \n\t"
0029         JUMP_TABLE_ENTRY
0030         : :  "i" (key), "i" (2 | branch) : : l_yes);
0031
0032     return false;
0033 l_yes:
0034     return true;
0035 }
0036
0037 #else /* !CONFIG_HAVE_JUMP_LABEL_HACK */
0038
0039 static __always_inline bool arch_static_branch(struct static_key * const key, const bool branch)
0040 {
0041     asm_volatile_goto("1:"
0042         ".byte " __stringify(BYTES_NOP5) "\n\t"
0043         JUMP_TABLE_ENTRY
0044         : :  "i" (key), "i" (branch) : : l_yes);
0045
0046     return false;
0047 l_yes:
0048     return true;
0049 }
0050
0051 #endif /* CONFIG_HAVE_JUMP_LABEL_HACK */
0052
0053 static __always_inline bool arch_static_branch_jump(struct static_key * const key, const bool branch)
0054 {
0055     asm_volatile_goto("1:"
0056         "jmp %l[l_yes]\n\t"
0057         JUMP_TABLE_ENTRY
0058         : :  "i" (key), "i" (branch) : : l_yes);
0059
0060     return false;
0061 l_yes:
0062     return true;
0063 }
0064
0065 extern int arch_jump_entry_size(struct jump_entry *entry);
0066
0067 #endif  /* __ASSEMBLY__ */
0068
0069 #endif