arch/arm64/include/asm/lse.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __ASM_LSE_H
   3 #define __ASM_LSE_H
   4
   5 #include <asm/atomic_ll_sc.h>
   6
   7 #ifdef CONFIG_ARM64_LSE_ATOMICS
   8
   9 #define __LSE_PREAMBLE  ".arch_extension lse\n"
  10
  11 #include <linux/compiler_types.h>
  12 #include <linux/export.h>
  13 #include <linux/stringify.h>
  14 #include <asm/alternative.h>
  15 #include <asm/alternative-macros.h>
  16 #include <asm/atomic_lse.h>
  17 #include <asm/cpucaps.h>
  18
  19 static __always_inline bool system_uses_lse_atomics(void)
  20 {
  21         return alternative_has_feature_likely(ARM64_HAS_LSE_ATOMICS);
  22 }
  23
  24 #define __lse_ll_sc_body(op, ...)                                       \
  25 ({                                                                      \
  26         system_uses_lse_atomics() ?                                     \
  27                 __lse_##op(__VA_ARGS__) :                               \
  28                 __ll_sc_##op(__VA_ARGS__);                              \
  29 })
  30
  31 /* In-line patching at runtime */
  32 #define ARM64_LSE_ATOMIC_INSN(llsc, lse)                                \
  33         ALTERNATIVE(llsc, __LSE_PREAMBLE lse, ARM64_HAS_LSE_ATOMICS)
  34
  35 #else   /* CONFIG_ARM64_LSE_ATOMICS */
  36
  37 static inline bool system_uses_lse_atomics(void) { return false; }
  38
  39 #define __lse_ll_sc_body(op, ...)               __ll_sc_##op(__VA_ARGS__)
  40
  41 #define ARM64_LSE_ATOMIC_INSN(llsc, lse)        llsc
  42
  43 #endif  /* CONFIG_ARM64_LSE_ATOMICS */
  44 #endif  /* __ASM_LSE_H */