From 1dc3f34f61044a19573b1ecc507081bfcb075739 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Tue, 24 Nov 2015 07:44:41 +0000 Subject: [PATCH] ArmVirtPkg/ArmVirtPlatformLib: reduce ID map size to GCD region size The ID mapping routines on virtual platforms simply map the entire hardware supported physical address space as device memory, and then punch some holes for regions that need to be mapped cacheable. On virtual platforms hosted on CPUs that support a large physical address range, this may result in a lot of overhead, i.e., 4 KB of page tables for each 512 GB of address space, which quickly adds up (i.e., 2 MB for the architectural maximum of 48 bits). Since there may be a platform specific limit to the size of the (I)PA space that is not reflected by CPU id registers, restrict the range of the ID mapping to gEmbeddedTokenSpaceGuid.PcdPrePiCpuMemorySize bits. This makes sense by itself, since we cannot manipulate mappings above that limit anwyay (because they are not covered by GCD), and it allows the PCD be set to a lower value by platforms whose (I)PA space is smaller than the hardware supported maximum. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel Reviewed-by: Laszlo Ersek Tested-by: Wei Huang git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18929 6f19259b-4bc3-4df7-8a09-765794883524 --- ArmVirtPkg/Library/ArmVirtPlatformLib/ArmVirtPlatformLib.inf | 1 + ArmVirtPkg/Library/ArmVirtPlatformLib/VirtMem.c | 4 +++- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/ArmVirtPkg/Library/ArmVirtPlatformLib/ArmVirtPlatformLib.inf b/ArmVirtPkg/Library/ArmVirtPlatformLib/ArmVirtPlatformLib.inf index 22ee3625c3..3cb3fb1f3a 100644 --- a/ArmVirtPkg/Library/ArmVirtPlatformLib/ArmVirtPlatformLib.inf +++ b/ArmVirtPkg/Library/ArmVirtPlatformLib/ArmVirtPlatformLib.inf @@ -61,3 +61,4 @@ gArmTokenSpaceGuid.PcdArmPrimaryCore gArmTokenSpaceGuid.PcdFdBaseAddress gArmTokenSpaceGuid.PcdFdSize + gEmbeddedTokenSpaceGuid.PcdPrePiCpuMemorySize diff --git a/ArmVirtPkg/Library/ArmVirtPlatformLib/VirtMem.c b/ArmVirtPkg/Library/ArmVirtPlatformLib/VirtMem.c index 530f7d608e..e5536ecd8e 100644 --- a/ArmVirtPkg/Library/ArmVirtPlatformLib/VirtMem.c +++ b/ArmVirtPkg/Library/ArmVirtPlatformLib/VirtMem.c @@ -97,7 +97,9 @@ ArmPlatformGetVirtualMemoryMap ( // Peripheral space after DRAM VirtualMemoryTable[2].PhysicalBase = VirtualMemoryTable[0].Length + VirtualMemoryTable[1].Length; VirtualMemoryTable[2].VirtualBase = VirtualMemoryTable[2].PhysicalBase; - VirtualMemoryTable[2].Length = ArmGetPhysAddrTop () - VirtualMemoryTable[2].PhysicalBase; + VirtualMemoryTable[2].Length = MIN (1ULL << FixedPcdGet8 (PcdPrePiCpuMemorySize), + ArmGetPhysAddrTop ()) - + VirtualMemoryTable[2].PhysicalBase; VirtualMemoryTable[2].Attributes = ARM_MEMORY_REGION_ATTRIBUTE_DEVICE; // Remap the FD region as normal executable memory -- 2.39.2