[mirror_ubuntu-bionic-kernel.git] / arch / openrisc / include / asm / cmpxchg.h

/*
 * Copyright (C) 2014 Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
 *
 * This file is licensed under the terms of the GNU General Public License
 * version 2.  This program is licensed "as is" without any warranty of any
 * kind, whether express or implied.
 */

#ifndef __ASM_OPENRISC_CMPXCHG_H
#define __ASM_OPENRISC_CMPXCHG_H

#include  <linux/types.h>

/*
 * This function doesn't exist, so you'll get a linker error
 * if something tries to do an invalid cmpxchg().
 */
extern void __cmpxchg_called_with_bad_pointer(void);

#define __HAVE_ARCH_CMPXCHG 1

static inline unsigned long
__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
{
	if (size != 4) {
		__cmpxchg_called_with_bad_pointer();
		return old;
	}

	__asm__ __volatile__(
		"1:	l.lwa %0, 0(%1)		\n"
		"	l.sfeq %0, %2		\n"
		"	l.bnf 2f		\n"
		"	 l.nop			\n"
		"	l.swa 0(%1), %3		\n"
		"	l.bnf 1b		\n"
		"	 l.nop			\n"
		"2:				\n"
		: "=&r"(old)
		: "r"(ptr), "r"(old), "r"(new)
		: "cc", "memory");

	return old;
}

#define cmpxchg(ptr, o, n)						\
	({								\
		(__typeof__(*(ptr))) __cmpxchg((ptr),			\
					       (unsigned long)(o),	\
					       (unsigned long)(n),	\
					       sizeof(*(ptr)));		\
	})

/*
 * This function doesn't exist, so you'll get a linker error if
 * something tries to do an invalidly-sized xchg().
 */
extern void __xchg_called_with_bad_pointer(void);

static inline unsigned long __xchg(unsigned long val, volatile void *ptr,
				   int size)
{
	if (size != 4) {
		__xchg_called_with_bad_pointer();
		return val;
	}

	__asm__ __volatile__(
		"1:	l.lwa %0, 0(%1)		\n"
		"	l.swa 0(%1), %2		\n"
		"	l.bnf 1b		\n"
		"	 l.nop			\n"
		: "=&r"(val)
		: "r"(ptr), "r"(val)
		: "cc", "memory");

	return val;
}

#define xchg(ptr, with) 						\
	({								\
		(__typeof__(*(ptr))) __xchg((unsigned long)(with),	\
					    (ptr),			\
					    sizeof(*(ptr)));		\
	})

#endif /* __ASM_OPENRISC_CMPXCHG_H */
Commit	Line	Data
11595172 SK	1	/*
	2	* Copyright (C) 2014 Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
	3	*
	4	* This file is licensed under the terms of the GNU General Public License
	5	* version 2. This program is licensed "as is" without any warranty of any
	6	* kind, whether express or implied.
	7	*/
	8
	9	#ifndef __ASM_OPENRISC_CMPXCHG_H
	10	#define __ASM_OPENRISC_CMPXCHG_H
	11
	12	#include <linux/types.h>
	13
	14	/*
	15	* This function doesn't exist, so you'll get a linker error
	16	* if something tries to do an invalid cmpxchg().
	17	*/
	18	extern void __cmpxchg_called_with_bad_pointer(void);
	19
	20	#define __HAVE_ARCH_CMPXCHG 1
	21
	22	static inline unsigned long
	23	__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
	24	{
	25	if (size != 4) {
	26	__cmpxchg_called_with_bad_pointer();
	27	return old;
	28	}
	29
	30	__asm__ __volatile__(
	31	"1: l.lwa %0, 0(%1) \n"
	32	" l.sfeq %0, %2 \n"
	33	" l.bnf 2f \n"
	34	" l.nop \n"
	35	" l.swa 0(%1), %3 \n"
	36	" l.bnf 1b \n"
	37	" l.nop \n"
	38	"2: \n"
	39	: "=&r"(old)
	40	: "r"(ptr), "r"(old), "r"(new)
	41	: "cc", "memory");
	42
	43	return old;
	44	}
	45
	46	#define cmpxchg(ptr, o, n) \
	47	({ \
	48	(__typeof__(*(ptr))) __cmpxchg((ptr), \
	49	(unsigned long)(o), \
	50	(unsigned long)(n), \
	51	sizeof(*(ptr))); \
	52	})
	53
	54	/*
	55	* This function doesn't exist, so you'll get a linker error if
	56	* something tries to do an invalidly-sized xchg().
	57	*/
	58	extern void __xchg_called_with_bad_pointer(void);
	59
	60	static inline unsigned long __xchg(unsigned long val, volatile void *ptr,
	61	int size)
	62	{
	63	if (size != 4) {
	64	__xchg_called_with_bad_pointer();
65	return val;
66	}
67
68	__asm__ __volatile__(
69	"1: l.lwa %0, 0(%1) \n"
70	" l.swa 0(%1), %2 \n"
71	" l.bnf 1b \n"
72	" l.nop \n"
73	: "=&r"(val)
74	: "r"(ptr), "r"(val)
75	: "cc", "memory");
76
77	return val;
78	}
79
8af42949 SH	80	#define xchg(ptr, with) \
	81	({ \
	82	(__typeof__(*(ptr))) __xchg((unsigned long)(with), \
	83	(ptr), \
	84	sizeof(*(ptr))); \
	85	})
11595172 SK	86
11595172 SK	87	#endif /* __ASM_OPENRISC_CMPXCHG_H */