MdeModulePkg/NvmExpressPei: Avoid updating the module-level variable

This commit is out of the scope for BZ-1409. The commit will remove the
call of RegisterForShadow() at the entry point of the driver. By doing so,
the driver is now possible to be executed without being re-loaded into
permanent memory.

Thus, this commit will update the NvmExpressPei driver to avoid updating
the content of a global variable.

Cc: Jian J Wang <jian.j.wang@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>

MdeModulePkg/Bus/Pci/NvmExpressPei/DmaMem.c

@@ -1,7 +1,7 @@
 /** @file
   The DMA memory help function.
 
-  Copyright (c) 2018, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2018 - 2019, Intel Corporation. All rights reserved.<BR>
 
   This program and the accompanying materials
   are licensed and made available under the terms and conditions
@@ -16,7 +16,33 @@
 
 #include "NvmExpressPei.h"
 
-EDKII_IOMMU_PPI  *mIoMmu;
+/**
+  Get IOMMU PPI.
+
+  @return Pointer to IOMMU PPI.
+
+**/
+EDKII_IOMMU_PPI *
+GetIoMmu (
+  VOID
+  )
+{
+  EFI_STATUS         Status;
+  EDKII_IOMMU_PPI    *IoMmu;
+
+  IoMmu  = NULL;
+  Status = PeiServicesLocatePpi (
+             &gEdkiiIoMmuPpiGuid,
+             0,
+             NULL,
+             (VOID **) &IoMmu
+             );
+  if (!EFI_ERROR (Status) && (IoMmu != NULL)) {
+    return IoMmu;
+  }
+
+  return NULL;
+}
 
 /**
   Provides the controller-specific addresses required to access system memory from a
@@ -46,18 +72,21 @@ IoMmuMap (
   OUT VOID                  **Mapping
   )
 {
-  EFI_STATUS  Status;
+  EFI_STATUS         Status;
-  UINT64      Attribute;
+  UINT64             Attribute;
+  EDKII_IOMMU_PPI    *IoMmu;
 
-  if (mIoMmu != NULL) {
+  IoMmu = GetIoMmu ();
-    Status = mIoMmu->Map (
+
-                       mIoMmu,
+  if (IoMmu != NULL) {
-                       Operation,
+    Status = IoMmu->Map (
-                       HostAddress,
+                     IoMmu,
-                       NumberOfBytes,
+                     Operation,
-                       DeviceAddress,
+                     HostAddress,
-                       Mapping
+                     NumberOfBytes,
-                       );
+                     DeviceAddress,
+                     Mapping
+                     );
     if (EFI_ERROR (Status)) {
       return EFI_OUT_OF_RESOURCES;
     }
@@ -78,11 +107,11 @@ IoMmuMap (
       ASSERT(FALSE);
       return EFI_INVALID_PARAMETER;
     }
-    Status = mIoMmu->SetAttribute (
+    Status = IoMmu->SetAttribute (
-                       mIoMmu,
+                      IoMmu,
-                       *Mapping,
+                      *Mapping,
-                       Attribute
+                      Attribute
-                       );
+                      );
     if (EFI_ERROR (Status)) {
       return Status;
     }
@@ -108,11 +137,14 @@ IoMmuUnmap (
   IN VOID                  *Mapping
   )
 {
-  EFI_STATUS  Status;
+  EFI_STATUS         Status;
+  EDKII_IOMMU_PPI    *IoMmu;
 
-  if (mIoMmu != NULL) {
+  IoMmu = GetIoMmu ();
-    Status = mIoMmu->SetAttribute (mIoMmu, Mapping, 0);
+
-    Status = mIoMmu->Unmap (mIoMmu, Mapping);
+  if (IoMmu != NULL) {
+    Status = IoMmu->SetAttribute (IoMmu, Mapping, 0);
+    Status = IoMmu->Unmap (IoMmu, Mapping);
   } else {
     Status = EFI_SUCCESS;
   }
@@ -148,39 +180,42 @@ IoMmuAllocateBuffer (
   EFI_STATUS            Status;
   UINTN                 NumberOfBytes;
   EFI_PHYSICAL_ADDRESS  HostPhyAddress;
+  EDKII_IOMMU_PPI       *IoMmu;
 
   *HostAddress = NULL;
   *DeviceAddress = 0;
 
-  if (mIoMmu != NULL) {
+  IoMmu = GetIoMmu ();
-    Status = mIoMmu->AllocateBuffer (
+
-                       mIoMmu,
+  if (IoMmu != NULL) {
-                       EfiBootServicesData,
+    Status = IoMmu->AllocateBuffer (
-                       Pages,
+                      IoMmu,
-                       HostAddress,
+                      EfiBootServicesData,
-                       0
+                      Pages,
-                       );
+                      HostAddress,
+                      0
+                      );
     if (EFI_ERROR (Status)) {
       return EFI_OUT_OF_RESOURCES;
     }
 
     NumberOfBytes = EFI_PAGES_TO_SIZE(Pages);
-    Status = mIoMmu->Map (
+    Status = IoMmu->Map (
-                       mIoMmu,
+                      IoMmu,
-                       EdkiiIoMmuOperationBusMasterCommonBuffer,
+                      EdkiiIoMmuOperationBusMasterCommonBuffer,
-                       *HostAddress,
+                      *HostAddress,
-                       &NumberOfBytes,
+                      &NumberOfBytes,
-                       DeviceAddress,
+                      DeviceAddress,
-                       Mapping
+                      Mapping
-                       );
+                      );
     if (EFI_ERROR (Status)) {
       return EFI_OUT_OF_RESOURCES;
     }
-    Status = mIoMmu->SetAttribute (
+    Status = IoMmu->SetAttribute (
-                       mIoMmu,
+                      IoMmu,
-                       *Mapping,
+                      *Mapping,
-                       EDKII_IOMMU_ACCESS_READ | EDKII_IOMMU_ACCESS_WRITE
+                      EDKII_IOMMU_ACCESS_READ | EDKII_IOMMU_ACCESS_WRITE
-                       );
+                      );
     if (EFI_ERROR (Status)) {
       return Status;
     }
@@ -219,31 +254,17 @@ IoMmuFreeBuffer (
   IN VOID                   *Mapping
   )
 {
-  EFI_STATUS  Status;
+  EFI_STATUS         Status;
+  EDKII_IOMMU_PPI    *IoMmu;
 
-  if (mIoMmu != NULL) {
+  IoMmu = GetIoMmu ();
-    Status = mIoMmu->SetAttribute (mIoMmu, Mapping, 0);
+
-    Status = mIoMmu->Unmap (mIoMmu, Mapping);
+  if (IoMmu != NULL) {
-    Status = mIoMmu->FreeBuffer (mIoMmu, Pages, HostAddress);
+    Status = IoMmu->SetAttribute (IoMmu, Mapping, 0);
+    Status = IoMmu->Unmap (IoMmu, Mapping);
+    Status = IoMmu->FreeBuffer (IoMmu, Pages, HostAddress);
   } else {
     Status = EFI_SUCCESS;
   }
   return Status;
 }
-
-/**
-  Initialize IOMMU.
-**/
-VOID
-IoMmuInit (
-  VOID
-  )
-{
-  PeiServicesLocatePpi (
-    &gEdkiiIoMmuPpiGuid,
-    0,
-    NULL,
-    (VOID **)&mIoMmu
-    );
-}
-

MdeModulePkg/Bus/Pci/NvmExpressPei/NvmExpressPei.c

@@ -2,7 +2,7 @@
   The NvmExpressPei driver is used to manage non-volatile memory subsystem
   which follows NVM Express specification at PEI phase.
 
-  Copyright (c) 2018, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2018 - 2019, Intel Corporation. All rights reserved.<BR>
 
   This program and the accompanying materials
   are licensed and made available under the terms and conditions
@@ -214,13 +214,6 @@ NvmExpressPeimEntry (
   PEI_NVME_CONTROLLER_PRIVATE_DATA         *Private;
   EFI_PHYSICAL_ADDRESS                     DeviceAddress;
 
-  //
-  // Shadow this PEIM to run from memory
-  //
-  if (!EFI_ERROR (PeiServicesRegisterForShadow (FileHandle))) {
-    return EFI_SUCCESS;
-  }
-
   //
   // Locate the NVME host controller PPI
   //
@@ -235,8 +228,6 @@ NvmExpressPeimEntry (
     return EFI_UNSUPPORTED;
   }
 
-  IoMmuInit ();
-
   Controller = 0;
   MmioBase   = 0;
   while (TRUE) {

MdeModulePkg/Bus/Pci/NvmExpressPei/NvmExpressPei.h

@@ -2,7 +2,7 @@
   The NvmExpressPei driver is used to manage non-volatile memory subsystem
   which follows NVM Express specification at PEI phase.
 
-  Copyright (c) 2018, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2018 - 2019, Intel Corporation. All rights reserved.<BR>
 
   This program and the accompanying materials
   are licensed and made available under the terms and conditions
@@ -147,13 +147,9 @@ struct _PEI_NVME_CONTROLLER_PRIVATE_DATA {
   CR (a, PEI_NVME_CONTROLLER_PRIVATE_DATA, EndOfPeiNotifyList, NVME_PEI_CONTROLLER_PRIVATE_DATA_SIGNATURE)
 
 
-/**
+//
-  Initialize IOMMU.
+// Internal functions
-**/
+//
-VOID
-IoMmuInit (
-  VOID
-  );
 
 /**
   Allocates pages that are suitable for an OperationBusMasterCommonBuffer or