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Merge branch 'upstream/ticketlock-cleanup' of git://github.com/jsgf/l…
…inux-xen into x86/spinlocks
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -1,5 +1,210 @@ | ||
| #ifndef ASM_X86_CMPXCHG_H | ||
| #define ASM_X86_CMPXCHG_H | ||
|
|
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| #include <linux/compiler.h> | ||
| #include <asm/alternative.h> /* Provides LOCK_PREFIX */ | ||
|
|
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| /* | ||
| * Non-existant functions to indicate usage errors at link time | ||
| * (or compile-time if the compiler implements __compiletime_error(). | ||
| */ | ||
| extern void __xchg_wrong_size(void) | ||
| __compiletime_error("Bad argument size for xchg"); | ||
| extern void __cmpxchg_wrong_size(void) | ||
| __compiletime_error("Bad argument size for cmpxchg"); | ||
| extern void __xadd_wrong_size(void) | ||
| __compiletime_error("Bad argument size for xadd"); | ||
|
|
||
| /* | ||
| * 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) | ||
|
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| #define __sync_cmpxchg(ptr, old, new, size) \ | ||
| __raw_cmpxchg((ptr), (old), (new), (size), "lock; ") | ||
|
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| #define __cmpxchg_local(ptr, old, new, size) \ | ||
| __raw_cmpxchg((ptr), (old), (new), (size), "") | ||
|
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| #ifdef CONFIG_X86_32 | ||
| # include "cmpxchg_32.h" | ||
| #else | ||
| # include "cmpxchg_64.h" | ||
| #endif | ||
|
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||
| #ifdef __HAVE_ARCH_CMPXCHG | ||
| #define cmpxchg(ptr, old, new) \ | ||
| __cmpxchg((ptr), (old), (new), sizeof(*ptr)) | ||
|
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| #define sync_cmpxchg(ptr, old, new) \ | ||
| __sync_cmpxchg((ptr), (old), (new), sizeof(*ptr)) | ||
|
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| #define cmpxchg_local(ptr, old, new) \ | ||
| __cmpxchg_local((ptr), (old), (new), sizeof(*ptr)) | ||
| #endif | ||
|
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| #define __xadd(ptr, inc, lock) \ | ||
| ({ \ | ||
| __typeof__ (*(ptr)) __ret = (inc); \ | ||
| switch (sizeof(*(ptr))) { \ | ||
| case __X86_CASE_B: \ | ||
| asm volatile (lock "xaddb %b0, %1\n" \ | ||
| : "+r" (__ret), "+m" (*(ptr)) \ | ||
| : : "memory", "cc"); \ | ||
| break; \ | ||
| case __X86_CASE_W: \ | ||
| asm volatile (lock "xaddw %w0, %1\n" \ | ||
| : "+r" (__ret), "+m" (*(ptr)) \ | ||
| : : "memory", "cc"); \ | ||
| break; \ | ||
| case __X86_CASE_L: \ | ||
| asm volatile (lock "xaddl %0, %1\n" \ | ||
| : "+r" (__ret), "+m" (*(ptr)) \ | ||
| : : "memory", "cc"); \ | ||
| break; \ | ||
| case __X86_CASE_Q: \ | ||
| asm volatile (lock "xaddq %q0, %1\n" \ | ||
| : "+r" (__ret), "+m" (*(ptr)) \ | ||
| : : "memory", "cc"); \ | ||
| break; \ | ||
| default: \ | ||
| __xadd_wrong_size(); \ | ||
| } \ | ||
| __ret; \ | ||
| }) | ||
|
|
||
| /* | ||
| * xadd() adds "inc" to "*ptr" and atomically returns the previous | ||
| * value of "*ptr". | ||
| * | ||
| * xadd() is locked when multiple CPUs are online | ||
| * xadd_sync() is always locked | ||
| * xadd_local() is never locked | ||
| */ | ||
| #define xadd(ptr, inc) __xadd((ptr), (inc), LOCK_PREFIX) | ||
| #define xadd_sync(ptr, inc) __xadd((ptr), (inc), "lock; ") | ||
| #define xadd_local(ptr, inc) __xadd((ptr), (inc), "") | ||
|
|
||
| #endif /* ASM_X86_CMPXCHG_H */ |
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