text: /*
   * Copyright 2009-2015 Samy Al Bahra.
   * Copyright 2012 João Fernandes.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   */
  
  #ifndef CK_PR_PPC_H
  #define CK_PR_PPC_H
  
  #ifndef CK_PR_H
  #error Do not include this file directly, use ck_pr.h
  #endif
  
  #include <ck_cc.h>
  #include <ck_md.h>
  
  /*
   * The following represent supported atomic operations.
   * These operations may be emulated.
   */
  #include "ck_f_pr.h"
  
  /*
   * Minimum interface requirement met.
   */
  #define CK_F_PR
  
  /*
   * This bounces the hardware thread from low to medium
   * priority. I am unsure of the benefits of this approach
   * but it is used by the Linux kernel.
   */
  CK_CC_INLINE static void
  ck_pr_stall(void)
  {
  
  	__asm__ __volatile__("or 1, 1, 1;"
  			     "or 2, 2, 2;" ::: "memory");
  	return;
  }
  
  #define CK_PR_FENCE(T, I)				\
  	CK_CC_INLINE static void			\
  	ck_pr_fence_strict_##T(void)			\
  	{						\
  		__asm__ __volatile__(I ::: "memory");   \
  	}
  
  CK_PR_FENCE(atomic, "lwsync")
  CK_PR_FENCE(atomic_store, "lwsync")
  CK_PR_FENCE(atomic_load, "sync")
  CK_PR_FENCE(store_atomic, "lwsync")
  CK_PR_FENCE(load_atomic, "lwsync")
  CK_PR_FENCE(store, "lwsync")
  CK_PR_FENCE(store_load, "sync")
  CK_PR_FENCE(load, "lwsync")
  CK_PR_FENCE(load_store, "lwsync")
  CK_PR_FENCE(memory, "sync")
  CK_PR_FENCE(acquire, "lwsync")
  CK_PR_FENCE(release, "lwsync")
  CK_PR_FENCE(acqrel, "lwsync")
  CK_PR_FENCE(lock, "lwsync")
  CK_PR_FENCE(unlock, "lwsync")
  
  #undef CK_PR_FENCE
  
  #define CK_PR_LOAD(S, M, T, C, I)					\
  	CK_CC_INLINE static T						\
  	ck_pr_md_load_##S(const M *target)				\
  	{								\
  		T r;							\
  		__asm__ __volatile__(I "%U1%X1 %0, %1"			\
  					: "=r" (r)			\
  					: "m"  (*(const C *)target)	\
  					: "memory");			\
  		return (r);						\
  	}
  
  CK_PR_LOAD(ptr, void, void *, uint32_t, "lwz")
  
  #define CK_PR_LOAD_S(S, T, I) CK_PR_LOAD(S, T, T, T, I)
  
  CK_PR_LOAD_S(32, uint32_t, "lwz")
  CK_PR_LOAD_S(16, uint16_t, "lhz")
  CK_PR_LOAD_S(8, uint8_t, "lbz")
  CK_PR_LOAD_S(uint, unsigned int, "lwz")
  CK_PR_LOAD_S(int, int, "lwz")
  CK_PR_LOAD_S(short, short, "lhz")
  CK_PR_LOAD_S(char, char, "lbz")
  
  #undef CK_PR_LOAD_S
  #undef CK_PR_LOAD
  
  #define CK_PR_STORE(S, M, T, C, I)				\
  	CK_CC_INLINE static void				\
  	ck_pr_md_store_##S(M *target, T v)			\
  	{							\
  		__asm__ __volatile__(I "%U0%X0 %1, %0"		\
  					: "=m" (*(C *)target)	\
  					: "r" (v)		\
  					: "memory");		\
  		return;						\
  	}
  
  CK_PR_STORE(ptr, void, const void *, uint32_t, "stw")
  
  #define CK_PR_STORE_S(S, T, I) CK_PR_STORE(S, T, T, T, I)
  
  CK_PR_STORE_S(32, uint32_t, "stw")
  CK_PR_STORE_S(16, uint16_t, "sth")
  CK_PR_STORE_S(8, uint8_t, "stb")
  CK_PR_STORE_S(uint, unsigned int, "stw")
  CK_PR_STORE_S(int, int, "stw")
  CK_PR_STORE_S(short, short, "sth")
  CK_PR_STORE_S(char, char, "stb")
  
  #undef CK_PR_STORE_S
  #undef CK_PR_STORE
  
  #define CK_PR_CAS(N, T, M)						\
  	CK_CC_INLINE static bool					\
  	ck_pr_cas_##N##_value(M *target, T compare, T set, M *value)	\
  	{								\
  		T previous;						\
  		__asm__ __volatile__("1:"				\
  				     "lwarx %0, 0, %1;"			\
  				     "cmpw  0, %0, %3;"			\
  				     "bne-  2f;"			\
  				     "stwcx. %2, 0, %1;"		\
  				     "bne-  1b;"			\
  				     "2:"				\
  					: "=&r" (previous)		\
  					: "r"   (target),		\
  					  "r"   (set),			\
  					  "r"   (compare)		\
  					: "memory", "cc");		\
  		*(T *)value = previous; 				\
  		return (previous == compare);				\
  	}								\
  	CK_CC_INLINE static bool					\
  	ck_pr_cas_##N(M *target, T compare, T set)			\
  	{								\
  		T previous;						\
  		__asm__ __volatile__("1:"				\
  				     "lwarx %0, 0, %1;"			\
  				     "cmpw  0, %0, %3;"			\
  				     "bne-  2f;"			\
  				     "stwcx. %2, 0, %1;"		\
  				     "bne-  1b;"			\
  				     "2:"				\
  					: "=&r" (previous)		\
  					: "r"   (target),		\
  					  "r"   (set),			\
  					  "r"   (compare)		\
  					: "memory", "cc");		\
  		return (previous == compare);				\
  	}
  
  CK_PR_CAS(ptr, void *, void)
  #define CK_PR_CAS_S(a, b) CK_PR_CAS(a, b, b)
  CK_PR_CAS_S(32, uint32_t)
  CK_PR_CAS_S(uint, unsigned int)
  CK_PR_CAS_S(int, int)
  
  #undef CK_PR_CAS_S
  #undef CK_PR_CAS
  
  #define CK_PR_FAS(N, M, T, W)					\
  	CK_CC_INLINE static T					\
  	ck_pr_fas_##N(M *target, T v)				\
  	{							\
  		T previous;					\
  		__asm__ __volatile__("1:"			\
  				     "l" W "arx %0, 0, %1;"	\
  				     "st" W "cx. %2, 0, %1;"	\
  				     "bne- 1b;"			\
  					: "=&r" (previous)	\
  					: "r"   (target),	\
  					  "r"   (v)		\
  					: "memory", "cc");	\
  		return (previous);				\
  	}
  
  CK_PR_FAS(32, uint32_t, uint32_t, "w")
  CK_PR_FAS(ptr, void, void *, "w")
  CK_PR_FAS(int, int, int, "w")
  CK_PR_FAS(uint, unsigned int, unsigned int, "w")
  
  #undef CK_PR_FAS
  
  #define CK_PR_UNARY(O, N, M, T, I, W)				\
  	CK_CC_INLINE static void				\
  	ck_pr_##O##_##N(M *target)				\
  	{							\
  		T previous;					\
  		__asm__ __volatile__("1:"			\
  				     "l" W "arx %0, 0, %1;"	\
  				      I ";"			\
  				     "st" W "cx. %0, 0, %1;"	\
  				     "bne-  1b;"		\
  					: "=&r" (previous)	\
  					: "r"   (target)	\
  					: "memory", "cc");	\
  		return;						\
  	}
  
  CK_PR_UNARY(inc, ptr, void, void *, "addic %0, %0, 1", "w")
  CK_PR_UNARY(dec, ptr, void, void *, "addic %0, %0, -1", "w")
  CK_PR_UNARY(not, ptr, void, void *, "not %0, %0", "w")
  CK_PR_UNARY(neg, ptr, void, void *, "neg %0, %0", "w")
  
  #define CK_PR_UNARY_S(S, T, W)					\
  	CK_PR_UNARY(inc, S, T, T, "addic %0, %0, 1", W)		\
  	CK_PR_UNARY(dec, S, T, T, "addic %0, %0, -1", W)	\
  	CK_PR_UNARY(not, S, T, T, "not %0, %0", W)		\
  	CK_PR_UNARY(neg, S, T, T, "neg %0, %0", W)
  
  CK_PR_UNARY_S(32, uint32_t, "w")
  CK_PR_UNARY_S(uint, unsigned int, "w")
  CK_PR_UNARY_S(int, int, "w")
  
  #undef CK_PR_UNARY_S
  #undef CK_PR_UNARY
  
  #define CK_PR_BINARY(O, N, M, T, I, W)				\
  	CK_CC_INLINE static void				\
  	ck_pr_##O##_##N(M *target, T delta)			\
  	{							\
  		T previous;					\
  		__asm__ __volatile__("1:"			\
  				     "l" W "arx %0, 0, %1;"	\
  				      I " %0, %2, %0;"		\
  				     "st" W "cx. %0, 0, %1;"	\
  				     "bne-  1b;"		\
  					: "=&r" (previous)	\
  					: "r"   (target),	\
  					  "r"   (delta)		\
  					: "memory", "cc");	\
  		return;						\
  	}
  
  CK_PR_BINARY(and, ptr, void, uintptr_t, "and", "w")
  CK_PR_BINARY(add, ptr, void, uintptr_t, "add", "w")
  CK_PR_BINARY(or, ptr, void, uintptr_t, "or", "w")
  CK_PR_BINARY(sub, ptr, void, uintptr_t, "sub", "w")
  CK_PR_BINARY(xor, ptr, void, uintptr_t, "xor", "w")
  
  #define CK_PR_BINARY_S(S, T, W)			\
  	CK_PR_BINARY(and, S, T, T, "and", W)	\
  	CK_PR_BINARY(add, S, T, T, "add", W)	\
  	CK_PR_BINARY(or, S, T, T, "or", W)	\
  	CK_PR_BINARY(sub, S, T, T, "subf", W)	\
  	CK_PR_BINARY(xor, S, T, T, "xor", W)
  
  CK_PR_BINARY_S(32, uint32_t, "w")
  CK_PR_BINARY_S(uint, unsigned int, "w")
  CK_PR_BINARY_S(int, int, "w")
  
  #undef CK_PR_BINARY_S
  #undef CK_PR_BINARY
  
  CK_CC_INLINE static void *
  ck_pr_faa_ptr(void *target, uintptr_t delta)
  {
  	uintptr_t previous, r;
  
  	__asm__ __volatile__("1:"
  			     "lwarx %0, 0, %2;"
  			     "add %1, %3, %0;"
  			     "stwcx. %1, 0, %2;"
  			     "bne-  1b;"
  				: "=&r" (previous),
  				  "=&r" (r)
  				: "r"   (target),
  				  "r"   (delta)
  				: "memory", "cc");
  
  	return (void *)(previous);
  }
  
  #define CK_PR_FAA(S, T, W)						\
  	CK_CC_INLINE static T						\
  	ck_pr_faa_##S(T *target, T delta)				\
  	{								\
  		T previous, r;						\
  		__asm__ __volatile__("1:"				\
  				     "l" W "arx %0, 0, %2;"		\
  				     "add %1, %3, %0;"			\
  				     "st" W "cx. %1, 0, %2;"		\
  				     "bne-  1b;"			\
  					: "=&r" (previous),		\
  					  "=&r" (r)			\
  					: "r"   (target),		\
  					  "r"   (delta)			\
  					: "memory", "cc");		\
  		return (previous);					\
  	}
  
  CK_PR_FAA(32, uint32_t, "w")
  CK_PR_FAA(uint, unsigned int, "w")
  CK_PR_FAA(int, int, "w")
  
  #undef CK_PR_FAA
  
  #endif /* CK_PR_PPC_H */
  
  