/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_POWERPC_CMPXCHG_H_ #define _ASM_POWERPC_CMPXCHG_H_ #ifdef __KERNEL__ #include <linux/compiler.h> #include <asm/synch.h> #include <asm/asm-compat.h> #include <linux/bug.h> #ifdef __BIG_ENDIAN #define BITOFF_CAL(size, off) ((sizeof(u32) - size - off) * BITS_PER_BYTE) #else #define BITOFF_CAL(size, off) (off * BITS_PER_BYTE) #endif #define XCHG_GEN(type, sfx, cl) \ static inline u32 __xchg_##type##sfx(volatile void *p, u32 val) \ { \ unsigned int prev, prev_mask, tmp, bitoff, off; \ \ off = (unsigned long)p % sizeof(u32); \ bitoff = BITOFF_CAL(sizeof(type), off); \ p -= off; \ val <<= bitoff; \ prev_mask = (u32)(type)-1 << bitoff; \ \ __asm__ __volatile__( \ "1: lwarx %0,0,%3\n" \ " andc %1,%0,%5\n" \ " or %1,%1,%4\n" \ PPC405_ERR77(0,%3) \ " stwcx. %1,0,%3\n" \ " bne- 1b\n" \ : "=&r" (prev), "=&r" (tmp), "+m" (*(u32*)p) \ : "r" (p), "r" (val), "r" (prev_mask) \ : "cc", cl); \ \ return prev >> bitoff; \ } #define CMPXCHG_GEN(type, sfx, br, br2, cl) \ static inline \ u32 __cmpxchg_##type##sfx(volatile void *p, u32 old, u32 new) \ { \ unsigned int prev, prev_mask, tmp, bitoff, off; \ \ off = (unsigned long)p % sizeof(u32); \ bitoff = BITOFF_CAL(sizeof(type), off); \ p -= off; \ old <<= bitoff; \ new <<= bitoff; \ prev_mask = (u32)(type)-1 << bitoff; \ \ __asm__ __volatile__( \ br \ "1: lwarx %0,0,%3\n" \ " and %1,%0,%6\n" \ " cmpw 0,%1,%4\n" \ " bne- 2f\n" \ " andc %1,%0,%6\n" \ " or %1,%1,%5\n" \ PPC405_ERR77(0,%3) \ " stwcx. %1,0,%3\n" \ " bne- 1b\n" \ br2 \ "\n" \ "2:" \ : "=&r" (prev), "=&r" (tmp), "+m" (*(u32*)p) \ : "r" (p), "r" (old), "r" (new), "r" (prev_mask) \ : "cc", cl); \ \ return prev >> bitoff; \ } /* * Atomic exchange * * Changes the memory location '*p' to be val and returns * the previous value stored there. */ XCHG_GEN(u8, _local, "memory"); XCHG_GEN(u8, _relaxed, "cc"); XCHG_GEN(u16, _local, "memory"); XCHG_GEN(u16, _relaxed, "cc"); static __always_inline unsigned long __xchg_u32_local(volatile void *p, unsigned long val) { unsigned long prev; __asm__ __volatile__( "1: lwarx %0,0,%2 \n" PPC405_ERR77(0,%2) " stwcx. %3,0,%2 \n\ bne- 1b" : "=&r" (prev), "+m" (*(volatile unsigned int *)p) : "r" (p), "r" (val) : "cc", "memory"); return prev; } static __always_inline unsigned long __xchg_u32_relaxed(u32 *p, unsigned long val) { unsigned long prev; __asm__ __volatile__( "1: lwarx %0,0,%2\n" PPC405_ERR77(0, %2) " stwcx. %3,0,%2\n" " bne- 1b" : "=&r" (prev), "+m" (*p) : "r" (p), "r" (val) : "cc"); return prev; } #ifdef CONFIG_PPC64 static __always_inline unsigned long __xchg_u64_local(volatile void *p, unsigned long val) { unsigned long prev; __asm__ __volatile__( "1: ldarx %0,0,%2 \n" PPC405_ERR77(0,%2) " stdcx. %3,0,%2 \n\ bne- 1b" : "=&r" (prev), "+m" (*(volatile unsigned long *)p) : "r" (p), "r" (val) : "cc", "memory"); return prev; } static __always_inline unsigned long __xchg_u64_relaxed(u64 *p, unsigned long val) { unsigned long prev; __asm__ __volatile__( "1: ldarx %0,0,%2\n" PPC405_ERR77(0, %2) " stdcx. %3,0,%2\n" " bne- 1b" : "=&r" (prev), "+m" (*p) : "r" (p), "r" (val) : "cc"); return prev; } #endif static __always_inline unsigned long __xchg_local(void *ptr, unsigned long x, unsigned int size) { switch (size) { case 1: return __xchg_u8_local(ptr, x); case 2: return __xchg_u16_local(ptr, x); case 4: return __xchg_u32_local(ptr, x); #ifdef CONFIG_PPC64 case 8: return __xchg_u64_local(ptr, x); #endif } BUILD_BUG_ON_MSG(1, "Unsupported size for __xchg"); return x; } static __always_inline unsigned long __xchg_relaxed(void *ptr, unsigned long x, unsigned int size) { switch (size) { case 1: return __xchg_u8_relaxed(ptr, x); case 2: return __xchg_u16_relaxed(ptr, x); case 4: return __xchg_u32_relaxed(ptr, x); #ifdef CONFIG_PPC64 case 8: return __xchg_u64_relaxed(ptr, x); #endif } BUILD_BUG_ON_MSG(1, "Unsupported size for __xchg_local"); return x; } #define xchg_local(ptr,x) \ ({ \ __typeof__(*(ptr)) _x_ = (x); \ (__typeof__(*(ptr))) __xchg_local((ptr), \ (unsigned long)_x_, sizeof(*(ptr))); \ }) #define xchg_relaxed(ptr, x) \ ({ \ __typeof__(*(ptr)) _x_ = (x); \ (__typeof__(*(ptr))) __xchg_relaxed((ptr), \ (unsigned long)_x_, sizeof(*(ptr))); \ }) /* * Compare and exchange - if *p == old, set it to new, * and return the old value of *p. */ CMPXCHG_GEN(u8, , PPC_ATOMIC_ENTRY_BARRIER, PPC_ATOMIC_EXIT_BARRIER, "memory"); CMPXCHG_GEN(u8, _local, , , "memory"); CMPXCHG_GEN(u8, _acquire, , PPC_ACQUIRE_BARRIER, "memory"); CMPXCHG_GEN(u8, _relaxed, , , "cc"); CMPXCHG_GEN(u16, , PPC_ATOMIC_ENTRY_BARRIER, PPC_ATOMIC_EXIT_BARRIER, "memory"); CMPXCHG_GEN(u16, _local, , , "memory"); CMPXCHG_GEN(u16, _acquire, , PPC_ACQUIRE_BARRIER, "memory"); CMPXCHG_GEN(u16, _relaxed, , , "cc"); static __always_inline unsigned long __cmpxchg_u32(volatile unsigned int *p, unsigned long old, unsigned long new) { unsigned int prev; __asm__ __volatile__ ( PPC_ATOMIC_ENTRY_BARRIER "1: lwarx %0,0,%2 # __cmpxchg_u32\n\ cmpw 0,%0,%3\n\ bne- 2f\n" PPC405_ERR77(0,%2) " stwcx. %4,0,%2\n\ bne- 1b" PPC_ATOMIC_EXIT_BARRIER "\n\ 2:" : "=&r" (prev), "+m" (*p) : "r" (p), "r" (old), "r" (new) : "cc", "memory"); return prev; } static __always_inline unsigned long __cmpxchg_u32_local(volatile unsigned int *p, unsigned long old, unsigned long new) { unsigned int prev; __asm__ __volatile__ ( "1: lwarx %0,0,%2 # __cmpxchg_u32\n\ cmpw 0,%0,%3\n\ bne- 2f\n" PPC405_ERR77(0,%2) " stwcx. %4,0,%2\n\ bne- 1b" "\n\ 2:" : "=&r" (prev), "+m" (*p) : "r" (p), "r" (old), "r" (new) : "cc", "memory"); return prev; } static __always_inline unsigned long __cmpxchg_u32_relaxed(u32 *p, unsigned long old, unsigned long new) { unsigned long prev; __asm__ __volatile__ ( "1: lwarx %0,0,%2 # __cmpxchg_u32_relaxed\n" " cmpw 0,%0,%3\n" " bne- 2f\n" PPC405_ERR77(0, %2) " stwcx. %4,0,%2\n" " bne- 1b\n" "2:" : "=&r" (prev), "+m" (*p) : "r" (p), "r" (old), "r" (new) : "cc"); return prev; } /* * cmpxchg family don't have order guarantee if cmp part fails, therefore we * can avoid superfluous barriers if we use assembly code to implement * cmpxchg() and cmpxchg_acquire(), however we don't do the similar for * cmpxchg_release() because that will result in putting a barrier in the * middle of a ll/sc loop, which is probably a bad idea. For example, this * might cause the conditional store more likely to fail. */ static __always_inline unsigned long __cmpxchg_u32_acquire(u32 *p, unsigned long old, unsigned long new) { unsigned long prev; __asm__ __volatile__ ( "1: lwarx %0,0,%2 # __cmpxchg_u32_acquire\n" " cmpw 0,%0,%3\n" " bne- 2f\n" PPC405_ERR77(0, %2) " stwcx. %4,0,%2\n" " bne- 1b\n" PPC_ACQUIRE_BARRIER "\n" "2:" : "=&r" (prev), "+m" (*p) : "r" (p), "r" (old), "r" (new) : "cc", "memory"); return prev; } #ifdef CONFIG_PPC64 static __always_inline unsigned long __cmpxchg_u64(volatile unsigned long *p, unsigned long old, unsigned long new) { unsigned long prev; __asm__ __volatile__ ( PPC_ATOMIC_ENTRY_BARRIER "1: ldarx %0,0,%2 # __cmpxchg_u64\n\ cmpd 0,%0,%3\n\ bne- 2f\n\ stdcx. %4,0,%2\n\ bne- 1b" PPC_ATOMIC_EXIT_BARRIER "\n\ 2:" : "=&r" (prev), "+m" (*p) : "r" (p), "r" (old), "r" (new) : "cc", "memory"); return prev; } static __always_inline unsigned long __cmpxchg_u64_local(volatile unsigned long *p, unsigned long old, unsigned long new) { unsigned long prev; __asm__ __volatile__ ( "1: ldarx %0,0,%2 # __cmpxchg_u64\n\ cmpd 0,%0,%3\n\ bne- 2f\n\ stdcx. %4,0,%2\n\ bne- 1b" "\n\ 2:" : "=&r" (prev), "+m" (*p) : "r" (p), "r" (old), "r" (new) : "cc", "memory"); return prev; } static __always_inline unsigned long __cmpxchg_u64_relaxed(u64 *p, unsigned long old, unsigned long new) { unsigned long prev; __asm__ __volatile__ ( "1: ldarx %0,0,%2 # __cmpxchg_u64_relaxed\n" " cmpd 0,%0,%3\n" " bne- 2f\n" " stdcx. %4,0,%2\n" " bne- 1b\n" "2:" : "=&r" (prev), "+m" (*p) : "r" (p), "r" (old), "r" (new) : "cc"); return prev; } static __always_inline unsigned long __cmpxchg_u64_acquire(u64 *p, unsigned long old, unsigned long new) { unsigned long prev; __asm__ __volatile__ ( "1: ldarx %0,0,%2 # __cmpxchg_u64_acquire\n" " cmpd 0,%0,%3\n" " bne- 2f\n" " stdcx. %4,0,%2\n" " bne- 1b\n" PPC_ACQUIRE_BARRIER "\n" "2:" : "=&r" (prev), "+m" (*p) : "r" (p), "r" (old), "r" (new) : "cc", "memory"); return prev; } #endif static __always_inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, unsigned int size) { switch (size) { case 1: return __cmpxchg_u8(ptr, old, new); case 2: return __cmpxchg_u16(ptr, old, new); case 4: return __cmpxchg_u32(ptr, old, new); #ifdef CONFIG_PPC64 case 8: return __cmpxchg_u64(ptr, old, new); #endif } BUILD_BUG_ON_MSG(1, "Unsupported size for __cmpxchg"); return old; } static __always_inline unsigned long __cmpxchg_local(void *ptr, unsigned long old, unsigned long new, unsigned int size) { switch (size) { case 1: return __cmpxchg_u8_local(ptr, old, new); case 2: return __cmpxchg_u16_local(ptr, old, new); case 4: return __cmpxchg_u32_local(ptr, old, new); #ifdef CONFIG_PPC64 case 8: return __cmpxchg_u64_local(ptr, old, new); #endif } BUILD_BUG_ON_MSG(1, "Unsupported size for __cmpxchg_local"); return old; } static __always_inline unsigned long __cmpxchg_relaxed(void *ptr, unsigned long old, unsigned long new, unsigned int size) { switch (size) { case 1: return __cmpxchg_u8_relaxed(ptr, old, new); case 2: return __cmpxchg_u16_relaxed(ptr, old, new); case 4: return __cmpxchg_u32_relaxed(ptr, old, new); #ifdef CONFIG_PPC64 case 8: return __cmpxchg_u64_relaxed(ptr, old, new); #endif } BUILD_BUG_ON_MSG(1, "Unsupported size for __cmpxchg_relaxed"); return old; } static __always_inline unsigned long __cmpxchg_acquire(void *ptr, unsigned long old, unsigned long new, unsigned int size) { switch (size) { case 1: return __cmpxchg_u8_acquire(ptr, old, new); case 2: return __cmpxchg_u16_acquire(ptr, old, new); case 4: return __cmpxchg_u32_acquire(ptr, old, new); #ifdef CONFIG_PPC64 case 8: return __cmpxchg_u64_acquire(ptr, old, new); #endif } BUILD_BUG_ON_MSG(1, "Unsupported size for __cmpxchg_acquire"); 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))); \ }) #define cmpxchg_local(ptr, o, n) \ ({ \ __typeof__(*(ptr)) _o_ = (o); \ __typeof__(*(ptr)) _n_ = (n); \ (__typeof__(*(ptr))) __cmpxchg_local((ptr), (unsigned long)_o_, \ (unsigned long)_n_, sizeof(*(ptr))); \ }) #define cmpxchg_relaxed(ptr, o, n) \ ({ \ __typeof__(*(ptr)) _o_ = (o); \ __typeof__(*(ptr)) _n_ = (n); \ (__typeof__(*(ptr))) __cmpxchg_relaxed((ptr), \ (unsigned long)_o_, (unsigned long)_n_, \ sizeof(*(ptr))); \ }) #define cmpxchg_acquire(ptr, o, n) \ ({ \ __typeof__(*(ptr)) _o_ = (o); \ __typeof__(*(ptr)) _n_ = (n); \ (__typeof__(*(ptr))) __cmpxchg_acquire((ptr), \ (unsigned long)_o_, (unsigned long)_n_, \ sizeof(*(ptr))); \ }) #ifdef CONFIG_PPC64 #define cmpxchg64(ptr, o, n) \ ({ \ BUILD_BUG_ON(sizeof(*(ptr)) != 8); \ cmpxchg((ptr), (o), (n)); \ }) #define cmpxchg64_local(ptr, o, n) \ ({ \ BUILD_BUG_ON(sizeof(*(ptr)) != 8); \ cmpxchg_local((ptr), (o), (n)); \ }) #define cmpxchg64_relaxed(ptr, o, n) \ ({ \ BUILD_BUG_ON(sizeof(*(ptr)) != 8); \ cmpxchg_relaxed((ptr), (o), (n)); \ }) #define cmpxchg64_acquire(ptr, o, n) \ ({ \ BUILD_BUG_ON(sizeof(*(ptr)) != 8); \ cmpxchg_acquire((ptr), (o), (n)); \ }) #else #include <asm-generic/cmpxchg-local.h> #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) #endif #endif /* __KERNEL__ */ #endif /* _ASM_POWERPC_CMPXCHG_H_ */