xnu-3789.51.2.tar.gz

[apple/xnu.git] / libkern / gen / OSAtomicOperations.c

diff --git a/libkern/gen/OSAtomicOperations.c b/libkern/gen/OSAtomicOperations.c
index 735fa2ac3719d70c5a453d1b8e03bf299884134e..5affc1eefdc73334b3a4eb6dac6882104c5707ec 100644 (file)
--- a/libkern/gen/OSAtomicOperations.c
+++ b/libkern/gen/OSAtomicOperations.c
@@ -1,143 +1,179 @@
 /*
 /*

- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2015 Apple Computer, Inc. All rights reserved.

  *
  *

- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@

  * 
  * 

- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License").  You may not use this file except in compliance with the
- * License.  Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.

  * 
  * 

- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER

  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,

- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.

  * 
  * 

- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@

  */
 
 #include <libkern/OSAtomic.h>
  */
 
 #include <libkern/OSAtomic.h>

+#include <kern/debug.h>
+#include <machine/atomic.h>

 
 enum {
        false   = 0,
        true    = 1
 };
 
 enum {
        false   = 0,
        true    = 1
 };

-#define        NULL 0L

 
 

+#ifndef NULL
+#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
 
 /*
  * 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);
+ *     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);
+}

 
 

-SInt32 OSAddAtomic(SInt32 amount, SInt32 * value)
+#undef OSCompareAndSwap16
+Boolean OSCompareAndSwap16(UInt16 oldValue, UInt16 newValue, volatile UInt16 *address)

 {
 {

-       SInt32  oldValue;
-       SInt32  newValue;
-       
-       do {
-               oldValue = *value;
-               newValue = oldValue + amount;
-       } while (! OSCompareAndSwap((UInt32) oldValue, (UInt32) newValue, (UInt32 *) value));
-       
-       return oldValue;
+       return __c11_atomic_compare_exchange_strong((_Atomic UInt16 *)address, &oldValue, newValue,
+                       memory_order_acq_rel_smp, memory_order_relaxed);

 }
 
 }
 

-SInt32 OSIncrementAtomic(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(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);

 }
 
 }
 

-#endif /* !__ppc__ */
+#undef OSCompareAndSwapPtr
+Boolean OSCompareAndSwapPtr(void *oldValue, void *newValue, void * volatile *address)
+{
+#if __LP64__
+  return OSCompareAndSwap64((UInt64)oldValue, (UInt64)newValue, (volatile UInt64 *)address);
+#else
+  return OSCompareAndSwap((UInt32)oldValue, (UInt32)newValue, (volatile UInt32 *)address);
+#endif
+}

 
 

-static UInt32  OSBitwiseAtomic(UInt32 and_mask, UInt32 or_mask, UInt32 xor_mask, UInt32 * value)
+SInt8 OSAddAtomic8(SInt32 amount, volatile SInt8 *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 SInt8*)address, amount, memory_order_relaxed);

 }
 
 }
 

-UInt32 OSBitAndAtomic(UInt32 mask, UInt32 * value)
+SInt16 OSAddAtomic16(SInt32 amount, volatile SInt16 *address)

 {
 {

-       return OSBitwiseAtomic(mask, 0, 0, value);
+       return __c11_atomic_fetch_add((_Atomic SInt16*)address, amount, memory_order_relaxed);

 }
 
 }
 

-UInt32 OSBitOrAtomic(UInt32 mask, UInt32 * value)
+#undef OSAddAtomic
+SInt32 OSAddAtomic(SInt32 amount, volatile SInt32 *address)

 {
 {

-       return OSBitwiseAtomic((UInt32) -1, mask, 0, value);
+       ALIGN_TEST(address, UInt32);
+       return __c11_atomic_fetch_add((_Atomic SInt32*)address, amount, memory_order_relaxed);

 }
 
 }
 

-UInt32 OSBitXorAtomic(UInt32 mask, UInt32 * value)
+#undef OSAddAtomic64
+SInt64 OSAddAtomic64(SInt64 amount, volatile SInt64 *address)

 {
 {

-       return OSBitwiseAtomic((UInt32) -1, 0, mask, 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);

 }
 
 }
 

+#undef OSAddAtomicLong
+long
+OSAddAtomicLong(long theAmount, volatile long *address)
+{
+#ifdef __LP64__
+       return (long)OSAddAtomic64((SInt64)theAmount, (SInt64*)address);
+#else
+       return (long)OSAddAtomic((SInt32)theAmount, address);
+#endif
+}

 
 

-static Boolean OSCompareAndSwap8(UInt8 oldValue8, UInt8 newValue8, UInt8 * value8)
+#undef OSIncrementAtomic
+SInt32 OSIncrementAtomic(volatile SInt32 * value)

 {
 {

-       UInt32          mask = 0x000000ff;
-       UInt32          newbits = (UInt32) newValue8;
-       int                     shift;
-       UInt32          alignment = ((UInt32) value8) & (sizeof(UInt32) - 1);
-       UInt32          oldValue;
-       UInt32          newValue;
-       UInt32 *        value;
-
-       switch (alignment) {
-               default:
-                       // assert(false);
-               case 0:
-                       value = (UInt32 *) value8;
-                       shift = 24;
-                       break;
-               case 1:
-                       value = (UInt32 *) (value8 + 1);
-                       shift = 16;
-                       break;
-               case 2:
-                       value = (UInt32 *) (value8 + 2);
-                       shift = 8;
-                       break;
-               case 3:
-                       value = (UInt32 *) (value8 + 3);
-                       shift = 0;
-                       break;
-       }
+       return OSAddAtomic(1, value);
+}

 
 

-       mask <<= shift;
-       newbits <<= shift;
-       
-       oldValue = *value;
-       newValue = (oldValue & ~mask) | (newbits & mask);
-       
-       return OSCompareAndSwap(oldValue, newValue, value);
+#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);
+}
+
+#undef OSBitOrAtomic
+UInt32 OSBitOrAtomic(UInt32 mask, volatile UInt32 * value)
+{
+       return __c11_atomic_fetch_or((_Atomic UInt32*)value, mask, memory_order_relaxed);

 }
 
 }
 

-static Boolean OSTestAndSetClear(UInt32 bit, Boolean wantSet, UInt8 * startAddress)
+#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)

 {
        UInt8           mask = 1;
        UInt8           oldValue;
 {
        UInt8           mask = 1;
        UInt8           oldValue;


@@ -152,185 +188,76 @@ static Boolean   OSTestAndSetClear(UInt32 bit, Boolean wantSet, UInt8 * startAddre
                if ((oldValue & mask) == wantValue) {
                        break;
                }
                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;
 }
 
        
        return (oldValue & mask) == wantValue;
 }
 

-Boolean        OSTestAndSet(UInt32 bit, UInt8 * startAddress)
+Boolean OSTestAndSet(UInt32 bit, volatile UInt8 * startAddress)

 {
        return OSTestAndSetClear(bit, true, startAddress);
 }
 
 {
        return OSTestAndSetClear(bit, true, startAddress);
 }
 

-Boolean        OSTestAndClear(UInt32 bit, UInt8 * startAddress)
+Boolean OSTestAndClear(UInt32 bit, volatile UInt8 * startAddress)

 {
        return OSTestAndSetClear(bit, false, startAddress);
 }
 
 {
        return OSTestAndSetClear(bit, false, startAddress);
 }
 

-void * OSDequeueAtomic(void ** inList, SInt32 inOffset)
-{
-       void *  oldListHead;
-       void *  newListHead;
-       
-       do {
-               oldListHead = *inList;
-               if (oldListHead == NULL) {
-                       break;
-               }
-               
-               newListHead = *(void **) (((char *) oldListHead) + inOffset);
-       } while (! OSCompareAndSwap((UInt32)oldListHead,
-                                       (UInt32)newListHead, (UInt32 *)inList));
-       
-       return oldListHead;
-}
-
-void   OSEnqueueAtomic(void ** inList, void * inNewLink, SInt32 inOffset)
-{
-       void *  oldListHead;
-       void *  newListHead = inNewLink;
-       void ** newLinkNextPtr = (void **) (((char *) inNewLink) + inOffset);
-       
-       do {
-               oldListHead = *inList;
-               *newLinkNextPtr = oldListHead;
-       } while (! OSCompareAndSwap((UInt32)oldListHead, (UInt32)newListHead,
-                                       (UInt32 *)inList));
-}
-

 /*
  * silly unaligned versions
  */
 
 /*
  * silly unaligned versions
  */
 

-SInt8  OSIncrementAtomic8(SInt8 * value)
+SInt8  OSIncrementAtomic8(volatile SInt8 * value)

 {
        return OSAddAtomic8(1, value);
 }
 
 {
        return OSAddAtomic8(1, value);
 }
 

-SInt8  OSDecrementAtomic8(SInt8 * value)
+SInt8  OSDecrementAtomic8(volatile SInt8 * value)

 {
        return OSAddAtomic8(-1, value);
 }
 
 {
        return OSAddAtomic8(-1, value);
 }
 

-SInt8  OSAddAtomic8(SInt32 amount, SInt8 * value)
-{
-       SInt8   oldValue;
-       SInt8   newValue;
-       
-       do {
-               oldValue = *value;
-               newValue = oldValue + amount;
-       } while (! OSCompareAndSwap8((UInt8) oldValue, (UInt8) newValue, (UInt8 *) value));
-       
-       return oldValue;
-}
-
-static UInt8   OSBitwiseAtomic8(UInt32 and_mask, UInt32 or_mask, UInt32 xor_mask, 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, UInt8 * value)
-{
-       return OSBitwiseAtomic8(mask, 0, 0, value);
-}
-
-UInt8  OSBitOrAtomic8(UInt32 mask, UInt8 * value)
+UInt8  OSBitAndAtomic8(UInt32 mask, volatile UInt8 * value)

 {
 {

-       return OSBitwiseAtomic8((UInt32) -1, mask, 0, value);
+       return __c11_atomic_fetch_and((_Atomic UInt8 *)value, mask, memory_order_relaxed);

 }
 
 }
 

-UInt8  OSBitXorAtomic8(UInt32 mask, UInt8 * value)
+UInt8  OSBitOrAtomic8(UInt32 mask, volatile UInt8 * value)

 {
 {

-       return OSBitwiseAtomic8((UInt32) -1, 0, mask, value);
+       return __c11_atomic_fetch_or((_Atomic UInt8 *)value, mask, memory_order_relaxed);

 }
 
 }
 

-
-static Boolean OSCompareAndSwap16(UInt16 oldValue16, UInt16 newValue16, UInt16 * value16)
+UInt8  OSBitXorAtomic8(UInt32 mask, volatile UInt8 * value)

 {
 {

-       UInt32          mask = 0x0000ffff;
-       UInt32          newbits = (UInt32) newValue16;
-       int                     shift;
-       UInt32          alignment = ((UInt32) value16) & (sizeof(UInt32) - 1);
-       UInt32          oldValue;
-       UInt32          newValue;
-       UInt32 *        value;
-
-       if (alignment == 2) {
-               value = (UInt32 *) (value16 - 1);
-               shift = 0;
-       }
-       else {
-               // assert(alignment == 0);
-               value = (UInt32 *) value16;
-               shift = 16;
-       }
-
-       mask <<= shift;
-       newbits <<= shift;
-       
-       oldValue = *value;
-       newValue = (oldValue & ~mask) | (newbits & mask);
-       
-       return OSCompareAndSwap(oldValue, newValue, value);
+       return __c11_atomic_fetch_xor((_Atomic UInt8 *)value, mask, memory_order_relaxed);

 }
 
 }
 

-SInt16 OSIncrementAtomic16(SInt16 * value)
+SInt16 OSIncrementAtomic16(volatile SInt16 * value)

 {
        return OSAddAtomic16(1, value);
 }
 
 {
        return OSAddAtomic16(1, value);
 }
 

-SInt16 OSDecrementAtomic16(SInt16 * value)
+SInt16 OSDecrementAtomic16(volatile SInt16 * value)

 {
        return OSAddAtomic16(-1, value);
 }
 
 {
        return OSAddAtomic16(-1, value);
 }
 

-SInt16 OSAddAtomic16(SInt32 amount, SInt16 * value)
-{
-       SInt16  oldValue;
-       SInt16  newValue;
-       
-       do {
-               oldValue = *value;
-               newValue = oldValue + amount;
-       } while (! OSCompareAndSwap16((UInt16) oldValue, (UInt16) newValue, (UInt16 *) value));
-       
-       return oldValue;
-}
-
-static UInt16  OSBitwiseAtomic16(UInt32 and_mask, UInt32 or_mask, UInt32 xor_mask, UInt16 * value)
+UInt16 OSBitAndAtomic16(UInt32 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;
+       return __c11_atomic_fetch_and((_Atomic UInt16 *)value, mask, memory_order_relaxed);

 }
 
 }
 

-UInt16 OSBitAndAtomic16(UInt32 mask, UInt16 * value)
+UInt16 OSBitOrAtomic16(UInt32 mask, volatile UInt16 * value)

 {
 {

-       return OSBitwiseAtomic16(mask, 0, 0, value);
+       return __c11_atomic_fetch_or((_Atomic UInt16 *)value, mask, memory_order_relaxed);

 }
 
 }
 

-UInt16 OSBitOrAtomic16(UInt32 mask, UInt16 * value)
+UInt16 OSBitXorAtomic16(UInt32 mask, volatile UInt16 * value)

 {
 {

-       return OSBitwiseAtomic16((UInt32) -1, mask, 0, value);
+       return __c11_atomic_fetch_xor((_Atomic UInt16 *)value, mask, memory_order_relaxed);

 }
 
 }
 

-UInt16 OSBitXorAtomic16(UInt32 mask, UInt16 * value)
-{
-       return OSBitwiseAtomic16((UInt32) -1, 0, mask, value);
-}
+// 19831745 - end of big hammer!
+#pragma clang diagnostic pop