StandaloneMmPkg/Core/Notify.c

   1 /** @file
   2   Support functions for UEFI protocol notification infrastructure.
   3
   4   Copyright (c) 2009 - 2015, Intel Corporation. All rights reserved.<BR>
   5   Copyright (c) 2016 - 2018, ARM Limited. All rights reserved.<BR>
   6   SPDX-License-Identifier: BSD-2-Clause-Patent
   7
   8 **/
   9
  10 #include "StandaloneMmCore.h"
  11
  12 /**
  13   Signal event for every protocol in protocol entry.
  14
  15   @param  Prot                   Protocol interface
  16
  17 **/
  18 VOID
  19 MmNotifyProtocol (
  20   IN PROTOCOL_INTERFACE  *Prot
  21   )
  22 {
  23   PROTOCOL_ENTRY   *ProtEntry;
  24   PROTOCOL_NOTIFY  *ProtNotify;
  25   LIST_ENTRY       *Link;
  26
  27   ProtEntry = Prot->Protocol;
  28   for (Link = ProtEntry->Notify.ForwardLink; Link != &ProtEntry->Notify; Link = Link->ForwardLink) {
  29     ProtNotify = CR (Link, PROTOCOL_NOTIFY, Link, PROTOCOL_NOTIFY_SIGNATURE);
  30     ProtNotify->Function (&ProtEntry->ProtocolID, Prot->Interface, Prot->Handle);
  31   }
  32 }
  33
  34 /**
  35   Removes Protocol from the protocol list (but not the handle list).
  36
  37   @param  Handle                 The handle to remove protocol on.
  38   @param  Protocol               GUID of the protocol to be moved
  39   @param  Interface              The interface of the protocol
  40
  41   @return Protocol Entry
  42
  43 **/
  44 PROTOCOL_INTERFACE *
  45 MmRemoveInterfaceFromProtocol (
  46   IN IHANDLE   *Handle,
  47   IN EFI_GUID  *Protocol,
  48   IN VOID      *Interface
  49   )
  50 {
  51   PROTOCOL_INTERFACE  *Prot;
  52   PROTOCOL_NOTIFY     *ProtNotify;
  53   PROTOCOL_ENTRY      *ProtEntry;
  54   LIST_ENTRY          *Link;
  55
  56   Prot = MmFindProtocolInterface (Handle, Protocol, Interface);
  57   if (Prot != NULL) {
  58     ProtEntry = Prot->Protocol;
  59
  60     //
  61     // If there's a protocol notify location pointing to this entry, back it up one
  62     //
  63     for (Link = ProtEntry->Notify.ForwardLink; Link != &ProtEntry->Notify; Link = Link->ForwardLink) {
  64       ProtNotify = CR (Link, PROTOCOL_NOTIFY, Link, PROTOCOL_NOTIFY_SIGNATURE);
  65
  66       if (ProtNotify->Position == &Prot->ByProtocol) {
  67         ProtNotify->Position = Prot->ByProtocol.BackLink;
  68       }
  69     }
  70
  71     //
  72     // Remove the protocol interface entry
  73     //
  74     RemoveEntryList (&Prot->ByProtocol);
  75   }
  76
  77   return Prot;
  78 }
  79
  80 /**
  81   Add a new protocol notification record for the request protocol.
  82
  83   @param  Protocol               The requested protocol to add the notify
  84                                  registration
  85   @param  Function               Points to the notification function
  86   @param  Registration           Returns the registration record
  87
  88   @retval EFI_SUCCESS            Successfully returned the registration record
  89                                  that has been added or unhooked
  90   @retval EFI_INVALID_PARAMETER  Protocol is NULL or Registration is NULL
  91   @retval EFI_OUT_OF_RESOURCES   Not enough memory resource to finish the request
  92   @retval EFI_NOT_FOUND          If the registration is not found when Function == NULL
  93
  94 **/
  95 EFI_STATUS
  96 EFIAPI
  97 MmRegisterProtocolNotify (
  98   IN  CONST EFI_GUID    *Protocol,
  99   IN  EFI_MM_NOTIFY_FN  Function,
 100   OUT VOID              **Registration
 101   )
 102 {
 103   PROTOCOL_ENTRY   *ProtEntry;
 104   PROTOCOL_NOTIFY  *ProtNotify;
 105   LIST_ENTRY       *Link;
 106   EFI_STATUS       Status;
 107
 108   if ((Protocol == NULL) || (Registration == NULL)) {
 109     return EFI_INVALID_PARAMETER;
 110   }
 111
 112   if (Function == NULL) {
 113     //
 114     // Get the protocol entry per Protocol
 115     //
 116     ProtEntry = MmFindProtocolEntry ((EFI_GUID *)Protocol, FALSE);
 117     if (ProtEntry != NULL) {
 118       ProtNotify = (PROTOCOL_NOTIFY *)*Registration;
 119       for (Link = ProtEntry->Notify.ForwardLink;
 120            Link != &ProtEntry->Notify;
 121            Link = Link->ForwardLink)
 122       {
 123         //
 124         // Compare the notification record
 125         //
 126         if (ProtNotify == (CR (Link, PROTOCOL_NOTIFY, Link, PROTOCOL_NOTIFY_SIGNATURE))) {
 127           //
 128           // If Registration is an existing registration, then unhook it
 129           //
 130           ProtNotify->Signature = 0;
 131           RemoveEntryList (&ProtNotify->Link);
 132           FreePool (ProtNotify);
 133           return EFI_SUCCESS;
 134         }
 135       }
 136     }
 137
 138     //
 139     // If the registration is not found
 140     //
 141     return EFI_NOT_FOUND;
 142   }
 143
 144   ProtNotify = NULL;
 145
 146   //
 147   // Get the protocol entry to add the notification too
 148   //
 149   ProtEntry = MmFindProtocolEntry ((EFI_GUID *)Protocol, TRUE);
 150   if (ProtEntry != NULL) {
 151     //
 152     // Find whether notification already exist
 153     //
 154     for (Link = ProtEntry->Notify.ForwardLink;
 155          Link != &ProtEntry->Notify;
 156          Link = Link->ForwardLink)
 157     {
 158       ProtNotify = CR (Link, PROTOCOL_NOTIFY, Link, PROTOCOL_NOTIFY_SIGNATURE);
 159       if (CompareGuid (&ProtNotify->Protocol->ProtocolID, Protocol) &&
 160           (ProtNotify->Function == Function))
 161       {
 162         //
 163         // Notification already exist
 164         //
 165         *Registration = ProtNotify;
 166
 167         return EFI_SUCCESS;
 168       }
 169     }
 170
 171     //
 172     // Allocate a new notification record
 173     //
 174     ProtNotify = AllocatePool (sizeof (PROTOCOL_NOTIFY));
 175     if (ProtNotify != NULL) {
 176       ProtNotify->Signature = PROTOCOL_NOTIFY_SIGNATURE;
 177       ProtNotify->Protocol  = ProtEntry;
 178       ProtNotify->Function  = Function;
 179       //
 180       // Start at the ending
 181       //
 182       ProtNotify->Position = ProtEntry->Protocols.BackLink;
 183
 184       InsertTailList (&ProtEntry->Notify, &ProtNotify->Link);
 185     }
 186   }
 187
 188   //
 189   // Done.  If we have a protocol notify entry, then return it.
 190   // Otherwise, we must have run out of resources trying to add one
 191   //
 192   Status = EFI_OUT_OF_RESOURCES;
 193   if (ProtNotify != NULL) {
 194     *Registration = ProtNotify;
 195     Status        = EFI_SUCCESS;
 196   }
 197
 198   return Status;
 199 }