MdeModulePkg/Core/PiSmmCore/Notify.c

   1 /** @file
   2   Support functions for UEFI protocol notification infrastructure.
   3
   4   Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR>
   5   SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9 #include "PiSmmCore.h"
  10
  11 /**
  12   Signal event for every protocol in protocol entry.
  13
  14   @param  Prot                   Protocol interface
  15
  16 **/
  17 VOID
  18 SmmNotifyProtocol (
  19   IN PROTOCOL_INTERFACE  *Prot
  20   )
  21 {
  22   PROTOCOL_ENTRY   *ProtEntry;
  23   PROTOCOL_NOTIFY  *ProtNotify;
  24   LIST_ENTRY       *Link;
  25
  26   ProtEntry = Prot->Protocol;
  27   for (Link = ProtEntry->Notify.ForwardLink; Link != &ProtEntry->Notify; Link = Link->ForwardLink) {
  28     ProtNotify = CR (Link, PROTOCOL_NOTIFY, Link, PROTOCOL_NOTIFY_SIGNATURE);
  29     ProtNotify->Function (&ProtEntry->ProtocolID, Prot->Interface, Prot->Handle);
  30   }
  31 }
  32
  33 /**
  34   Removes Protocol from the protocol list (but not the handle list).
  35
  36   @param  Handle                 The handle to remove protocol on.
  37   @param  Protocol               GUID of the protocol to be moved
  38   @param  Interface              The interface of the protocol
  39
  40   @return Protocol Entry
  41
  42 **/
  43 PROTOCOL_INTERFACE *
  44 SmmRemoveInterfaceFromProtocol (
  45   IN IHANDLE   *Handle,
  46   IN EFI_GUID  *Protocol,
  47   IN VOID      *Interface
  48   )
  49 {
  50   PROTOCOL_INTERFACE  *Prot;
  51   PROTOCOL_NOTIFY     *ProtNotify;
  52   PROTOCOL_ENTRY      *ProtEntry;
  53   LIST_ENTRY          *Link;
  54
  55   Prot = SmmFindProtocolInterface (Handle, Protocol, Interface);
  56   if (Prot != NULL) {
  57     ProtEntry = Prot->Protocol;
  58
  59     //
  60     // If there's a protocol notify location pointing to this entry, back it up one
  61     //
  62     for (Link = ProtEntry->Notify.ForwardLink; Link != &ProtEntry->Notify; Link = Link->ForwardLink) {
  63       ProtNotify = CR (Link, PROTOCOL_NOTIFY, Link, PROTOCOL_NOTIFY_SIGNATURE);
  64
  65       if (ProtNotify->Position == &Prot->ByProtocol) {
  66         ProtNotify->Position = Prot->ByProtocol.BackLink;
  67       }
  68     }
  69
  70     //
  71     // Remove the protocol interface entry
  72     //
  73     RemoveEntryList (&Prot->ByProtocol);
  74   }
  75
  76   return Prot;
  77 }
  78
  79 /**
  80   Add a new protocol notification record for the request protocol.
  81
  82   @param  Protocol               The requested protocol to add the notify
  83                                  registration
  84   @param  Function               Points to the notification function
  85   @param  Registration           Returns the registration record
  86
  87   @retval EFI_SUCCESS            Successfully returned the registration record
  88                                  that has been added or unhooked
  89   @retval EFI_INVALID_PARAMETER  Protocol is NULL or Registration is NULL
  90   @retval EFI_OUT_OF_RESOURCES   Not enough memory resource to finish the request
  91   @retval EFI_NOT_FOUND          If the registration is not found when Function == NULL
  92
  93 **/
  94 EFI_STATUS
  95 EFIAPI
  96 SmmRegisterProtocolNotify (
  97   IN  CONST EFI_GUID     *Protocol,
  98   IN  EFI_SMM_NOTIFY_FN  Function,
  99   OUT VOID               **Registration
 100   )
 101 {
 102   PROTOCOL_ENTRY   *ProtEntry;
 103   PROTOCOL_NOTIFY  *ProtNotify;
 104   LIST_ENTRY       *Link;
 105   EFI_STATUS       Status;
 106
 107   if ((Protocol == NULL) || (Registration == NULL)) {
 108     return EFI_INVALID_PARAMETER;
 109   }
 110
 111   if (Function == NULL) {
 112     //
 113     // Get the protocol entry per Protocol
 114     //
 115     ProtEntry = SmmFindProtocolEntry ((EFI_GUID *)Protocol, FALSE);
 116     if (ProtEntry != NULL) {
 117       ProtNotify = (PROTOCOL_NOTIFY *)*Registration;
 118       for (Link = ProtEntry->Notify.ForwardLink;
 119            Link != &ProtEntry->Notify;
 120            Link = Link->ForwardLink)
 121       {
 122         //
 123         // Compare the notification record
 124         //
 125         if (ProtNotify == (CR (Link, PROTOCOL_NOTIFY, Link, PROTOCOL_NOTIFY_SIGNATURE))) {
 126           //
 127           // If Registration is an existing registration, then unhook it
 128           //
 129           ProtNotify->Signature = 0;
 130           RemoveEntryList (&ProtNotify->Link);
 131           FreePool (ProtNotify);
 132           return EFI_SUCCESS;
 133         }
 134       }
 135     }
 136
 137     //
 138     // If the registration is not found
 139     //
 140     return EFI_NOT_FOUND;
 141   }
 142
 143   ProtNotify = NULL;
 144
 145   //
 146   // Get the protocol entry to add the notification too
 147   //
 148   ProtEntry = SmmFindProtocolEntry ((EFI_GUID *)Protocol, TRUE);
 149   if (ProtEntry != NULL) {
 150     //
 151     // Find whether notification already exist
 152     //
 153     for (Link = ProtEntry->Notify.ForwardLink;
 154          Link != &ProtEntry->Notify;
 155          Link = Link->ForwardLink)
 156     {
 157       ProtNotify = CR (Link, PROTOCOL_NOTIFY, Link, PROTOCOL_NOTIFY_SIGNATURE);
 158       if (CompareGuid (&ProtNotify->Protocol->ProtocolID, Protocol) &&
 159           (ProtNotify->Function == Function))
 160       {
 161         //
 162         // Notification already exist
 163         //
 164         *Registration = ProtNotify;
 165
 166         return EFI_SUCCESS;
 167       }
 168     }
 169
 170     //
 171     // Allocate a new notification record
 172     //
 173     ProtNotify = AllocatePool (sizeof (PROTOCOL_NOTIFY));
 174     if (ProtNotify != NULL) {
 175       ProtNotify->Signature = PROTOCOL_NOTIFY_SIGNATURE;
 176       ProtNotify->Protocol  = ProtEntry;
 177       ProtNotify->Function  = Function;
 178       //
 179       // Start at the ending
 180       //
 181       ProtNotify->Position = ProtEntry->Protocols.BackLink;
 182
 183       InsertTailList (&ProtEntry->Notify, &ProtNotify->Link);
 184     }
 185   }
 186
 187   //
 188   // Done.  If we have a protocol notify entry, then return it.
 189   // Otherwise, we must have run out of resources trying to add one
 190   //
 191   Status = EFI_OUT_OF_RESOURCES;
 192   if (ProtNotify != NULL) {
 193     *Registration = ProtNotify;
 194     Status        = EFI_SUCCESS;
 195   }
 196
 197   return Status;
 198 }