From 6ea34e3a459733d3c27617dfb1cee2d841193ca2 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Tue, 14 Apr 2015 11:54:40 +0000 Subject: ArmPkg: remove cache maintenance by VA operation range size threshold This removes the range size threshold for virtual address based cache maintenance instructions that operate on VA ranges to be 'promoted' to use set/way instructions. Doing so is unsafe: set/way operations are fundamentally different from VA operations, and really only suitable for cleaning or invalidating a cache when turning it on or off. To quote the ARM ARM (DDI0487A_d G3.4): """ Since the set/way instructions are performed only locally, there is no guarantee of the atomicity of cache maintenance between different PEs, even if those different PEs are each performing the same cache maintenance instructions at the same time. Since any cacheable line can be allocated into the cache at any time, it is possible for [a] cache line to migrate from an entry in the cache of one PE to the cache of a different PE in a manner that the cache line avoids being affected by set/way based cache maintenance. Therefore, ARM strongly discourages the use of set/way instructions to manage coherency in coherent systems. """ Contributed-under: TianoCore Contribution Agreement 1.0 Reviewed-by: Olivier Martin Signed-off-by: Ard Biesheuvel git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@17176 6f19259b-4bc3-4df7-8a09-765794883524 --- ArmPkg/Library/ArmLib/AArch64/AArch64Lib.inf | 3 --- ArmPkg/Library/ArmLib/AArch64/AArch64LibPrePi.inf | 3 --- ArmPkg/Library/ArmLib/AArch64/AArch64LibSec.inf | 3 --- 3 files changed, 9 deletions(-) (limited to 'ArmPkg/Library/ArmLib/AArch64') diff --git a/ArmPkg/Library/ArmLib/AArch64/AArch64Lib.inf b/ArmPkg/Library/ArmLib/AArch64/AArch64Lib.inf index e5247848b5..dd585dea91 100644 --- a/ArmPkg/Library/ArmLib/AArch64/AArch64Lib.inf +++ b/ArmPkg/Library/ArmLib/AArch64/AArch64Lib.inf @@ -41,6 +41,3 @@ [Protocols] gEfiCpuArchProtocolGuid - -[FixedPcd] - gArmTokenSpaceGuid.PcdArmCacheOperationThreshold diff --git a/ArmPkg/Library/ArmLib/AArch64/AArch64LibPrePi.inf b/ArmPkg/Library/ArmLib/AArch64/AArch64LibPrePi.inf index 3a99e1b713..23fbe86731 100644 --- a/ArmPkg/Library/ArmLib/AArch64/AArch64LibPrePi.inf +++ b/ArmPkg/Library/ArmLib/AArch64/AArch64LibPrePi.inf @@ -43,6 +43,3 @@ [Protocols] gEfiCpuArchProtocolGuid - -[FixedPcd] - gArmTokenSpaceGuid.PcdArmCacheOperationThreshold diff --git a/ArmPkg/Library/ArmLib/AArch64/AArch64LibSec.inf b/ArmPkg/Library/ArmLib/AArch64/AArch64LibSec.inf index 57ac694cd7..302c09af49 100644 --- a/ArmPkg/Library/ArmLib/AArch64/AArch64LibSec.inf +++ b/ArmPkg/Library/ArmLib/AArch64/AArch64LibSec.inf @@ -38,6 +38,3 @@ [Protocols] gEfiCpuArchProtocolGuid - -[FixedPcd] - gArmTokenSpaceGuid.PcdArmCacheOperationThreshold -- cgit v1.2.3