arm/sys/OSAtomic_resolvers.c

   1 /*
   2  * Copyright (c) 2010 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 /*
  25  * This holds the C versions of OSAtomic.s resolver functions, used by
  26  * everyone except dyld.
  27  */
  28
  29 #include <arm/arch.h>
  30 #if defined(_ARM_ARCH_7)
  31
  32 #include <stdlib.h>
  33 #include <machine/cpu_capabilities.h>
  34 #include <mach/machine.h>
  35
  36 #if defined(VARIANT_DYLD)
  37
  38 #define _STRDEF(x) __STRING(x)
  39
  40 #define makeResolver_up_mp(name) \
  41         void* name ## $VARIANT$up(void); \
  42         void* name ## $VARIANT$mp(void); \
  43         void* name ## Resolver(void) __asm__( "_" #name ); \
  44         void* name ## Resolver(void) { \
  45                 __asm__ __volatile__ ( \
  46                         "ldr ip, L" #name "$commpage ;" \
  47                         "ldr ip, [ip] ;" \
  48                         "tst ip, $(" _STRDEF(kUP) ") ;" \
  49                         "bne 1f ; " \
  50                         "b   _" __STRING(name) "$VARIANT$mp ;" \
  51                         "1: b   _" __STRING(name) "$VARIANT$up ;" \
  52                         "L" #name "$commpage: .long " _STRDEF(_COMM_PAGE_CPU_CAPABILITIES) " ;" \
  53                         : : : ); \
  54         }
  55
  56 #define makeResolver_up_mp_wfe(name) makeResolver_up_mp(name)
  57
  58 #else
  59
  60 #define makeResolver_up_mp(name) \
  61         void name ## $VARIANT$up(void); \
  62         void name ## $VARIANT$mp(void); \
  63         void* name ## Resolver(void) __asm__( "_" #name ) ; \
  64         void* name ## Resolver(void) { \
  65                 __asm__(".symbol_resolver _" #name); \
  66                 /* return MP variant functions on kNumCPUs > 1 */ \
  67                 if ((*(uint32_t*)(uintptr_t)_COMM_PAGE_CPU_CAPABILITIES & kUP) == 0) { \
  68                         return name ## $VARIANT$mp; \
  69                 } \
  70                 return name ## $VARIANT$up; \
  71         }
  72
  73 #define makeResolver_up_mp_wfe(name) \
  74         void name ## $VARIANT$up(void); \
  75         void name ## $VARIANT$mp(void); \
  76         void name ## $VARIANT$wfe(void); \
  77         void* name ## Resolver(void) __asm__( "_" #name ) ; \
  78         void* name ## Resolver(void) { \
  79                 __asm__(".symbol_resolver _" #name); \
  80                 uint32_t caps = *(uint32_t*)(uintptr_t)_COMM_PAGE_CPU_CAPABILITIES; \
  81                 /* return WFE variant if we will get woken up */ \
  82                 if ((caps & (kHasEvent | kUP)) == kHasEvent) { \
  83                         return name ## $VARIANT$wfe; \
  84                 } \
  85                 /* return MP variant functions on kNumCPUs > 1 */ \
  86                 else if ((caps & kUP) == 0) { \
  87                         return name ## $VARIANT$mp; \
  88                 } \
  89                 return name ## $VARIANT$up; \
  90         }
  91
  92 #endif // defined VARIANT_DYLD
  93
  94 #include "OSAtomic_resolvers.h"
  95
  96 #else // defined _ARM_ARCH_7
  97
  98 typedef int emptyFilesArentCFiles;
  99
 100 #endif // defined _ARM_ARCH_7 && !defined VARIANT_DYLD