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ScsiPortValidateRange routine

The ScsiPortValidateRange routine indicates whether the specified access range values have already been claimed in the registry by another driver.

Syntax


BOOLEAN ScsiPortValidateRange(
  _In_ PVOID                 HwDeviceExtension,
  _In_ INTERFACE_TYPE        BusType,
  _In_ ULONG                 SystemIoBusNumber,
  _In_ SCSI_PHYSICAL_ADDRESS IoAddress,
  _In_ ULONG                 NumberOfBytes,
  _In_ BOOLEAN               InIoSpace
);

Parameters

HwDeviceExtension [in]

Pointer to the hardware device extension. This is a per-HBA storage area that the port driver allocates and initializes on behalf of the miniport driver. Miniport drivers usually store HBA-specific information in this extension, such as the state of the HBA and the HBA's mapped access ranges. This area is available to the miniport driver in the DeviceExtension->HwDeviceExtension member of the HBA's device object immediately after the miniport driver calls ScsiPortInitialize. The port driver frees this memory when it removes the device.

BusType [in]

Specifies the value of the AdapterInterfaceType member in the PORT_CONFIGURATION_INFORMATION structure when HwScsiFindAdapter is called.

SystemIoBusNumber [in]

Specifies the value of the SystemIoBusNumber member in the configuration information when HwScsiFindAdapter is called.

IoAddress [in]

Specifies a bus-relative base address for the range of ports or device memory to be validated before the miniport driver's HwScsiFindAdapter routine attempts to map the access range for the adapter at that address.

NumberOfBytes [in]

Specifies the size in bytes or number of elements in the range.

InIoSpace [in]

Indicates when TRUE that the range is in I/O space, rather than in memory. When FALSE, the range is in memory space.

Return value

ScsiPortValidateRange returns TRUE if the HwScsiFindAdapter routine can safely map and use the mapped range to access the adapter. ScsiPortValidateRange returns FALSE if the specified access range values have already been claimed in the registry by another driver.

Remarks

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

If the operating system-specific port driver initializes any AccessRanges element of the PORT_CONFIGURATION_INFORMATION structure before it calls the miniport driver's HwScsiFindAdapter routine, the miniport driver must pass the supplied values to ScsiPortGetDeviceBase and use the mapped logical addresses for the range to determine whether an HBA is one that it supports.

The port driver either fills an ACCESS_RANGE-type element with a complete description of a bus-relative address range for an adapter, or the port driver zeros all members of the element.

For input AccessRanges elements set with default zeros, the HwScsiFindAdapter routine can attempt to locate an adapter it supports on the given I/O bus. In these circumstances, a miniport driver usually has a set of driver-determined default addresses for its type(s) of HBA. However, a previously loaded driver might already be using an initialized adapter at one of this miniport driver's default address ranges, particularly in x86-only systems in which some devices are initialized in x86 real mode. To prevent such a device from being inadvertently reprogrammed, each miniport driver's HwScsiFindAdapter routine should call ScsiPortValidateRange before it maps any driver-supplied addresses with ScsiPortGetDeviceBase and then uses the mapped logical addresses to interrogate adapters on an I/O bus.

If ScsiPortValidateRange returns FALSE, HwScsiFindAdapter must not attempt to map the input range addresses because another driver has already claimed the range in the registry.

If ScsiPortValidateRange returns TRUE, HwScsiFindAdapter can safely do the following:

  1. Map the bus-relative range addresses to system-space logical range addresses with ScsiPortGetDeviceBase.

  2. Use the mapped logical addresses with the ScsiPortRead/WriteXxx to determine whether the adapter actually is an HBA that the driver supports.

If a miniport driver uses a range successfully passed to ScsiPortValidateRange for an HBA it supports, that driver must invert the InIoSpace value when it sets the RangeInMemory member of an AccessRanges element in the PORT_CONFIGURATION_INFORMATION.

Requirements

Target platform

Desktop

Header

Srb.h (include Miniport.h or Scsi.h)

Library

Scsiport.lib

See also

ACCESS_RANGE
HwScsiFindAdapter
PORT_CONFIGURATION_INFORMATION (SCSI)
ScsiPortGetDeviceBase
ScsiPortInitialize

 

 

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