From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Date: Fri, 9 Sep 2016 08:01:56 +0000 (+0100)
Subject: ArmPkg/ArmMmuLib: base page table VA size on GCD memory map size
X-Git-Tag: edk2-stable201903~5783
X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=commitdiff_plain;h=dd82465a9f0f0beff0e4d74c6e3192b966853332

ArmPkg/ArmMmuLib: base page table VA size on GCD memory map size

As reported by Eugene, the practice of sizing the address space in the
virtual memory system based on the maximum address in the table passed
to ArmConfigureMmu() is problematic, since it fails to take into account
the fact that the GCD memory space may be extended at a later time, both
for memory and for MMIO. So instead, choose the VA size identical to the
GCD memory map size, which is based on PcdPrePiCpuMemorySize on ARM
systems.

Reported-by: Eugene Cohen <eugene@hp.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Eugene Cohen <eugene@hp.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
---

diff --git a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
index 57e789f68b..1fb3bbec63 100644
--- a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
+++ b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
@@ -555,9 +555,7 @@ ArmConfigureMmu (
   VOID*                         TranslationTable;
   VOID*                         TranslationTableBuffer;
   UINT32                        TranslationTableAttribute;
-  ARM_MEMORY_REGION_DESCRIPTOR *MemoryTableEntry;
   UINT64                        MaxAddress;
-  UINT64                        TopAddress;
   UINTN                         T0SZ;
   UINTN                         RootTableEntryCount;
   UINTN                         RootTableEntrySize;
@@ -569,16 +567,8 @@ ArmConfigureMmu (
     return RETURN_INVALID_PARAMETER;
   }
 
-  // Identify the highest address of the memory table
-  MaxAddress = MemoryTable->PhysicalBase + MemoryTable->Length - 1;
-  MemoryTableEntry = MemoryTable;
-  while (MemoryTableEntry->Length != 0) {
-    TopAddress = MemoryTableEntry->PhysicalBase + MemoryTableEntry->Length - 1;
-    if (TopAddress > MaxAddress) {
-      MaxAddress = TopAddress;
-    }
-    MemoryTableEntry++;
-  }
+  // Cover the entire GCD memory space
+  MaxAddress = (1UL << PcdGet8 (PcdPrePiCpuMemorySize)) - 1;
 
   // Lookup the Table Level to get the information
   LookupAddresstoRootTable (MaxAddress, &T0SZ, &RootTableEntryCount);
diff --git a/ArmPkg/Library/ArmMmuLib/ArmMmuBaseLib.inf b/ArmPkg/Library/ArmMmuLib/ArmMmuBaseLib.inf
index 1533c2944e..b9f264de8d 100644
--- a/ArmPkg/Library/ArmMmuLib/ArmMmuBaseLib.inf
+++ b/ArmPkg/Library/ArmMmuLib/ArmMmuBaseLib.inf
@@ -32,6 +32,7 @@
 
 [Packages]
   ArmPkg/ArmPkg.dec
+  EmbeddedPkg/EmbeddedPkg.dec
   MdePkg/MdePkg.dec
 
 [LibraryClasses]
@@ -39,5 +40,8 @@
   CacheMaintenanceLib
   MemoryAllocationLib
 
+[Pcd.AARCH64]
+  gEmbeddedTokenSpaceGuid.PcdPrePiCpuMemorySize
+
 [Pcd.ARM]
   gArmTokenSpaceGuid.PcdNormalMemoryNonshareableOverride
diff --git a/ArmPkg/Library/ArmMmuLib/ArmMmuPeiLib.inf b/ArmPkg/Library/ArmMmuLib/ArmMmuPeiLib.inf
index 14ebf8de67..ecf13f7907 100644
--- a/ArmPkg/Library/ArmMmuLib/ArmMmuPeiLib.inf
+++ b/ArmPkg/Library/ArmMmuLib/ArmMmuPeiLib.inf
@@ -28,9 +28,13 @@
 
 [Packages]
   ArmPkg/ArmPkg.dec
+  EmbeddedPkg/EmbeddedPkg.dec
   MdePkg/MdePkg.dec
 
 [LibraryClasses]
   ArmLib
   CacheMaintenanceLib
   MemoryAllocationLib
+
+[Pcd.AARCH64]
+  gEmbeddedTokenSpaceGuid.PcdPrePiCpuMemorySize