MdeModulePkg/Library: make ArmFfaPeiLib available early PEIM stage

commit 26fb5edff3
("MdeModulePkg/ArmFfaLib: Add depex on gEfiPeiMemoryDiscoveredPpiGuid")
restricts ArmFfaPeiLib usage only after PEI phase can be used
permanent memory. However, This would be problem for PEIM
which runs before gEfiPeiMemoryDiscoveredPpiGuid Ppi installed.
(i.e) Tcg2Pei PEIM.

To resolve this, remove dependency on gEfiPeiMemoryDiscoveredPpiGuid
and let ArmFfaPeiLib remap the Rx/Tx buffer after
gEfiPeiMemoryDiscoveredPpiGuid is installed so that ArmFfaPeiLib can be
used with temporary memory.

Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Fixes: 26fb5edff3 ("MdeModulePkg/ArmFfaLib: ...")

MdeModulePkg/Library/ArmFfaLib/ArmFfaPeiLib.c

@@ -34,6 +34,89 @@
 #include "ArmFfaCommon.h"
 #include "ArmFfaRxTxMap.h"
 
+/**
+  Update Rx/TX buffer information.
+
+  @param  BufferInfo            Rx/Tx buffer information.
+
+**/
+STATIC
+VOID
+EFIAPI
+UpdateRxTxBufferInfo (
+  OUT ARM_FFA_RX_TX_BUFFER_INFO  *BufferInfo
+  )
+{
+  BufferInfo->TxBufferAddr = (VOID *)(UINTN)PcdGet64 (PcdFfaTxBuffer);
+  BufferInfo->TxBufferSize = PcdGet64 (PcdFfaTxRxPageCount) * EFI_PAGE_SIZE;
+  BufferInfo->RxBufferAddr = (VOID *)(UINTN)PcdGet64 (PcdFfaRxBuffer);
+  BufferInfo->RxBufferSize = PcdGet64 (PcdFfaTxRxPageCount) * EFI_PAGE_SIZE;
+}
+
+/**
+  Notification service to be called when gEfiPeiMemoryDiscoveredPpiGuid is installed.
+  This function change reamp Rx/Tx buffer with permanent memory from
+  temporary Rx/Tx buffer.
+
+  Since, the Rx/Tx buffer is chanaged after gEfiPeiMemoryDiscoveredPpiGuid is installed,
+  the Rx/Tx buffer should be gotten in each PEIM entrypoint
+  via "ArmFfaGetRxTxBuffers()" for PEIM registered as shadow and
+  call that function always then, it always gets proper Rx/Tx buffer.
+
+  @param  PeiServices                 Indirect reference to the PEI Services Table.
+  @param  NotifyDescriptor            Address of the notification descriptor data structure.
+                                      Type EFI_PEI_NOTIFY_DESCRIPTOR is defined above.
+  @param  Ppi                         Address of the PPI that was installed.
+
+  @retval EFI_STATUS                  This function will install a PPI to PPI database.
+                                      The status code will be the code for (*PeiServices)->InstallPpi.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+PeiServicesMemoryDiscoveredNotifyCallback (
+  IN EFI_PEI_SERVICES           **PeiServices,
+  IN EFI_PEI_NOTIFY_DESCRIPTOR  *NotifyDescriptor,
+  IN VOID                       *Ppi
+  )
+{
+  EFI_STATUS                 Status;
+  EFI_HOB_GUID_TYPE          *RxTxBufferHob;
+  ARM_FFA_RX_TX_BUFFER_INFO  *BufferInfo;
+
+  RxTxBufferHob = GetFirstGuidHob (&gArmFfaRxTxBufferInfoGuid);
+  ASSERT (RxTxBufferHob != NULL);
+  BufferInfo = GET_GUID_HOB_DATA (RxTxBufferHob);
+
+  /*
+   * Temporary memory doesn't need to be free.
+   * otherwise PEI memory manager using permanent memory will be confused.
+   */
+  PcdSet64S (PcdFfaTxBuffer, 0x00);
+  PcdSet64S (PcdFfaRxBuffer, 0x00);
+
+  Status = ArmFfaLibRxTxUnmap ();
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  Status = ArmFfaLibRxTxMap ();
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  UpdateRxTxBufferInfo (BufferInfo);
+
+  return EFI_SUCCESS;
+}
+
+STATIC EFI_PEI_NOTIFY_DESCRIPTOR  mNotifyOnPeiMemoryDiscovered = {
+  (EFI_PEI_PPI_DESCRIPTOR_NOTIFY_CALLBACK | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
+  &gEfiPeiMemoryDiscoveredPpiGuid,
+  PeiServicesMemoryDiscoveredNotifyCallback
+};
+
 /**
   ArmFfaLib Constructor.
 
@@ -54,6 +137,7 @@ ArmFfaPeiLibConstructor (
   EFI_STATUS                 Status;
   EFI_HOB_GUID_TYPE          *RxTxBufferHob;
   ARM_FFA_RX_TX_BUFFER_INFO  *BufferInfo;
+  VOID                       *Dummy;
 
   Status = ArmFfaLibCommonInit ();
   if (EFI_ERROR (Status)) {
@@ -90,10 +174,19 @@ ArmFfaPeiLibConstructor (
       return EFI_OUT_OF_RESOURCES;
     }
 
-    BufferInfo->TxBufferAddr = (VOID *)(UINTN)PcdGet64 (PcdFfaTxBuffer);
-    BufferInfo->TxBufferSize = PcdGet64 (PcdFfaTxRxPageCount) * EFI_PAGE_SIZE;
-    BufferInfo->RxBufferAddr = (VOID *)(UINTN)PcdGet64 (PcdFfaRxBuffer);
-    BufferInfo->RxBufferSize = PcdGet64 (PcdFfaTxRxPageCount) * EFI_PAGE_SIZE;
+    UpdateRxTxBufferInfo (BufferInfo);
+
+    Status = (*PeiServices)->LocatePpi (
+                               PeiServices,
+                               &gEfiPeiMemoryDiscoveredPpiGuid,
+                               0,
+                               NULL,
+                               &Dummy
+                               );
+    if (EFI_ERROR (Status)) {
+      Status = (*PeiServices)->NotifyPpi (PeiServices, &mNotifyOnPeiMemoryDiscovered);
+      ASSERT_EFI_ERROR (Status);
+    }
   }
 
   return EFI_SUCCESS;

MdeModulePkg/Library/ArmFfaLib/ArmFfaPeiLib.inf

@@ -44,5 +44,5 @@
 [Guids]
   gArmFfaRxTxBufferInfoGuid
 
-[Depex]
+[Ppis]
   gEfiPeiMemoryDiscoveredPpiGuid