system76-edk2/MdeModulePkg/Core/Dxe/Hand/Notify.c

/** @file
  Support functions for UEFI protocol notification infrastructure.

Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
(C) Copyright 2015 Hewlett Packard Enterprise Development LP<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include "DxeMain.h"
#include "Handle.h"
#include "Event.h"

/**
  Signal event for every protocol in protocol entry.

  @param  ProtEntry              Protocol entry

**/
VOID
CoreNotifyProtocolEntry (
  IN PROTOCOL_ENTRY  *ProtEntry
  )
{
  PROTOCOL_NOTIFY  *ProtNotify;
  LIST_ENTRY       *Link;

  ASSERT_LOCKED (&gProtocolDatabaseLock);

  for (Link = ProtEntry->Notify.ForwardLink; Link != &ProtEntry->Notify; Link = Link->ForwardLink) {
    ProtNotify = CR (Link, PROTOCOL_NOTIFY, Link, PROTOCOL_NOTIFY_SIGNATURE);
    CoreSignalEvent (ProtNotify->Event);
  }
}

/**
  Removes Protocol from the protocol list (but not the handle list).

  @param  Handle                 The handle to remove protocol on.
  @param  Protocol               GUID of the protocol to be moved
  @param  Interface              The interface of the protocol

  @return Protocol Entry

**/
PROTOCOL_INTERFACE *
CoreRemoveInterfaceFromProtocol (
  IN IHANDLE   *Handle,
  IN EFI_GUID  *Protocol,
  IN VOID      *Interface
  )
{
  PROTOCOL_INTERFACE  *Prot;
  PROTOCOL_NOTIFY     *ProtNotify;
  PROTOCOL_ENTRY      *ProtEntry;
  LIST_ENTRY          *Link;

  ASSERT_LOCKED (&gProtocolDatabaseLock);

  Prot = CoreFindProtocolInterface (Handle, Protocol, Interface);
  if (Prot != NULL) {
    ProtEntry = Prot->Protocol;

    //
    // If there's a protocol notify location pointing to this entry, back it up one
    //
    for (Link = ProtEntry->Notify.ForwardLink; Link != &ProtEntry->Notify; Link = Link->ForwardLink) {
      ProtNotify = CR (Link, PROTOCOL_NOTIFY, Link, PROTOCOL_NOTIFY_SIGNATURE);

      if (ProtNotify->Position == &Prot->ByProtocol) {
        ProtNotify->Position = Prot->ByProtocol.BackLink;
      }
    }

    //
    // Remove the protocol interface entry
    //
    RemoveEntryList (&Prot->ByProtocol);
  }

  return Prot;
}

/**
  Add a new protocol notification record for the request protocol.

  @param  Protocol               The requested protocol to add the notify
                                 registration
  @param  Event                  The event to signal
  @param  Registration           Returns the registration record

  @retval EFI_INVALID_PARAMETER  Invalid parameter
  @retval EFI_SUCCESS            Successfully returned the registration record
                                 that has been added

**/
EFI_STATUS
EFIAPI
CoreRegisterProtocolNotify (
  IN EFI_GUID   *Protocol,
  IN EFI_EVENT  Event,
  OUT  VOID     **Registration
  )
{
  PROTOCOL_ENTRY   *ProtEntry;
  PROTOCOL_NOTIFY  *ProtNotify;
  EFI_STATUS       Status;

  if ((Protocol == NULL) || (Event == NULL) || (Registration == NULL)) {
    return EFI_INVALID_PARAMETER;
  }

  CoreAcquireProtocolLock ();

  ProtNotify = NULL;

  //
  // Get the protocol entry to add the notification too
  //

  ProtEntry = CoreFindProtocolEntry (Protocol, TRUE);
  if (ProtEntry != NULL) {
    //
    // Allocate a new notification record
    //
    ProtNotify = AllocatePool (sizeof (PROTOCOL_NOTIFY));
    if (ProtNotify != NULL) {
      ((IEVENT *)Event)->ExFlag |= EVT_EXFLAG_EVENT_PROTOCOL_NOTIFICATION;
      ProtNotify->Signature      = PROTOCOL_NOTIFY_SIGNATURE;
      ProtNotify->Protocol       = ProtEntry;
      ProtNotify->Event          = Event;
      //
      // start at the begining
      //
      ProtNotify->Position = &ProtEntry->Protocols;

      InsertTailList (&ProtEntry->Notify, &ProtNotify->Link);
    }
  }

  CoreReleaseProtocolLock ();

  //
  // Done.  If we have a protocol notify entry, then return it.
  // Otherwise, we must have run out of resources trying to add one
  //

  Status = EFI_OUT_OF_RESOURCES;
  if (ProtNotify != NULL) {
    *Registration = ProtNotify;
    Status        = EFI_SUCCESS;
  }

  return Status;
}

/**
  Reinstall a protocol interface on a device handle.  The OldInterface for Protocol is replaced by the NewInterface.

  @param  UserHandle             Handle on which the interface is to be
                                 reinstalled
  @param  Protocol               The numeric ID of the interface
  @param  OldInterface           A pointer to the old interface
  @param  NewInterface           A pointer to the new interface

  @retval EFI_SUCCESS            The protocol interface was installed
  @retval EFI_NOT_FOUND          The OldInterface on the handle was not found
  @retval EFI_INVALID_PARAMETER  One of the parameters has an invalid value

**/
EFI_STATUS
EFIAPI
CoreReinstallProtocolInterface (
  IN EFI_HANDLE  UserHandle,
  IN EFI_GUID    *Protocol,
  IN VOID        *OldInterface,
  IN VOID        *NewInterface
  )
{
  EFI_STATUS          Status;
  IHANDLE             *Handle;
  PROTOCOL_INTERFACE  *Prot;
  PROTOCOL_ENTRY      *ProtEntry;

  if (Protocol == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // Lock the protocol database
  //
  CoreAcquireProtocolLock ();

  Status = CoreValidateHandle (UserHandle);
  if (EFI_ERROR (Status)) {
    goto Done;
  }

  Handle = (IHANDLE *)UserHandle;
  //
  // Check that Protocol exists on UserHandle, and Interface matches the interface in the database
  //
  Prot = CoreFindProtocolInterface (UserHandle, Protocol, OldInterface);
  if (Prot == NULL) {
    Status = EFI_NOT_FOUND;
    goto Done;
  }

  //
  // Attempt to disconnect all drivers that are using the protocol interface that is about to be reinstalled
  //
  Status = CoreDisconnectControllersUsingProtocolInterface (
             UserHandle,
             Prot
             );
  if (EFI_ERROR (Status)) {
    //
    // One or more drivers refused to release, so return the error
    //
    goto Done;
  }

  //
  // Remove the protocol interface from the protocol
  //
  Prot = CoreRemoveInterfaceFromProtocol (Handle, Protocol, OldInterface);

  if (Prot == NULL) {
    Status = EFI_NOT_FOUND;
    goto Done;
  }

  ProtEntry = Prot->Protocol;

  //
  // Update the interface on the protocol
  //
  Prot->Interface = NewInterface;

  //
  // Add this protocol interface to the tail of the
  // protocol entry
  //
  InsertTailList (&ProtEntry->Protocols, &Prot->ByProtocol);

  //
  // Update the Key to show that the handle has been created/modified
  //
  gHandleDatabaseKey++;
  Handle->Key = gHandleDatabaseKey;

  //
  // Release the lock and connect all drivers to UserHandle
  //
  CoreReleaseProtocolLock ();
  //
  // Return code is ignored on purpose.
  //
  CoreConnectController (
    UserHandle,
    NULL,
    NULL,
    TRUE
    );
  CoreAcquireProtocolLock ();

  //
  // Notify the notification list for this protocol
  //
  CoreNotifyProtocolEntry (ProtEntry);

  Status = EFI_SUCCESS;

Done:
  CoreReleaseProtocolLock ();

  return Status;
}