/** @file XenBus Bus driver implementation. 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: SPDX-License-Identifier: MIT **/ #include #include "XenBus.h" #include "GrantTable.h" #include "XenStore.h" #include "EventChannel.h" #include 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 ((DEBUG_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 ((DEBUG_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 ((DEBUG_ERROR, "open by child controller fail (%r)\n", Status)); goto ErrorOpenProtocolByChild; } } else { DEBUG ((DEBUG_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 ((DEBUG_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 ((DEBUG_ERROR, "XenBus: failed to write new state\n")); goto Out; } DEBUG ((DEBUG_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 };