libkern/libkern/sysctl.h

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