From e9826380d83d1bda3ee5663bf3fa4667a6fbe60a Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Thu, 18 Aug 2011 11:48:06 -0700 Subject: x86, cmpxchg: Unify cmpxchg into cmpxchg.h Everything that's actually common between 32 and 64-bit is moved into cmpxchg.h. xchg/cmpxchg will fail with a link error if they're passed an unsupported size (which includes 64-bit args on 32-bit systems). Signed-off-by: Jeremy Fitzhardinge Link: http://lkml.kernel.org/r/4E5BCC40.3030501@goop.org Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/cmpxchg.h | 155 ++++++++++++++++++++++++++++++++++++++ arch/x86/include/asm/cmpxchg_32.h | 113 --------------------------- arch/x86/include/asm/cmpxchg_64.h | 131 -------------------------------- 3 files changed, 155 insertions(+), 244 deletions(-) diff --git a/arch/x86/include/asm/cmpxchg.h b/arch/x86/include/asm/cmpxchg.h index a460fa088d4c..efe3ec778a58 100644 --- a/arch/x86/include/asm/cmpxchg.h +++ b/arch/x86/include/asm/cmpxchg.h @@ -1,5 +1,160 @@ +#ifndef ASM_X86_CMPXCHG_H +#define ASM_X86_CMPXCHG_H + +#include /* Provides LOCK_PREFIX */ + +/* Non-existant functions to indicate usage errors at link time. */ +extern void __xchg_wrong_size(void); +extern void __cmpxchg_wrong_size(void); + +/* + * Constants for operation sizes. On 32-bit, the 64-bit size it set to + * -1 because sizeof will never return -1, thereby making those switch + * case statements guaranteeed dead code which the compiler will + * eliminate, and allowing the "missing symbol in the default case" to + * indicate a usage error. + */ +#define __X86_CASE_B 1 +#define __X86_CASE_W 2 +#define __X86_CASE_L 4 +#ifdef CONFIG_64BIT +#define __X86_CASE_Q 8 +#else +#define __X86_CASE_Q -1 /* sizeof will never return -1 */ +#endif + +/* + * Note: no "lock" prefix even on SMP: xchg always implies lock anyway. + * Since this is generally used to protect other memory information, we + * use "asm volatile" and "memory" clobbers to prevent gcc from moving + * information around. + */ +#define __xchg(x, ptr, size) \ +({ \ + __typeof(*(ptr)) __x = (x); \ + switch (size) { \ + case __X86_CASE_B: \ + { \ + volatile u8 *__ptr = (volatile u8 *)(ptr); \ + asm volatile("xchgb %0,%1" \ + : "=q" (__x), "+m" (*__ptr) \ + : "0" (__x) \ + : "memory"); \ + break; \ + } \ + case __X86_CASE_W: \ + { \ + volatile u16 *__ptr = (volatile u16 *)(ptr); \ + asm volatile("xchgw %0,%1" \ + : "=r" (__x), "+m" (*__ptr) \ + : "0" (__x) \ + : "memory"); \ + break; \ + } \ + case __X86_CASE_L: \ + { \ + volatile u32 *__ptr = (volatile u32 *)(ptr); \ + asm volatile("xchgl %0,%1" \ + : "=r" (__x), "+m" (*__ptr) \ + : "0" (__x) \ + : "memory"); \ + break; \ + } \ + case __X86_CASE_Q: \ + { \ + volatile u64 *__ptr = (volatile u64 *)(ptr); \ + asm volatile("xchgq %0,%1" \ + : "=r" (__x), "+m" (*__ptr) \ + : "0" (__x) \ + : "memory"); \ + break; \ + } \ + default: \ + __xchg_wrong_size(); \ + } \ + __x; \ +}) + +#define xchg(ptr, v) \ + __xchg((v), (ptr), sizeof(*ptr)) + +/* + * Atomic compare and exchange. Compare OLD with MEM, if identical, + * store NEW in MEM. Return the initial value in MEM. Success is + * indicated by comparing RETURN with OLD. + */ +#define __raw_cmpxchg(ptr, old, new, size, lock) \ +({ \ + __typeof__(*(ptr)) __ret; \ + __typeof__(*(ptr)) __old = (old); \ + __typeof__(*(ptr)) __new = (new); \ + switch (size) { \ + case __X86_CASE_B: \ + { \ + volatile u8 *__ptr = (volatile u8 *)(ptr); \ + asm volatile(lock "cmpxchgb %2,%1" \ + : "=a" (__ret), "+m" (*__ptr) \ + : "q" (__new), "0" (__old) \ + : "memory"); \ + break; \ + } \ + case __X86_CASE_W: \ + { \ + volatile u16 *__ptr = (volatile u16 *)(ptr); \ + asm volatile(lock "cmpxchgw %2,%1" \ + : "=a" (__ret), "+m" (*__ptr) \ + : "r" (__new), "0" (__old) \ + : "memory"); \ + break; \ + } \ + case __X86_CASE_L: \ + { \ + volatile u32 *__ptr = (volatile u32 *)(ptr); \ + asm volatile(lock "cmpxchgl %2,%1" \ + : "=a" (__ret), "+m" (*__ptr) \ + : "r" (__new), "0" (__old) \ + : "memory"); \ + break; \ + } \ + case __X86_CASE_Q: \ + { \ + volatile u64 *__ptr = (volatile u64 *)(ptr); \ + asm volatile(lock "cmpxchgq %2,%1" \ + : "=a" (__ret), "+m" (*__ptr) \ + : "r" (__new), "0" (__old) \ + : "memory"); \ + break; \ + } \ + default: \ + __cmpxchg_wrong_size(); \ + } \ + __ret; \ +}) + +#define __cmpxchg(ptr, old, new, size) \ + __raw_cmpxchg((ptr), (old), (new), (size), LOCK_PREFIX) + +#define __sync_cmpxchg(ptr, old, new, size) \ + __raw_cmpxchg((ptr), (old), (new), (size), "lock; ") + +#define __cmpxchg_local(ptr, old, new, size) \ + __raw_cmpxchg((ptr), (old), (new), (size), "") + #ifdef CONFIG_X86_32 # include "cmpxchg_32.h" #else # include "cmpxchg_64.h" #endif + +#ifdef __HAVE_ARCH_CMPXCHG +#define cmpxchg(ptr, old, new) \ + __cmpxchg((ptr), (old), (new), sizeof(*ptr)) + +#define sync_cmpxchg(ptr, old, new) \ + __sync_cmpxchg((ptr), (old), (new), sizeof(*ptr)) + +#define cmpxchg_local(ptr, old, new) \ + __cmpxchg_local((ptr), (old), (new), sizeof(*ptr)) +#endif + +#endif /* ASM_X86_CMPXCHG_H */ diff --git a/arch/x86/include/asm/cmpxchg_32.h b/arch/x86/include/asm/cmpxchg_32.h index 59d8e36d1eed..fbebb07dd80b 100644 --- a/arch/x86/include/asm/cmpxchg_32.h +++ b/arch/x86/include/asm/cmpxchg_32.h @@ -1,62 +1,11 @@ #ifndef _ASM_X86_CMPXCHG_32_H #define _ASM_X86_CMPXCHG_32_H -#include /* Provides LOCK_PREFIX */ - /* * Note: if you use set64_bit(), __cmpxchg64(), or their variants, you * you need to test for the feature in boot_cpu_data. */ -extern void __xchg_wrong_size(void); -extern void __cmpxchg_wrong_size(void); - -/* - * Note: no "lock" prefix even on SMP: xchg always implies lock anyway. - * Since this is generally used to protect other memory information, we - * use "asm volatile" and "memory" clobbers to prevent gcc from moving - * information around. - */ -#define __xchg(x, ptr, size) \ -({ \ - __typeof(*(ptr)) __x = (x); \ - switch (size) { \ - case 1: \ - { \ - volatile u8 *__ptr = (volatile u8 *)(ptr); \ - asm volatile("xchgb %0,%1" \ - : "=q" (__x), "+m" (*__ptr) \ - : "0" (__x) \ - : "memory"); \ - break; \ - } \ - case 2: \ - { \ - volatile u16 *__ptr = (volatile u16 *)(ptr); \ - asm volatile("xchgw %0,%1" \ - : "=r" (__x), "+m" (*__ptr) \ - : "0" (__x) \ - : "memory"); \ - break; \ - } \ - case 4: \ - { \ - volatile u32 *__ptr = (volatile u32 *)(ptr); \ - asm volatile("xchgl %0,%1" \ - : "=r" (__x), "+m" (*__ptr) \ - : "0" (__x) \ - : "memory"); \ - break; \ - } \ - default: \ - __xchg_wrong_size(); \ - } \ - __x; \ -}) - -#define xchg(ptr, v) \ - __xchg((v), (ptr), sizeof(*ptr)) - /* * CMPXCHG8B only writes to the target if we had the previous * value in registers, otherwise it acts as a read and gives us the @@ -85,70 +34,8 @@ static inline void set_64bit(volatile u64 *ptr, u64 value) : "memory"); } -/* - * Atomic compare and exchange. Compare OLD with MEM, if identical, - * store NEW in MEM. Return the initial value in MEM. Success is - * indicated by comparing RETURN with OLD. - */ -#define __raw_cmpxchg(ptr, old, new, size, lock) \ -({ \ - __typeof__(*(ptr)) __ret; \ - __typeof__(*(ptr)) __old = (old); \ - __typeof__(*(ptr)) __new = (new); \ - switch (size) { \ - case 1: \ - { \ - volatile u8 *__ptr = (volatile u8 *)(ptr); \ - asm volatile(lock "cmpxchgb %2,%1" \ - : "=a" (__ret), "+m" (*__ptr) \ - : "q" (__new), "0" (__old) \ - : "memory"); \ - break; \ - } \ - case 2: \ - { \ - volatile u16 *__ptr = (volatile u16 *)(ptr); \ - asm volatile(lock "cmpxchgw %2,%1" \ - : "=a" (__ret), "+m" (*__ptr) \ - : "r" (__new), "0" (__old) \ - : "memory"); \ - break; \ - } \ - case 4: \ - { \ - volatile u32 *__ptr = (volatile u32 *)(ptr); \ - asm volatile(lock "cmpxchgl %2,%1" \ - : "=a" (__ret), "+m" (*__ptr) \ - : "r" (__new), "0" (__old) \ - : "memory"); \ - break; \ - } \ - default: \ - __cmpxchg_wrong_size(); \ - } \ - __ret; \ -}) - -#define __cmpxchg(ptr, old, new, size) \ - __raw_cmpxchg((ptr), (old), (new), (size), LOCK_PREFIX) - -#define __sync_cmpxchg(ptr, old, new, size) \ - __raw_cmpxchg((ptr), (old), (new), (size), "lock; ") - -#define __cmpxchg_local(ptr, old, new, size) \ - __raw_cmpxchg((ptr), (old), (new), (size), "") - #ifdef CONFIG_X86_CMPXCHG #define __HAVE_ARCH_CMPXCHG 1 - -#define cmpxchg(ptr, old, new) \ - __cmpxchg((ptr), (old), (new), sizeof(*ptr)) - -#define sync_cmpxchg(ptr, old, new) \ - __sync_cmpxchg((ptr), (old), (new), sizeof(*ptr)) - -#define cmpxchg_local(ptr, old, new) \ - __cmpxchg_local((ptr), (old), (new), sizeof(*ptr)) #endif #ifdef CONFIG_X86_CMPXCHG64 diff --git a/arch/x86/include/asm/cmpxchg_64.h b/arch/x86/include/asm/cmpxchg_64.h index 5bfa560ef14e..285da02c38fa 100644 --- a/arch/x86/include/asm/cmpxchg_64.h +++ b/arch/x86/include/asm/cmpxchg_64.h @@ -1,66 +1,6 @@ #ifndef _ASM_X86_CMPXCHG_64_H #define _ASM_X86_CMPXCHG_64_H -#include /* Provides LOCK_PREFIX */ - -extern void __xchg_wrong_size(void); -extern void __cmpxchg_wrong_size(void); - -/* - * Note: no "lock" prefix even on SMP: xchg always implies lock anyway. - * Since this is generally used to protect other memory information, we - * use "asm volatile" and "memory" clobbers to prevent gcc from moving - * information around. - */ -#define __xchg(x, ptr, size) \ -({ \ - __typeof(*(ptr)) __x = (x); \ - switch (size) { \ - case 1: \ - { \ - volatile u8 *__ptr = (volatile u8 *)(ptr); \ - asm volatile("xchgb %0,%1" \ - : "=q" (__x), "+m" (*__ptr) \ - : "0" (__x) \ - : "memory"); \ - break; \ - } \ - case 2: \ - { \ - volatile u16 *__ptr = (volatile u16 *)(ptr); \ - asm volatile("xchgw %0,%1" \ - : "=r" (__x), "+m" (*__ptr) \ - : "0" (__x) \ - : "memory"); \ - break; \ - } \ - case 4: \ - { \ - volatile u32 *__ptr = (volatile u32 *)(ptr); \ - asm volatile("xchgl %0,%1" \ - : "=r" (__x), "+m" (*__ptr) \ - : "0" (__x) \ - : "memory"); \ - break; \ - } \ - case 8: \ - { \ - volatile u64 *__ptr = (volatile u64 *)(ptr); \ - asm volatile("xchgq %0,%1" \ - : "=r" (__x), "+m" (*__ptr) \ - : "0" (__x) \ - : "memory"); \ - break; \ - } \ - default: \ - __xchg_wrong_size(); \ - } \ - __x; \ -}) - -#define xchg(ptr, v) \ - __xchg((v), (ptr), sizeof(*ptr)) - static inline void set_64bit(volatile u64 *ptr, u64 val) { *ptr = val; @@ -68,77 +8,6 @@ static inline void set_64bit(volatile u64 *ptr, u64 val) #define __HAVE_ARCH_CMPXCHG 1 -/* - * Atomic compare and exchange. Compare OLD with MEM, if identical, - * store NEW in MEM. Return the initial value in MEM. Success is - * indicated by comparing RETURN with OLD. - */ -#define __raw_cmpxchg(ptr, old, new, size, lock) \ -({ \ - __typeof__(*(ptr)) __ret; \ - __typeof__(*(ptr)) __old = (old); \ - __typeof__(*(ptr)) __new = (new); \ - switch (size) { \ - case 1: \ - { \ - volatile u8 *__ptr = (volatile u8 *)(ptr); \ - asm volatile(lock "cmpxchgb %2,%1" \ - : "=a" (__ret), "+m" (*__ptr) \ - : "q" (__new), "0" (__old) \ - : "memory"); \ - break; \ - } \ - case 2: \ - { \ - volatile u16 *__ptr = (volatile u16 *)(ptr); \ - asm volatile(lock "cmpxchgw %2,%1" \ - : "=a" (__ret), "+m" (*__ptr) \ - : "r" (__new), "0" (__old) \ - : "memory"); \ - break; \ - } \ - case 4: \ - { \ - volatile u32 *__ptr = (volatile u32 *)(ptr); \ - asm volatile(lock "cmpxchgl %2,%1" \ - : "=a" (__ret), "+m" (*__ptr) \ - : "r" (__new), "0" (__old) \ - : "memory"); \ - break; \ - } \ - case 8: \ - { \ - volatile u64 *__ptr = (volatile u64 *)(ptr); \ - asm volatile(lock "cmpxchgq %2,%1" \ - : "=a" (__ret), "+m" (*__ptr) \ - : "r" (__new), "0" (__old) \ - : "memory"); \ - break; \ - } \ - default: \ - __cmpxchg_wrong_size(); \ - } \ - __ret; \ -}) - -#define __cmpxchg(ptr, old, new, size) \ - __raw_cmpxchg((ptr), (old), (new), (size), LOCK_PREFIX) - -#define __sync_cmpxchg(ptr, old, new, size) \ - __raw_cmpxchg((ptr), (old), (new), (size), "lock; ") - -#define __cmpxchg_local(ptr, old, new, size) \ - __raw_cmpxchg((ptr), (old), (new), (size), "") - -#define cmpxchg(ptr, old, new) \ - __cmpxchg((ptr), (old), (new), sizeof(*ptr)) - -#define sync_cmpxchg(ptr, old, new) \ - __sync_cmpxchg((ptr), (old), (new), sizeof(*ptr)) - -#define cmpxchg_local(ptr, old, new) \ - __cmpxchg_local((ptr), (old), (new), sizeof(*ptr)) - #define cmpxchg64(ptr, o, n) \ ({ \ BUILD_BUG_ON(sizeof(*(ptr)) != 8); \ -- cgit v1.2.3-59-g8ed1b