libkern/libkern/sysctl.h

   1 /*
   2  * Copyright (c) 2003-2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22
  23 #ifndef LIBKERN_SYSCTL_H
  24 #define LIBKERN_SYSCTL_H
  25
  26 #include <sys/cdefs.h>
  27
  28 __BEGIN_DECLS
  29
  30 #include <sys/types.h>
  31
  32 /*
  33  * These are the support HW selectors for sysctlbyname.  Parameters that are byte counts or frequencies are 64 bit numbers.
  34  * All other parameters are 32 bit numbers.
  35  *
  36  *   hw.memsize                - The number of bytes of physical memory in the system.
  37  *
  38  *   hw.ncpu                   - The maximum number of processors that could be available this boot.
  39  *                               Use this value for sizing of static per processor arrays; i.e. processor load statistics.
  40  *
  41  *   hw.activecpu              - The number of processors currently available for executing threads.
  42  *                               Use this number to determine the number threads to create in SMP aware applications.
  43  *                               This number can change when power management modes are changed.
  44  *
  45  *   hw.physicalcpu            - The number of physical processors available in the current power management mode.
  46  *   hw.physicalcpu_max        - The maximum number of physical processors that could be available this boot
  47  *
  48  *   hw.logicalcpu             - The number of logical processors available in the current power management mode.
  49  *   hw.logicalcpu_max         - The maximum number of logical processors that could be available this boot
  50  *
  51  *   hw.tbfrequency            - This gives the time base frequency used by the OS and is the basis of all timing services.
  52  *                               In general is is better to use mach's or higher level timing services, but this value
  53  *                               is needed to convert the PPC Time Base registers to real time.
  54  *
  55  *   hw.cpufrequency           - These values provide the current, min and max cpu frequency.  The min and max are for
  56  *   hw.cpufrequency_max       - all power management modes.  The current frequency is the max frequency in the current mode.
  57  *   hw.cpufrequency_min       - All frequencies are in Hz.
  58  *
  59  *   hw.busfrequency           - These values provide the current, min and max bus frequency.  The min and max are for
  60  *   hw.busfrequency_max       - all power management modes.  The current frequency is the max frequency in the current mode.
  61  *   hw.busfrequency_min       - All frequencies are in Hz.
  62  *
  63  *   hw.cputype                - These values provide the mach-o cpu type and subtype.  A complete list is in <mach/machine.h>
  64  *   hw.cpusubtype             - These values should be used to determine what processor family the running cpu is from so that
  65  *                               the best binary can be chosen, or the best dynamic code generated.  They should not be used
  66  *                               to determine if a given processor feature is available.
  67  *   hw.cputhreadtype          - This value will be present if the processor supports threads.  Like hw.cpusubtype this selector
  68  *                               should not be used to infer features, and only used to name the processors thread architecture.
  69  *                               The values are defined in <mach/machine.h>
  70  *
  71  *   hw.byteorder              - Gives the byte order of the processor.  4321 for big endian, 1234 for little.
  72  *
  73  *   hw.pagesize               - Gives the size in bytes of the pages used by the processor and VM system.
  74  *
  75  *   hw.cachelinesize          - Gives the size in bytes of the processor's cache lines.
  76  *                               This value should be use to control the strides of loops that use cache control instructions
  77  *                               like dcbz, dcbt or dcbst.
  78  *
  79  *   hw.l1dcachesize           - These values provide the size in bytes of the L1, L2 and L3 caches.  If a cache is not present
  80  *   hw.l1icachesize           - then the selector will return and error.
  81  *   hw.l2cachesize            -
  82  *   hw.l3cachesize            -
  83  *
  84  *
  85  * These are the selectors for optional processor features.  Selectors that return errors are not support on the system.
  86  * Supported features will return 1 if they are recommended or 0 if they are supported but are not expected to help performance.
  87  * Future versions of these selectors may return larger values as necessary so it is best to test for non zero.
  88  *
  89  *   hw.optional.floatingpoint - Floating Point Instructions
  90  *   hw.optional.altivec       - AltiVec Instructions
  91  *   hw.optional.graphicsops   - Graphics Operations
  92  *   hw.optional.64bitops      - 64-bit Instructions
  93  *   hw.optional.fsqrt         - HW Floating Point Square Root Instruction
  94  *   hw.optional.stfiwx        - Store Floating Point as Integer Word Indexed Instructions
  95  *   hw.optional.dcba          - Data Cache Block Allocate Instruction
  96  *   hw.optional.datastreams   - Data Streams Instructions
  97  *   hw.optional.dcbtstreams   - Data Cache Block Touch Steams Instruction Form
  98  *
  99  */
 100
 101 /*
 102  * Sysctl handling
 103  */
 104 int     sysctlbyname(const char *, void *, size_t *, void *, size_t);
 105
 106 __END_DECLS
 107
 108 #endif  /* LIBKERN_SYSCTL_H */