text: /* Copyright (c) 2013 The Regents of the University of California
   * Barret Rhoden <brho@cs.berkeley.edu>
   * Kevin Klues <klueska@cs.berkeley.edu>
   *
   * Spinlocks and Spin-PDR locks (preemption detection/recovery)
   *
   * This file is part of Parlib.
   * 
   * Parlib is free software: you can redistribute it and/or modify
   * it under the terms of the Lesser GNU General Public License as published by
   * the Free Software Foundation, either version 3 of the License, or
   * (at your option) any later version.
   * 
   * Parlib is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * Lesser GNU General Public License for more details.
   * 
   * See COPYING.LESSER for details on the GNU Lesser General Public License.
   * See COPYING for details on the GNU General Public License. */
  
  #ifndef SPINLOCK_H
  #define SPINLOCK_H
  
  #include <arch/arch.h>
  #include <arch/atomic.h>
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  #define SPINLOCK_INITIALIZER {0}
  
  typedef struct {
    int lock;
  } spinlock_t;
  
  void spinlock_init(spinlock_t *lock);
  int spinlock_trylock(spinlock_t *lock);
  void spinlock_lock(spinlock_t *lock);
  void spinlock_unlock(spinlock_t *lock);
  
  /* RISCV doesn't support CAS, so til it does, we use the NO_CAS, even if they
   * didn't ask for it in their config. */
  #ifdef __riscv__
  # ifndef CONFIG_SPINPDR_NO_CAS
  #  define CONFIG_SPINPDR_NO_CAS 1
  # endif
  #endif
  
  /* Two different versions, with and without CAS.  Default is with CAS. */
  #ifndef CONFIG_SPINPDR_NO_CAS
  
  # define SPINPDR_UNLOCKED ((uint32_t)-1)
  
  struct spin_pdr_lock {
  	uint32_t lock;
  };
  # define SPINPDR_INITIALIZER {SPINPDR_UNLOCKED}
  
  #else /* NO_CAS */
  
  # define SPINPDR_VCOREID_UNKNOWN ((uint32_t)-1)
  
  struct spin_pdr_lock {
  	spinlock_t spinlock;
  	uint32_t lockholder;
  };
  # define SPINPDR_INITIALIZER {SPINLOCK_INITIALIZER, SPINPDR_VCOREID_UNKNOWN}
  
  #endif /* CONFIG_SPINPDR_NO_CAS */
  
  typedef struct spin_pdr_lock spinpdrlock_t;
  
  void spin_pdr_init(struct spin_pdr_lock *pdr_lock);
  void spin_pdr_lock(struct spin_pdr_lock *pdr_lock);
  void spin_pdr_unlock(struct spin_pdr_lock *pdr_lock);
  
  #ifdef __cplusplus
  }
  #endif
  
  
  #endif // SPINLOCK_H
  