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/xtensa/include/asm/cmpxchg.h | 162 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 162 insertions(+) create mode 100644 arch/xtensa/include/asm/cmpxchg.h (limited to 'arch/xtensa/include/asm/cmpxchg.h') diff --git a/arch/xtensa/include/asm/cmpxchg.h b/arch/xtensa/include/asm/cmpxchg.h new file mode 100644 index 000000000..201e9009e --- /dev/null +++ b/arch/xtensa/include/asm/cmpxchg.h @@ -0,0 +1,162 @@ +/* + * Atomic xchg and cmpxchg operations. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2001 - 2005 Tensilica Inc. + */ + +#ifndef _XTENSA_CMPXCHG_H +#define _XTENSA_CMPXCHG_H + +#ifndef __ASSEMBLY__ + +#include + +/* + * cmpxchg + */ + +static inline unsigned long +__cmpxchg_u32(volatile int *p, int old, int new) +{ +#if XCHAL_HAVE_S32C1I + __asm__ __volatile__( + " wsr %2, scompare1\n" + " s32c1i %0, %1, 0\n" + : "+a" (new) + : "a" (p), "a" (old) + : "memory" + ); + + return new; +#else + __asm__ __volatile__( + " rsil a15, "__stringify(TOPLEVEL)"\n" + " l32i %0, %1, 0\n" + " bne %0, %2, 1f\n" + " s32i %3, %1, 0\n" + "1:\n" + " wsr a15, ps\n" + " rsync\n" + : "=&a" (old) + : "a" (p), "a" (old), "r" (new) + : "a15", "memory"); + return old; +#endif +} +/* 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); + +static __inline__ unsigned long +__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size) +{ + switch (size) { + case 4: return __cmpxchg_u32(ptr, old, new); + default: __cmpxchg_called_with_bad_pointer(); + return old; + } +} + +#define cmpxchg(ptr,o,n) \ + ({ __typeof__(*(ptr)) _o_ = (o); \ + __typeof__(*(ptr)) _n_ = (n); \ + (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \ + (unsigned long)_n_, sizeof (*(ptr))); \ + }) + +#include + +static inline unsigned long __cmpxchg_local(volatile void *ptr, + unsigned long old, + unsigned long new, int size) +{ + switch (size) { + case 4: + return __cmpxchg_u32(ptr, old, new); + default: + return __cmpxchg_local_generic(ptr, old, new, size); + } + + return old; +} + +/* + * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make + * them available. + */ +#define cmpxchg_local(ptr, o, n) \ + ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\ + (unsigned long)(n), sizeof(*(ptr)))) +#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) +#define cmpxchg64(ptr, o, n) cmpxchg64_local((ptr), (o), (n)) + +/* + * xchg_u32 + * + * Note that a15 is used here because the register allocation + * done by the compiler is not guaranteed and a window overflow + * may not occur between the rsil and wsr instructions. By using + * a15 in the rsil, the machine is guaranteed to be in a state + * where no register reference will cause an overflow. + */ + +static inline unsigned long xchg_u32(volatile int * m, unsigned long val) +{ +#if XCHAL_HAVE_S32C1I + unsigned long tmp, result; + __asm__ __volatile__( + "1: l32i %1, %2, 0\n" + " mov %0, %3\n" + " wsr %1, scompare1\n" + " s32c1i %0, %2, 0\n" + " bne %0, %1, 1b\n" + : "=&a" (result), "=&a" (tmp) + : "a" (m), "a" (val) + : "memory" + ); + return result; +#else + unsigned long tmp; + __asm__ __volatile__( + " rsil a15, "__stringify(TOPLEVEL)"\n" + " l32i %0, %1, 0\n" + " s32i %2, %1, 0\n" + " wsr a15, ps\n" + " rsync\n" + : "=&a" (tmp) + : "a" (m), "a" (val) + : "a15", "memory"); + return tmp; +#endif +} + +#define xchg(ptr,x) \ + ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)))) + +/* + * This only works if the compiler isn't horribly bad at optimizing. + * gcc-2.5.8 reportedly can't handle this, but I define that one to + * be dead anyway. + */ + +extern void __xchg_called_with_bad_pointer(void); + +static __inline__ unsigned long +__xchg(unsigned long x, volatile void * ptr, int size) +{ + switch (size) { + case 4: + return xchg_u32(ptr, x); + } + __xchg_called_with_bad_pointer(); + return x; +} + +#endif /* __ASSEMBLY__ */ + +#endif /* _XTENSA_CMPXCHG_H */ -- cgit v1.2.3