From 76cb841cb886eef6b3bee341a2266c76578724ad Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 03:02:30 +0200 Subject: Adding upstream version 4.19.249. Signed-off-by: Daniel Baumann --- arch/sh/include/asm/cmpxchg-xchg.h | 52 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 arch/sh/include/asm/cmpxchg-xchg.h (limited to 'arch/sh/include/asm/cmpxchg-xchg.h') diff --git a/arch/sh/include/asm/cmpxchg-xchg.h b/arch/sh/include/asm/cmpxchg-xchg.h new file mode 100644 index 000000000..593a97047 --- /dev/null +++ b/arch/sh/include/asm/cmpxchg-xchg.h @@ -0,0 +1,52 @@ +#ifndef __ASM_SH_CMPXCHG_XCHG_H +#define __ASM_SH_CMPXCHG_XCHG_H + +/* + * Copyright (C) 2016 Red Hat, Inc. + * Author: Michael S. Tsirkin + * + * This work is licensed under the terms of the GNU GPL, version 2. See the + * file "COPYING" in the main directory of this archive for more details. + */ +#include +#include +#include + +/* + * Portable implementations of 1 and 2 byte xchg using a 4 byte cmpxchg. + * Note: this header isn't self-contained: before including it, __cmpxchg_u32 + * must be defined first. + */ +static inline u32 __xchg_cmpxchg(volatile void *ptr, u32 x, int size) +{ + int off = (unsigned long)ptr % sizeof(u32); + volatile u32 *p = ptr - off; +#ifdef __BIG_ENDIAN + int bitoff = (sizeof(u32) - size - off) * BITS_PER_BYTE; +#else + int bitoff = off * BITS_PER_BYTE; +#endif + u32 bitmask = ((0x1 << size * BITS_PER_BYTE) - 1) << bitoff; + u32 oldv, newv; + u32 ret; + + do { + oldv = READ_ONCE(*p); + ret = (oldv & bitmask) >> bitoff; + newv = (oldv & ~bitmask) | (x << bitoff); + } while (__cmpxchg_u32(p, oldv, newv) != oldv); + + return ret; +} + +static inline unsigned long xchg_u16(volatile u16 *m, unsigned long val) +{ + return __xchg_cmpxchg(m, val, sizeof *m); +} + +static inline unsigned long xchg_u8(volatile u8 *m, unsigned long val) +{ + return __xchg_cmpxchg(m, val, sizeof *m); +} + +#endif /* __ASM_SH_CMPXCHG_XCHG_H */ -- cgit v1.2.3