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DXGK_SPB_INTERFACE structure (dispmprt.h)

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The DXGK_SPB_INTERFACE structure contains pointers to functions in the Simple Peripheral Bus (SPB) Interface that a Windows Display Driver Model (WDDM) 1.2 and later display miniport driver can call to inspect and alter SPB resources.

Syntax

typedef struct _DXGK_SPB_INTERFACE {
  USHORT                 Size;
  USHORT                 Version;
  PVOID                  Context;
  PINTERFACE_REFERENCE   InterfaceReference;
  PINTERFACE_DEREFERENCE InterfaceDereference;
  NTSTATUS(HANDLE DeviceHandle,LARGE_INTEGER SpbReourceId,UNICODE_STRING *SpbResourceSubName,ACCESS_MASK DesiredAccess,ULONG ShareAccess,ULONG OpenOptions,VOID **SpbResource)              * )(OpenSpbResource;
  NTSTATUS()(HANDLE DeviceHandle,VOID *SpbResource)              * CloseSpbResource;
  NTSTATUS(ANDLE DeviceHandle,VOID *SpbResource,ULONG Length,VOID *Buffer,LARGE_INTEGER *ByteOffset,HANDLE EventHandle,IO_STATUS_BLOCK *IoStatusBlock)              * )(HReadSpbResource;
  NTSTATUS(ANDLE DeviceHandle,VOID *SpbResource,ULONG Length,VOID *Buffer,LARGE_INTEGER *ByteOffset,HANDLE EventHandle,IO_STATUS_BLOCK *IoStatusBlock)              * )(HWriteSpbResource;
  NTSTATUS(ANDLE DeviceHandle,VOID *SpbResource,ULONG IoControlCode,ULONG InBufferSize,VOID *InputBuffer,ULONG OutBufferSize,VOID *OutputBuffer,HANDLE EventHandle,IO_STATUS_BLOCK *IoStatusBlock)              * )(HSpbResourceIoControl;
} DXGK_SPB_INTERFACE, *PDXGK_SPB_INTERFACE;

Members

Size

The size, in bytes, of this structure.

Version

The version number of the SPB interface. Version number constants are defined in Dispmprt.h (for example, DXGK_SPB_INTERFACE_VERSION_1).

Context

A pointer to a context that is provided by the display miniport driver.

InterfaceReference

A pointer to an interface reference function that is implemented by the display miniport driver.

InterfaceDereference

A pointer to an interface dereference function that is implemented by the display miniport driver.

OpenSpbResource

Opens a Simple Peripheral Bus (SPB) resource. All input parameters are supplied by the display miniport driver.

OpenSpbResource Parameter Description
DeviceHandle Handle that represents a display adapter. The display miniport driver previously obtained this handle in the DeviceHandle member of the DXGKRNL_INTERFACE structure that was passed to the DxgkDdiStartDevice function.
SpbReourceId The resource ID of the SPB resource hub.
SpbResourceSubName Optional pointer to the Unicode SPB resource subname.
DesiredAccess An ACCESS_MASK value that determines the requested access to the SPB resource. For more information, see the DesiredAccess parameter of the ZwCreateFile function.
ShareAccess Type of share access for the file. For more information, see the ShareAccess parameter of ZwCreateFile.
OpenOptions The options to apply when opening the SPB resource. For more information, see the CreateOptions parameter of ZwCreateFile.
SpbResource A pointer to a buffer that is used to return the handle to the SPB resource.

CloseSpbResource

Closes an SPB resource. All input parameters are supplied by the display miniport driver.

Closing an open object handle causes that handle to become invalid. The system also decrements the handle count for the object and checks whether the object can be deleted. The system does not actually delete the object until all of the object's handles are closed and no referenced pointers remain.

The driver must call CloseSpbResource to close every handle that it has opened with OpenSpbResource as soon as the handle is no longer required.

Callers of CloseSpbResource should not assume that this function automatically waits for all I/O to complete prior to returning.

CloseSpbResource Parameter Description
DeviceHandle A handle that represents a display adapter. The display miniport driver previously obtained this handle in the DeviceHandle member of the DXGKRNL_INTERFACE structure that was passed to the DxgkDdiStartDevice function.
SpbResource A pointer to an SPB resource that the display miniport driver opened using the OpenSpbResource function.

ReadSpbResource

Reads data from an open SPB resource. All input parameters are supplied by the display miniport driver.

If the call to OpenSpbResource set either of the OpenOptions flags FILE_SYNCHRONOUS_IO_ALERT or FILE_SYNCHRONOUS_IO_NONALERT (defined in Wdm.h), the I/O Manager maintains the current file position. If so, the caller of ReadSpbResource can specify that the current file position offset be used instead of an explicit ByteOffset value. This specification can be made by using one of the following methods:

  • Specify a pointer to a LARGE_INTEGER value with the HighPart member set to -1 and the LowPart member set to the system-defined value FILE_USE_FILE_POINTER_POSITION (defined in Wdm.h).
  • Pass a NULL pointer for ByteOffset.

ReadSpbResource updates the current file position by adding the number of bytes read when it completes the read operation, if it is using the current file position maintained by the I/O Manager.

Even when the I/O Manager is maintaining the current file position, the caller can reset this position by passing an explicit ByteOffset value to ReadSpbResource. Doing this automatically changes the current file position to that ByteOffset value, performs the read operation, and then updates the position according to the number of bytes actually read. This technique gives the caller atomic seek-and-read service.

OpenSpbResource Parameter Description
DeviceHandle A handle that represents a display adapter. The display miniport driver previously obtained this handle in the DeviceHandle member of the DXGKRNL_INTERFACE structure that was passed to the DxgkDdiStartDevice function.
SpbResource A pointer to an SPB resource that the display miniport driver opened using the OpenSpbResource function.
Length The size, in bytes, of the buffer pointed to by the Buffer parameter.
Buffer A pointer to a buffer that receives the data read from the specified SPB resource.
ByteOffset An optional pointer to a variable that specifies the starting byte offset in the SPB resource where the read operation will begin. If an attempt is made to read beyond the end of the file, ReadSpbResource returns an error.
EventHandle An optional handle for a caller-created event. If this parameter is supplied, the caller will be put into a wait state until the read operation is completed and the given event is set to the Signaled state. This parameter can be NULL.
IoStatusBlock A pointer to an IO_STATUS_BLOCK structure that receives the final completion status and information about the requested read operation. The Information member of the IO_STATUS_BLOCK structure receives the number of bytes actually read from the SPB resource.

WriteSpbResource

Writes data to an open SPB resource.

If the call to the OpenSpbResource function set only the DesiredAccess flag FILE_APPEND_DATA, the ByteOffset parameter is ignored. In this case, data in the buffer pointed to by the Buffer parameter, for Length bytes, is written starting at the current end of file.

If the call to OpenSpbResource set either of the CreateOptions flags, FILE_SYNCHRONOUS_IO_ALERT or FILE_SYNCHRONOUS_IO_NONALERT, the I/O Manager maintains the current file position. If so, the caller of WriteSpbResource can specify that the current file position offset be used instead of an explicit ByteOffset value. This specification can be made by using one of the following methods:

  • Specify a pointer to a LARGE_INTEGER value with the HighPart member set to -1 and the LowPart member set to the system-defined value FILE_USE_FILE_POINTER_POSITION (defined in Wdm.h).
  • Pass a NULL pointer for ByteOffset.

WriteSpbResource updates the current file position by adding the number of bytes written when it completes the write operation, if it is using the current file position maintained by the I/O Manager.

Even when the I/O Manager is maintaining the current file position, the caller can reset this position by passing an explicit ByteOffset value to WriteSpbResource. Doing this automatically changes the current file position to that ByteOffset value, performs the write operation, and then updates the position according to the number of bytes actually written. This technique gives the caller atomic seek-and-write service.

It is also possible to cause a write operation to start at the current end of file by specifying for ByteOffset a pointer to a LARGE_INTEGER value with HighPart set to -1 and LowPart set to FILE_WRITE_TO_END_OF_FILE. This works regardless of whether the I/O Manager is maintaining the current file position.

WriteSpbResource Parameter Description
DeviceHandle A handle that represents a display adapter. The display miniport driver previously obtained this handle in the DeviceHandle member of the DXGKRNL_INTERFACE structure that was passed to the DxgkDdiStartDevice function.
SpbResource A pointer to an SPB resource that the display miniport driver opened using the OpenSpbResource function.
Length The size, in bytes, of the buffer pointed to by the Buffer parameter.
Buffer A pointer to a caller-allocated buffer that contains the data to be written to the specified SPB resource.
ByteOffset An optional pointer to a variable that specifies the starting byte offset in the SPB resource where the write operation will begin. If the Length and ByteOffset parameters specify a write operation past the current end-of-file mark, WriteSpbResource automatically extends the file and updates the end-of-file mark; any bytes that are not explicitly written between such old and new end-of-file marks are defined to be zero.
EventHandle An optional handle for a caller-created event. If this parameter is supplied, the caller will be put into a wait state until the write operation is completed and the given event is set to the Signaled state. This parameter can be NULL.
IoStatusBlock A pointer to an IO_STATUS_BLOCK structure that receives the final completion status and information about the requested write operation. The Information member of the IO_STATUS_BLOCK structure receives the number of bytes actually written to the SPB resource.

SpbResourceIoControl

Performs an I/O control operation on an open Simple Peripheral Bus (SPB) resource. All input parameters are supplied by the display miniport driver.

If the caller opened the file for asynchronous I/O (with neither FILE_SYNCHRONOUS_XXX create/open option set), the specified event, if any, will be set to the Signaled state when the device control operation completes. Otherwise, the file object specified by the DeviceHandle parameter will be set to the Signaled state.

SpbResourceIoControl Parameter Description
DeviceHandle A handle that represents a display adapter. The display miniport driver previously obtained this handle in the DeviceHandle member of the DXGKRNL_INTERFACE structure that was passed to the DxgkDdiStartDevice function.
SpbResource A pointer to an SPB resource that the display miniport driver opened using the OpenSpbResource function.
IoControlCode A device I/O control code (IOCTL_XXX) that indicates which device I/O control operation is to be carried out on, usually by the underlying device driver. The value of this parameter determines the format and required length of the InputBuffer and OutputBuffer parameters, as well as which of the following parameter pairs are required.
InBufferSize The size, in bytes, of the buffer pointed to by the InputBuffer parameter. This value is ignored if InputBuffer is NULL.
InputBuffer A pointer to a caller-allocated input buffer that contains device-specific information to be given to the target device. If the IoControlCode parameter specifies an operation that does not require input data, this pointer can be NULL.
OutBufferSize The size, in bytes, of the buffer pointed to by the OutputBuffer parameter. This value is ignored if OutputBuffer is NULL.
OutputBuffer A pointer to a caller-allocated output buffer in which information is returned from the target device. If the IoControlCode parameter specifies an operation that does not produce output data, this pointer can be NULL.
EventHandle An optional handle for a caller-created event. If this parameter is supplied, the caller will be put into a wait state until the requested operation is completed and the given event is set to the Signaled state. This parameter can be NULL.
IoStatusBlock A pointer to a variable that receives the final completion status and information about the requested I/O control operation. For successful calls that return data, the number of bytes written to the buffer pointed to by the OutputBuffer parameter is returned in the Information member of the IO_STATUS_BLOCK structure.

Remarks

To use this structure's functions, first supply the Size and Version members of the DXGK_SPB_INTERFACE structure. Then call the DxgkCbQueryServices function with the ServicesType parameter set to a value of DxgkServicesFirmwareTable, and set the Interface parameter to the address (cast as PINTERFACE) of the DXGK_SPB_INTERFACE structure.

For more information on SPB architecture, see Simple Peripheral Buses and SPB Peripheral Driver Design Guide**.

Requirements

Requirement Value
Minimum supported client Windows 8
Minimum supported server Windows Server 2012
Header dispmprt.h (include Dispmprt.h)