ScsiPortGetBusData

ScsiPortGetBusData

ULONG
ScsiPortGetBusData(
IN PVOID DeviceExtension,
IN ULONG BusDataType,
IN ULONG SystemIoBusNumber,
IN ULONG SlotNumber,
IN PVOID Buffer,
IN ULONG Length
);

ScsiPortGetBusData returns bus-type-specific configuration information that a miniport's HwScsiFindAdapter routine might use to determine whether it supports a particular adapter on a particular I/O bus and to configure the HBA if it does.

Parameters

DeviceExtension

Points to the miniport driver's per-HBA storage area.

BusDataType

Specifies the type of bus-specific configuration data to be returned. Currently, this value can be one of the following: Cmos, EisaConfiguration, Pos, or PCIConfiguration. However, additional types of bus configuration will be supported in the future. The upper bound on the types supported is always MaximumBusDataType.

SystemIoBusNumber

Specifies the system-assigned number of the I/O bus. The miniport driver's HwScsiFindAdapter routine obtains this value from the input PORT_CONFIGURATION_INFORMATION SystemIoBusNumber member.

SlotNumber

Specifies the logical slot number or location of the device.

If PCIConfiguration is specified as the BusDataType, this parameter must be specified as a PCI_SLOT_NUMBER-type value.

Buffer

Points to a buffer or area to which the configuration data is returned or, if the given Length is zero, points to a location to which the OS-specific port driver returns a pointer to a buffer that it allocates.

Length

Specifies the maximum number of bytes to return at Buffer, or zero if the caller requires the OS-specific port driver to allocate a buffer to contain the data.

Return Value

ScsiPortGetBusData returns the number of bytes of configuration information it stored in the buffer.

When the input BusDataType is PCIConfiguration, ScsiPortGetBusData can return either of the following values to indicate an error:

Value	Meaning
0 (zero)	The PCI bus does not exist.
2	The PCI bus exists, but there is no device at the given PCI SlotNumber. The Buffer contains the value PCI_INVALID_VENDOR_ID at the PCI_COMMON_CONFIG VendorId member.

Comments

ScsiPortGetBusData can be called only from a miniport driver's HwScsiFindAdapter routine. Calls from other miniport routines will result in system failure or incorrect operation for the caller.

Configuration data returned by ScsiPortGetBusData is valid only until the miniport calls ScsiPortGetBusData again. As soon as the caller's HwScsiFindAdapter routine returns control, any returned configuration data becomes invalid.