[mirror_edk2.git] / OvmfPkg / XenPvBlkDxe / XenPvBlkDxe.c

/** @file\r
  This driver produce a BlockIo protocol instance for a Xen PV block device.\r
\r
  This driver support XenBus protocol of type 'vbd'. Every function that\r
  comsume XenBus protocol are in BlockFront, which the implementation to access\r
  a Xen PV device. The BlockIo implementation is in it's one file and will call\r
  BlockFront functions.\r
\r
  Copyright (C) 2014, Citrix Ltd.\r
\r
  This program and the accompanying materials\r
  are licensed and made available under the terms and conditions of the BSD License\r
  which accompanies this distribution.  The full text of the license may be found at\r
  http://opensource.org/licenses/bsd-license.php\r
\r
  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
\r
**/\r
\r
#include "XenPvBlkDxe.h"\r
\r
#include "BlockFront.h"\r
\r
\r
///\r
/// Driver Binding Protocol instance\r
///\r
EFI_DRIVER_BINDING_PROTOCOL gXenPvBlkDxeDriverBinding = {\r
  XenPvBlkDxeDriverBindingSupported,\r
  XenPvBlkDxeDriverBindingStart,\r
  XenPvBlkDxeDriverBindingStop,\r
  XEN_PV_BLK_DXE_VERSION,\r
  NULL,\r
  NULL\r
};\r
\r
\r
/**\r
  Unloads an image.\r
\r
  @param  ImageHandle           Handle that identifies the image to be unloaded.\r
\r
  @retval EFI_SUCCESS           The image has been unloaded.\r
  @retval EFI_INVALID_PARAMETER ImageHandle is not a valid image handle.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
XenPvBlkDxeUnload (\r
  IN EFI_HANDLE  ImageHandle\r
  )\r
{\r
  EFI_STATUS  Status;\r
\r
  EFI_HANDLE  *HandleBuffer;\r
  UINTN       HandleCount;\r
  UINTN       Index;\r
\r
\r
  //\r
  // Retrieve array of all handles in the handle database\r
  //\r
  Status = gBS->LocateHandleBuffer (\r
                  AllHandles,\r
                  NULL,\r
                  NULL,\r
                  &HandleCount,\r
                  &HandleBuffer\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
  //\r
  // Disconnect the current driver from handles in the handle database\r
  //\r
  for (Index = 0; Index < HandleCount; Index++) {\r
    gBS->DisconnectController (HandleBuffer[Index], gImageHandle, NULL);\r
  }\r
\r
  //\r
  // Free the array of handles\r
  //\r
  FreePool (HandleBuffer);\r
\r
\r
  //\r
  // Uninstall protocols installed in the driver entry point\r
  //\r
  Status = gBS->UninstallMultipleProtocolInterfaces (\r
                  ImageHandle,\r
                  &gEfiDriverBindingProtocolGuid, &gXenPvBlkDxeDriverBinding,\r
                  &gEfiComponentNameProtocolGuid,  &gXenPvBlkDxeComponentName,\r
                  &gEfiComponentName2ProtocolGuid, &gXenPvBlkDxeComponentName2,\r
                  NULL\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  This is the declaration of an EFI image entry point. This entry point is\r
  the same for UEFI Applications, UEFI OS Loaders, and UEFI Drivers including\r
  both device drivers and bus drivers.\r
\r
  @param  ImageHandle           The firmware allocated handle for the UEFI image.\r
  @param  SystemTable           A pointer to the EFI System Table.\r
\r
  @retval EFI_SUCCESS           The operation completed successfully.\r
  @retval Others                An unexpected error occurred.\r
**/\r
EFI_STATUS\r
EFIAPI\r
XenPvBlkDxeDriverEntryPoint (\r
  IN EFI_HANDLE        ImageHandle,\r
  IN EFI_SYSTEM_TABLE  *SystemTable\r
  )\r
{\r
  EFI_STATUS  Status;\r
\r
  //\r
  // Install UEFI Driver Model protocol(s).\r
  //\r
  Status = EfiLibInstallDriverBindingComponentName2 (\r
             ImageHandle,\r
             SystemTable,\r
             &gXenPvBlkDxeDriverBinding,\r
             ImageHandle,\r
             &gXenPvBlkDxeComponentName,\r
             &gXenPvBlkDxeComponentName2\r
             );\r
  ASSERT_EFI_ERROR (Status);\r
\r
  return Status;\r
}\r
\r
\r
/**\r
  Tests to see if this driver supports a given controller. If a child device is provided,\r
  it further tests to see if this driver supports creating a handle for the specified child device.\r
\r
  This function checks to see if the driver specified by This supports the device specified by\r
  ControllerHandle. Drivers will typically use the device path attached to\r
  ControllerHandle and/or the services from the bus I/O abstraction attached to\r
  ControllerHandle to determine if the driver supports ControllerHandle. This function\r
  may be called many times during platform initialization. In order to reduce boot times, the tests\r
  performed by this function must be very small, and take as little time as possible to execute. This\r
  function must not change the state of any hardware devices, and this function must be aware that the\r
  device specified by ControllerHandle may already be managed by the same driver or a\r
  different driver. This function must match its calls to AllocatePages() with FreePages(),\r
  AllocatePool() with FreePool(), and OpenProtocol() with CloseProtocol().\r
  Because ControllerHandle may have been previously started by the same driver, if a protocol is\r
  already in the opened state, then it must not be closed with CloseProtocol(). This is required\r
  to guarantee the state of ControllerHandle is not modified by this function.\r
\r
  @param[in]  This                 A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.\r
  @param[in]  ControllerHandle     The handle of the controller to test. This handle\r
                                   must support a protocol interface that supplies\r
                                   an I/O abstraction to the driver.\r
  @param[in]  RemainingDevicePath  A pointer to the remaining portion of a device path.  This\r
                                   parameter is ignored by device drivers, and is optional for bus\r
                                   drivers. For bus drivers, if this parameter is not NULL, then\r
                                   the bus driver must determine if the bus controller specified\r
                                   by ControllerHandle and the child controller specified\r
                                   by RemainingDevicePath are both supported by this\r
                                   bus driver.\r
\r
  @retval EFI_SUCCESS              The device specified by ControllerHandle and\r
                                   RemainingDevicePath is supported by the driver specified by This.\r
  @retval EFI_ALREADY_STARTED      The device specified by ControllerHandle and\r
                                   RemainingDevicePath is already being managed by the driver\r
                                   specified by This.\r
  @retval EFI_ACCESS_DENIED        The device specified by ControllerHandle and\r
                                   RemainingDevicePath is already being managed by a different\r
                                   driver or an application that requires exclusive access.\r
                                   Currently not implemented.\r
  @retval EFI_UNSUPPORTED          The device specified by ControllerHandle and\r
                                   RemainingDevicePath is not supported by the driver specified by This.\r
**/\r
EFI_STATUS\r
EFIAPI\r
XenPvBlkDxeDriverBindingSupported (\r
  IN EFI_DRIVER_BINDING_PROTOCOL  *This,\r
  IN EFI_HANDLE                   ControllerHandle,\r
  IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath OPTIONAL\r
  )\r
{\r
  EFI_STATUS Status;\r
  XENBUS_PROTOCOL *XenBusIo;\r
\r
  Status = gBS->OpenProtocol (\r
                ControllerHandle,\r
                &gXenBusProtocolGuid,\r
                (VOID **)&XenBusIo,\r
                This->DriverBindingHandle,\r
                ControllerHandle,\r
                EFI_OPEN_PROTOCOL_BY_DRIVER\r
                );\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
  if (AsciiStrCmp (XenBusIo->Type, "vbd") == 0) {\r
    Status = EFI_SUCCESS;\r
  } else {\r
    Status = EFI_UNSUPPORTED;\r
  }\r
\r
  gBS->CloseProtocol (ControllerHandle, &gXenBusProtocolGuid,\r
                      This->DriverBindingHandle, ControllerHandle);\r
\r
  return Status;\r
}\r
\r
/**\r
  Starts a device controller.\r
\r
  The Start() function is designed to be invoked from the EFI boot service ConnectController().\r
  As a result, much of the error checking on the parameters to Start() has been moved into this\r
  common boot service. It is legal to call Start() from other locations,\r
  but the following calling restrictions must be followed, or the system behavior will not be deterministic.\r
  1. ControllerHandle must be a valid EFI_HANDLE.\r
  2. If RemainingDevicePath is not NULL, then it must be a pointer to a naturally aligned\r
     EFI_DEVICE_PATH_PROTOCOL.\r
  3. Prior to calling Start(), the Supported() function for the driver specified by This must\r
     have been called with the same calling parameters, and Supported() must have returned EFI_SUCCESS.\r
\r
  @param[in]  This                 A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.\r
  @param[in]  ControllerHandle     The handle of the controller to start. This handle\r
                                   must support a protocol interface that supplies\r
                                   an I/O abstraction to the driver.\r
  @param[in]  RemainingDevicePath  A pointer to the remaining portion of a device path.  This\r
                                   parameter is ignored by device drivers, and is optional for bus\r
                                   drivers. For a bus driver, if this parameter is NULL, then handles\r
                                   for all the children of Controller are created by this driver.\r
                                   If this parameter is not NULL and the first Device Path Node is\r
                                   not the End of Device Path Node, then only the handle for the\r
                                   child device specified by the first Device Path Node of\r
                                   RemainingDevicePath is created by this driver.\r
                                   If the first Device Path Node of RemainingDevicePath is\r
                                   the End of Device Path Node, no child handle is created by this\r
                                   driver.\r
\r
  @retval EFI_SUCCESS              The device was started.\r
  @retval EFI_DEVICE_ERROR         The device could not be started due to a device error.Currently not implemented.\r
  @retval EFI_OUT_OF_RESOURCES     The request could not be completed due to a lack of resources.\r
  @retval Others                   The driver failded to start the device.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
XenPvBlkDxeDriverBindingStart (\r
  IN EFI_DRIVER_BINDING_PROTOCOL  *This,\r
  IN EFI_HANDLE                   ControllerHandle,\r
  IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath OPTIONAL\r
  )\r
{\r
  EFI_STATUS Status;\r
  XENBUS_PROTOCOL *XenBusIo;\r
  XEN_BLOCK_FRONT_DEVICE *Dev;\r
\r
  Status = gBS->OpenProtocol (\r
                ControllerHandle,\r
                &gXenBusProtocolGuid,\r
                (VOID **)&XenBusIo,\r
                This->DriverBindingHandle,\r
                ControllerHandle,\r
                EFI_OPEN_PROTOCOL_BY_DRIVER\r
                );\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
  Status = XenPvBlockFrontInitialization (XenBusIo, XenBusIo->Node, &Dev);\r
  if (EFI_ERROR (Status)) {\r
    goto CloseProtocol;\r
  }\r
\r
  return EFI_SUCCESS;\r
\r
CloseProtocol:\r
  gBS->CloseProtocol (ControllerHandle, &gXenBusProtocolGuid,\r
                      This->DriverBindingHandle, ControllerHandle);\r
  return Status;\r
}\r
\r
/**\r
  Stops a device controller.\r
\r
  The Stop() function is designed to be invoked from the EFI boot service DisconnectController().\r
  As a result, much of the error checking on the parameters to Stop() has been moved\r
  into this common boot service. It is legal to call Stop() from other locations,\r
  but the following calling restrictions must be followed, or the system behavior will not be deterministic.\r
  1. ControllerHandle must be a valid EFI_HANDLE that was used on a previous call to this\r
     same driver's Start() function.\r
  2. The first NumberOfChildren handles of ChildHandleBuffer must all be a valid\r
     EFI_HANDLE. In addition, all of these handles must have been created in this driver's\r
     Start() function, and the Start() function must have called OpenProtocol() on\r
     ControllerHandle with an Attribute of EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER.\r
\r
  @param[in]  This              A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.\r
  @param[in]  ControllerHandle  A handle to the device being stopped. The handle must\r
                                support a bus specific I/O protocol for the driver\r
                                to use to stop the device.\r
  @param[in]  NumberOfChildren  The number of child device handles in ChildHandleBuffer.\r
  @param[in]  ChildHandleBuffer An array of child handles to be freed. May be NULL\r
                                if NumberOfChildren is 0.\r
\r
  @retval EFI_SUCCESS           The device was stopped.\r
  @retval EFI_DEVICE_ERROR      The device could not be stopped due to a device error.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
XenPvBlkDxeDriverBindingStop (\r
  IN EFI_DRIVER_BINDING_PROTOCOL  *This,\r
  IN EFI_HANDLE                   ControllerHandle,\r
  IN UINTN                        NumberOfChildren,\r
  IN EFI_HANDLE                   *ChildHandleBuffer OPTIONAL\r
  )\r
{\r
  gBS->CloseProtocol (ControllerHandle, &gXenBusProtocolGuid,\r
         This->DriverBindingHandle, ControllerHandle);\r
\r
  return EFI_SUCCESS;\r
}\r
Commit	Line	Data
de671da8 AP	1	/** @file\r
	2	This driver produce a BlockIo protocol instance for a Xen PV block device.\r
	3	\r
	4	This driver support XenBus protocol of type 'vbd'. Every function that\r
	5	comsume XenBus protocol are in BlockFront, which the implementation to access\r
	6	a Xen PV device. The BlockIo implementation is in it's one file and will call\r
	7	BlockFront functions.\r
	8	\r
	9	Copyright (C) 2014, Citrix Ltd.\r
	10	\r
	11	This program and the accompanying materials\r
	12	are licensed and made available under the terms and conditions of the BSD License\r
	13	which accompanies this distribution. The full text of the license may be found at\r
	14	http://opensource.org/licenses/bsd-license.php\r
	15	\r
	16	THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
	17	WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
	18	\r
	19	**/\r
	20	\r
	21	#include "XenPvBlkDxe.h"\r
	22	\r
5cce8524 ST	23	#include "BlockFront.h"\r
5cce8524 ST	24	\r
de671da8 AP	25	\r
	26	///\r
	27	/// Driver Binding Protocol instance\r
	28	///\r
	29	EFI_DRIVER_BINDING_PROTOCOL gXenPvBlkDxeDriverBinding = {\r
	30	XenPvBlkDxeDriverBindingSupported,\r
	31	XenPvBlkDxeDriverBindingStart,\r
	32	XenPvBlkDxeDriverBindingStop,\r
	33	XEN_PV_BLK_DXE_VERSION,\r
	34	NULL,\r
	35	NULL\r
	36	};\r
	37	\r
	38	\r
	39	/**\r
	40	Unloads an image.\r
	41	\r
	42	@param ImageHandle Handle that identifies the image to be unloaded.\r
	43	\r
	44	@retval EFI_SUCCESS The image has been unloaded.\r
	45	@retval EFI_INVALID_PARAMETER ImageHandle is not a valid image handle.\r
	46	\r
	47	**/\r
	48	EFI_STATUS\r
	49	EFIAPI\r
	50	XenPvBlkDxeUnload (\r
	51	IN EFI_HANDLE ImageHandle\r
	52	)\r
	53	{\r
	54	EFI_STATUS Status;\r
	55	\r
	56	EFI_HANDLE *HandleBuffer;\r
	57	UINTN HandleCount;\r
	58	UINTN Index;\r
	59	\r
	60	\r
	61	//\r
	62	// Retrieve array of all handles in the handle database\r
	63	//\r
	64	Status = gBS->LocateHandleBuffer (\r
	65	AllHandles,\r
	66	NULL,\r
	67	NULL,\r
	68	&HandleCount,\r
	69	&HandleBuffer\r
	70	);\r
	71	if (EFI_ERROR (Status)) {\r
	72	return Status;\r
	73	}\r
	74	\r
	75	//\r
	76	// Disconnect the current driver from handles in the handle database\r
	77	//\r
	78	for (Index = 0; Index < HandleCount; Index++) {\r
	79	gBS->DisconnectController (HandleBuffer[Index], gImageHandle, NULL);\r
	80	}\r
	81	\r
	82	//\r
	83	// Free the array of handles\r
	84	//\r
	85	FreePool (HandleBuffer);\r
	86	\r
	87	\r
	88	//\r
89	// Uninstall protocols installed in the driver entry point\r
90	//\r
91	Status = gBS->UninstallMultipleProtocolInterfaces (\r
92	ImageHandle,\r
93	&gEfiDriverBindingProtocolGuid, &gXenPvBlkDxeDriverBinding,\r
94	&gEfiComponentNameProtocolGuid, &gXenPvBlkDxeComponentName,\r
95	&gEfiComponentName2ProtocolGuid, &gXenPvBlkDxeComponentName2,\r
96	NULL\r
97	);\r
98	if (EFI_ERROR (Status)) {\r
99	return Status;\r
100	}\r
101	\r
102	return EFI_SUCCESS;\r
103	}\r
104	\r
105	/**\r
106	This is the declaration of an EFI image entry point. This entry point is\r
107	the same for UEFI Applications, UEFI OS Loaders, and UEFI Drivers including\r
108	both device drivers and bus drivers.\r
109	\r
110	@param ImageHandle The firmware allocated handle for the UEFI image.\r
111	@param SystemTable A pointer to the EFI System Table.\r
112	\r
113	@retval EFI_SUCCESS The operation completed successfully.\r
114	@retval Others An unexpected error occurred.\r
115	**/\r
116	EFI_STATUS\r
117	EFIAPI\r
118	XenPvBlkDxeDriverEntryPoint (\r
119	IN EFI_HANDLE ImageHandle,\r
120	IN EFI_SYSTEM_TABLE *SystemTable\r
121	)\r
122	{\r
123	EFI_STATUS Status;\r
124	\r
125	//\r
126	// Install UEFI Driver Model protocol(s).\r
127	//\r
128	Status = EfiLibInstallDriverBindingComponentName2 (\r
129	ImageHandle,\r
130	SystemTable,\r
131	&gXenPvBlkDxeDriverBinding,\r
132	ImageHandle,\r
133	&gXenPvBlkDxeComponentName,\r
134	&gXenPvBlkDxeComponentName2\r
135	);\r
136	ASSERT_EFI_ERROR (Status);\r
137	\r
138	return Status;\r
139	}\r
140	\r
141	\r
142	/**\r
143	Tests to see if this driver supports a given controller. If a child device is provided,\r
144	it further tests to see if this driver supports creating a handle for the specified child device.\r
145	\r
146	This function checks to see if the driver specified by This supports the device specified by\r
147	ControllerHandle. Drivers will typically use the device path attached to\r
148	ControllerHandle and/or the services from the bus I/O abstraction attached to\r
149	ControllerHandle to determine if the driver supports ControllerHandle. This function\r
150	may be called many times during platform initialization. In order to reduce boot times, the tests\r
151	performed by this function must be very small, and take as little time as possible to execute. This\r
152	function must not change the state of any hardware devices, and this function must be aware that the\r
153	device specified by ControllerHandle may already be managed by the same driver or a\r
154	different driver. This function must match its calls to AllocatePages() with FreePages(),\r
155	AllocatePool() with FreePool(), and OpenProtocol() with CloseProtocol().\r
156	Because ControllerHandle may have been previously started by the same driver, if a protocol is\r
157	already in the opened state, then it must not be closed with CloseProtocol(). This is required\r
158	to guarantee the state of ControllerHandle is not modified by this function.\r
159	\r
160	@param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.\r
161	@param[in] ControllerHandle The handle of the controller to test. This handle\r
162	must support a protocol interface that supplies\r
163	an I/O abstraction to the driver.\r
164	@param[in] RemainingDevicePath A pointer to the remaining portion of a device path. This\r
165	parameter is ignored by device drivers, and is optional for bus\r
166	drivers. For bus drivers, if this parameter is not NULL, then\r
167	the bus driver must determine if the bus controller specified\r
168	by ControllerHandle and the child controller specified\r
169	by RemainingDevicePath are both supported by this\r
170	bus driver.\r
171	\r
172	@retval EFI_SUCCESS The device specified by ControllerHandle and\r
173	RemainingDevicePath is supported by the driver specified by This.\r
174	@retval EFI_ALREADY_STARTED The device specified by ControllerHandle and\r
175	RemainingDevicePath is already being managed by the driver\r
176	specified by This.\r
177	@retval EFI_ACCESS_DENIED The device specified by ControllerHandle and\r
178	RemainingDevicePath is already being managed by a different\r
179	driver or an application that requires exclusive access.\r
180	Currently not implemented.\r
181	@retval EFI_UNSUPPORTED The device specified by ControllerHandle and\r
182	RemainingDevicePath is not supported by the driver specified by This.\r
183	**/\r
184	EFI_STATUS\r
185	EFIAPI\r
186	XenPvBlkDxeDriverBindingSupported (\r
187	IN EFI_DRIVER_BINDING_PROTOCOL *This,\r
188	IN EFI_HANDLE ControllerHandle,\r
189	IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath OPTIONAL\r
190	)\r
191	{\r
192	EFI_STATUS Status;\r
193	XENBUS_PROTOCOL *XenBusIo;\r
194	\r
195	Status = gBS->OpenProtocol (\r
196	ControllerHandle,\r
197	&gXenBusProtocolGuid,\r
198	(VOID **)&XenBusIo,\r
199	This->DriverBindingHandle,\r
200	ControllerHandle,\r
201	EFI_OPEN_PROTOCOL_BY_DRIVER\r
202	);\r
203	if (EFI_ERROR (Status)) {\r
204	return Status;\r
205	}\r
206	if (AsciiStrCmp (XenBusIo->Type, "vbd") == 0) {\r
207	Status = EFI_SUCCESS;\r
208	} else {\r
209	Status = EFI_UNSUPPORTED;\r
210	}\r
211	\r
212	gBS->CloseProtocol (ControllerHandle, &gXenBusProtocolGuid,\r
213	This->DriverBindingHandle, ControllerHandle);\r
214	\r
215	return Status;\r
216	}\r
217	\r
218	/**\r
219	Starts a device controller.\r
220	\r
221	The Start() function is designed to be invoked from the EFI boot service ConnectController().\r
222	As a result, much of the error checking on the parameters to Start() has been moved into this\r
223	common boot service. It is legal to call Start() from other locations,\r
224	but the following calling restrictions must be followed, or the system behavior will not be deterministic.\r
225	1. ControllerHandle must be a valid EFI_HANDLE.\r
226	2. If RemainingDevicePath is not NULL, then it must be a pointer to a naturally aligned\r
227	EFI_DEVICE_PATH_PROTOCOL.\r
228	3. Prior to calling Start(), the Supported() function for the driver specified by This must\r
229	have been called with the same calling parameters, and Supported() must have returned EFI_SUCCESS.\r
230	\r
231	@param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.\r
232	@param[in] ControllerHandle The handle of the controller to start. This handle\r
233	must support a protocol interface that supplies\r
234	an I/O abstraction to the driver.\r
235	@param[in] RemainingDevicePath A pointer to the remaining portion of a device path. This\r
236	parameter is ignored by device drivers, and is optional for bus\r
237	drivers. For a bus driver, if this parameter is NULL, then handles\r
238	for all the children of Controller are created by this driver.\r
239	If this parameter is not NULL and the first Device Path Node is\r
240	not the End of Device Path Node, then only the handle for the\r
241	child device specified by the first Device Path Node of\r
242	RemainingDevicePath is created by this driver.\r
243	If the first Device Path Node of RemainingDevicePath is\r
244	the End of Device Path Node, no child handle is created by this\r
245	driver.\r
246	\r
247	@retval EFI_SUCCESS The device was started.\r
248	@retval EFI_DEVICE_ERROR The device could not be started due to a device error.Currently not implemented.\r
249	@retval EFI_OUT_OF_RESOURCES The request could not be completed due to a lack of resources.\r
250	@retval Others The driver failded to start the device.\r
251	\r
252	**/\r
253	EFI_STATUS\r
254	EFIAPI\r
255	XenPvBlkDxeDriverBindingStart (\r
256	IN EFI_DRIVER_BINDING_PROTOCOL *This,\r
257	IN EFI_HANDLE ControllerHandle,\r
258	IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath OPTIONAL\r
259	)\r
260	{\r
261	EFI_STATUS Status;\r
262	XENBUS_PROTOCOL *XenBusIo;\r
5cce8524	263	XEN_BLOCK_FRONT_DEVICE *Dev;\r
de671da8 AP	264	\r
	265	Status = gBS->OpenProtocol (\r
	266	ControllerHandle,\r
	267	&gXenBusProtocolGuid,\r
	268	(VOID **)&XenBusIo,\r
	269	This->DriverBindingHandle,\r
	270	ControllerHandle,\r
	271	EFI_OPEN_PROTOCOL_BY_DRIVER\r
	272	);\r
	273	if (EFI_ERROR (Status)) {\r
	274	return Status;\r
	275	}\r
	276	\r
5cce8524 ST	277	Status = XenPvBlockFrontInitialization (XenBusIo, XenBusIo->Node, &Dev);\r
	278	if (EFI_ERROR (Status)) {\r
	279	goto CloseProtocol;\r
	280	}\r
	281	\r
de671da8	282	return EFI_SUCCESS;\r
5cce8524 ST	283	\r
	284	CloseProtocol:\r
	285	gBS->CloseProtocol (ControllerHandle, &gXenBusProtocolGuid,\r
	286	This->DriverBindingHandle, ControllerHandle);\r
	287	return Status;\r
de671da8 AP	288	}\r
	289	\r
	290	/**\r
	291	Stops a device controller.\r
	292	\r
	293	The Stop() function is designed to be invoked from the EFI boot service DisconnectController().\r
	294	As a result, much of the error checking on the parameters to Stop() has been moved\r
	295	into this common boot service. It is legal to call Stop() from other locations,\r
	296	but the following calling restrictions must be followed, or the system behavior will not be deterministic.\r
	297	1. ControllerHandle must be a valid EFI_HANDLE that was used on a previous call to this\r
	298	same driver's Start() function.\r
	299	2. The first NumberOfChildren handles of ChildHandleBuffer must all be a valid\r
	300	EFI_HANDLE. In addition, all of these handles must have been created in this driver's\r
	301	Start() function, and the Start() function must have called OpenProtocol() on\r
	302	ControllerHandle with an Attribute of EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER.\r
	303	\r
	304	@param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.\r
	305	@param[in] ControllerHandle A handle to the device being stopped. The handle must\r
	306	support a bus specific I/O protocol for the driver\r
	307	to use to stop the device.\r
	308	@param[in] NumberOfChildren The number of child device handles in ChildHandleBuffer.\r
	309	@param[in] ChildHandleBuffer An array of child handles to be freed. May be NULL\r
	310	if NumberOfChildren is 0.\r
	311	\r
	312	@retval EFI_SUCCESS The device was stopped.\r
	313	@retval EFI_DEVICE_ERROR The device could not be stopped due to a device error.\r
	314	\r
	315	**/\r
	316	EFI_STATUS\r
	317	EFIAPI\r
	318	XenPvBlkDxeDriverBindingStop (\r
	319	IN EFI_DRIVER_BINDING_PROTOCOL *This,\r
	320	IN EFI_HANDLE ControllerHandle,\r
	321	IN UINTN NumberOfChildren,\r
	322	IN EFI_HANDLE *ChildHandleBuffer OPTIONAL\r
	323	)\r
	324	{\r
	325	gBS->CloseProtocol (ControllerHandle, &gXenBusProtocolGuid,\r
	326	This->DriverBindingHandle, ControllerHandle);\r
	327	\r
	328	return EFI_SUCCESS;\r
	329	}\r