OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.c

   1 /** @file
   2   This driver produce a BlockIo protocol instance for a Xen PV block device.
   3
   4   This driver support XenBus protocol of type 'vbd'. Every function that
   5   comsume XenBus protocol are in BlockFront, which the implementation to access
   6   a Xen PV device. The BlockIo implementation is in it's one file and will call
   7   BlockFront functions.
   8
   9   Copyright (C) 2014, Citrix Ltd.
  10
  11   This program and the accompanying materials
  12   are licensed and made available under the terms and conditions of the BSD License
  13   which accompanies this distribution.  The full text of the license may be found at
  14   http://opensource.org/licenses/bsd-license.php
  15
  16   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  17   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  18
  19 **/
  20
  21 #include "XenPvBlkDxe.h"
  22
  23
  24 ///
  25 /// Driver Binding Protocol instance
  26 ///
  27 EFI_DRIVER_BINDING_PROTOCOL gXenPvBlkDxeDriverBinding = {
  28   XenPvBlkDxeDriverBindingSupported,
  29   XenPvBlkDxeDriverBindingStart,
  30   XenPvBlkDxeDriverBindingStop,
  31   XEN_PV_BLK_DXE_VERSION,
  32   NULL,
  33   NULL
  34 };
  35
  36
  37 /**
  38   Unloads an image.
  39
  40   @param  ImageHandle           Handle that identifies the image to be unloaded.
  41
  42   @retval EFI_SUCCESS           The image has been unloaded.
  43   @retval EFI_INVALID_PARAMETER ImageHandle is not a valid image handle.
  44
  45 **/
  46 EFI_STATUS
  47 EFIAPI
  48 XenPvBlkDxeUnload (
  49   IN EFI_HANDLE  ImageHandle
  50   )
  51 {
  52   EFI_STATUS  Status;
  53
  54   EFI_HANDLE  *HandleBuffer;
  55   UINTN       HandleCount;
  56   UINTN       Index;
  57
  58
  59   //
  60   // Retrieve array of all handles in the handle database
  61   //
  62   Status = gBS->LocateHandleBuffer (
  63                   AllHandles,
  64                   NULL,
  65                   NULL,
  66                   &HandleCount,
  67                   &HandleBuffer
  68                   );
  69   if (EFI_ERROR (Status)) {
  70     return Status;
  71   }
  72
  73   //
  74   // Disconnect the current driver from handles in the handle database
  75   //
  76   for (Index = 0; Index < HandleCount; Index++) {
  77     gBS->DisconnectController (HandleBuffer[Index], gImageHandle, NULL);
  78   }
  79
  80   //
  81   // Free the array of handles
  82   //
  83   FreePool (HandleBuffer);
  84
  85
  86   //
  87   // Uninstall protocols installed in the driver entry point
  88   //
  89   Status = gBS->UninstallMultipleProtocolInterfaces (
  90                   ImageHandle,
  91                   &gEfiDriverBindingProtocolGuid, &gXenPvBlkDxeDriverBinding,
  92                   &gEfiComponentNameProtocolGuid,  &gXenPvBlkDxeComponentName,
  93                   &gEfiComponentName2ProtocolGuid, &gXenPvBlkDxeComponentName2,
  94                   NULL
  95                   );
  96   if (EFI_ERROR (Status)) {
  97     return Status;
  98   }
  99
 100   return EFI_SUCCESS;
 101 }
 102
 103 /**
 104   This is the declaration of an EFI image entry point. This entry point is
 105   the same for UEFI Applications, UEFI OS Loaders, and UEFI Drivers including
 106   both device drivers and bus drivers.
 107
 108   @param  ImageHandle           The firmware allocated handle for the UEFI image.
 109   @param  SystemTable           A pointer to the EFI System Table.
 110
 111   @retval EFI_SUCCESS           The operation completed successfully.
 112   @retval Others                An unexpected error occurred.
 113 **/
 114 EFI_STATUS
 115 EFIAPI
 116 XenPvBlkDxeDriverEntryPoint (
 117   IN EFI_HANDLE        ImageHandle,
 118   IN EFI_SYSTEM_TABLE  *SystemTable
 119   )
 120 {
 121   EFI_STATUS  Status;
 122
 123   //
 124   // Install UEFI Driver Model protocol(s).
 125   //
 126   Status = EfiLibInstallDriverBindingComponentName2 (
 127              ImageHandle,
 128              SystemTable,
 129              &gXenPvBlkDxeDriverBinding,
 130              ImageHandle,
 131              &gXenPvBlkDxeComponentName,
 132              &gXenPvBlkDxeComponentName2
 133              );
 134   ASSERT_EFI_ERROR (Status);
 135
 136   return Status;
 137 }
 138
 139
 140 /**
 141   Tests to see if this driver supports a given controller. If a child device is provided,
 142   it further tests to see if this driver supports creating a handle for the specified child device.
 143
 144   This function checks to see if the driver specified by This supports the device specified by
 145   ControllerHandle. Drivers will typically use the device path attached to
 146   ControllerHandle and/or the services from the bus I/O abstraction attached to
 147   ControllerHandle to determine if the driver supports ControllerHandle. This function
 148   may be called many times during platform initialization. In order to reduce boot times, the tests
 149   performed by this function must be very small, and take as little time as possible to execute. This
 150   function must not change the state of any hardware devices, and this function must be aware that the
 151   device specified by ControllerHandle may already be managed by the same driver or a
 152   different driver. This function must match its calls to AllocatePages() with FreePages(),
 153   AllocatePool() with FreePool(), and OpenProtocol() with CloseProtocol().
 154   Because ControllerHandle may have been previously started by the same driver, if a protocol is
 155   already in the opened state, then it must not be closed with CloseProtocol(). This is required
 156   to guarantee the state of ControllerHandle is not modified by this function.
 157
 158   @param[in]  This                 A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
 159   @param[in]  ControllerHandle     The handle of the controller to test. This handle
 160                                    must support a protocol interface that supplies
 161                                    an I/O abstraction to the driver.
 162   @param[in]  RemainingDevicePath  A pointer to the remaining portion of a device path.  This
 163                                    parameter is ignored by device drivers, and is optional for bus
 164                                    drivers. For bus drivers, if this parameter is not NULL, then
 165                                    the bus driver must determine if the bus controller specified
 166                                    by ControllerHandle and the child controller specified
 167                                    by RemainingDevicePath are both supported by this
 168                                    bus driver.
 169
 170   @retval EFI_SUCCESS              The device specified by ControllerHandle and
 171                                    RemainingDevicePath is supported by the driver specified by This.
 172   @retval EFI_ALREADY_STARTED      The device specified by ControllerHandle and
 173                                    RemainingDevicePath is already being managed by the driver
 174                                    specified by This.
 175   @retval EFI_ACCESS_DENIED        The device specified by ControllerHandle and
 176                                    RemainingDevicePath is already being managed by a different
 177                                    driver or an application that requires exclusive access.
 178                                    Currently not implemented.
 179   @retval EFI_UNSUPPORTED          The device specified by ControllerHandle and
 180                                    RemainingDevicePath is not supported by the driver specified by This.
 181 **/
 182 EFI_STATUS
 183 EFIAPI
 184 XenPvBlkDxeDriverBindingSupported (
 185   IN EFI_DRIVER_BINDING_PROTOCOL  *This,
 186   IN EFI_HANDLE                   ControllerHandle,
 187   IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath OPTIONAL
 188   )
 189 {
 190   EFI_STATUS Status;
 191   XENBUS_PROTOCOL *XenBusIo;
 192
 193   Status = gBS->OpenProtocol (
 194                 ControllerHandle,
 195                 &gXenBusProtocolGuid,
 196                 (VOID **)&XenBusIo,
 197                 This->DriverBindingHandle,
 198                 ControllerHandle,
 199                 EFI_OPEN_PROTOCOL_BY_DRIVER
 200                 );
 201   if (EFI_ERROR (Status)) {
 202     return Status;
 203   }
 204   if (AsciiStrCmp (XenBusIo->Type, "vbd") == 0) {
 205     Status = EFI_SUCCESS;
 206   } else {
 207     Status = EFI_UNSUPPORTED;
 208   }
 209
 210   gBS->CloseProtocol (ControllerHandle, &gXenBusProtocolGuid,
 211                       This->DriverBindingHandle, ControllerHandle);
 212
 213   return Status;
 214 }
 215
 216 /**
 217   Starts a device controller.
 218
 219   The Start() function is designed to be invoked from the EFI boot service ConnectController().
 220   As a result, much of the error checking on the parameters to Start() has been moved into this
 221   common boot service. It is legal to call Start() from other locations,
 222   but the following calling restrictions must be followed, or the system behavior will not be deterministic.
 223   1. ControllerHandle must be a valid EFI_HANDLE.
 224   2. If RemainingDevicePath is not NULL, then it must be a pointer to a naturally aligned
 225      EFI_DEVICE_PATH_PROTOCOL.
 226   3. Prior to calling Start(), the Supported() function for the driver specified by This must
 227      have been called with the same calling parameters, and Supported() must have returned EFI_SUCCESS.
 228
 229   @param[in]  This                 A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
 230   @param[in]  ControllerHandle     The handle of the controller to start. This handle
 231                                    must support a protocol interface that supplies
 232                                    an I/O abstraction to the driver.
 233   @param[in]  RemainingDevicePath  A pointer to the remaining portion of a device path.  This
 234                                    parameter is ignored by device drivers, and is optional for bus
 235                                    drivers. For a bus driver, if this parameter is NULL, then handles
 236                                    for all the children of Controller are created by this driver.
 237                                    If this parameter is not NULL and the first Device Path Node is
 238                                    not the End of Device Path Node, then only the handle for the
 239                                    child device specified by the first Device Path Node of
 240                                    RemainingDevicePath is created by this driver.
 241                                    If the first Device Path Node of RemainingDevicePath is
 242                                    the End of Device Path Node, no child handle is created by this
 243                                    driver.
 244
 245   @retval EFI_SUCCESS              The device was started.
 246   @retval EFI_DEVICE_ERROR         The device could not be started due to a device error.Currently not implemented.
 247   @retval EFI_OUT_OF_RESOURCES     The request could not be completed due to a lack of resources.
 248   @retval Others                   The driver failded to start the device.
 249
 250 **/
 251 EFI_STATUS
 252 EFIAPI
 253 XenPvBlkDxeDriverBindingStart (
 254   IN EFI_DRIVER_BINDING_PROTOCOL  *This,
 255   IN EFI_HANDLE                   ControllerHandle,
 256   IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath OPTIONAL
 257   )
 258 {
 259   EFI_STATUS Status;
 260   XENBUS_PROTOCOL *XenBusIo;
 261
 262   Status = gBS->OpenProtocol (
 263                 ControllerHandle,
 264                 &gXenBusProtocolGuid,
 265                 (VOID **)&XenBusIo,
 266                 This->DriverBindingHandle,
 267                 ControllerHandle,
 268                 EFI_OPEN_PROTOCOL_BY_DRIVER
 269                 );
 270   if (EFI_ERROR (Status)) {
 271     return Status;
 272   }
 273
 274   return EFI_SUCCESS;
 275 }
 276
 277 /**
 278   Stops a device controller.
 279
 280   The Stop() function is designed to be invoked from the EFI boot service DisconnectController().
 281   As a result, much of the error checking on the parameters to Stop() has been moved
 282   into this common boot service. It is legal to call Stop() from other locations,
 283   but the following calling restrictions must be followed, or the system behavior will not be deterministic.
 284   1. ControllerHandle must be a valid EFI_HANDLE that was used on a previous call to this
 285      same driver's Start() function.
 286   2. The first NumberOfChildren handles of ChildHandleBuffer must all be a valid
 287      EFI_HANDLE. In addition, all of these handles must have been created in this driver's
 288      Start() function, and the Start() function must have called OpenProtocol() on
 289      ControllerHandle with an Attribute of EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER.
 290
 291   @param[in]  This              A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
 292   @param[in]  ControllerHandle  A handle to the device being stopped. The handle must
 293                                 support a bus specific I/O protocol for the driver
 294                                 to use to stop the device.
 295   @param[in]  NumberOfChildren  The number of child device handles in ChildHandleBuffer.
 296   @param[in]  ChildHandleBuffer An array of child handles to be freed. May be NULL
 297                                 if NumberOfChildren is 0.
 298
 299   @retval EFI_SUCCESS           The device was stopped.
 300   @retval EFI_DEVICE_ERROR      The device could not be stopped due to a device error.
 301
 302 **/
 303 EFI_STATUS
 304 EFIAPI
 305 XenPvBlkDxeDriverBindingStop (
 306   IN EFI_DRIVER_BINDING_PROTOCOL  *This,
 307   IN EFI_HANDLE                   ControllerHandle,
 308   IN UINTN                        NumberOfChildren,
 309   IN EFI_HANDLE                   *ChildHandleBuffer OPTIONAL
 310   )
 311 {
 312   gBS->CloseProtocol (ControllerHandle, &gXenBusProtocolGuid,
 313          This->DriverBindingHandle, ControllerHandle);
 314
 315   return EFI_SUCCESS;
 316 }