libkern/libkern/sysctl.h

   1 /*
   2  * Copyright (c) 2003-2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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.  The rights granted to you under the
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30
  31 #ifndef LIBKERN_SYSCTL_H
  32 #define LIBKERN_SYSCTL_H
  33
  34 #include <sys/cdefs.h>
  35
  36 __BEGIN_DECLS
  37
  38 #include <sys/types.h>
  39
  40 /*
  41  * These are the support HW selectors for sysctlbyname.  Parameters that are byte counts or frequencies are 64 bit numbers.
  42  * All other parameters are 32 bit numbers.
  43  *
  44  *   hw.memsize                - The number of bytes of physical memory in the system.
  45  *
  46  *   hw.ncpu                   - The maximum number of processors that could be available this boot.
  47  *                               Use this value for sizing of static per processor arrays; i.e. processor load statistics.
  48  *
  49  *   hw.activecpu              - The number of processors currently available for executing threads.
  50  *                               Use this number to determine the number threads to create in SMP aware applications.
  51  *                               This number can change when power management modes are changed.
  52  *
  53  *   hw.physicalcpu            - The number of physical processors available in the current power management mode.
  54  *   hw.physicalcpu_max        - The maximum number of physical processors that could be available this boot
  55  *
  56  *   hw.logicalcpu             - The number of logical processors available in the current power management mode.
  57  *   hw.logicalcpu_max         - The maximum number of logical processors that could be available this boot
  58  *
  59  *   hw.tbfrequency            - This gives the time base frequency used by the OS and is the basis of all timing services.
  60  *                               In general is is better to use mach's or higher level timing services, but this value
  61  *                               is needed to convert the PPC Time Base registers to real time.
  62  *
  63  *   hw.cpufrequency           - These values provide the current, min and max cpu frequency.  The min and max are for
  64  *   hw.cpufrequency_max       - all power management modes.  The current frequency is the max frequency in the current mode.
  65  *   hw.cpufrequency_min       - All frequencies are in Hz.
  66  *
  67  *   hw.busfrequency           - These values provide the current, min and max bus frequency.  The min and max are for
  68  *   hw.busfrequency_max       - all power management modes.  The current frequency is the max frequency in the current mode.
  69  *   hw.busfrequency_min       - All frequencies are in Hz.
  70  *
  71  *   hw.cputype                - These values provide the mach-o cpu type and subtype.  A complete list is in <mach/machine.h>
  72  *   hw.cpusubtype             - These values should be used to determine what processor family the running cpu is from so that
  73  *                               the best binary can be chosen, or the best dynamic code generated.  They should not be used
  74  *                               to determine if a given processor feature is available.
  75  *   hw.cputhreadtype          - This value will be present if the processor supports threads.  Like hw.cpusubtype this selector
  76  *                               should not be used to infer features, and only used to name the processors thread architecture.
  77  *                               The values are defined in <mach/machine.h>
  78  *
  79  *   hw.byteorder              - Gives the byte order of the processor.  4321 for big endian, 1234 for little.
  80  *
  81  *   hw.pagesize               - Gives the size in bytes of the pages used by the processor and VM system.
  82  *
  83  *   hw.cachelinesize          - Gives the size in bytes of the processor's cache lines.
  84  *                               This value should be use to control the strides of loops that use cache control instructions
  85  *                               like dcbz, dcbt or dcbst.
  86  *
  87  *   hw.l1dcachesize           - These values provide the size in bytes of the L1, L2 and L3 caches.  If a cache is not present
  88  *   hw.l1icachesize           - then the selector will return and error.
  89  *   hw.l2cachesize            -
  90  *   hw.l3cachesize            -
  91  *
  92  *
  93  * These are the selectors for optional processor features.  Selectors that return errors are not support on the system.
  94  * Supported features will return 1 if they are recommended or 0 if they are supported but are not expected to help performance.
  95  * Future versions of these selectors may return larger values as necessary so it is best to test for non zero.
  96  *
  97  *   hw.optional.floatingpoint - Floating Point Instructions
  98  *   hw.optional.altivec       - AltiVec Instructions
  99  *   hw.optional.graphicsops   - Graphics Operations
 100  *   hw.optional.64bitops      - 64-bit Instructions
 101  *   hw.optional.fsqrt         - HW Floating Point Square Root Instruction
 102  *   hw.optional.stfiwx        - Store Floating Point as Integer Word Indexed Instructions
 103  *   hw.optional.dcba          - Data Cache Block Allocate Instruction
 104  *   hw.optional.datastreams   - Data Streams Instructions
 105  *   hw.optional.dcbtstreams   - Data Cache Block Touch Steams Instruction Form
 106  *
 107  */
 108
 109 /*
 110  * Sysctl handling
 111  */
 112 int     sysctlbyname(const char *, void *, size_t *, void *, size_t);
 113
 114 __END_DECLS
 115
 116 #endif  /* LIBKERN_SYSCTL_H */