include/urcu/uatomic/riscv.h

   1 // SPDX-FileCopyrightText: 2018 Michael Jeanson <mjeanson@efficios.com>
   2 //
   3 // SPDX-License-Identifier: MIT
   4
   5 /*
   6  * Atomic exchange operations for the RISC-V architecture.
   7  *
   8  * Let the compiler do it.
   9  */
  10
  11 /*
  12  * See <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104831> for details.
  13  *
  14  * Until the following patches are backported, Userspace RCU is broken for the
  15  * RISC-V architecture when compiled with GCC.
  16  *
  17  *  - <https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=4990cf84c460f064d6281d0813f20b0ef20c7448>
  18  *  - <https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=4990cf84c460f064d6281d0813f20b0ef20c7448>
  19  *  - <https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d199d2e56da2379004e7e0457150409c0c99d3e6>
  20  */
  21 #if defined(__GNUC__)
  22 #  error "Implementations of some atomic operations of GCC for RISC-V \
  23           are insufficient for sequential consistency. For this reason \
  24           Userspace RCU is currently marked as 'broken' for RISC-V with \
  25           GCC. However, it is still possible to use other toolchains."
  26 #endif
  27
  28 #ifndef _URCU_ARCH_UATOMIC_RISCV_H
  29 #define _URCU_ARCH_UATOMIC_RISCV_H
  30
  31 #include <urcu/compiler.h>
  32 #include <urcu/system.h>
  33
  34 #ifdef __cplusplus
  35 extern "C" {
  36 #endif
  37
  38 #define UATOMIC_HAS_ATOMIC_BYTE
  39 #define UATOMIC_HAS_ATOMIC_SHORT
  40
  41 #ifdef __cplusplus
  42 }
  43 #endif
  44
  45 #include <urcu/uatomic/generic.h>
  46
  47 #endif /* _URCU_ARCH_UATOMIC_RISCV_H */