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AIX Version 4.3 Kernel and Subsystems Technical Reference, Volume 1

d_unmap_list Kernel Service

Purpose

Deallocates resources previously allocated on a d_map_list call.

Syntax

#include <sys/dma.h>
   
void d_unmap_list (*handle, *bus_list)
struct d_handle *handle
struct dio *bus_list 
Note: The following is the interface definition for d_unmap_list when the DMA_ADDRESS_64 and DMA_ENABLE_64 flags are set on the d_map_init call.
void d_unmap_list (*handle, 
*bus_list)
struct d_handle *handle;
struct dio_64 *bus_list;

Parameters

handle Indicates the unique handle returned by the d_map_init kernel service.
bus_list Specifies a list of bus addresses and lengths.

Description

The d_unmap_list kernel service is a bus-specific utility routine determined by the d_map_init kernel service that deallocates resources previously allocated on a d_map_list call.

The d_unmap_list kernel service must be called after I/O completion involving the area mapped by the prior d_map_list call. Some device drivers might choose to leave pages mapped for a long-term mapping of certain memory buffers. In this case, the driver must call d_unmap_list when it no longer needs the long-term mapping.

Note: You can use the D_UNMAP_LIST macro provided in the /usr/include/sys/dma.h file to code calls to the d_unmap_list kernel service. If not, you must ensure that the d_unmap_list function pointer is non-NULL before attempting the call. Not all platforms require the unmapping service.

Implementation Specifics

The d_unmap_list kernel service is part of the base device package of your platform.

Related Information

The d_map_init kernel service, d_map_list kernel service.


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