text: // SPDX-License-Identifier: Apache-2.0
  /* Copyright 2017 IBM Corp. */
  
  #ifndef __CMPXCHG_H
  #define __CMPXCHG_H
  
  #ifndef __TEST__
  /*
   * Bare cmpxchg, no barriers.
   */
  static inline uint32_t __cmpxchg32(uint32_t *mem, uint32_t old, uint32_t new)
  {
  	uint32_t prev;
  
  	asm volatile(
  		"# __cmpxchg32		\n"
  		"1:	lwarx	%0,0,%2	\n"
  		"	cmpw	%0,%3	\n"
  		"	bne-	2f	\n"
  		"	stwcx.	%4,0,%2	\n"
  		"	bne-	1b	\n"
  		"2:			\n"
  
  		: "=&r"(prev), "+m"(*mem)
  		: "r"(mem), "r"(old), "r"(new)
  		: "cr0");
  
  	return prev;
  }
  
  static inline uint64_t __cmpxchg64(uint64_t *mem, uint64_t old, uint64_t new)
  {
  	uint64_t prev;
  
  	asm volatile(
  		"# __cmpxchg64		\n"
  		"1:	ldarx	%0,0,%2	\n"
  		"	cmpd	%0,%3	\n"
  		"	bne-	2f	\n"
  		"	stdcx.	%4,0,%2	\n"
  		"	bne-	1b	\n"
  		"2:			\n"
  
  		: "=&r"(prev), "+m"(*mem)
  		: "r"(mem), "r"(old), "r"(new)
  		: "cr0");
  
  	return prev;
  }
  
  static inline uint32_t cmpxchg32(uint32_t *mem, uint32_t old, uint32_t new)
  {
  	uint32_t prev;
  
  	sync();
  	prev = __cmpxchg32(mem, old,new);
  	sync();
  
  	return prev;
  }
  #endif /* __TEST_ */
  
  #endif /* __CMPXCHG_H */
  
  
  