From b86cf14f240e002e001fd4f2bf49114c7836fd5c Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Fri, 9 Sep 2022 15:23:12 +1000 Subject: [PATCH] powerpc: add compile-time support for lbarx, lharx ISA v2.06 (POWER7 and up) as well as e6500 support lbarx and lharx. Add a compile option that allows code to use it, and add support in cmpxchg and xchg 8 and 16 bit values without shifting and masking. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220909052312.63916-1-npiggin@gmail.com --- arch/powerpc/Kconfig | 3 + arch/powerpc/include/asm/cmpxchg.h | 231 ++++++++++++++++++++++++++++++++- arch/powerpc/lib/sstep.c | 21 +-- arch/powerpc/platforms/Kconfig.cputype | 5 + 4 files changed, 249 insertions(+), 11 deletions(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 699df27..4fd4924 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -293,6 +293,9 @@ config PPC_BARRIER_NOSPEC default y depends on PPC_BOOK3S_64 || PPC_E500 +config PPC_HAS_LBARX_LHARX + bool + config EARLY_PRINTK bool default y diff --git a/arch/powerpc/include/asm/cmpxchg.h b/arch/powerpc/include/asm/cmpxchg.h index 05f246c..d0ea057 100644 --- a/arch/powerpc/include/asm/cmpxchg.h +++ b/arch/powerpc/include/asm/cmpxchg.h @@ -77,10 +77,76 @@ u32 __cmpxchg_##type##sfx(volatile void *p, u32 old, u32 new) \ * the previous value stored there. */ +#ifndef CONFIG_PPC_HAS_LBARX_LHARX XCHG_GEN(u8, _local, "memory"); XCHG_GEN(u8, _relaxed, "cc"); XCHG_GEN(u16, _local, "memory"); XCHG_GEN(u16, _relaxed, "cc"); +#else +static __always_inline unsigned long +__xchg_u8_local(volatile void *p, unsigned long val) +{ + unsigned long prev; + + __asm__ __volatile__( +"1: lbarx %0,0,%2 # __xchg_u8_local\n" +" stbcx. %3,0,%2 \n" +" bne- 1b" + : "=&r" (prev), "+m" (*(volatile unsigned char *)p) + : "r" (p), "r" (val) + : "cc", "memory"); + + return prev; +} + +static __always_inline unsigned long +__xchg_u8_relaxed(u8 *p, unsigned long val) +{ + unsigned long prev; + + __asm__ __volatile__( +"1: lbarx %0,0,%2 # __xchg_u8_relaxed\n" +" stbcx. %3,0,%2\n" +" bne- 1b" + : "=&r" (prev), "+m" (*p) + : "r" (p), "r" (val) + : "cc"); + + return prev; +} + +static __always_inline unsigned long +__xchg_u16_local(volatile void *p, unsigned long val) +{ + unsigned long prev; + + __asm__ __volatile__( +"1: lharx %0,0,%2 # __xchg_u16_local\n" +" sthcx. %3,0,%2\n" +" bne- 1b" + : "=&r" (prev), "+m" (*(volatile unsigned short *)p) + : "r" (p), "r" (val) + : "cc", "memory"); + + return prev; +} + +static __always_inline unsigned long +__xchg_u16_relaxed(u16 *p, unsigned long val) +{ + unsigned long prev; + + __asm__ __volatile__( +"1: lharx %0,0,%2 # __xchg_u16_relaxed\n" +" sthcx. %3,0,%2\n" +" bne- 1b" + : "=&r" (prev), "+m" (*p) + : "r" (p), "r" (val) + : "cc"); + + return prev; +} +#endif static __always_inline unsigned long __xchg_u32_local(volatile void *p, unsigned long val) @@ -198,11 +264,12 @@ __xchg_relaxed(void *ptr, unsigned long x, unsigned int size) (__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. */ - +#ifndef CONFIG_PPC_HAS_LBARX_LHARX 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"); @@ -211,6 +278,168 @@ 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"); +#else +static __always_inline unsigned long +__cmpxchg_u8(volatile unsigned char *p, unsigned long old, unsigned long new) +{ + unsigned int prev; + + __asm__ __volatile__ ( + PPC_ATOMIC_ENTRY_BARRIER +"1: lbarx %0,0,%2 # __cmpxchg_u8\n" +" cmpw 0,%0,%3\n" +" bne- 2f\n" +" stbcx. %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_u8_local(volatile unsigned char *p, unsigned long old, + unsigned long new) +{ + unsigned int prev; + + __asm__ __volatile__ ( +"1: lbarx %0,0,%2 # __cmpxchg_u8_local\n" +" cmpw 0,%0,%3\n" +" bne- 2f\n" +" stbcx. %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_u8_relaxed(u8 *p, unsigned long old, unsigned long new) +{ + unsigned long prev; + + __asm__ __volatile__ ( +"1: lbarx %0,0,%2 # __cmpxchg_u8_relaxed\n" +" cmpw 0,%0,%3\n" +" bne- 2f\n" +" stbcx. %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_u8_acquire(u8 *p, unsigned long old, unsigned long new) +{ + unsigned long prev; + + __asm__ __volatile__ ( +"1: lbarx %0,0,%2 # __cmpxchg_u8_acquire\n" +" cmpw 0,%0,%3\n" +" bne- 2f\n" +" stbcx. %4,0,%2\n" +" bne- 1b\n" + PPC_ACQUIRE_BARRIER +"2:" + : "=&r" (prev), "+m" (*p) + : "r" (p), "r" (old), "r" (new) + : "cc", "memory"); + + return prev; +} + +static __always_inline unsigned long +__cmpxchg_u16(volatile unsigned short *p, unsigned long old, unsigned long new) +{ + unsigned int prev; + + __asm__ __volatile__ ( + PPC_ATOMIC_ENTRY_BARRIER +"1: lharx %0,0,%2 # __cmpxchg_u16\n" +" cmpw 0,%0,%3\n" +" bne- 2f\n" +" sthcx. %4,0,%2\n" +" bne- 1b\n" + PPC_ATOMIC_EXIT_BARRIER +"2:" + : "=&r" (prev), "+m" (*p) + : "r" (p), "r" (old), "r" (new) + : "cc", "memory"); + + return prev; +} + +static __always_inline unsigned long +__cmpxchg_u16_local(volatile unsigned short *p, unsigned long old, + unsigned long new) +{ + unsigned int prev; + + __asm__ __volatile__ ( +"1: lharx %0,0,%2 # __cmpxchg_u16_local\n" +" cmpw 0,%0,%3\n" +" bne- 2f\n" +" sthcx. %4,0,%2\n" +" bne- 1b" +"2:" + : "=&r" (prev), "+m" (*p) + : "r" (p), "r" (old), "r" (new) + : "cc", "memory"); + + return prev; +} + +static __always_inline unsigned long +__cmpxchg_u16_relaxed(u16 *p, unsigned long old, unsigned long new) +{ + unsigned long prev; + + __asm__ __volatile__ ( +"1: lharx %0,0,%2 # __cmpxchg_u16_relaxed\n" +" cmpw 0,%0,%3\n" +" bne- 2f\n" +" sthcx. %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_u16_acquire(u16 *p, unsigned long old, unsigned long new) +{ + unsigned long prev; + + __asm__ __volatile__ ( +"1: lharx %0,0,%2 # __cmpxchg_u16_acquire\n" +" cmpw 0,%0,%3\n" +" bne- 2f\n" +" sthcx. %4,0,%2\n" +" bne- 1b\n" + PPC_ACQUIRE_BARRIER +"2:" + : "=&r" (prev), "+m" (*p) + : "r" (p), "r" (old), "r" (new) + : "cc", "memory"); + + return prev; +} +#endif static __always_inline unsigned long __cmpxchg_u32(volatile unsigned int *p, unsigned long old, unsigned long new) diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index 398b569..38158b7 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c @@ -2284,15 +2284,7 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs, op->type = MKOP(STCX, 0, 4); break; -#ifdef __powerpc64__ - case 84: /* ldarx */ - op->type = MKOP(LARX, 0, 8); - break; - - case 214: /* stdcx. */ - op->type = MKOP(STCX, 0, 8); - break; - +#ifdef CONFIG_PPC_HAS_LBARX_LHARX case 52: /* lbarx */ op->type = MKOP(LARX, 0, 1); break; @@ -2308,6 +2300,15 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs, case 726: /* sthcx. */ op->type = MKOP(STCX, 0, 2); break; +#endif +#ifdef __powerpc64__ + case 84: /* ldarx */ + op->type = MKOP(LARX, 0, 8); + break; + + case 214: /* stdcx. */ + op->type = MKOP(STCX, 0, 8); + break; case 276: /* lqarx */ if (!((rd & 1) || rd == ra || rd == rb)) @@ -3334,7 +3335,7 @@ int emulate_loadstore(struct pt_regs *regs, struct instruction_op *op) err = 0; val = 0; switch (size) { -#ifdef __powerpc64__ +#ifdef CONFIG_PPC_HAS_LBARX_LHARX case 1: __get_user_asmx(val, ea, err, "lbarx"); break; diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype index 0c4eed9..7bac213 100644 --- a/arch/powerpc/platforms/Kconfig.cputype +++ b/arch/powerpc/platforms/Kconfig.cputype @@ -135,6 +135,7 @@ config GENERIC_CPU depends on PPC_BOOK3S_64 && CPU_LITTLE_ENDIAN select ARCH_HAS_FAST_MULTIPLIER select PPC_64S_HASH_MMU + select PPC_HAS_LBARX_LHARX config POWERPC_CPU bool "Generic 32 bits powerpc" @@ -160,17 +161,20 @@ config POWER7_CPU depends on PPC_BOOK3S_64 select ARCH_HAS_FAST_MULTIPLIER select PPC_64S_HASH_MMU + select PPC_HAS_LBARX_LHARX config POWER8_CPU bool "POWER8" depends on PPC_BOOK3S_64 select ARCH_HAS_FAST_MULTIPLIER select PPC_64S_HASH_MMU + select PPC_HAS_LBARX_LHARX config POWER9_CPU bool "POWER9" depends on PPC_BOOK3S_64 select ARCH_HAS_FAST_MULTIPLIER + select PPC_HAS_LBARX_LHARX config POWER10_CPU bool "POWER10" @@ -184,6 +188,7 @@ config E5500_CPU config E6500_CPU bool "Freescale e6500" depends on PPC64 && PPC_E500 + select PPC_HAS_LBARX_LHARX config 405_CPU bool "40x family" -- 2.7.4