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Diffstat (limited to '')
-rw-r--r-- | arch/powerpc/include/asm/cmpxchg.h | 531 |
1 files changed, 531 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/cmpxchg.h b/arch/powerpc/include/asm/cmpxchg.h new file mode 100644 index 000000000..05f246c0e --- /dev/null +++ b/arch/powerpc/include/asm/cmpxchg.h @@ -0,0 +1,531 @@ +/* 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 <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" \ +" 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" \ +" 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" +" 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" +" 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" +" 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" +" 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 arch_xchg_local(ptr,x) \ + ({ \ + __typeof__(*(ptr)) _x_ = (x); \ + (__typeof__(*(ptr))) __xchg_local((ptr), \ + (unsigned long)_x_, sizeof(*(ptr))); \ + }) + +#define arch_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" +" 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" +" 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" +" 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" +" 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 arch_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 arch_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 arch_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 arch_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 arch_cmpxchg64(ptr, o, n) \ + ({ \ + BUILD_BUG_ON(sizeof(*(ptr)) != 8); \ + arch_cmpxchg((ptr), (o), (n)); \ + }) +#define arch_cmpxchg64_local(ptr, o, n) \ + ({ \ + BUILD_BUG_ON(sizeof(*(ptr)) != 8); \ + arch_cmpxchg_local((ptr), (o), (n)); \ + }) +#define arch_cmpxchg64_relaxed(ptr, o, n) \ +({ \ + BUILD_BUG_ON(sizeof(*(ptr)) != 8); \ + arch_cmpxchg_relaxed((ptr), (o), (n)); \ +}) +#define arch_cmpxchg64_acquire(ptr, o, n) \ +({ \ + BUILD_BUG_ON(sizeof(*(ptr)) != 8); \ + arch_cmpxchg_acquire((ptr), (o), (n)); \ +}) +#else +#include <asm-generic/cmpxchg-local.h> +#define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n)) +#endif + +#endif /* __KERNEL__ */ +#endif /* _ASM_POWERPC_CMPXCHG_H_ */ |