arch/x86/include/asm/jump_label.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_X86_JUMP_LABEL_H
   3 #define _ASM_X86_JUMP_LABEL_H
   4
   5 #define HAVE_JUMP_LABEL_BATCH
   6
   7 #define JUMP_LABEL_NOP_SIZE 5
   8
   9 #include <asm/asm.h>
  10 #include <asm/nops.h>
  11
  12 #ifndef __ASSEMBLY__
  13
  14 #include <linux/stringify.h>
  15 #include <linux/types.h>
  16
  17 static __always_inline bool arch_static_branch(struct static_key * const key, const bool branch)
  18 {
  19         asm_volatile_goto("1:"
  20                 ".byte " __stringify(BYTES_NOP5) "\n\t"
  21                 ".pushsection __jump_table,  \"aw\" \n\t"
  22                 _ASM_ALIGN "\n\t"
  23                 ".long 1b - ., %l[l_yes] - . \n\t"
  24                 _ASM_PTR "%c0 + %c1 - .\n\t"
  25                 ".popsection \n\t"
  26                 : :  "i" (key), "i" (branch) : : l_yes);
  27
  28         return false;
  29 l_yes:
  30         return true;
  31 }
  32
  33 static __always_inline bool arch_static_branch_jump(struct static_key * const key, const bool branch)
  34 {
  35         asm_volatile_goto("1:"
  36                 ".byte 0xe9\n\t .long %l[l_yes] - 2f\n\t"
  37                 "2:\n\t"
  38                 ".pushsection __jump_table,  \"aw\" \n\t"
  39                 _ASM_ALIGN "\n\t"
  40                 ".long 1b - ., %l[l_yes] - . \n\t"
  41                 _ASM_PTR "%c0 + %c1 - .\n\t"
  42                 ".popsection \n\t"
  43                 : :  "i" (key), "i" (branch) : : l_yes);
  44
  45         return false;
  46 l_yes:
  47         return true;
  48 }
  49
  50 #else   /* __ASSEMBLY__ */
  51
  52 .macro STATIC_JUMP_IF_TRUE target, key, def
  53 .Lstatic_jump_\@:
  54         .if \def
  55         /* Equivalent to "jmp.d32 \target" */
  56         .byte           0xe9
  57         .long           \target - .Lstatic_jump_after_\@
  58 .Lstatic_jump_after_\@:
  59         .else
  60         .byte           BYTES_NOP5
  61         .endif
  62         .pushsection __jump_table, "aw"
  63         _ASM_ALIGN
  64         .long           .Lstatic_jump_\@ - ., \target - .
  65         _ASM_PTR        \key - .
  66         .popsection
  67 .endm
  68
  69 .macro STATIC_JUMP_IF_FALSE target, key, def
  70 .Lstatic_jump_\@:
  71         .if \def
  72         .byte           BYTES_NOP5
  73         .else
  74         /* Equivalent to "jmp.d32 \target" */
  75         .byte           0xe9
  76         .long           \target - .Lstatic_jump_after_\@
  77 .Lstatic_jump_after_\@:
  78         .endif
  79         .pushsection __jump_table, "aw"
  80         _ASM_ALIGN
  81         .long           .Lstatic_jump_\@ - ., \target - .
  82         _ASM_PTR        \key + 1 - .
  83         .popsection
  84 .endm
  85
  86 #endif  /* __ASSEMBLY__ */
  87
  88 #endif