OvmfPkg/XenPvBlkDxe/DriverBinding.h

   1 /** @file
   2   Driver Binding functions declaration for XenPvBlk driver.
   3
   4   Copyright (C) 2014, Citrix Ltd.
   5
   6   SPDX-License-Identifier: BSD-2-Clause-Patent
   7
   8 **/
   9
  10 /**
  11   Tests to see if this driver supports a given controller. If a child device is provided,
  12   it further tests to see if this driver supports creating a handle for the specified child device.
  13
  14   This function checks to see if the driver specified by This supports the device specified by
  15   ControllerHandle. Drivers will typically use the device path attached to
  16   ControllerHandle and/or the services from the bus I/O abstraction attached to
  17   ControllerHandle to determine if the driver supports ControllerHandle. This function
  18   may be called many times during platform initialization. In order to reduce boot times, the tests
  19   performed by this function must be very small, and take as little time as possible to execute. This
  20   function must not change the state of any hardware devices, and this function must be aware that the
  21   device specified by ControllerHandle may already be managed by the same driver or a
  22   different driver. This function must match its calls to AllocatePages() with FreePages(),
  23   AllocatePool() with FreePool(), and OpenProtocol() with CloseProtocol().
  24   Because ControllerHandle may have been previously started by the same driver, if a protocol is
  25   already in the opened state, then it must not be closed with CloseProtocol(). This is required
  26   to guarantee the state of ControllerHandle is not modified by this function.
  27
  28   @param[in]  This                 A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
  29   @param[in]  ControllerHandle     The handle of the controller to test. This handle
  30                                    must support a protocol interface that supplies
  31                                    an I/O abstraction to the driver.
  32   @param[in]  RemainingDevicePath  A pointer to the remaining portion of a device path.  This
  33                                    parameter is ignored by device drivers, and is optional for bus
  34                                    drivers. For bus drivers, if this parameter is not NULL, then
  35                                    the bus driver must determine if the bus controller specified
  36                                    by ControllerHandle and the child controller specified
  37                                    by RemainingDevicePath are both supported by this
  38                                    bus driver.
  39
  40   @retval EFI_SUCCESS              The device specified by ControllerHandle and
  41                                    RemainingDevicePath is supported by the driver specified by This.
  42   @retval EFI_ALREADY_STARTED      The device specified by ControllerHandle and
  43                                    RemainingDevicePath is already being managed by the driver
  44                                    specified by This.
  45   @retval EFI_ACCESS_DENIED        The device specified by ControllerHandle and
  46                                    RemainingDevicePath is already being managed by a different
  47                                    driver or an application that requires exclusive access.
  48                                    Currently not implemented.
  49   @retval EFI_UNSUPPORTED          The device specified by ControllerHandle and
  50                                    RemainingDevicePath is not supported by the driver specified by This.
  51 **/
  52 EFI_STATUS
  53 EFIAPI
  54 XenPvBlkDxeDriverBindingSupported (
  55   IN EFI_DRIVER_BINDING_PROTOCOL  *This,
  56   IN EFI_HANDLE                   ControllerHandle,
  57   IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath OPTIONAL
  58   );
  59
  60 /**
  61   Starts a device controller or a bus controller.
  62
  63   The Start() function is designed to be invoked from the EFI boot service ConnectController().
  64   As a result, much of the error checking on the parameters to Start() has been moved into this
  65   common boot service. It is legal to call Start() from other locations,
  66   but the following calling restrictions must be followed, or the system behavior will not be deterministic.
  67   1. ControllerHandle must be a valid EFI_HANDLE.
  68   2. If RemainingDevicePath is not NULL, then it must be a pointer to a naturally aligned
  69      EFI_DEVICE_PATH_PROTOCOL.
  70   3. Prior to calling Start(), the Supported() function for the driver specified by This must
  71      have been called with the same calling parameters, and Supported() must have returned EFI_SUCCESS.
  72
  73   @param[in]  This                 A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
  74   @param[in]  ControllerHandle     The handle of the controller to start. This handle
  75                                    must support a protocol interface that supplies
  76                                    an I/O abstraction to the driver.
  77   @param[in]  RemainingDevicePath  A pointer to the remaining portion of a device path.  This
  78                                    parameter is ignored by device drivers, and is optional for bus
  79                                    drivers. For a bus driver, if this parameter is NULL, then handles
  80                                    for all the children of Controller are created by this driver.
  81                                    If this parameter is not NULL and the first Device Path Node is
  82                                    not the End of Device Path Node, then only the handle for the
  83                                    child device specified by the first Device Path Node of
  84                                    RemainingDevicePath is created by this driver.
  85                                    If the first Device Path Node of RemainingDevicePath is
  86                                    the End of Device Path Node, no child handle is created by this
  87                                    driver.
  88
  89   @retval EFI_SUCCESS              The device was started.
  90   @retval EFI_DEVICE_ERROR         The device could not be started due to a device error.Currently not implemented.
  91   @retval EFI_OUT_OF_RESOURCES     The request could not be completed due to a lack of resources.
  92   @retval Others                   The driver failed to start the device.
  93
  94 **/
  95 EFI_STATUS
  96 EFIAPI
  97 XenPvBlkDxeDriverBindingStart (
  98   IN EFI_DRIVER_BINDING_PROTOCOL  *This,
  99   IN EFI_HANDLE                   ControllerHandle,
 100   IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath OPTIONAL
 101   );
 102
 103 /**
 104   Stops a device controller or a bus controller.
 105
 106   The Stop() function is designed to be invoked from the EFI boot service DisconnectController().
 107   As a result, much of the error checking on the parameters to Stop() has been moved
 108   into this common boot service. It is legal to call Stop() from other locations,
 109   but the following calling restrictions must be followed, or the system behavior will not be deterministic.
 110   1. ControllerHandle must be a valid EFI_HANDLE that was used on a previous call to this
 111      same driver's Start() function.
 112   2. The first NumberOfChildren handles of ChildHandleBuffer must all be a valid
 113      EFI_HANDLE. In addition, all of these handles must have been created in this driver's
 114      Start() function, and the Start() function must have called OpenProtocol() on
 115      ControllerHandle with an Attribute of EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER.
 116
 117   @param[in]  This              A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
 118   @param[in]  ControllerHandle  A handle to the device being stopped. The handle must
 119                                 support a bus specific I/O protocol for the driver
 120                                 to use to stop the device.
 121   @param[in]  NumberOfChildren  The number of child device handles in ChildHandleBuffer.
 122   @param[in]  ChildHandleBuffer An array of child handles to be freed. May be NULL
 123                                 if NumberOfChildren is 0.
 124
 125   @retval EFI_SUCCESS           The device was stopped.
 126   @retval EFI_DEVICE_ERROR      The device could not be stopped due to a device error.
 127
 128 **/
 129 EFI_STATUS
 130 EFIAPI
 131 XenPvBlkDxeDriverBindingStop (
 132   IN EFI_DRIVER_BINDING_PROTOCOL  *This,
 133   IN  EFI_HANDLE                  ControllerHandle,
 134   IN  UINTN                       NumberOfChildren,
 135   IN  EFI_HANDLE                  *ChildHandleBuffer OPTIONAL
 136   );