XenBus.c

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#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
};
 
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;
}
 
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);
}
 
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
};