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StorPortAllocateMdl function (storport.h)

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The StorPortAllocateMdl routine allocates an MDL to describe the given non-paged pool memory.

Syntax

ULONG StorPortAllocateMdl(
  [in]  PVOID HwDeviceExtension,
  [in]  PVOID BufferPointer,
  [in]  ULONG NumberOfBytes,
  [out] PVOID *Mdl
);

Parameters

[in] HwDeviceExtension

A pointer to the hardware device extension for the host bus adapter (HBA).

[in] BufferPointer

A pointer to the base virtual address of the buffer that the MDL is to describe.

[in] NumberOfBytes

This parameter specifies the length, in bytes, of the buffer that the MDL is to describe.

[out] Mdl

A pointer to receive the allocated MDL.

Return value

StorPortAllocateMdl returns one of the following status codes:

Return code Description
STOR_STATUS_NOT_IMPLEMENTED
 This function is not implemented on the active operating system.
STOR_STATUS_SUCCESS
 Indicates that the routine allocated the MDL successfully.
STOR_STATUS_INVALID_PARAMETER
 The pointer to receive the MDL is NULL.

The pointer to the buffer is NULL.
STOR_STATUS_INVALID_IRQL
 The call was made at an invalid IRQL.
STOR_STATUS_INSUFFICIENT_RESOURCES
 Unable to allocate MDL to describe the given buffer.

Remarks

A miniport driver calls the StorPortAllocateMdl routine to allocate an MDL to describe a block of memory from the non-paged pool. To free the MDL, the miniport driver calls the StorPortFreeMdl routine.

Requirements

Requirement Value
Target Platform Universal
Header storport.h (include Storport.h)
IRQL <=DISPATCH_LEVEL
DDI compliance rules StorPortIrql(storport)