arch/arm64/include/asm/atomic_ll_sc.h - kernel/msm-4.9 - Gitiles

 /*
  * Based on arch/arm/include/asm/atomic.h
  *
  * Copyright (C) 1996 Russell King.
  * Copyright (C) 2002 Deep Blue Solutions Ltd.
  * Copyright (C) 2012 ARM Ltd.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  * This program 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
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */

 #ifndef __ASM_ATOMIC_LL_SC_H
 #define __ASM_ATOMIC_LL_SC_H

 #ifndef __ARM64_IN_ATOMIC_IMPL
 #error "please don't include this file directly"
 #endif

 /*
  * AArch64 UP and SMP safe atomic ops.  We use load exclusive and
  * store exclusive to ensure that these are atomic.  We may loop
  * to ensure that the update happens.
  *
  * NOTE: these functions do *not* follow the PCS and must explicitly
  * save any clobbered registers other than x0 (regardless of return
  * value).  This is achieved through -fcall-saved-* compiler flags for
  * this file, which unfortunately don't work on a per-function basis
  * (the optimize attribute silently ignores these options).
  */

 #define ATOMIC_OP(op, asm_op)						\
 __LL_SC_INLINE void							\
 __LL_SC_PREFIX(atomic_##op(int i, atomic_t *v))				\
 {									\
 	unsigned long tmp;						\
 	int result;							\
 									\
 	asm volatile("// atomic_" #op "\n"				\
 "1:	ldxr	%w0, %2\n"						\
 "	" #asm_op "	%w0, %w0, %w3\n"				\
 "	stxr	%w1, %w0, %2\n"						\
 "	cbnz	%w1, 1b"						\
 	: "=&r" (result), "=&r" (tmp), "+Q" (v->counter)		\
 	: "Ir" (i));							\
 }									\
 __LL_SC_EXPORT(atomic_##op);

 #define ATOMIC_OP_RETURN(op, asm_op)					\
 __LL_SC_INLINE int							\
 __LL_SC_PREFIX(atomic_##op##_return(int i, atomic_t *v))		\
 {									\
 	unsigned long tmp;						\
 	int result;							\
 									\
 	asm volatile("// atomic_" #op "_return\n"			\
 "1:	ldxr	%w0, %2\n"						\
 "	" #asm_op "	%w0, %w0, %w3\n"				\
 "	stlxr	%w1, %w0, %2\n"						\
 "	cbnz	%w1, 1b"						\
 	: "=&r" (result), "=&r" (tmp), "+Q" (v->counter)		\
 	: "Ir" (i)							\
 	: "memory");							\
 									\
 	smp_mb();							\
 	return result;							\
 }									\
 __LL_SC_EXPORT(atomic_##op##_return);

 #define ATOMIC_OPS(op, asm_op)						\
 	ATOMIC_OP(op, asm_op)						\
 	ATOMIC_OP_RETURN(op, asm_op)

 ATOMIC_OPS(add, add)
 ATOMIC_OPS(sub, sub)

 ATOMIC_OP(and, and)
 ATOMIC_OP(andnot, bic)
 ATOMIC_OP(or, orr)
 ATOMIC_OP(xor, eor)

 #undef ATOMIC_OPS
 #undef ATOMIC_OP_RETURN
 #undef ATOMIC_OP

 __LL_SC_INLINE int
 __LL_SC_PREFIX(atomic_cmpxchg(atomic_t *ptr, int old, int new))
 {
 	unsigned long tmp;
 	int oldval;

 	asm volatile("// atomic_cmpxchg\n"
 "1:	ldxr	%w1, %2\n"
 "	eor	%w0, %w1, %w3\n"
 "	cbnz	%w0, 2f\n"
 "	stlxr	%w0, %w4, %2\n"
 "	cbnz	%w0, 1b\n"
 "	dmb	ish\n"
 "2:"
 	: "=&r" (tmp), "=&r" (oldval), "+Q" (ptr->counter)
 	: "Lr" (old), "r" (new)
 	: "memory");

 	return oldval;
 }
 __LL_SC_EXPORT(atomic_cmpxchg);

 #define ATOMIC64_OP(op, asm_op)						\
 __LL_SC_INLINE void							\
 __LL_SC_PREFIX(atomic64_##op(long i, atomic64_t *v))			\
 {									\
 	long result;							\
 	unsigned long tmp;						\
 									\
 	asm volatile("// atomic64_" #op "\n"				\
 "1:	ldxr	%0, %2\n"						\
 "	" #asm_op "	%0, %0, %3\n"					\
 "	stxr	%w1, %0, %2\n"						\
 "	cbnz	%w1, 1b"						\
 	: "=&r" (result), "=&r" (tmp), "+Q" (v->counter)		\
 	: "Ir" (i));							\
 }									\
 __LL_SC_EXPORT(atomic64_##op);

 #define ATOMIC64_OP_RETURN(op, asm_op)					\
 __LL_SC_INLINE long							\
 __LL_SC_PREFIX(atomic64_##op##_return(long i, atomic64_t *v))		\
 {									\
 	long result;							\
 	unsigned long tmp;						\
 									\
 	asm volatile("// atomic64_" #op "_return\n"			\
 "1:	ldxr	%0, %2\n"						\
 "	" #asm_op "	%0, %0, %3\n"					\
 "	stlxr	%w1, %0, %2\n"						\
 "	cbnz	%w1, 1b"						\
 	: "=&r" (result), "=&r" (tmp), "+Q" (v->counter)		\
 	: "Ir" (i)							\
 	: "memory");							\
 									\
 	smp_mb();							\
 	return result;							\
 }									\
 __LL_SC_EXPORT(atomic64_##op##_return);

 #define ATOMIC64_OPS(op, asm_op)					\
 	ATOMIC64_OP(op, asm_op)						\
 	ATOMIC64_OP_RETURN(op, asm_op)

 ATOMIC64_OPS(add, add)
 ATOMIC64_OPS(sub, sub)

 ATOMIC64_OP(and, and)
 ATOMIC64_OP(andnot, bic)
 ATOMIC64_OP(or, orr)
 ATOMIC64_OP(xor, eor)

 #undef ATOMIC64_OPS
 #undef ATOMIC64_OP_RETURN
 #undef ATOMIC64_OP

 __LL_SC_INLINE long
 __LL_SC_PREFIX(atomic64_cmpxchg(atomic64_t *ptr, long old, long new))
 {
 	long oldval;
 	unsigned long res;

 	asm volatile("// atomic64_cmpxchg\n"
 "1:	ldxr	%1, %2\n"
 "	eor	%0, %1, %3\n"
 "	cbnz	%w0, 2f\n"
 "	stlxr	%w0, %4, %2\n"
 "	cbnz	%w0, 1b\n"
 "	dmb	ish\n"
 "2:"
 	: "=&r" (res), "=&r" (oldval), "+Q" (ptr->counter)
 	: "Lr" (old), "r" (new)
 	: "memory");

 	return oldval;
 }
 __LL_SC_EXPORT(atomic64_cmpxchg);

 __LL_SC_INLINE long
 __LL_SC_PREFIX(atomic64_dec_if_positive(atomic64_t *v))
 {
 	long result;
 	unsigned long tmp;

 	asm volatile("// atomic64_dec_if_positive\n"
 "1:	ldxr	%0, %2\n"
 "	subs	%0, %0, #1\n"
 "	b.mi	2f\n"
 "	stlxr	%w1, %0, %2\n"
 "	cbnz	%w1, 1b\n"
 "	dmb	ish\n"
 "2:"
 	: "=&r" (result), "=&r" (tmp), "+Q" (v->counter)
 	:
 	: "cc", "memory");

 	return result;
 }
 __LL_SC_EXPORT(atomic64_dec_if_positive);

 #define __CMPXCHG_CASE(w, sz, name, mb, rel, cl)			\
 __LL_SC_INLINE unsigned long						\
 __LL_SC_PREFIX(__cmpxchg_case_##name(volatile void *ptr,		\
 				     unsigned long old,			\
 				     unsigned long new))		\
 {									\
 	unsigned long tmp, oldval;					\
 									\
 	asm volatile(							\
 	"1:	ldxr" #sz "\t%" #w "[oldval], %[v]\n"			\
 	"	eor	%" #w "[tmp], %" #w "[oldval], %" #w "[old]\n"	\
 	"	cbnz	%" #w "[tmp], 2f\n"				\
 	"	st" #rel "xr" #sz "\t%w[tmp], %" #w "[new], %[v]\n"	\
 	"	cbnz	%w[tmp], 1b\n"					\
 	"	" #mb "\n"						\
 	"	mov	%" #w "[oldval], %" #w "[old]\n"		\
 	"2:"								\
 	: [tmp] "=&r" (tmp), [oldval] "=&r" (oldval),			\
 	  [v] "+Q" (*(unsigned long *)ptr)				\
 	: [old] "Lr" (old), [new] "r" (new)				\
 	: cl);								\
 									\
 	return oldval;							\
 }									\
 __LL_SC_EXPORT(__cmpxchg_case_##name);

 __CMPXCHG_CASE(w, b,    1,        ,  ,         )
 __CMPXCHG_CASE(w, h,    2,        ,  ,         )
 __CMPXCHG_CASE(w,  ,    4,        ,  ,         )
 __CMPXCHG_CASE( ,  ,    8,        ,  ,         )
 __CMPXCHG_CASE(w, b, mb_1, dmb ish, l, "memory")
 __CMPXCHG_CASE(w, h, mb_2, dmb ish, l, "memory")
 __CMPXCHG_CASE(w,  , mb_4, dmb ish, l, "memory")
 __CMPXCHG_CASE( ,  , mb_8, dmb ish, l, "memory")

 #undef __CMPXCHG_CASE

 #define __CMPXCHG_DBL(name, mb, rel, cl)				\
 __LL_SC_INLINE int							\
 __LL_SC_PREFIX(__cmpxchg_double##name(unsigned long old1,		\
 				      unsigned long old2,		\
 				      unsigned long new1,		\
 				      unsigned long new2,		\
 				      volatile void *ptr))		\
 {									\
 	unsigned long tmp, ret;						\
 									\
 	asm volatile("// __cmpxchg_double" #name "\n"			\
 	"1:	ldxp	%0, %1, %2\n"					\
 	"	eor	%0, %0, %3\n"					\
 	"	eor	%1, %1, %4\n"					\
 	"	orr	%1, %0, %1\n"					\
 	"	cbnz	%1, 2f\n"					\
 	"	st" #rel "xp	%w0, %5, %6, %2\n"			\
 	"	cbnz	%w0, 1b\n"					\
 	"	" #mb "\n"						\
 	"2:"								\
 	: "=&r" (tmp), "=&r" (ret), "+Q" (*(unsigned long *)ptr)	\
 	: "r" (old1), "r" (old2), "r" (new1), "r" (new2)		\
 	: cl);								\
 									\
 	return ret;							\
 }									\
 __LL_SC_EXPORT(__cmpxchg_double##name);

 __CMPXCHG_DBL(   ,        ,  ,         )
 __CMPXCHG_DBL(_mb, dmb ish, l, "memory")

 #undef __CMPXCHG_DBL

 #endif	/* __ASM_ATOMIC_LL_SC_H */
	/*
	* Based on arch/arm/include/asm/atomic.h
	*
	* Copyright (C) 1996 Russell King.
	* Copyright (C) 2002 Deep Blue Solutions Ltd.
	* Copyright (C) 2012 ARM Ltd.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* This program 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
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	*/

	#ifndef __ASM_ATOMIC_LL_SC_H
	#define __ASM_ATOMIC_LL_SC_H

	#ifndef __ARM64_IN_ATOMIC_IMPL
	#error "please don't include this file directly"
	#endif

	/*
	* AArch64 UP and SMP safe atomic ops. We use load exclusive and
	* store exclusive to ensure that these are atomic. We may loop
	* to ensure that the update happens.
	*
	* NOTE: these functions do not follow the PCS and must explicitly
	* save any clobbered registers other than x0 (regardless of return
	* value). This is achieved through -fcall-saved-* compiler flags for
	* this file, which unfortunately don't work on a per-function basis
	* (the optimize attribute silently ignores these options).
	*/

	#define ATOMIC_OP(op, asm_op) \
	__LL_SC_INLINE void \
	__LL_SC_PREFIX(atomic_##op(int i, atomic_t *v)) \
	{ \
	unsigned long tmp; \
	int result; \
	\
	asm volatile("// atomic_" #op "\n" \
	"1: ldxr %w0, %2\n" \
	" " #asm_op " %w0, %w0, %w3\n" \
	" stxr %w1, %w0, %2\n" \
	" cbnz %w1, 1b" \
	: "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \
	: "Ir" (i)); \
	} \
	__LL_SC_EXPORT(atomic_##op);

	#define ATOMIC_OP_RETURN(op, asm_op) \
	__LL_SC_INLINE int \
	__LL_SC_PREFIX(atomic_##op##_return(int i, atomic_t *v)) \
	{ \
	unsigned long tmp; \
	int result; \
	\
	asm volatile("// atomic_" #op "_return\n" \
	"1: ldxr %w0, %2\n" \
	" " #asm_op " %w0, %w0, %w3\n" \
	" stlxr %w1, %w0, %2\n" \
	" cbnz %w1, 1b" \
	: "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \
	: "Ir" (i) \
	: "memory"); \
	\
	smp_mb(); \
	return result; \
	} \
	__LL_SC_EXPORT(atomic_##op##_return);

	#define ATOMIC_OPS(op, asm_op) \
	ATOMIC_OP(op, asm_op) \
	ATOMIC_OP_RETURN(op, asm_op)

	ATOMIC_OPS(add, add)
	ATOMIC_OPS(sub, sub)

	ATOMIC_OP(and, and)
	ATOMIC_OP(andnot, bic)
	ATOMIC_OP(or, orr)
	ATOMIC_OP(xor, eor)

	#undef ATOMIC_OPS
	#undef ATOMIC_OP_RETURN
	#undef ATOMIC_OP

	__LL_SC_INLINE int
	__LL_SC_PREFIX(atomic_cmpxchg(atomic_t *ptr, int old, int new))
	{
	unsigned long tmp;
	int oldval;

	asm volatile("// atomic_cmpxchg\n"
	"1: ldxr %w1, %2\n"
	" eor %w0, %w1, %w3\n"
	" cbnz %w0, 2f\n"
	" stlxr %w0, %w4, %2\n"
	" cbnz %w0, 1b\n"
	" dmb ish\n"
	"2:"
	: "=&r" (tmp), "=&r" (oldval), "+Q" (ptr->counter)
	: "Lr" (old), "r" (new)
	: "memory");

	return oldval;
	}
	__LL_SC_EXPORT(atomic_cmpxchg);

	#define ATOMIC64_OP(op, asm_op) \
	__LL_SC_INLINE void \
	__LL_SC_PREFIX(atomic64_##op(long i, atomic64_t *v)) \
	{ \
	long result; \
	unsigned long tmp; \
	\
	asm volatile("// atomic64_" #op "\n" \
	"1: ldxr %0, %2\n" \
	" " #asm_op " %0, %0, %3\n" \
	" stxr %w1, %0, %2\n" \
	" cbnz %w1, 1b" \
	: "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \
	: "Ir" (i)); \
	} \
	__LL_SC_EXPORT(atomic64_##op);

	#define ATOMIC64_OP_RETURN(op, asm_op) \
	__LL_SC_INLINE long \
	__LL_SC_PREFIX(atomic64_##op##_return(long i, atomic64_t *v)) \
	{ \
	long result; \
	unsigned long tmp; \
	\
	asm volatile("// atomic64_" #op "_return\n" \
	"1: ldxr %0, %2\n" \
	" " #asm_op " %0, %0, %3\n" \
	" stlxr %w1, %0, %2\n" \
	" cbnz %w1, 1b" \
	: "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \
	: "Ir" (i) \
	: "memory"); \
	\
	smp_mb(); \
	return result; \
	} \
	__LL_SC_EXPORT(atomic64_##op##_return);

	#define ATOMIC64_OPS(op, asm_op) \
	ATOMIC64_OP(op, asm_op) \
	ATOMIC64_OP_RETURN(op, asm_op)

	ATOMIC64_OPS(add, add)
	ATOMIC64_OPS(sub, sub)

	ATOMIC64_OP(and, and)
	ATOMIC64_OP(andnot, bic)
	ATOMIC64_OP(or, orr)
	ATOMIC64_OP(xor, eor)

	#undef ATOMIC64_OPS
	#undef ATOMIC64_OP_RETURN
	#undef ATOMIC64_OP

	__LL_SC_INLINE long
	__LL_SC_PREFIX(atomic64_cmpxchg(atomic64_t *ptr, long old, long new))
	{
	long oldval;
	unsigned long res;

	asm volatile("// atomic64_cmpxchg\n"
	"1: ldxr %1, %2\n"
	" eor %0, %1, %3\n"
	" cbnz %w0, 2f\n"
	" stlxr %w0, %4, %2\n"
	" cbnz %w0, 1b\n"
	" dmb ish\n"
	"2:"
	: "=&r" (res), "=&r" (oldval), "+Q" (ptr->counter)
	: "Lr" (old), "r" (new)
	: "memory");

	return oldval;
	}
	__LL_SC_EXPORT(atomic64_cmpxchg);

	__LL_SC_INLINE long
	__LL_SC_PREFIX(atomic64_dec_if_positive(atomic64_t *v))
	{
	long result;
	unsigned long tmp;

	asm volatile("// atomic64_dec_if_positive\n"
	"1: ldxr %0, %2\n"
	" subs %0, %0, #1\n"
	" b.mi 2f\n"
	" stlxr %w1, %0, %2\n"
	" cbnz %w1, 1b\n"
	" dmb ish\n"
	"2:"
	: "=&r" (result), "=&r" (tmp), "+Q" (v->counter)
	:
	: "cc", "memory");

	return result;
	}
	__LL_SC_EXPORT(atomic64_dec_if_positive);

	#define __CMPXCHG_CASE(w, sz, name, mb, rel, cl) \
	__LL_SC_INLINE unsigned long \
	__LL_SC_PREFIX(__cmpxchg_case_##name(volatile void *ptr, \
	unsigned long old, \
	unsigned long new)) \
	{ \
	unsigned long tmp, oldval; \
	\
	asm volatile( \
	"1: ldxr" #sz "\t%" #w "[oldval], %[v]\n" \
	" eor %" #w "[tmp], %" #w "[oldval], %" #w "[old]\n" \
	" cbnz %" #w "[tmp], 2f\n" \
	" st" #rel "xr" #sz "\t%w[tmp], %" #w "[new], %[v]\n" \
	" cbnz %w[tmp], 1b\n" \
	" " #mb "\n" \
	" mov %" #w "[oldval], %" #w "[old]\n" \
	"2:" \
	: [tmp] "=&r" (tmp), [oldval] "=&r" (oldval), \
	[v] "+Q" ((unsigned long )ptr) \
	: [old] "Lr" (old), [new] "r" (new) \
	: cl); \
	\
	return oldval; \
	} \
	__LL_SC_EXPORT(__cmpxchg_case_##name);

	__CMPXCHG_CASE(w, b, 1, , , )
	__CMPXCHG_CASE(w, h, 2, , , )
	__CMPXCHG_CASE(w, , 4, , , )
	__CMPXCHG_CASE( , , 8, , , )
	__CMPXCHG_CASE(w, b, mb_1, dmb ish, l, "memory")
	__CMPXCHG_CASE(w, h, mb_2, dmb ish, l, "memory")
	__CMPXCHG_CASE(w, , mb_4, dmb ish, l, "memory")
	__CMPXCHG_CASE( , , mb_8, dmb ish, l, "memory")

	#undef __CMPXCHG_CASE

	#define __CMPXCHG_DBL(name, mb, rel, cl) \
	__LL_SC_INLINE int \
	__LL_SC_PREFIX(__cmpxchg_double##name(unsigned long old1, \
	unsigned long old2, \
	unsigned long new1, \
	unsigned long new2, \
	volatile void *ptr)) \
	{ \
	unsigned long tmp, ret; \
	\
	asm volatile("// __cmpxchg_double" #name "\n" \
	"1: ldxp %0, %1, %2\n" \
	" eor %0, %0, %3\n" \
	" eor %1, %1, %4\n" \
	" orr %1, %0, %1\n" \
	" cbnz %1, 2f\n" \
	" st" #rel "xp %w0, %5, %6, %2\n" \
	" cbnz %w0, 1b\n" \
	" " #mb "\n" \
	"2:" \
	: "=&r" (tmp), "=&r" (ret), "+Q" ((unsigned long )ptr) \
	: "r" (old1), "r" (old2), "r" (new1), "r" (new2) \
	: cl); \
	\
	return ret; \
	} \
	__LL_SC_EXPORT(__cmpxchg_double##name);

	__CMPXCHG_DBL( , , , )
	__CMPXCHG_DBL(_mb, dmb ish, l, "memory")

	#undef __CMPXCHG_DBL

	#endif /* __ASM_ATOMIC_LL_SC_H */