[PATCH v3 04/16] ArmVirtPkg/QemuVirtMemInfoLib: remove 1:1 mapping of top of PA range

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

Currently, we map DRAM as EFI_MEMORY_WB, and the remainder of the
entire virtual address space is mapped with EFI_MEMORY_UC attributes,
regardless of whether any devices actually reside there.

Now that we are relaxing the address space limit to more than 40 bits,
mapping all that address space actually takes up more space in page
tables than we have so far made available as temporary RAM. So let's
get rid of the mapping rather than increasing the available RAM, given
that the mapping is not particularly useful anyway.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 ArmVirtPkg/Library/QemuVirtMemInfoLib/QemuVirtMemInfoLib.inf    |  7 ----
 ArmVirtPkg/Library/QemuVirtMemInfoLib/QemuVirtMemInfoPeiLib.inf |  7 ----
 ArmVirtPkg/Library/QemuVirtMemInfoLib/QemuVirtMemInfoLib.c      | 25 +++----------
 ArmVirtPkg/Library/QemuVirtMemInfoLib/AArch64/PhysAddrTop.S     | 39 --------------------
 ArmVirtPkg/Library/QemuVirtMemInfoLib/Arm/PhysAddrTop.S         | 24 ------------
 5 files changed, 5 insertions(+), 97 deletions(-)

diff --git a/ArmVirtPkg/Library/QemuVirtMemInfoLib/QemuVirtMemInfoLib.inf b/ArmVirtPkg/Library/QemuVirtMemInfoLib/QemuVirtMemInfoLib.inf
index c72a97f9e78a..5c5b841051ad 100644
--- a/ArmVirtPkg/Library/QemuVirtMemInfoLib/QemuVirtMemInfoLib.inf
+++ b/ArmVirtPkg/Library/QemuVirtMemInfoLib/QemuVirtMemInfoLib.inf
@@ -24,12 +24,6 @@ [Defines]
 [Sources]
   QemuVirtMemInfoLib.c
 
-[Sources.ARM]
-  Arm/PhysAddrTop.S
-
-[Sources.AARCH64]
-  AArch64/PhysAddrTop.S
-
 [Packages]
   ArmPkg/ArmPkg.dec
   ArmVirtPkg/ArmVirtPkg.dec
@@ -51,4 +45,3 @@ [Pcd]
 
 [FixedPcd]
   gArmTokenSpaceGuid.PcdFdSize
-  gEmbeddedTokenSpaceGuid.PcdPrePiCpuMemorySize
diff --git a/ArmVirtPkg/Library/QemuVirtMemInfoLib/QemuVirtMemInfoPeiLib.inf b/ArmVirtPkg/Library/QemuVirtMemInfoLib/QemuVirtMemInfoPeiLib.inf
index e4032d3efb53..d12089760b22 100644
--- a/ArmVirtPkg/Library/QemuVirtMemInfoLib/QemuVirtMemInfoPeiLib.inf
+++ b/ArmVirtPkg/Library/QemuVirtMemInfoLib/QemuVirtMemInfoPeiLib.inf
@@ -26,12 +26,6 @@ [Sources]
   QemuVirtMemInfoLib.c
   QemuVirtMemInfoPeiLibConstructor.c
 
-[Sources.ARM]
-  Arm/PhysAddrTop.S
-
-[Sources.AARCH64]
-  AArch64/PhysAddrTop.S
-
 [Packages]
   ArmPkg/ArmPkg.dec
   ArmVirtPkg/ArmVirtPkg.dec
@@ -55,4 +49,3 @@ [Pcd]
 [FixedPcd]
   gArmTokenSpaceGuid.PcdFdSize
   gArmVirtTokenSpaceGuid.PcdDeviceTreeInitialBaseAddress
-  gEmbeddedTokenSpaceGuid.PcdPrePiCpuMemorySize
diff --git a/ArmVirtPkg/Library/QemuVirtMemInfoLib/QemuVirtMemInfoLib.c b/ArmVirtPkg/Library/QemuVirtMemInfoLib/QemuVirtMemInfoLib.c
index 760bcc169cf4..0285a11b1d77 100644
--- a/ArmVirtPkg/Library/QemuVirtMemInfoLib/QemuVirtMemInfoLib.c
+++ b/ArmVirtPkg/Library/QemuVirtMemInfoLib/QemuVirtMemInfoLib.c
@@ -21,11 +21,6 @@
 // Number of Virtual Memory Map Descriptors
 #define MAX_VIRTUAL_MEMORY_MAP_DESCRIPTORS          5
 
-EFI_PHYSICAL_ADDRESS
-ArmGetPhysAddrTop (
-  VOID
-  );
-
 /**
   Return the Virtual Memory Map of your platform
 
@@ -45,7 +40,6 @@ ArmVirtGetMemoryMap (
   )
 {
   ARM_MEMORY_REGION_DESCRIPTOR  *VirtualMemoryTable;
-  UINT64                        TopOfMemory;
 
   ASSERT (VirtualMemoryMap != NULL);
 
@@ -78,23 +72,14 @@ ArmVirtGetMemoryMap (
   VirtualMemoryTable[1].Length       = VirtualMemoryTable[0].PhysicalBase;
   VirtualMemoryTable[1].Attributes   = ARM_MEMORY_REGION_ATTRIBUTE_DEVICE;
 
-  // Peripheral space after DRAM
-  TopOfMemory = MIN (1ULL << FixedPcdGet8 (PcdPrePiCpuMemorySize),
-                     ArmGetPhysAddrTop ());
-  VirtualMemoryTable[2].PhysicalBase = VirtualMemoryTable[0].Length + VirtualMemoryTable[1].Length;
-  VirtualMemoryTable[2].VirtualBase  = VirtualMemoryTable[2].PhysicalBase;
-  VirtualMemoryTable[2].Length       = TopOfMemory -
-                                       VirtualMemoryTable[2].PhysicalBase;
-  VirtualMemoryTable[2].Attributes   = ARM_MEMORY_REGION_ATTRIBUTE_DEVICE;
-
   // Remap the FD region as normal executable memory
-  VirtualMemoryTable[3].PhysicalBase = PcdGet64 (PcdFdBaseAddress);
-  VirtualMemoryTable[3].VirtualBase  = VirtualMemoryTable[3].PhysicalBase;
-  VirtualMemoryTable[3].Length       = FixedPcdGet32 (PcdFdSize);
-  VirtualMemoryTable[3].Attributes   = ARM_MEMORY_REGION_ATTRIBUTE_WRITE_BACK;
+  VirtualMemoryTable[2].PhysicalBase = PcdGet64 (PcdFdBaseAddress);
+  VirtualMemoryTable[2].VirtualBase  = VirtualMemoryTable[2].PhysicalBase;
+  VirtualMemoryTable[2].Length       = FixedPcdGet32 (PcdFdSize);
+  VirtualMemoryTable[2].Attributes   = ARM_MEMORY_REGION_ATTRIBUTE_WRITE_BACK;
 
   // End of Table
-  ZeroMem (&VirtualMemoryTable[4], sizeof (ARM_MEMORY_REGION_DESCRIPTOR));
+  ZeroMem (&VirtualMemoryTable[3], sizeof (ARM_MEMORY_REGION_DESCRIPTOR));
 
   *VirtualMemoryMap = VirtualMemoryTable;
 }
diff --git a/ArmVirtPkg/Library/QemuVirtMemInfoLib/AArch64/PhysAddrTop.S b/ArmVirtPkg/Library/QemuVirtMemInfoLib/AArch64/PhysAddrTop.S
deleted file mode 100644
index a1f6a194d59b..000000000000
--- a/ArmVirtPkg/Library/QemuVirtMemInfoLib/AArch64/PhysAddrTop.S
+++ /dev/null
@@ -1,39 +0,0 @@
-#
-#  Copyright (c) 2011-2013, ARM Limited. All rights reserved.
-#  Copyright (c) 2016-2017, Linaro Limited. All rights reserved.
-#
-#  This program and the accompanying materials
-#  are licensed and made available under the terms and conditions of the BSD License
-#  which accompanies this distribution.  The full text of the license may be found at
-#  http://opensource.org/licenses/bsd-license.php
-#
-#  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
-#  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
-#
-#
-
-#include <AsmMacroIoLibV8.h>
-
-//EFI_PHYSICAL_ADDRESS
-//GetPhysAddrTop (
-//  VOID
-//  );
-ASM_FUNC(ArmGetPhysAddrTop)
-  mrs   x0, id_aa64mmfr0_el1
-  adr   x1, .LPARanges
-  and   x0, x0, #7
-  ldrb  w1, [x1, x0]
-  mov   x0, #1
-  lsl   x0, x0, x1
-  ret
-
-//
-// Bits 0..2 of the AA64MFR0_EL1 system register encode the size of the
-// physical address space support on this CPU:
-// 0 == 32 bits, 1 == 36 bits, etc etc
-// 6 and 7 are reserved
-//
-.LPARanges:
-  .byte 32, 36, 40, 42, 44, 48, -1, -1
-
-ASM_FUNCTION_REMOVE_IF_UNREFERENCED
diff --git a/ArmVirtPkg/Library/QemuVirtMemInfoLib/Arm/PhysAddrTop.S b/ArmVirtPkg/Library/QemuVirtMemInfoLib/Arm/PhysAddrTop.S
deleted file mode 100644
index 9cd81529fb3d..000000000000
--- a/ArmVirtPkg/Library/QemuVirtMemInfoLib/Arm/PhysAddrTop.S
+++ /dev/null
@@ -1,24 +0,0 @@
-#
-#  Copyright (c) 2011-2013, ARM Limited. All rights reserved.
-#  Copyright (c) 2014-2017, Linaro Limited. All rights reserved.
-#
-#  This program and the accompanying materials
-#  are licensed and made available under the terms and conditions of the BSD License
-#  which accompanies this distribution.  The full text of the license may be found at
-#  http://opensource.org/licenses/bsd-license.php
-#
-#  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
-#  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
-#
-#
-
-#include <AsmMacroIoLib.h>
-
-//EFI_PHYSICAL_ADDRESS
-//GetPhysAddrTop (
-//  VOID
-//  );
-ASM_FUNC(ArmGetPhysAddrTop)
-  mov   r0, #0x00000000
-  mov   r1, #0x10000
-  bx    lr
-- 
2.19.1