/** @file
XenBus Bus driver implemtation.
This file implement the necessary to discover and enumerate Xen PV devices
through XenStore.
Copyright (C) 2010 Spectra Logic Corporation
Copyright (C) 2008 Doug Rabson
Copyright (C) 2005 Rusty Russell, IBM Corporation
Copyright (C) 2005 Mike Wray, Hewlett-Packard
Copyright (C) 2005 XenSource Ltd
Copyright (C) 2014, Citrix Ltd.
This file may be distributed separately from the Linux kernel, or
incorporated into other software packages, subject to the following license:
Permission is hereby granted, free of charge, to any person obtaining a copy
of this source file (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use, copy, modify,
merge, publish, distribute, sublicense, and/or sell copies of the Software,
and to permit persons to whom the Software is furnished to do so, subject to
the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
IN THE SOFTWARE.
**/
#include <Library/PrintLib.h>
#include "XenBus.h"
#include "GrantTable.h"
#include "XenStore.h"
#include "EventChannel.h"
#include <IndustryStandard/Xen/io/xenbus.h>
STATIC XENBUS_PRIVATE_DATA gXenBusPrivateData;
STATIC XENBUS_DEVICE_PATH gXenBusDevicePathTemplate = {
{ // Vendor
{ // Vendor.Header
HARDWARE_DEVICE_PATH, // Vendor.Header.Type
HW_VENDOR_DP, // Vendor.Header.SubType
{
(UINT8) (sizeof (XENBUS_DEVICE_PATH)), // Vendor.Header.Length[0]
(UINT8) (sizeof (XENBUS_DEVICE_PATH) >> 8), // Vendor.Header.Length[1]
}
},
XENBUS_PROTOCOL_GUID, // Vendor.Guid
},
0, // Type
0 // DeviceId
};
/**
Search our internal record of configured devices (not the XenStore) to
determine if the XenBus device indicated by Node is known to the system.
@param Dev The XENBUS_DEVICE instance to search for device children.
@param Node The XenStore node path for the device to find.
@return The XENBUS_PRIVATE_DATA of the found device if any, or NULL.
*/
STATIC
XENBUS_PRIVATE_DATA *
XenBusDeviceInitialized (
IN XENBUS_DEVICE *Dev,
IN CONST CHAR8 *Node
)
{
LIST_ENTRY *Entry;
XENBUS_PRIVATE_DATA *Child;
XENBUS_PRIVATE_DATA *Result;
if (IsListEmpty (&Dev->ChildList)) {
return NULL;
}
Result = NULL;
for (Entry = GetFirstNode (&Dev->ChildList);
!IsNodeAtEnd (&Dev->ChildList, Entry);
Entry = GetNextNode (&Dev->ChildList, Entry)) {
Child = XENBUS_PRIVATE_DATA_FROM_LINK (Entry);
if (!AsciiStrCmp (Child->XenBusIo.Node, Node)) {
Result = Child;
break;
}
}
return (Result);
}
STATIC
XenbusState
XenBusReadDriverState (
IN CONST CHAR8 *Path
)
{
XenbusState State;
CHAR8 *Ptr = NULL;
XENSTORE_STATUS Status;
Status = XenStoreRead (XST_NIL, Path, "state", NULL, (VOID **)&Ptr);
if (Status != XENSTORE_STATUS_SUCCESS) {
State = XenbusStateClosed;
} else {
State = AsciiStrDecimalToUintn (Ptr);
}
if (Ptr != NULL) {
FreePool (Ptr);
}
return State;
}
//
// Callers should ensure that they are only one calling XenBusAddDevice.
//
STATIC
EFI_STATUS
XenBusAddDevice (
XENBUS_DEVICE *Dev,
CONST CHAR8 *Type,
CONST CHAR8 *Id)
{
CHAR8 DevicePath[XENSTORE_ABS_PATH_MAX];
XENSTORE_STATUS StatusXenStore;
XENBUS_PRIVATE_DATA *Private;
EFI_STATUS Status;
XENBUS_DEVICE_PATH *TempXenBusPath;
VOID *ChildXenIo;
AsciiSPrint (DevicePath, sizeof (DevicePath),
"device/%a/%a", Type, Id);
if (XenStorePathExists (XST_NIL, DevicePath, "")) {
XENBUS_PRIVATE_DATA *Child;
enum xenbus_state State;
CHAR8 *BackendPath;
Child = XenBusDeviceInitialized (Dev, DevicePath);
if (Child != NULL) {
/*
* We are already tracking this node
*/
Status = EFI_SUCCESS;
goto out;
}
State = XenBusReadDriverState (DevicePath);
if (State != XenbusStateInitialising) {
/*
* Device is not new, so ignore it. This can
* happen if a device is going away after
* switching to Closed.
*/
DEBUG ((EFI_D_INFO, "XenBus: Device %a ignored. "
"State %d\n", DevicePath, State));
Status = EFI_SUCCESS;
goto out;
}
StatusXenStore = XenStoreRead (XST_NIL, DevicePath, "backend",
NULL, (VOID **) &BackendPath);
if (StatusXenStore != XENSTORE_STATUS_SUCCESS) {
DEBUG ((EFI_D_ERROR, "xenbus: %a no backend path.\n", DevicePath));
Status = EFI_NOT_FOUND;
goto out;
}
Private = AllocateCopyPool (sizeof (*Private), &gXenBusPrivateData);
Private->XenBusIo.Type = AsciiStrDup (Type);
Private->XenBusIo.Node = AsciiStrDup (DevicePath);
Private->XenBusIo.Backend = BackendPath;
Private->XenBusIo.DeviceId = (UINT16)AsciiStrDecimalToUintn (Id);
Private->Dev = Dev;
TempXenBusPath = AllocateCopyPool (sizeof (XENBUS_DEVICE_PATH),
&gXenBusDevicePathTemplate);
if (!AsciiStrCmp (Private->XenBusIo.Type, "vbd")) {
TempXenBusPath->Type = XENBUS_DEVICE_PATH_TYPE_VBD;
}
TempXenBusPath->DeviceId = Private->XenBusIo.DeviceId;
Private->DevicePath = (XENBUS_DEVICE_PATH *)AppendDevicePathNode (
Dev->DevicePath,
&TempXenBusPath->Vendor.Header);
FreePool (TempXenBusPath);
InsertTailList (&Dev->ChildList, &Private->Link);
Status = gBS->InstallMultipleProtocolInterfaces (
&Private->Handle,
&gEfiDevicePathProtocolGuid, Private->DevicePath,
&gXenBusProtocolGuid, &Private->XenBusIo,
NULL);
if (EFI_ERROR (Status)) {
goto ErrorInstallProtocol;
}
Status = gBS->OpenProtocol (Dev->ControllerHandle,
&gXenIoProtocolGuid,
&ChildXenIo, Dev->This->DriverBindingHandle,
Private->Handle,
EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_ERROR, "open by child controller fail (%r)\n",
Status));
goto ErrorOpenProtocolByChild;
}
} else {
DEBUG ((EFI_D_ERROR, "XenBus: does not exist: %a\n", DevicePath));
Status = EFI_NOT_FOUND;
}
return Status;
ErrorOpenProtocolByChild:
gBS->UninstallMultipleProtocolInterfaces (
&Private->Handle,
&gEfiDevicePathProtocolGuid, Private->DevicePath,
&gXenBusProtocolGuid, &Private->XenBusIo,
NULL);
ErrorInstallProtocol:
RemoveEntryList (&Private->Link);
FreePool (Private->DevicePath);
FreePool ((VOID *) Private->XenBusIo.Backend);
FreePool ((VOID *) Private->XenBusIo.Node);
FreePool ((VOID *) Private->XenBusIo.Type);
FreePool (Private);
out:
return Status;
}
/**
Enumerate all devices of the given type on this bus.
@param Dev A XENBUS_DEVICE instance.
@param Type String indicating the device sub-tree (e.g. "vfb", "vif")
to enumerate.
Devices that are found are been initialize via XenBusAddDevice ().
XenBusAddDevice () ignores duplicate detects and ignores duplicate devices,
so it can be called unconditionally for any device found in the XenStore.
*/
STATIC
VOID
XenBusEnumerateDeviceType (
XENBUS_DEVICE *Dev,
CONST CHAR8 *Type
)
{
CONST CHAR8 **Directory;
UINTN Index;
UINT32 Count;
XENSTORE_STATUS Status;
Status = XenStoreListDirectory (XST_NIL,
"device", Type,
&Count, &Directory);
if (Status != XENSTORE_STATUS_SUCCESS) {
return;
}
for (Index = 0; Index < Count; Index++) {
XenBusAddDevice (Dev, Type, Directory[Index]);
}
FreePool ((VOID*)Directory);
}
/**
Enumerate the devices on a XenBus bus and install a XenBus Protocol instance.
Caller should ensure that it is the only one to call this function. This
function cannot be called concurrently.
@param Dev A XENBUS_DEVICE instance.
@return On success, XENSTORE_STATUS_SUCCESS. Otherwise an errno value
indicating the type of failure.
*/
XENSTORE_STATUS
XenBusEnumerateBus (
XENBUS_DEVICE *Dev
)
{
CONST CHAR8 **Types;
UINTN Index;
UINT32 Count;
XENSTORE_STATUS Status;
Status = XenStoreListDirectory (XST_NIL,
"device", "",
&Count, &Types);
if (Status != XENSTORE_STATUS_SUCCESS) {
return Status;
}
for (Index = 0; Index < Count; Index++) {
XenBusEnumerateDeviceType (Dev, Types[Index]);
}
FreePool ((VOID*)Types);
return XENSTORE_STATUS_SUCCESS;
}
STATIC
XENSTORE_STATUS
EFIAPI
XenBusSetState (
IN XENBUS_PROTOCOL *This,
IN CONST XENSTORE_TRANSACTION *Transaction,
IN enum xenbus_state NewState
)
{
enum xenbus_state CurrentState;
XENSTORE_STATUS Status;
CHAR8 *Temp;
DEBUG ((EFI_D_INFO, "XenBus: Set state to %d\n", NewState));
Status = XenStoreRead (Transaction, This->Node, "state", NULL, (VOID **)&Temp);
if (Status != XENSTORE_STATUS_SUCCESS) {
goto Out;
}
CurrentState = AsciiStrDecimalToUintn (Temp);
FreePool (Temp);
if (CurrentState == NewState) {
goto Out;
}
do {
Status = XenStoreSPrint (Transaction, This->Node, "state", "%d", NewState);
} while (Status == XENSTORE_STATUS_EAGAIN);
if (Status != XENSTORE_STATUS_SUCCESS) {
DEBUG ((EFI_D_ERROR, "XenBus: failed to write new state\n"));
goto Out;
}
DEBUG ((EFI_D_INFO, "XenBus: Set state to %d, done\n", NewState));
Out:
return Status;
}
STATIC XENBUS_PRIVATE_DATA gXenBusPrivateData = {
XENBUS_PRIVATE_DATA_SIGNATURE, // Signature
{ NULL, NULL }, // Link
NULL, // Handle
{ // XenBusIo
XenBusXenStoreRead, // XenBusIo.XsRead
XenBusXenStoreBackendRead, // XenBusIo.XsBackendRead
XenBusXenStoreSPrint, // XenBusIo.XsPrintf
XenBusXenStoreRemove, // XenBusIo.XsRemove
XenBusXenStoreTransactionStart, // XenBusIo.XsTransactionStart
XenBusXenStoreTransactionEnd, // XenBusIo.XsTransactionEnd
XenBusSetState, // XenBusIo.SetState
XenBusGrantAccess, // XenBusIo.GrantAccess
XenBusGrantEndAccess, // XenBusIo.GrantEndAccess
XenBusEventChannelAllocate, // XenBusIo.EventChannelAllocate
XenBusEventChannelNotify, // XenBusIo.EventChannelNotify
XenBusEventChannelClose, // XenBusIo.EventChannelClose
XenBusRegisterWatch, // XenBusIo.RegisterWatch
XenBusRegisterWatchBackend, // XenBusIo.RegisterWatchBackend
XenBusUnregisterWatch, // XenBusIo.UnregisterWatch
XenBusWaitForWatch, // XenBusIo.WaitForWatch
NULL, // XenBusIo.Type
0, // XenBusIo.DeviceId
NULL, // XenBusIo.Node
NULL, // XenBusIo.Backend
},
NULL, // Dev
NULL // DevicePath
};