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

/** @file\r
  This driver produces XenBus Protocol instances for each Xen PV devices.\r
\r
  This XenBus bus driver will first initialize differente services in order to\r
  enumerate the ParaVirtualized devices available.\r
\r
  Those services are:\r
    - HyperCall\r
    - Event Channel\r
    - Grant Table\r
    - XenStore\r
    - XenBus\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 <IndustryStandard/Pci.h>\r
#include <IndustryStandard/Acpi.h>\r
#include <Library/DebugLib.h>\r
\r
#include "XenBusDxe.h"\r
\r
\r
///\r
/// Driver Binding Protocol instance\r
///\r
EFI_DRIVER_BINDING_PROTOCOL gXenBusDxeDriverBinding = {\r
  XenBusDxeDriverBindingSupported,\r
  XenBusDxeDriverBindingStart,\r
  XenBusDxeDriverBindingStop,\r
  XENBUS_DXE_VERSION,\r
  NULL,\r
  NULL\r
};\r
\r
\r
STATIC EFI_LOCK       mMyDeviceLock = EFI_INITIALIZE_LOCK_VARIABLE (TPL_CALLBACK);\r
STATIC XENBUS_DEVICE *mMyDevice = NULL;\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
XenBusDxeUnload (\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
  // 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, &gXenBusDxeDriverBinding,\r
                  &gEfiComponentNameProtocolGuid,  &gXenBusDxeComponentName,\r
                  &gEfiComponentName2ProtocolGuid, &gXenBusDxeComponentName2,\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
XenBusDxeDriverEntryPoint (\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
             &gXenBusDxeDriverBinding,\r
             ImageHandle,\r
             &gXenBusDxeComponentName,\r
             &gXenBusDxeComponentName2\r
             );\r
  ASSERT_EFI_ERROR (Status);\r
\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
  @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
XenBusDxeDriverBindingSupported (\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
  EFI_PCI_IO_PROTOCOL *PciIo;\r
  PCI_TYPE00          Pci;\r
\r
  Status = gBS->OpenProtocol (\r
                     ControllerHandle,\r
                     &gEfiPciIoProtocolGuid,\r
                     (VOID **)&PciIo,\r
                     This->DriverBindingHandle,\r
                     ControllerHandle,\r
                     EFI_OPEN_PROTOCOL_BY_DRIVER\r
                     );\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
  Status = PciIo->Pci.Read (PciIo, EfiPciIoWidthUint32, 0,\r
                            sizeof Pci / sizeof (UINT32), &Pci);\r
\r
  if (Status == EFI_SUCCESS) {\r
    if (Pci.Hdr.VendorId == PCI_VENDOR_ID_XEN &&\r
        Pci.Hdr.DeviceId == PCI_DEVICE_ID_XEN_PLATFORM) {\r
      Status = EFI_SUCCESS;\r
    } else {\r
      Status = EFI_UNSUPPORTED;\r
    }\r
  }\r
\r
  gBS->CloseProtocol (ControllerHandle, &gEfiPciIoProtocolGuid,\r
         This->DriverBindingHandle, ControllerHandle);\r
\r
  return Status;\r
}\r
\r
VOID\r
EFIAPI\r
NotifyExitBoot (\r
  IN EFI_EVENT Event,\r
  IN VOID *Context\r
  )\r
{\r
  XENBUS_DEVICE *Dev = Context;\r
\r
  gBS->DisconnectController(Dev->ControllerHandle,\r
                            Dev->This->DriverBindingHandle, NULL);\r
}\r
\r
/**\r
  Starts a bus 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
XenBusDxeDriverBindingStart (\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_DEVICE *Dev;\r
\r
  Dev = AllocateZeroPool (sizeof (*Dev));\r
  Dev->Signature = XENBUS_DEVICE_SIGNATURE;\r
  Dev->This = This;\r
  Dev->ControllerHandle = ControllerHandle;\r
\r
  EfiAcquireLock (&mMyDeviceLock);\r
  if (mMyDevice != NULL) {\r
    EfiReleaseLock (&mMyDeviceLock);\r
    //\r
    // There is already a XenBus running, only one can be used at a time.\r
    //\r
    Status = EFI_ALREADY_STARTED;\r
    goto ErrorAllocated;\r
  }\r
  mMyDevice = Dev;\r
  EfiReleaseLock (&mMyDeviceLock);\r
\r
  Status = gBS->CreateEvent (EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_CALLBACK,\r
                             NotifyExitBoot,\r
                             (VOID*) Dev,\r
                             &Dev->ExitBootEvent);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  return EFI_SUCCESS;\r
\r
ErrorAllocated:\r
  FreePool (Dev);\r
  return Status;\r
}\r
\r
/**\r
  Stops a bus 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
XenBusDxeDriverBindingStop (\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
  XENBUS_DEVICE *Dev = mMyDevice;\r
\r
  gBS->CloseEvent (Dev->ExitBootEvent);\r
\r
  mMyDevice = NULL;\r
  FreePool (Dev);\r
  return EFI_SUCCESS;\r
}\r
Commit	Line	Data
e65e8802 AP	1	/** @file\r
	2	This driver produces XenBus Protocol instances for each Xen PV devices.\r
	3	\r
	4	This XenBus bus driver will first initialize differente services in order to\r
	5	enumerate the ParaVirtualized devices available.\r
	6	\r
	7	Those services are:\r
	8	- HyperCall\r
	9	- Event Channel\r
	10	- Grant Table\r
	11	- XenStore\r
	12	- XenBus\r
	13	\r
	14	Copyright (C) 2014, Citrix Ltd.\r
	15	\r
	16	This program and the accompanying materials\r
	17	are licensed and made available under the terms and conditions of the BSD License\r
	18	which accompanies this distribution. The full text of the license may be found at\r
	19	http://opensource.org/licenses/bsd-license.php\r
	20	\r
	21	THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
	22	WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
	23	\r
	24	**/\r
	25	\r
	26	#include <IndustryStandard/Pci.h>\r
	27	#include <IndustryStandard/Acpi.h>\r
	28	#include <Library/DebugLib.h>\r
	29	\r
	30	#include "XenBusDxe.h"\r
	31	\r
	32	\r
	33	///\r
	34	/// Driver Binding Protocol instance\r
	35	///\r
	36	EFI_DRIVER_BINDING_PROTOCOL gXenBusDxeDriverBinding = {\r
	37	XenBusDxeDriverBindingSupported,\r
	38	XenBusDxeDriverBindingStart,\r
	39	XenBusDxeDriverBindingStop,\r
	40	XENBUS_DXE_VERSION,\r
	41	NULL,\r
	42	NULL\r
	43	};\r
	44	\r
	45	\r
a154f420 AP	46	STATIC EFI_LOCK mMyDeviceLock = EFI_INITIALIZE_LOCK_VARIABLE (TPL_CALLBACK);\r
	47	STATIC XENBUS_DEVICE *mMyDevice = NULL;\r
	48	\r
e65e8802 AP	49	/**\r
	50	Unloads an image.\r
	51	\r
	52	@param ImageHandle Handle that identifies the image to be unloaded.\r
	53	\r
	54	@retval EFI_SUCCESS The image has been unloaded.\r
	55	@retval EFI_INVALID_PARAMETER ImageHandle is not a valid image handle.\r
	56	\r
	57	**/\r
	58	EFI_STATUS\r
	59	EFIAPI\r
	60	XenBusDxeUnload (\r
	61	IN EFI_HANDLE ImageHandle\r
	62	)\r
	63	{\r
	64	EFI_STATUS Status;\r
	65	\r
	66	EFI_HANDLE *HandleBuffer;\r
	67	UINTN HandleCount;\r
	68	UINTN Index;\r
	69	\r
	70	//\r
	71	// Retrieve array of all handles in the handle database\r
	72	//\r
	73	Status = gBS->LocateHandleBuffer (\r
	74	AllHandles,\r
	75	NULL,\r
	76	NULL,\r
	77	&HandleCount,\r
	78	&HandleBuffer\r
	79	);\r
	80	if (EFI_ERROR (Status)) {\r
	81	return Status;\r
	82	}\r
	83	\r
	84	//\r
	85	// Disconnect the current driver from handles in the handle database\r
	86	//\r
	87	for (Index = 0; Index < HandleCount; Index++) {\r
	88	gBS->DisconnectController (HandleBuffer[Index], gImageHandle, NULL);\r
	89	}\r
	90	\r
	91	//\r
	92	// Free the array of handles\r
	93	//\r
	94	FreePool (HandleBuffer);\r
	95	\r
	96	\r
	97	//\r
	98	// Uninstall protocols installed in the driver entry point\r
	99	//\r
	100	Status = gBS->UninstallMultipleProtocolInterfaces (\r
	101	ImageHandle,\r
	102	&gEfiDriverBindingProtocolGuid, &gXenBusDxeDriverBinding,\r
	103	&gEfiComponentNameProtocolGuid, &gXenBusDxeComponentName,\r
	104	&gEfiComponentName2ProtocolGuid, &gXenBusDxeComponentName2,\r
	105	NULL\r
	106	);\r
	107	if (EFI_ERROR (Status)) {\r
	108	return Status;\r
	109	}\r
	110	\r
	111	return EFI_SUCCESS;\r
	112	}\r
113	\r
114	/**\r
115	This is the declaration of an EFI image entry point. This entry point is\r
116	the same for UEFI Applications, UEFI OS Loaders, and UEFI Drivers including\r
117	both device drivers and bus drivers.\r
118	\r
119	@param ImageHandle The firmware allocated handle for the UEFI image.\r
120	@param SystemTable A pointer to the EFI System Table.\r
121	\r
122	@retval EFI_SUCCESS The operation completed successfully.\r
123	@retval Others An unexpected error occurred.\r
124	**/\r
125	EFI_STATUS\r
126	EFIAPI\r
127	XenBusDxeDriverEntryPoint (\r
128	IN EFI_HANDLE ImageHandle,\r
129	IN EFI_SYSTEM_TABLE *SystemTable\r
130	)\r
131	{\r
132	EFI_STATUS Status;\r
133	\r
134	//\r
135	// Install UEFI Driver Model protocol(s).\r
136	//\r
137	Status = EfiLibInstallDriverBindingComponentName2 (\r
138	ImageHandle,\r
139	SystemTable,\r
140	&gXenBusDxeDriverBinding,\r
141	ImageHandle,\r
142	&gXenBusDxeComponentName,\r
143	&gXenBusDxeComponentName2\r
144	);\r
145	ASSERT_EFI_ERROR (Status);\r
146	\r
147	\r
148	return Status;\r
149	}\r
150	\r
151	\r
152	/**\r
153	Tests to see if this driver supports a given controller. If a child device is provided,\r
154	it further tests to see if this driver supports creating a handle for the specified child device.\r
155	\r
156	@param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.\r
157	@param[in] ControllerHandle The handle of the controller to test. This handle\r
158	must support a protocol interface that supplies\r
159	an I/O abstraction to the driver.\r
160	@param[in] RemainingDevicePath A pointer to the remaining portion of a device path. This\r
161	parameter is ignored by device drivers, and is optional for bus\r
162	drivers. For bus drivers, if this parameter is not NULL, then\r
163	the bus driver must determine if the bus controller specified\r
164	by ControllerHandle and the child controller specified\r
165	by RemainingDevicePath are both supported by this\r
166	bus driver.\r
167	\r
168	@retval EFI_SUCCESS The device specified by ControllerHandle and\r
169	RemainingDevicePath is supported by the driver specified by This.\r
170	@retval EFI_ALREADY_STARTED The device specified by ControllerHandle and\r
171	RemainingDevicePath is already being managed by the driver\r
172	specified by This.\r
173	@retval EFI_ACCESS_DENIED The device specified by ControllerHandle and\r
174	RemainingDevicePath is already being managed by a different\r
175	driver or an application that requires exclusive access.\r
176	Currently not implemented.\r
177	@retval EFI_UNSUPPORTED The device specified by ControllerHandle and\r
178	RemainingDevicePath is not supported by the driver specified by This.\r
179	**/\r
180	EFI_STATUS\r
181	EFIAPI\r
182	XenBusDxeDriverBindingSupported (\r
183	IN EFI_DRIVER_BINDING_PROTOCOL *This,\r
184	IN EFI_HANDLE ControllerHandle,\r
185	IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath OPTIONAL\r
186	)\r
187	{\r
188	EFI_STATUS Status;\r
189	EFI_PCI_IO_PROTOCOL *PciIo;\r
190	PCI_TYPE00 Pci;\r
191	\r
192	Status = gBS->OpenProtocol (\r
193	ControllerHandle,\r
194	&gEfiPciIoProtocolGuid,\r
195	(VOID **)&PciIo,\r
196	This->DriverBindingHandle,\r
197	ControllerHandle,\r
198	EFI_OPEN_PROTOCOL_BY_DRIVER\r
199	);\r
200	if (EFI_ERROR (Status)) {\r
201	return Status;\r
202	}\r
203	\r
204	Status = PciIo->Pci.Read (PciIo, EfiPciIoWidthUint32, 0,\r
205	sizeof Pci / sizeof (UINT32), &Pci);\r
206	\r
207	if (Status == EFI_SUCCESS) {\r
208	if (Pci.Hdr.VendorId == PCI_VENDOR_ID_XEN &&\r
209	Pci.Hdr.DeviceId == PCI_DEVICE_ID_XEN_PLATFORM) {\r
210	Status = EFI_SUCCESS;\r
211	} else {\r
212	Status = EFI_UNSUPPORTED;\r
213	}\r
214	}\r
215	\r
216	gBS->CloseProtocol (ControllerHandle, &gEfiPciIoProtocolGuid,\r
217	This->DriverBindingHandle, ControllerHandle);\r
218	\r
219	return Status;\r
220	}\r
221	\r
a154f420 AP	222	VOID\r
	223	EFIAPI\r
	224	NotifyExitBoot (\r
	225	IN EFI_EVENT Event,\r
	226	IN VOID *Context\r
	227	)\r
	228	{\r
	229	XENBUS_DEVICE *Dev = Context;\r
	230	\r
	231	gBS->DisconnectController(Dev->ControllerHandle,\r
	232	Dev->This->DriverBindingHandle, NULL);\r
	233	}\r
	234	\r
e65e8802 AP	235	/**\r
	236	Starts a bus controller.\r
	237	\r
	238	The Start() function is designed to be invoked from the EFI boot service ConnectController().\r
	239	As a result, much of the error checking on the parameters to Start() has been moved into this\r
	240	common boot service. It is legal to call Start() from other locations,\r
	241	but the following calling restrictions must be followed, or the system behavior will not be deterministic.\r
	242	1. ControllerHandle must be a valid EFI_HANDLE.\r
	243	2. If RemainingDevicePath is not NULL, then it must be a pointer to a naturally aligned\r
	244	EFI_DEVICE_PATH_PROTOCOL.\r
	245	3. Prior to calling Start(), the Supported() function for the driver specified by This must\r
	246	have been called with the same calling parameters, and Supported() must have returned EFI_SUCCESS.\r
	247	\r
	248	@param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.\r
	249	@param[in] ControllerHandle The handle of the controller to start. This handle\r
	250	must support a protocol interface that supplies\r
	251	an I/O abstraction to the driver.\r
	252	@param[in] RemainingDevicePath A pointer to the remaining portion of a device path. This\r
	253	parameter is ignored by device drivers, and is optional for bus\r
	254	drivers. For a bus driver, if this parameter is NULL, then handles\r
	255	for all the children of Controller are created by this driver.\r
	256	If this parameter is not NULL and the first Device Path Node is\r
	257	not the End of Device Path Node, then only the handle for the\r
	258	child device specified by the first Device Path Node of\r
	259	RemainingDevicePath is created by this driver.\r
	260	If the first Device Path Node of RemainingDevicePath is\r
	261	the End of Device Path Node, no child handle is created by this\r
	262	driver.\r
	263	\r
	264	@retval EFI_SUCCESS The device was started.\r
	265	@retval EFI_DEVICE_ERROR The device could not be started due to a device error.Currently not implemented.\r
	266	@retval EFI_OUT_OF_RESOURCES The request could not be completed due to a lack of resources.\r
	267	@retval Others The driver failded to start the device.\r
	268	\r
	269	**/\r
	270	EFI_STATUS\r
	271	EFIAPI\r
	272	XenBusDxeDriverBindingStart (\r
	273	IN EFI_DRIVER_BINDING_PROTOCOL *This,\r
	274	IN EFI_HANDLE ControllerHandle,\r
	275	IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath OPTIONAL\r
	276	)\r
	277	{\r
a154f420 AP	278	EFI_STATUS Status;\r
	279	XENBUS_DEVICE *Dev;\r
	280	\r
	281	Dev = AllocateZeroPool (sizeof (*Dev));\r
	282	Dev->Signature = XENBUS_DEVICE_SIGNATURE;\r
	283	Dev->This = This;\r
	284	Dev->ControllerHandle = ControllerHandle;\r
	285	\r
	286	EfiAcquireLock (&mMyDeviceLock);\r
	287	if (mMyDevice != NULL) {\r
	288	EfiReleaseLock (&mMyDeviceLock);\r
	289	//\r
	290	// There is already a XenBus running, only one can be used at a time.\r
	291	//\r
	292	Status = EFI_ALREADY_STARTED;\r
	293	goto ErrorAllocated;\r
	294	}\r
	295	mMyDevice = Dev;\r
	296	EfiReleaseLock (&mMyDeviceLock);\r
	297	\r
	298	Status = gBS->CreateEvent (EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_CALLBACK,\r
	299	NotifyExitBoot,\r
	300	(VOID*) Dev,\r
	301	&Dev->ExitBootEvent);\r
	302	ASSERT_EFI_ERROR (Status);\r
	303	\r
	304	return EFI_SUCCESS;\r
	305	\r
	306	ErrorAllocated:\r
	307	FreePool (Dev);\r
	308	return Status;\r
e65e8802 AP	309	}\r
	310	\r
	311	/**\r
	312	Stops a bus controller.\r
	313	\r
	314	The Stop() function is designed to be invoked from the EFI boot service DisconnectController().\r
	315	As a result, much of the error checking on the parameters to Stop() has been moved\r
	316	into this common boot service. It is legal to call Stop() from other locations,\r
	317	but the following calling restrictions must be followed, or the system behavior will not be deterministic.\r
	318	1. ControllerHandle must be a valid EFI_HANDLE that was used on a previous call to this\r
	319	same driver's Start() function.\r
	320	2. The first NumberOfChildren handles of ChildHandleBuffer must all be a valid\r
	321	EFI_HANDLE. In addition, all of these handles must have been created in this driver's\r
	322	Start() function, and the Start() function must have called OpenProtocol() on\r
	323	ControllerHandle with an Attribute of EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER.\r
	324	\r
	325	@param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.\r
	326	@param[in] ControllerHandle A handle to the device being stopped. The handle must\r
	327	support a bus specific I/O protocol for the driver\r
	328	to use to stop the device.\r
	329	@param[in] NumberOfChildren The number of child device handles in ChildHandleBuffer.\r
	330	@param[in] ChildHandleBuffer An array of child handles to be freed. May be NULL\r
	331	if NumberOfChildren is 0.\r
	332	\r
	333	@retval EFI_SUCCESS The device was stopped.\r
	334	@retval EFI_DEVICE_ERROR The device could not be stopped due to a device error.\r
	335	\r
	336	**/\r
	337	EFI_STATUS\r
	338	EFIAPI\r
	339	XenBusDxeDriverBindingStop (\r
	340	IN EFI_DRIVER_BINDING_PROTOCOL *This,\r
	341	IN EFI_HANDLE ControllerHandle,\r
	342	IN UINTN NumberOfChildren,\r
	343	IN EFI_HANDLE *ChildHandleBuffer OPTIONAL\r
	344	)\r
	345	{\r
a154f420 AP	346	XENBUS_DEVICE *Dev = mMyDevice;\r
	347	\r
	348	gBS->CloseEvent (Dev->ExitBootEvent);\r
	349	\r
	350	mMyDevice = NULL;\r
	351	FreePool (Dev);\r
	352	return EFI_SUCCESS;\r
e65e8802	353	}\r