projects / apple / xnu.git / blame
| Commit | Line | Data |
|---|---|---|
| 13fec989 A |
1 | <h2>vm_wire</h2> |
| 2 | <hr> | |
| 3 | <p> | |
| 4 | <strong>Function</strong> - Modify the target region's paging characteristics. | |
| 5 | <h3>SYNOPSIS</h3> | |
| 6 | <pre> | |
| 7 | <strong>kern_return_t vm_wire</strong> | |
| 8 | <strong>(host_priv_t</strong> <var>host</var>, | |
| 9 | <strong>vm_task_t</strong> <var>target_task</var>, | |
| 10 | <strong>vm_address_t</strong> <var>address</var>, | |
| 11 | <strong>vm_size_t</strong> <var>size</var>, | |
| 12 | <strong>vm_prot_t</strong> <var>wired_access</var><strong>);</strong> | |
| 13 | </pre> | |
| 14 | <h3>PARAMETERS</h3> | |
| 15 | <dl> | |
| 16 | <p> | |
| 17 | <dt> <var>host</var> | |
| 18 | <dd> | |
| 19 | [in host-control send right] | |
| 20 | The control port for the host for which | |
| 21 | information is to be obtained. | |
| 22 | <p> | |
| 23 | <dt> <var>target_task</var> | |
| 24 | <dd> | |
| 25 | [in task send right] | |
| 26 | The port for the task whose address space contains | |
| 27 | the region. | |
| 28 | <p> | |
| 29 | <dt> <var>address</var> | |
| 30 | <dd> | |
| 31 | [in scalar] | |
| 32 | The starting address for the region. | |
| 33 | <p> | |
| 34 | <dt> <var>size</var> | |
| 35 | <dd> | |
| 36 | [in scalar] | |
| 37 | The number of bytes in the region. | |
| 38 | <p> | |
| 39 | <dt> <var>wired_access</var> | |
| 40 | <dd> | |
| 41 | [in scalar] | |
| 42 | The pageability of the region. The following values cause | |
| 43 | the region to be wired and protected as specified | |
| 44 | (values may be combined): | |
| 45 | <dl> | |
| 46 | <dt> <strong>VM_PROT_READ</strong> | |
| 47 | <dt> <strong>VM_PROT_WRITE</strong> | |
| 48 | <dt> <strong>VM_PROT_execute</strong> | |
| 49 | </dl> | |
| 50 | <p> | |
| 51 | The following value causes the region to be unwired (made pageable): | |
| 52 | <dl> | |
| 53 | <dt> <strong>VM_PROT_NONE</strong> | |
| 54 | </dl> | |
| 55 | </dl> | |
| 56 | <h3>DESCRIPTION</h3> | |
| 57 | <p> | |
| 58 | The <strong>vm_wire</strong> function sets the pageability privileges | |
| 59 | for a region within the | |
| 60 | specified task's address space. <var>wired_access</var> specifies the types | |
| 61 | of accesses to | |
| 62 | the memory region which must not suffer from (internal) faults | |
| 63 | of any kind after | |
| 64 | this call returns. A non-null <var>wired_access</var> value indicates that | |
| 65 | the page is to be | |
| 66 | "wired" into memory; a null value indicates "un-wiring". The kernel maintains | |
| 67 | for the region a count of the number of times the region is wired. A page is | |
| 68 | wired into physical memory if any task accessing it has a non-zero wired count | |
| 69 | for the page. | |
| 70 | <p> | |
| 71 | The region starts at the beginning of the virtual page containing | |
| 72 | <var>address</var>; it ends at the end of the virtual page containing | |
| 73 | <var>address</var> + <var>size</var> - 1. Because of this | |
| 74 | rounding to virtual page boundaries, the amount of memory affected may be | |
| 75 | greater than <var>size</var>. Use <strong>host_page_size</strong> to find the current | |
| 76 | virtual page size. | |
| 77 | <h3>NOTES</h3> | |
| 78 | <p> | |
| 79 | This interface is machine word length specific because of the virtual address | |
| 80 | parameter. | |
| 81 | <h3>RETURN VALUES</h3> | |
| 82 | <dl> | |
| 83 | <p> | |
| 84 | <dt> <strong>KERN_INVALID_ADDRESS</strong> | |
| 85 | <dd> | |
| 86 | The address is illegal or specifies a non-allocated region. | |
| 87 | </dl> | |
| 88 | <h3>RELATED INFORMATION</h3> | |
| 89 | <p> | |
| 90 | Functions: | |
| 91 | <a href="thread_wire.html"><strong>thread_wire</strong></a>. |