osfmk/man/vm_machine_attribute.html

   1 <h2>vm_machine_attribute</h2>
   2 <hr>
   3 <p>
   4 <strong>Function</strong> - Get/set the target memory region's special attributes.
   5 <h3>SYNOPSIS</h3>
   6 <pre>
   7 <strong>kern_return_t   vm_machine_attribute</strong>
   8                 <strong>(vm_task_t</strong>                          <var>target_task</var>,
   9                  <strong>vm_address_t</strong>                           <var>address</var>,
  10                  <strong>vm_size_t</strong>                                 <var>size</var>,
  11                  <strong>vm_machine_attribute_t</strong>               <var>attribute</var>,
  12                  <strong>vm_machine_attribute_val_t</strong>               <var>value</var><strong>);</strong>
  13 </pre>
  14 <h3>PARAMETERS</h3>
  15 <dl>
  16 <p>
  17 <dt> <var>target_task</var>
  18 <dd>
  19 [in task send right]
  20 The port for the task in whose address space the
  21 memory object is to be manipulated.
  22 <p>
  23 <dt> <var>address</var>
  24 <dd>
  25 [in scalar]
  26 The starting address for the memory region.  The granularity
  27 of rounding of this value to page boundaries is implementation
  28 dependent.
  29 <p>
  30 <dt> <var>size</var>
  31 <dd>
  32 [in scalar]
  33 The number of bytes in the region.  The granularity of
  34 rounding of this value to page boundaries is implementation dependent.
  35 <p>
  36 <dt> <var>attribute</var>
  37 <dd>
  38 [in scalar]
  39 The name of the attribute to be get/set.  Possible values are:
  40 <dl>
  41 <p>
  42 <dt> <strong>MATTR_CACHE</strong>
  43 <dd>
  44 Cachability.  Aside from the generic values listed below, the
  45 following special values are defined:
  46 <dl>
  47 <p>
  48 <dt> <strong>MATTR_VAL_CACHE_FLUSH</strong>
  49 <dd>
  50 Flush from all caches
  51 <p>
  52 <dt> <strong>MATTR_VAL_DCACHE_FLUSH</strong>
  53 <dd>
  54 Flush from data caches
  55 <p>
  56 <dt> <strong>MATTR_VAL_ICACHE_FLUSH</strong>
  57 <dd>
  58 Flush from instruction caches
  59 </dl>
  60 <p>
  61 <dt> <strong>MATTR_MIGRATE</strong>
  62 <dd>
  63 Migratability.
  64 <p>
  65 <dt> <strong>MATTR_REPLICATE</strong>
  66 <dd>
  67 Replicability.
  68 </dl>
  69 <p>
  70 <dt> <var>value</var>
  71 <dd>
  72 [pointer to in/out scalar]
  73 The new value for the attribute.  The old value
  74 is also returned in this variable.  The new value can be a specific value
  75 listed above, or one of the following generic values:
  76 <dl>
  77 <p>
  78 <dt> <strong>MATTR_VAL_OFF</strong>
  79 <dd>
  80 Turn attribute off.
  81 <p>
  82 <dt> <strong>MATTR_VAL_ON</strong>
  83 <dd>
  84 Turn attribute on.
  85 <p>
  86 <dt> <strong>MATTR_VAL_GET</strong>
  87 <dd>
  88 No change, just return current value.
  89 </dl>
  90 </dl>
  91 <h3>DESCRIPTION</h3>
  92 <p>
  93 The <strong>vm_machine_attribute</strong> function gets and sets special
  94 attributes of the
  95 memory region implemented by the underlying <strong>pmap</strong> module.  These attributes
  96 are properties such as cachability, migratability and replicability.
  97 The behavior of this function is machine dependent.
  98 <h3>NOTES</h3>
  99 <p>
 100 This interface is machine word length specific because of the virtual address
 101 parameter.
 102 <h3>RETURN VALUES</h3>
 103 <dl>
 104 <p>
 105 <dt> <strong>KERN_INVALID_ADDRESS</strong>
 106 <dd>
 107 The address is illegal or specifies a non-allocated region.
 108 </dl>
 109 <h3>RELATED INFORMATION</h3>
 110 <p>
 111 Functions:
 112 <a href="vm_wire.html"><strong>vm_wire</strong></a>.