ArmPkg/ArmMmuLib: take the CPU supported maximum PA space into account

[mirror_edk2.git] / ArmPkg / Library / ArmMmuLib / AArch64 / ArmMmuLibCore.c

diff --git a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
index 4b62ecb6a47650b318b852815f02e26251b8b789..5403b8d4070e8a8b81eb2e568f7190d3e297bf8a 100644 (file)
--- a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
+++ b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
@@ -604,8 +604,15 @@ ArmConfigureMmu (
     return EFI_INVALID_PARAMETER;\r
   }\r
 \r
-  // Cover the entire GCD memory space\r
-  MaxAddress = (1UL << PcdGet8 (PcdPrePiCpuMemorySize)) - 1;\r
+  //\r
+  // Limit the virtual address space to what we can actually use: UEFI\r
+  // mandates a 1:1 mapping, so no point in making the virtual address\r
+  // space larger than the physical address space. We also have to take\r
+  // into account the architectural limitations that result from UEFI's\r
+  // use of 4 KB pages.\r
+  //\r
+  MaxAddress = MIN (LShiftU64 (1ULL, ArmGetPhysicalAddressBits ()) - 1,\r
+                    MAX_ADDRESS);\r
 \r
   // Lookup the Table Level to get the information\r
   LookupAddresstoRootTable (MaxAddress, &T0SZ, &RootTableEntryCount);\r