1  /* Copyright (C) 2022-2023 Free Software Foundation, Inc.
       2     Contributed by Xiongchuan Tan <xc-tan@outlook.com>.
       3  
       4     This file is part of the GNU Transactional Memory Library (libitm).
       5  
       6     Libitm is free software; you can redistribute it and/or modify it
       7     under the terms of the GNU General Public License as published by
       8     the Free Software Foundation; either version 3 of the License, or
       9     (at your option) any later version.
      10  
      11     Libitm is distributed in the hope that it will be useful, but WITHOUT ANY
      12     WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
      13     FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
      14     more details.
      15  
      16     Under Section 7 of GPL version 3, you are granted additional
      17     permissions described in the GCC Runtime Library Exception, version
      18     3.1, as published by the Free Software Foundation.
      19  
      20     You should have received a copy of the GNU General Public License and
      21     a copy of the GCC Runtime Library Exception along with this program;
      22     see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
      23     <http://www.gnu.org/licenses/>.  */
      24  
      25  namespace GTM HIDDEN {
      26  
      27  typedef struct gtm_jmpbuf
      28    {
      29      long int pc;
      30      void *cfa;
      31      long int s[12]; /* Saved registers, s0 is fp */
      32  
      33  #if __riscv_xlen == 32
      34      /* Ensure that the stack is 16-byte aligned */
      35      long int padding[2];
      36  #endif
      37  
      38      /* FP saved registers */
      39  #if defined(__riscv_flen) && __riscv_flen == 64
      40      double fs[12];
      41  #elif defined(__riscv_flen) && __riscv_flen == 32
      42      float fs[12];
      43  #elif defined(__riscv_flen)
      44  #  error Q-extension unsupported
      45  #endif
      46    } gtm_jmpbuf;
      47  
      48  /* The size of one line in hardware caches (in bytes). */
      49  /* 64 bytes is a suggested value in the RVA profiles (see
      50     https://github.com/riscv/riscv-profiles/blob/main/profiles.adoc). */
      51  #define HW_CACHELINE_SIZE 64
      52  
      53  static inline void
      54  cpu_relax (void)
      55  {
      56    #ifdef __riscv_zihintpause
      57        __asm volatile ("pause");
      58    #else
      59        /* Encoding of the pause instruction */
      60        __asm volatile (".4byte 0x100000F");
      61    #endif
      62  }
      63  
      64  } // namespace GTM