/** @file
This driver produces XenBus Protocol instances for each Xen PV devices.
This XenBus bus driver will first initialize differente services in order to
enumerate the ParaVirtualized devices available.
Those services are:
- HyperCall
- Event Channel
- Grant Table
- XenStore
- XenBus
Copyright (C) 2014, Citrix Ltd.
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#include <Library/DebugLib.h>
#include <Library/XenHypercallLib.h>
#include "XenBusDxe.h"
#include "GrantTable.h"
#include "XenStore.h"
#include "XenBus.h"
#include <IndustryStandard/Xen/hvm/params.h>
#include <IndustryStandard/Xen/memory.h>
///
/// Driver Binding Protocol instance
///
EFI_DRIVER_BINDING_PROTOCOL gXenBusDxeDriverBinding = {
XenBusDxeDriverBindingSupported,
XenBusDxeDriverBindingStart,
XenBusDxeDriverBindingStop,
XENBUS_DXE_VERSION,
NULL,
NULL
};
STATIC EFI_LOCK mMyDeviceLock = EFI_INITIALIZE_LOCK_VARIABLE (TPL_CALLBACK);
STATIC XENBUS_DEVICE *mMyDevice = NULL;
/**
Map the shared_info_t page into memory.
@param Dev A XENBUS_DEVICE instance.
@retval EFI_SUCCESS Dev->SharedInfo whill contain a pointer to
the shared info page
@retval EFI_LOAD_ERROR The shared info page could not be mapped. The
hypercall returned an error.
**/
STATIC
EFI_STATUS
XenGetSharedInfoPage (
IN OUT XENBUS_DEVICE *Dev
)
{
xen_add_to_physmap_t Parameter;
ASSERT (Dev->SharedInfo == NULL);
Parameter.domid = DOMID_SELF;
Parameter.space = XENMAPSPACE_shared_info;
Parameter.idx = 0;
//
// using reserved page because the page is not released when Linux is
// starting because of the add_to_physmap. QEMU might try to access the
// page, and fail because it have no right to do so (segv).
//
Dev->SharedInfo = AllocateReservedPages (1);
Parameter.gpfn = (UINTN) Dev->SharedInfo >> EFI_PAGE_SHIFT;
if (XenHypercallMemoryOp (XENMEM_add_to_physmap, &Parameter) != 0) {
FreePages (Dev->SharedInfo, 1);
Dev->SharedInfo = NULL;
return EFI_LOAD_ERROR;
}
return EFI_SUCCESS;
}
/**
Unloads an image.
@param ImageHandle Handle that identifies the image to be unloaded.
@retval EFI_SUCCESS The image has been unloaded.
@retval EFI_INVALID_PARAMETER ImageHandle is not a valid image handle.
**/
EFI_STATUS
EFIAPI
XenBusDxeUnload (
IN EFI_HANDLE ImageHandle
)
{
EFI_STATUS Status;
EFI_HANDLE *HandleBuffer;
UINTN HandleCount;
UINTN Index;
//
// Retrieve array of all handles in the handle database
//
Status = gBS->LocateHandleBuffer (
AllHandles,
NULL,
NULL,
&HandleCount,
&HandleBuffer
);
if (EFI_ERROR (Status)) {
return Status;
}
//
// Disconnect the current driver from handles in the handle database
//
for (Index = 0; Index < HandleCount; Index++) {
gBS->DisconnectController (HandleBuffer[Index], gImageHandle, NULL);
}
//
// Free the array of handles
//
FreePool (HandleBuffer);
//
// Uninstall protocols installed in the driver entry point
//
Status = gBS->UninstallMultipleProtocolInterfaces (
ImageHandle,
&gEfiDriverBindingProtocolGuid, &gXenBusDxeDriverBinding,
&gEfiComponentNameProtocolGuid, &gXenBusDxeComponentName,
&gEfiComponentName2ProtocolGuid, &gXenBusDxeComponentName2,
NULL
);
if (EFI_ERROR (Status)) {
return Status;
}
return EFI_SUCCESS;
}
/**
This is the declaration of an EFI image entry point. This entry point is
the same for UEFI Applications, UEFI OS Loaders, and UEFI Drivers including
both device drivers and bus drivers.
@param ImageHandle The firmware allocated handle for the UEFI image.
@param SystemTable A pointer to the EFI System Table.
@retval EFI_SUCCESS The operation completed successfully.
@retval EFI_ABORTED Xen hypercalls are not available.
@retval Others An unexpected error occurred.
**/
EFI_STATUS
EFIAPI
XenBusDxeDriverEntryPoint (
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
{
EFI_STATUS Status;
if (! XenHypercallIsAvailable ()) {
return EFI_ABORTED;
}
//
// Install UEFI Driver Model protocol(s).
//
Status = EfiLibInstallDriverBindingComponentName2 (
ImageHandle,
SystemTable,
&gXenBusDxeDriverBinding,
ImageHandle,
&gXenBusDxeComponentName,
&gXenBusDxeComponentName2
);
ASSERT_EFI_ERROR (Status);
return Status;
}
/**
Tests to see if this driver supports a given controller. If a child device is provided,
it further tests to see if this driver supports creating a handle for the specified child device.
@param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
@param[in] ControllerHandle The handle of the controller to test. This handle
must support a protocol interface that supplies
an I/O abstraction to the driver.
@param[in] RemainingDevicePath A pointer to the remaining portion of a device path. This
parameter is ignored by device drivers, and is optional for bus
drivers. For bus drivers, if this parameter is not NULL, then
the bus driver must determine if the bus controller specified
by ControllerHandle and the child controller specified
by RemainingDevicePath are both supported by this
bus driver.
@retval EFI_SUCCESS The device specified by ControllerHandle and
RemainingDevicePath is supported by the driver specified by This.
@retval EFI_ALREADY_STARTED The device specified by ControllerHandle and
RemainingDevicePath is already being managed by the driver
specified by This.
@retval EFI_ACCESS_DENIED The device specified by ControllerHandle and
RemainingDevicePath is already being managed by a different
driver or an application that requires exclusive access.
Currently not implemented.
@retval EFI_UNSUPPORTED The device specified by ControllerHandle and
RemainingDevicePath is not supported by the driver specified by This.
**/
EFI_STATUS
EFIAPI
XenBusDxeDriverBindingSupported (
IN EFI_DRIVER_BINDING_PROTOCOL *This,
IN EFI_HANDLE ControllerHandle,
IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath OPTIONAL
)
{
EFI_STATUS Status;
XENIO_PROTOCOL *XenIo;
Status = gBS->OpenProtocol (
ControllerHandle,
&gXenIoProtocolGuid,
(VOID **)&XenIo,
This->DriverBindingHandle,
ControllerHandle,
EFI_OPEN_PROTOCOL_BY_DRIVER
);
if (EFI_ERROR (Status)) {
return Status;
}
gBS->CloseProtocol (ControllerHandle, &gXenIoProtocolGuid,
This->DriverBindingHandle, ControllerHandle);
return Status;
}
VOID
EFIAPI
NotifyExitBoot (
IN EFI_EVENT Event,
IN VOID *Context
)
{
XENBUS_DEVICE *Dev = Context;
gBS->DisconnectController(Dev->ControllerHandle,
Dev->This->DriverBindingHandle, NULL);
}
/**
Starts a bus controller.
The Start() function is designed to be invoked from the EFI boot service ConnectController().
As a result, much of the error checking on the parameters to Start() has been moved into this
common boot service. It is legal to call Start() from other locations,
but the following calling restrictions must be followed, or the system behavior will not be deterministic.
1. ControllerHandle must be a valid EFI_HANDLE.
2. If RemainingDevicePath is not NULL, then it must be a pointer to a naturally aligned
EFI_DEVICE_PATH_PROTOCOL.
3. Prior to calling Start(), the Supported() function for the driver specified by This must
have been called with the same calling parameters, and Supported() must have returned EFI_SUCCESS.
@param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
@param[in] ControllerHandle The handle of the controller to start. This handle
must support a protocol interface that supplies
an I/O abstraction to the driver.
@param[in] RemainingDevicePath A pointer to the remaining portion of a device path. This
parameter is ignored by device drivers, and is optional for bus
drivers. For a bus driver, if this parameter is NULL, then handles
for all the children of Controller are created by this driver.
If this parameter is not NULL and the first Device Path Node is
not the End of Device Path Node, then only the handle for the
child device specified by the first Device Path Node of
RemainingDevicePath is created by this driver.
If the first Device Path Node of RemainingDevicePath is
the End of Device Path Node, no child handle is created by this
driver.
@retval EFI_SUCCESS The device was started.
@retval EFI_DEVICE_ERROR The device could not be started due to a device error.Currently not implemented.
@retval EFI_OUT_OF_RESOURCES The request could not be completed due to a lack of resources.
@retval EFI_UNSUPPORTED Something is missing on the system that
prevent to start the edvice.
@retval Others The driver failded to start the device.
**/
EFI_STATUS
EFIAPI
XenBusDxeDriverBindingStart (
IN EFI_DRIVER_BINDING_PROTOCOL *This,
IN EFI_HANDLE ControllerHandle,
IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath OPTIONAL
)
{
EFI_STATUS Status;
XENBUS_DEVICE *Dev;
XENIO_PROTOCOL *XenIo;
EFI_DEVICE_PATH_PROTOCOL *DevicePath;
Status = gBS->OpenProtocol (
ControllerHandle,
&gXenIoProtocolGuid,
(VOID**)&XenIo,
This->DriverBindingHandle,
ControllerHandle,
EFI_OPEN_PROTOCOL_BY_DRIVER
);
if (EFI_ERROR (Status)) {
return Status;
}
Status = gBS->OpenProtocol (
ControllerHandle,
&gEfiDevicePathProtocolGuid,
(VOID **) &DevicePath,
This->DriverBindingHandle,
ControllerHandle,
EFI_OPEN_PROTOCOL_BY_DRIVER
);
if (EFI_ERROR (Status)) {
goto ErrorOpenningProtocol;
}
Dev = AllocateZeroPool (sizeof (*Dev));
Dev->Signature = XENBUS_DEVICE_SIGNATURE;
Dev->This = This;
Dev->ControllerHandle = ControllerHandle;
Dev->XenIo = XenIo;
Dev->DevicePath = DevicePath;
InitializeListHead (&Dev->ChildList);
EfiAcquireLock (&mMyDeviceLock);
if (mMyDevice != NULL) {
EfiReleaseLock (&mMyDeviceLock);
//
// There is already a XenBus running, only one can be used at a time.
//
Status = EFI_ALREADY_STARTED;
goto ErrorAllocated;
}
mMyDevice = Dev;
EfiReleaseLock (&mMyDeviceLock);
Status = XenGetSharedInfoPage (Dev);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_ERROR, "XenBus: Unable to get the shared info page.\n"));
Status = EFI_UNSUPPORTED;
goto ErrorAllocated;
}
XenGrantTableInit (Dev);
Status = XenStoreInit (Dev);
ASSERT_EFI_ERROR (Status);
XenBusEnumerateBus (Dev);
Status = gBS->CreateEvent (EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_CALLBACK,
NotifyExitBoot,
(VOID*) Dev,
&Dev->ExitBootEvent);
ASSERT_EFI_ERROR (Status);
return EFI_SUCCESS;
ErrorAllocated:
FreePool (Dev);
gBS->CloseProtocol (ControllerHandle, &gEfiDevicePathProtocolGuid,
This->DriverBindingHandle, ControllerHandle);
ErrorOpenningProtocol:
gBS->CloseProtocol (ControllerHandle, &gXenIoProtocolGuid,
This->DriverBindingHandle, ControllerHandle);
return Status;
}
/**
Stops a bus controller.
The Stop() function is designed to be invoked from the EFI boot service DisconnectController().
As a result, much of the error checking on the parameters to Stop() has been moved
into this common boot service. It is legal to call Stop() from other locations,
but the following calling restrictions must be followed, or the system behavior will not be deterministic.
1. ControllerHandle must be a valid EFI_HANDLE that was used on a previous call to this
same driver's Start() function.
2. The first NumberOfChildren handles of ChildHandleBuffer must all be a valid
EFI_HANDLE. In addition, all of these handles must have been created in this driver's
Start() function, and the Start() function must have called OpenProtocol() on
ControllerHandle with an Attribute of EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER.
@param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
@param[in] ControllerHandle A handle to the device being stopped. The handle must
support a bus specific I/O protocol for the driver
to use to stop the device.
@param[in] NumberOfChildren The number of child device handles in ChildHandleBuffer.
@param[in] ChildHandleBuffer An array of child handles to be freed. May be NULL
if NumberOfChildren is 0.
@retval EFI_SUCCESS The device was stopped.
@retval EFI_DEVICE_ERROR The device could not be stopped due to a device error.
**/
EFI_STATUS
EFIAPI
XenBusDxeDriverBindingStop (
IN EFI_DRIVER_BINDING_PROTOCOL *This,
IN EFI_HANDLE ControllerHandle,
IN UINTN NumberOfChildren,
IN EFI_HANDLE *ChildHandleBuffer OPTIONAL
)
{
UINTN Index;
XENBUS_PROTOCOL *XenBusIo;
XENBUS_PRIVATE_DATA *ChildData;
EFI_STATUS Status;
XENBUS_DEVICE *Dev = mMyDevice;
for (Index = 0; Index < NumberOfChildren; Index++) {
Status = gBS->OpenProtocol (
ChildHandleBuffer[Index],
&gXenBusProtocolGuid,
(VOID **) &XenBusIo,
This->DriverBindingHandle,
ControllerHandle,
EFI_OPEN_PROTOCOL_GET_PROTOCOL);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_ERROR, "XenBusDxe: get children protocol failed: %r\n", Status));
continue;
}
ChildData = XENBUS_PRIVATE_DATA_FROM_THIS (XenBusIo);
Status = gBS->DisconnectController (ChildData->Handle, NULL, NULL);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_ERROR, "XenBusDxe: error disconnecting child: %r\n",
Status));
continue;
}
Status = gBS->UninstallMultipleProtocolInterfaces (
ChildData->Handle,
&gEfiDevicePathProtocolGuid, ChildData->DevicePath,
&gXenBusProtocolGuid, &ChildData->XenBusIo,
NULL);
ASSERT_EFI_ERROR (Status);
FreePool ((VOID*)ChildData->XenBusIo.Type);
FreePool ((VOID*)ChildData->XenBusIo.Node);
FreePool ((VOID*)ChildData->XenBusIo.Backend);
FreePool (ChildData->DevicePath);
RemoveEntryList (&ChildData->Link);
FreePool (ChildData);
}
if (NumberOfChildren > 0) {
return EFI_SUCCESS;
}
gBS->CloseEvent (Dev->ExitBootEvent);
XenStoreDeinit (Dev);
XenGrantTableDeinit (Dev);
gBS->CloseProtocol (ControllerHandle, &gEfiDevicePathProtocolGuid,
This->DriverBindingHandle, ControllerHandle);
gBS->CloseProtocol (ControllerHandle, &gXenIoProtocolGuid,
This->DriverBindingHandle, ControllerHandle);
mMyDevice = NULL;
FreePool (Dev);
return EFI_SUCCESS;
}