X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/2d21ac55c334faf3a56e5634905ed6987fc787d4..813fb2f63a553c957e917ede5f119b021d6ce391:/libkern/gen/OSAtomicOperations.c diff --git a/libkern/gen/OSAtomicOperations.c b/libkern/gen/OSAtomicOperations.c index bbdb0d970..5affc1eef 100644 --- a/libkern/gen/OSAtomicOperations.c +++ b/libkern/gen/OSAtomicOperations.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2000-2015 Apple Computer, Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * @@ -27,6 +27,8 @@ */ #include +#include +#include enum { false = 0, @@ -37,116 +39,138 @@ enum { #define NULL ((void *)0) #endif +#define ATOMIC_DEBUG DEBUG + +#if ATOMIC_DEBUG +#define ALIGN_TEST(p,t) do{if((uintptr_t)p&(sizeof(t)-1)) panic("Unaligned atomic pointer %p\n",p);}while(0) +#else +#define ALIGN_TEST(p,t) do{}while(0) +#endif + +// 19831745 - start of big hammer! +#pragma clang diagnostic push +#pragma clang diagnostic ignored "-Wcast-qual" + /* * atomic operations - * these are _the_ atomic operations, currently cast atop CompareAndSwap, - * which is implemented in assembler. if we are worried about the cost of - * this layering (we shouldn't be), then all this stuff could be - * implemented in assembler, as it is in MacOS8/9 - * (derived from SuperMario/NativeLibs/IO/DriverServices/Synchronization.s, - * which I wrote for NuKernel in a previous life with a different last name...) - * - * native Boolean CompareAndSwap(UInt32 oldValue, UInt32 newValue, UInt32 * oldValuePtr); - * - * We've since implemented a few more of these -- OSAddAtomic, OSDequeueAtomic, - * OSEnqueueAtomic etc -- in assembler, either for speed or correctness. See also the - * commpage atomic operations, and the platform specific versions. - * Like standards, there are a lot of atomic ops to choose from! + * These are _the_ atomic operations, now implemented via compiler built-ins. + * It is expected that this C implementation is a candidate for Link-Time- + * Optimization inlining, whereas the assembler implementations they replace + * were not. */ -#ifndef __ppc__ +#undef OSCompareAndSwap8 +Boolean OSCompareAndSwap8(UInt8 oldValue, UInt8 newValue, volatile UInt8 *address) +{ + return __c11_atomic_compare_exchange_strong((_Atomic UInt8 *)address, &oldValue, newValue, + memory_order_acq_rel_smp, memory_order_relaxed); +} +#undef OSCompareAndSwap16 +Boolean OSCompareAndSwap16(UInt16 oldValue, UInt16 newValue, volatile UInt16 *address) +{ + return __c11_atomic_compare_exchange_strong((_Atomic UInt16 *)address, &oldValue, newValue, + memory_order_acq_rel_smp, memory_order_relaxed); +} -SInt32 OSIncrementAtomic(volatile SInt32 * value) +#undef OSCompareAndSwap +Boolean OSCompareAndSwap(UInt32 oldValue, UInt32 newValue, volatile UInt32 *address) { - return OSAddAtomic(1, value); + ALIGN_TEST(address, UInt32); + return __c11_atomic_compare_exchange_strong((_Atomic UInt32 *)address, &oldValue, newValue, + memory_order_acq_rel_smp, memory_order_relaxed); } -SInt32 OSDecrementAtomic(volatile SInt32 * value) +#undef OSCompareAndSwap64 +Boolean OSCompareAndSwap64(UInt64 oldValue, UInt64 newValue, volatile UInt64 *address) { - return OSAddAtomic(-1, value); + /* + * _Atomic uint64 requires 8-byte alignment on all architectures. + * This silences the compiler cast warning. ALIGN_TEST() verifies + * that the cast was legal, if defined. + */ + _Atomic UInt64 *aligned_addr = (_Atomic UInt64 *)(uintptr_t)address; + + ALIGN_TEST(address, UInt64); + return __c11_atomic_compare_exchange_strong(aligned_addr, &oldValue, newValue, + memory_order_acq_rel_smp, memory_order_relaxed); } -#ifdef CMPXCHG8B -void * OSDequeueAtomic(void * volatile * inList, SInt32 inOffset) +#undef OSCompareAndSwapPtr +Boolean OSCompareAndSwapPtr(void *oldValue, void *newValue, void * volatile *address) { - /* The _pointer_ is volatile, not the listhead itself */ - void * volatile oldListHead; - void * volatile newListHead; - - do { - oldListHead = *inList; - if (oldListHead == NULL) { - break; - } - - newListHead = *(void * volatile *) (((char *) oldListHead) + inOffset); - } while (! OSCompareAndSwap((UInt32)oldListHead, - (UInt32)newListHead, (volatile UInt32 *)inList)); - return oldListHead; +#if __LP64__ + return OSCompareAndSwap64((UInt64)oldValue, (UInt64)newValue, (volatile UInt64 *)address); +#else + return OSCompareAndSwap((UInt32)oldValue, (UInt32)newValue, (volatile UInt32 *)address); +#endif } -void OSEnqueueAtomic(void * volatile * inList, void * inNewLink, SInt32 inOffset) +SInt8 OSAddAtomic8(SInt32 amount, volatile SInt8 *address) { - /* The _pointer_ is volatile, not the listhead itself */ - void * volatile oldListHead; - void * volatile newListHead = inNewLink; - void * volatile * newLinkNextPtr = (void * volatile *) (((char *) inNewLink) + inOffset); - - do { - oldListHead = *inList; - *newLinkNextPtr = oldListHead; - } while (! OSCompareAndSwap((UInt32)oldListHead, (UInt32)newListHead, - (volatile UInt32 *)inList)); + return __c11_atomic_fetch_add((_Atomic SInt8*)address, amount, memory_order_relaxed); } -#endif /* CMPXCHG8B */ -#endif /* !__ppc__ */ -static UInt32 OSBitwiseAtomic(UInt32 and_mask, UInt32 or_mask, UInt32 xor_mask, volatile UInt32 * value) +SInt16 OSAddAtomic16(SInt32 amount, volatile SInt16 *address) { - UInt32 oldValue; - UInt32 newValue; - - do { - oldValue = *value; - newValue = ((oldValue & and_mask) | or_mask) ^ xor_mask; - } while (! OSCompareAndSwap(oldValue, newValue, value)); - - return oldValue; + return __c11_atomic_fetch_add((_Atomic SInt16*)address, amount, memory_order_relaxed); } -UInt32 OSBitAndAtomic(UInt32 mask, volatile UInt32 * value) +#undef OSAddAtomic +SInt32 OSAddAtomic(SInt32 amount, volatile SInt32 *address) { - return OSBitwiseAtomic(mask, 0, 0, value); + ALIGN_TEST(address, UInt32); + return __c11_atomic_fetch_add((_Atomic SInt32*)address, amount, memory_order_relaxed); } -UInt32 OSBitOrAtomic(UInt32 mask, volatile UInt32 * value) +#undef OSAddAtomic64 +SInt64 OSAddAtomic64(SInt64 amount, volatile SInt64 *address) { - return OSBitwiseAtomic((UInt32) -1, mask, 0, value); + _Atomic SInt64* aligned_address = (_Atomic SInt64*)(uintptr_t)address; + + ALIGN_TEST(address, SInt64); + return __c11_atomic_fetch_add(aligned_address, amount, memory_order_relaxed); } -UInt32 OSBitXorAtomic(UInt32 mask, volatile UInt32 * value) +#undef OSAddAtomicLong +long +OSAddAtomicLong(long theAmount, volatile long *address) { - return OSBitwiseAtomic((UInt32) -1, 0, mask, value); +#ifdef __LP64__ + return (long)OSAddAtomic64((SInt64)theAmount, (SInt64*)address); +#else + return (long)OSAddAtomic((SInt32)theAmount, address); +#endif } -static Boolean OSCompareAndSwap8(UInt8 oldValue8, UInt8 newValue8, volatile UInt8 * value8) +#undef OSIncrementAtomic +SInt32 OSIncrementAtomic(volatile SInt32 * value) { - UInt32 mask = 0x000000ff; - UInt32 alignment = ((UInt32) value8) & (sizeof(UInt32) - 1); - UInt32 shiftValues = (24 << 24) | (16 << 16) | (8 << 8); - int shift = (UInt32) *(((UInt8 *) &shiftValues) + alignment); - volatile UInt32 * value32 = (volatile UInt32 *) (value8 - alignment); - UInt32 oldValue; - UInt32 newValue; + return OSAddAtomic(1, value); +} - mask <<= shift; +#undef OSDecrementAtomic +SInt32 OSDecrementAtomic(volatile SInt32 * value) +{ + return OSAddAtomic(-1, value); +} + +#undef OSBitAndAtomic +UInt32 OSBitAndAtomic(UInt32 mask, volatile UInt32 * value) +{ + return __c11_atomic_fetch_and((_Atomic UInt32*)value, mask, memory_order_relaxed); +} - oldValue = *value32; - oldValue = (oldValue & ~mask) | (oldValue8 << shift); - newValue = (oldValue & ~mask) | (newValue8 << shift); +#undef OSBitOrAtomic +UInt32 OSBitOrAtomic(UInt32 mask, volatile UInt32 * value) +{ + return __c11_atomic_fetch_or((_Atomic UInt32*)value, mask, memory_order_relaxed); +} - return OSCompareAndSwap(oldValue, newValue, value32); +#undef OSBitXorAtomic +UInt32 OSBitXorAtomic(UInt32 mask, volatile UInt32 * value) +{ + return __c11_atomic_fetch_xor((_Atomic UInt32*)value, mask, memory_order_relaxed); } static Boolean OSTestAndSetClear(UInt32 bit, Boolean wantSet, volatile UInt8 * startAddress) @@ -164,7 +188,8 @@ static Boolean OSTestAndSetClear(UInt32 bit, Boolean wantSet, volatile UInt8 * s if ((oldValue & mask) == wantValue) { break; } - } while (! OSCompareAndSwap8(oldValue, (oldValue & ~mask) | wantValue, startAddress)); + } while (! __c11_atomic_compare_exchange_strong((_Atomic UInt8 *)startAddress, + &oldValue, (oldValue & ~mask) | wantValue, memory_order_relaxed, memory_order_relaxed)); return (oldValue & mask) == wantValue; } @@ -193,64 +218,19 @@ SInt8 OSDecrementAtomic8(volatile SInt8 * value) return OSAddAtomic8(-1, value); } -SInt8 OSAddAtomic8(SInt32 amount, volatile SInt8 * value) -{ - SInt8 oldValue; - SInt8 newValue; - - do { - oldValue = *value; - newValue = oldValue + amount; - } while (! OSCompareAndSwap8((UInt8) oldValue, (UInt8) newValue, (volatile UInt8 *) value)); - - return oldValue; -} - -static UInt8 OSBitwiseAtomic8(UInt32 and_mask, UInt32 or_mask, UInt32 xor_mask, volatile UInt8 * value) -{ - UInt8 oldValue; - UInt8 newValue; - - do { - oldValue = *value; - newValue = ((oldValue & and_mask) | or_mask) ^ xor_mask; - } while (! OSCompareAndSwap8(oldValue, newValue, value)); - - return oldValue; -} - UInt8 OSBitAndAtomic8(UInt32 mask, volatile UInt8 * value) { - return OSBitwiseAtomic8(mask, 0, 0, value); + return __c11_atomic_fetch_and((_Atomic UInt8 *)value, mask, memory_order_relaxed); } UInt8 OSBitOrAtomic8(UInt32 mask, volatile UInt8 * value) { - return OSBitwiseAtomic8((UInt32) -1, mask, 0, value); + return __c11_atomic_fetch_or((_Atomic UInt8 *)value, mask, memory_order_relaxed); } UInt8 OSBitXorAtomic8(UInt32 mask, volatile UInt8 * value) { - return OSBitwiseAtomic8((UInt32) -1, 0, mask, value); -} - -static Boolean OSCompareAndSwap16(UInt16 oldValue16, UInt16 newValue16, volatile UInt16 * value16) -{ - UInt32 mask = 0x0000ffff; - UInt32 alignment = ((UInt32) value16) & (sizeof(UInt32) - 1); - UInt32 shiftValues = (16 << 24) | (16 << 16); - UInt32 shift = (UInt32) *(((UInt8 *) &shiftValues) + alignment); - volatile UInt32 * value32 = (volatile UInt32 *) (((UInt32) value16) - alignment); - UInt32 oldValue; - UInt32 newValue; - - mask <<= shift; - - oldValue = *value32; - oldValue = (oldValue & ~mask) | (oldValue16 << shift); - newValue = (oldValue & ~mask) | (newValue16 << shift); - - return OSCompareAndSwap(oldValue, newValue, value32); + return __c11_atomic_fetch_xor((_Atomic UInt8 *)value, mask, memory_order_relaxed); } SInt16 OSIncrementAtomic16(volatile SInt16 * value) @@ -263,44 +243,21 @@ SInt16 OSDecrementAtomic16(volatile SInt16 * value) return OSAddAtomic16(-1, value); } -SInt16 OSAddAtomic16(SInt32 amount, volatile SInt16 * value) -{ - SInt16 oldValue; - SInt16 newValue; - - do { - oldValue = *value; - newValue = oldValue + amount; - } while (! OSCompareAndSwap16((UInt16) oldValue, (UInt16) newValue, (volatile UInt16 *) value)); - - return oldValue; -} - -static UInt16 OSBitwiseAtomic16(UInt32 and_mask, UInt32 or_mask, UInt32 xor_mask, volatile UInt16 * value) -{ - UInt16 oldValue; - UInt16 newValue; - - do { - oldValue = *value; - newValue = ((oldValue & and_mask) | or_mask) ^ xor_mask; - } while (! OSCompareAndSwap16(oldValue, newValue, value)); - - return oldValue; -} - UInt16 OSBitAndAtomic16(UInt32 mask, volatile UInt16 * value) { - return OSBitwiseAtomic16(mask, 0, 0, value); + return __c11_atomic_fetch_and((_Atomic UInt16 *)value, mask, memory_order_relaxed); } UInt16 OSBitOrAtomic16(UInt32 mask, volatile UInt16 * value) { - return OSBitwiseAtomic16((UInt32) -1, mask, 0, value); + return __c11_atomic_fetch_or((_Atomic UInt16 *)value, mask, memory_order_relaxed); } UInt16 OSBitXorAtomic16(UInt32 mask, volatile UInt16 * value) { - return OSBitwiseAtomic16((UInt32) -1, 0, mask, value); + return __c11_atomic_fetch_xor((_Atomic UInt16 *)value, mask, memory_order_relaxed); } +// 19831745 - end of big hammer! +#pragma clang diagnostic pop +