libkern/libkern/sysctl.h

   1 /*
   2  * Copyright (c) 2003-2004 Apple Computer, 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 #ifndef LIBKERN_SYSCTL_H
  25 #define LIBKERN_SYSCTL_H
  26
  27 #include <sys/cdefs.h>
  28
  29 __BEGIN_DECLS
  30
  31 #include <sys/types.h>
  32
  33 /*
  34  * These are the support HW selectors for sysctlbyname.  Parameters that are byte counts or frequencies are 64 bit numbers.
  35  * All other parameters are 32 bit numbers.
  36  *
  37  *   hw.memsize                - The number of bytes of physical memory in the system.
  38  *
  39  *   hw.ncpu                   - The maximum number of processors that could be available this boot.
  40  *                               Use this value for sizing of static per processor arrays; i.e. processor load statistics.
  41  *
  42  *   hw.activecpu              - The number of processors currently available for executing threads.
  43  *                               Use this number to determine the number threads to create in SMP aware applications.
  44  *                               This number can change when power management modes are changed.
  45  *
  46  *   hw.physicalcpu            - The number of physical processors available in the current power management mode.
  47  *   hw.physicalcpu_max        - The maximum number of physical processors that could be available this boot
  48  *
  49  *   hw.logicalcpu             - The number of logical processors available in the current power management mode.
  50  *   hw.logicalcpu_max         - The maximum number of logical processors that could be available this boot
  51  *
  52  *   hw.tbfrequency            - This gives the time base frequency used by the OS and is the basis of all timing services.
  53  *                               In general is is better to use mach's or higher level timing services, but this value
  54  *                               is needed to convert the PPC Time Base registers to real time.
  55  *
  56  *   hw.cpufrequency           - These values provide the current, min and max cpu frequency.  The min and max are for
  57  *   hw.cpufrequency_max       - all power management modes.  The current frequency is the max frequency in the current mode.
  58  *   hw.cpufrequency_min       - All frequencies are in Hz.
  59  *
  60  *   hw.busfrequency           - These values provide the current, min and max bus frequency.  The min and max are for
  61  *   hw.busfrequency_max       - all power management modes.  The current frequency is the max frequency in the current mode.
  62  *   hw.busfrequency_min       - All frequencies are in Hz.
  63  *
  64  *   hw.cputype                - These values provide the mach-o cpu type and subtype.  A complete list is in <mach/machine.h>
  65  *   hw.cpusubtype             - These values should be used to determine what processor family the running cpu is from so that
  66  *                               the best binary can be chosen, or the best dynamic code generated.  They should not be used
  67  *                               to determine if a given processor feature is available.
  68  *   hw.cputhreadtype          - This value will be present if the processor supports threads.  Like hw.cpusubtype this selector
  69  *                               should not be used to infer features, and only used to name the processors thread architecture.
  70  *                               The values are defined in <mach/machine.h>
  71  *
  72  *   hw.byteorder              - Gives the byte order of the processor.  4321 for big endian, 1234 for little.
  73  *
  74  *   hw.pagesize               - Gives the size in bytes of the pages used by the processor and VM system.
  75  *
  76  *   hw.cachelinesize          - Gives the size in bytes of the processor's cache lines.
  77  *                               This value should be use to control the strides of loops that use cache control instructions
  78  *                               like dcbz, dcbt or dcbst.
  79  *
  80  *   hw.l1dcachesize           - These values provide the size in bytes of the L1, L2 and L3 caches.  If a cache is not present
  81  *   hw.l1icachesize           - then the selector will return and error.
  82  *   hw.l2cachesize            -
  83  *   hw.l3cachesize            -
  84  *
  85  *
  86  * These are the selectors for optional processor features.  Selectors that return errors are not support on the system.
  87  * Supported features will return 1 if they are recommended or 0 if they are supported but are not expected to help performance.
  88  * Future versions of these selectors may return larger values as necessary so it is best to test for non zero.
  89  *
  90  *   hw.optional.floatingpoint - Floating Point Instructions
  91  *   hw.optional.altivec       - AltiVec Instructions
  92  *   hw.optional.graphicsops   - Graphics Operations
  93  *   hw.optional.64bitops      - 64-bit Instructions
  94  *   hw.optional.fsqrt         - HW Floating Point Square Root Instruction
  95  *   hw.optional.stfiwx        - Store Floating Point as Integer Word Indexed Instructions
  96  *   hw.optional.dcba          - Data Cache Block Allocate Instruction
  97  *   hw.optional.datastreams   - Data Streams Instructions
  98  *   hw.optional.dcbtstreams   - Data Cache Block Touch Steams Instruction Form
  99  *
 100  */
 101
 102 /*
 103  * Sysctl handling
 104  */
 105 int     sysctlbyname(const char *, void *, size_t *, void *, size_t);
 106
 107 __END_DECLS
 108
 109 #endif  /* LIBKERN_SYSCTL_H */