diff options
| -rw-r--r-- | arch/x86/include/asm/atomic.h | 8 | ||||
| -rw-r--r-- | arch/x86/include/asm/atomic64_64.h | 6 | ||||
| -rw-r--r-- | arch/x86/include/asm/cmpxchg.h | 205 | ||||
| -rw-r--r-- | arch/x86/include/asm/cmpxchg_32.h | 114 | ||||
| -rw-r--r-- | arch/x86/include/asm/cmpxchg_64.h | 131 | ||||
| -rw-r--r-- | arch/x86/include/asm/rwsem.h | 8 | ||||
| -rw-r--r-- | arch/x86/include/asm/spinlock.h | 114 | ||||
| -rw-r--r-- | arch/x86/include/asm/spinlock_types.h | 22 | ||||
| -rw-r--r-- | arch/x86/include/asm/uv/uv_bau.h | 6 |
9 files changed, 257 insertions, 357 deletions
diff --git a/arch/x86/include/asm/atomic.h b/arch/x86/include/asm/atomic.h index 10572e309ab..58cb6d4085f 100644 --- a/arch/x86/include/asm/atomic.h +++ b/arch/x86/include/asm/atomic.h @@ -172,18 +172,14 @@ static inline int atomic_add_negative(int i, atomic_t *v) */ static inline int atomic_add_return(int i, atomic_t *v) { - int __i; #ifdef CONFIG_M386 + int __i; unsigned long flags; if (unlikely(boot_cpu_data.x86 <= 3)) goto no_xadd; #endif /* Modern 486+ processor */ - __i = i; - asm volatile(LOCK_PREFIX "xaddl %0, %1" - : "+r" (i), "+m" (v->counter) - : : "memory"); - return i + __i; + return i + xadd(&v->counter, i); #ifdef CONFIG_M386 no_xadd: /* Legacy 386 processor */ diff --git a/arch/x86/include/asm/atomic64_64.h b/arch/x86/include/asm/atomic64_64.h index 017594d403f..0e1cbfc8ee0 100644 --- a/arch/x86/include/asm/atomic64_64.h +++ b/arch/x86/include/asm/atomic64_64.h @@ -170,11 +170,7 @@ static inline int atomic64_add_negative(long i, atomic64_t *v) */ static inline long atomic64_add_return(long i, atomic64_t *v) { - long __i = i; - asm volatile(LOCK_PREFIX "xaddq %0, %1;" - : "+r" (i), "+m" (v->counter) - : : "memory"); - return i + __i; + return i + xadd(&v->counter, i); } static inline long atomic64_sub_return(long i, atomic64_t *v) diff --git a/arch/x86/include/asm/cmpxchg.h b/arch/x86/include/asm/cmpxchg.h index a460fa088d4..5d3acdf5a7a 100644 --- a/arch/x86/include/asm/cmpxchg.h +++ b/arch/x86/include/asm/cmpxchg.h @@ -1,5 +1,210 @@ +#ifndef ASM_X86_CMPXCHG_H +#define ASM_X86_CMPXCHG_H + +#include <linux/compiler.h> +#include <asm/alternative.h> /* Provides LOCK_PREFIX */ + +/* + * 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) + +#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 + +#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 */ diff --git a/arch/x86/include/asm/cmpxchg_32.h b/arch/x86/include/asm/cmpxchg_32.h index 3deb7250624..fbebb07dd80 100644 --- a/arch/x86/include/asm/cmpxchg_32.h +++ b/arch/x86/include/asm/cmpxchg_32.h @@ -1,61 +1,11 @@ #ifndef _ASM_X86_CMPXCHG_32_H #define _ASM_X86_CMPXCHG_32_H -#include <linux/bitops.h> /* for 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); - -/* - * 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 @@ -84,72 +34,8 @@ static inline void set_64bit(volatile u64 *ptr, u64 value) : "memory"); } -extern void __cmpxchg_wrong_size(void); - -/* - * 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 7cf5c0a2443..285da02c38f 100644 --- a/arch/x86/include/asm/cmpxchg_64.h +++ b/arch/x86/include/asm/cmpxchg_64.h @@ -1,144 +1,13 @@ #ifndef _ASM_X86_CMPXCHG_64_H #define _ASM_X86_CMPXCHG_64_H -#include <asm/alternative.h> /* Provides LOCK_PREFIX */ - static inline void set_64bit(volatile u64 *ptr, u64 val) { *ptr = val; } -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)) - #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); \ diff --git a/arch/x86/include/asm/rwsem.h b/arch/x86/include/asm/rwsem.h index df4cd32b4cc..2dbe4a721ce 100644 --- a/arch/x86/include/asm/rwsem.h +++ b/arch/x86/include/asm/rwsem.h @@ -204,13 +204,7 @@ static inline void rwsem_atomic_add(long delta, struct rw_semaphore *sem) */ static inline long rwsem_atomic_update(long delta, struct rw_semaphore *sem) { - long tmp = delta; - - asm volatile(LOCK_PREFIX "xadd %0,%1" - : "+r" (tmp), "+m" (sem->count) - : : "memory"); - - return tmp + delta; + return delta + xadd(&sem->count, delta); } #endif /* __KERNEL__ */ diff --git a/arch/x86/include/asm/spinlock.h b/arch/x86/include/asm/spinlock.h index ee67edf86fd..972c260919a 100644 --- a/arch/x86/include/asm/spinlock.h +++ b/arch/x86/include/asm/spinlock.h @@ -49,109 +49,49 @@ * issues and should be optimal for the uncontended case. Note the tail must be * in the high part, because a wide xadd increment of the low part would carry * up and contaminate the high part. - * - * With fewer than 2^8 possible CPUs, we can use x86's partial registers to - * save some instructions and make the code more elegant. There really isn't - * much between them in performance though, especially as locks are out of line. */ -#if (NR_CPUS < 256) -#define TICKET_SHIFT 8 - static __always_inline void __ticket_spin_lock(arch_spinlock_t *lock) { - short inc = 0x0100; - - asm volatile ( - LOCK_PREFIX "xaddw %w0, %1\n" - "1:\t" - "cmpb %h0, %b0\n\t" - "je 2f\n\t" - "rep ; nop\n\t" - "movb %1, %b0\n\t" - /* don't need lfence here, because loads are in-order */ - "jmp 1b\n" - "2:" - : "+Q" (inc), "+m" (lock->slock) - : - : "memory", "cc"); + register struct __raw_tickets inc = { .tail = 1 }; + + inc = xadd(&lock->tickets, inc); + + for (;;) { + if (inc.head == inc.tail) + break; + cpu_relax(); + inc.head = ACCESS_ONCE(lock->tickets.head); + } + barrier(); /* make sure nothing creeps before the lock is taken */ } static __always_inline int __ticket_spin_trylock(arch_spinlock_t *lock) { - int tmp, new; - - asm volatile("movzwl %2, %0\n\t" - "cmpb %h0,%b0\n\t" - "leal 0x100(%" REG_PTR_MODE "0), %1\n\t" - "jne 1f\n\t" - LOCK_PREFIX "cmpxchgw %w1,%2\n\t" - "1:" - "sete %b1\n\t" - "movzbl %b1,%0\n\t" - : "=&a" (tmp), "=&q" (new), "+m" (lock->slock) - : - : "memory", "cc"); + arch_spinlock_t old, new; + + old.tickets = ACCESS_ONCE(lock->tickets); + if (old.tickets.head != old.tickets.tail) + return 0; + + new.head_tail = old.head_tail + (1 << TICKET_SHIFT); - return tmp; + /* cmpxchg is a full barrier, so nothing can move before it */ + return cmpxchg(&lock->head_tail, old.head_tail, new.head_tail) == old.head_tail; } +#if (NR_CPUS < 256) static __always_inline void __ticket_spin_unlock(arch_spinlock_t *lock) { asm volatile(UNLOCK_LOCK_PREFIX "incb %0" - : "+m" (lock->slock) + : "+m" (lock->head_tail) : : "memory", "cc"); } #else -#define TICKET_SHIFT 16 - -static __always_inline void __ticket_spin_lock(arch_spinlock_t *lock) -{ - int inc = 0x00010000; - int tmp; - - asm volatile(LOCK_PREFIX "xaddl %0, %1\n" - "movzwl %w0, %2\n\t" - "shrl $16, %0\n\t" - "1:\t" - "cmpl %0, %2\n\t" - "je 2f\n\t" - "rep ; nop\n\t" - "movzwl %1, %2\n\t" - /* don't need lfence here, because loads are in-order */ - "jmp 1b\n" - "2:" - : "+r" (inc), "+m" (lock->slock), "=&r" (tmp) - : - : "memory", "cc"); -} - -static __always_inline int __ticket_spin_trylock(arch_spinlock_t *lock) -{ - int tmp; - int new; - - asm volatile("movl %2,%0\n\t" - "movl %0,%1\n\t" - "roll $16, %0\n\t" - "cmpl %0,%1\n\t" - "leal 0x00010000(%" REG_PTR_MODE "0), %1\n\t" - "jne 1f\n\t" - LOCK_PREFIX "cmpxchgl %1,%2\n\t" - "1:" - "sete %b1\n\t" - "movzbl %b1,%0\n\t" - : "=&a" (tmp), "=&q" (new), "+m" (lock->slock) - : - : "memory", "cc"); - - return tmp; -} - static __always_inline void __ticket_spin_unlock(arch_spinlock_t *lock) { asm volatile(UNLOCK_LOCK_PREFIX "incw %0" - : "+m" (lock->slock) + : "+m" (lock->head_tail) : : "memory", "cc"); } @@ -159,16 +99,16 @@ static __always_inline void __ticket_spin_unlock(arch_spinlock_t *lock) static inline int __ticket_spin_is_locked(arch_spinlock_t *lock) { - int tmp = ACCESS_ONCE(lock->slock); + struct __raw_tickets tmp = ACCESS_ONCE(lock->tickets); - return !!(((tmp >> TICKET_SHIFT) ^ tmp) & ((1 << TICKET_SHIFT) - 1)); + return !!(tmp.tail ^ tmp.head); } static inline int __ticket_spin_is_contended(arch_spinlock_t *lock) { - int tmp = ACCESS_ONCE(lock->slock); + struct __raw_tickets tmp = ACCESS_ONCE(lock->tickets); - return (((tmp >> TICKET_SHIFT) - tmp) & ((1 << TICKET_SHIFT) - 1)) > 1; + return ((tmp.tail - tmp.head) & TICKET_MASK) > 1; } #ifndef CONFIG_PARAVIRT_SPINLOCKS diff --git a/arch/x86/include/asm/spinlock_types.h b/arch/x86/include/asm/spinlock_types.h index 7c7a486fcb6..8ebd5df7451 100644 --- a/arch/x86/include/asm/spinlock_types.h +++ b/arch/x86/include/asm/spinlock_types.h @@ -5,11 +5,29 @@ # error "please don't include this file directly" #endif +#include <linux/types.h> + +#if (CONFIG_NR_CPUS < 256) +typedef u8 __ticket_t; +typedef u16 __ticketpair_t; +#else +typedef u16 __ticket_t; +typedef u32 __ticketpair_t; +#endif + +#define TICKET_SHIFT (sizeof(__ticket_t) * 8) +#define TICKET_MASK ((__ticket_t)((1 << TICKET_SHIFT) - 1)) + typedef struct arch_spinlock { - unsigned int slock; + union { + __ticketpair_t head_tail; + struct __raw_tickets { + __ticket_t head, tail; + } tickets; + }; } arch_spinlock_t; -#define __ARCH_SPIN_LOCK_UNLOCKED { 0 } +#define __ARCH_SPIN_LOCK_UNLOCKED { { 0 } } #include <asm/rwlock.h> diff --git a/arch/x86/include/asm/uv/uv_bau.h b/arch/x86/include/asm/uv/uv_bau.h index 37d369859c8..c568ccca6e0 100644 --- a/arch/x86/include/asm/uv/uv_bau.h +++ b/arch/x86/include/asm/uv/uv_bau.h @@ -656,11 +656,7 @@ static inline int atomic_read_short(const struct atomic_short *v) */ static inline int atom_asr(short i, struct atomic_short *v) { - short __i = i; - asm volatile(LOCK_PREFIX "xaddw %0, %1" - : "+r" (i), "+m" (v->counter) - : : "memory"); - return i + __i; + return i + xadd(&v->counter, i); } /* |