This introduces a special version of ArmMmuLib for PEIMs that takes care only to perform cache maintenance on the live entry replacement routine if the module is not executing in place. Not only is such cache maintenance unnecessary in that case, it may be actively harmful on some systems that fail to tolerate cache maintenance operations on NOR flash regions.
Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel <[email protected]> --- ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuPeiLibConstructor.c | 61 ++++++++++++++++++++ ArmPkg/Library/ArmMmuLib/ArmMmuPeiLib.inf | 36 ++++++++++++ 2 files changed, 97 insertions(+) diff --git a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuPeiLibConstructor.c b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuPeiLibConstructor.c new file mode 100644 index 000000000000..d370b507a807 --- /dev/null +++ b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuPeiLibConstructor.c @@ -0,0 +1,61 @@ +#/* @file +# +# Copyright (c) 2016, 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 <Base.h> + +#include <Library/ArmLib.h> +#include <Library/ArmMmuLib.h> +#include <Library/CacheMaintenanceLib.h> +#include <Library/DebugLib.h> + +EFI_STATUS +EFIAPI +ArmMmuPeiLibConstructor ( + IN EFI_PEI_FILE_HANDLE FileHandle, + IN CONST EFI_PEI_SERVICES **PeiServices + ) +{ + extern UINT32 ArmReplaceLiveTranslationEntrySize; + + EFI_FV_FILE_INFO FileInfo; + EFI_STATUS Status; + + ASSERT (FileHandle != NULL); + + Status = (*PeiServices)->FfsGetFileInfo (FileHandle, &FileInfo); + ASSERT_EFI_ERROR (Status); + + // + // Some platforms do not cope very well with cache maintenance being + // performed on regions backed by NOR flash. Since the firmware image + // can be assumed to be clean to the PoC when running XIP, even when PEI + // is executing from DRAM, we only need to perform the cache maintenance + // when not executing in place. + // + if ((UINTN)FileInfo.Buffer <= (UINTN)ArmReplaceLiveTranslationEntry && + ((UINTN)FileInfo.Buffer + FileInfo.BufferSize >= + (UINTN)ArmReplaceLiveTranslationEntry + ArmReplaceLiveTranslationEntrySize)) { + DEBUG ((EFI_D_INFO, "ArmMmuLib: skipping cache maintenance on XIP PEIM\n")); + } else { + DEBUG ((EFI_D_INFO, "ArmMmuLib: performing cache maintenance on shadowed PEIM\n")); + // + // The ArmReplaceLiveTranslationEntry () helper function may be invoked + // with the MMU off so we have to ensure that it gets cleaned to the PoC + // + WriteBackDataCacheRange (ArmReplaceLiveTranslationEntry, + ArmReplaceLiveTranslationEntrySize); + } + + return RETURN_SUCCESS; +} diff --git a/ArmPkg/Library/ArmMmuLib/ArmMmuPeiLib.inf b/ArmPkg/Library/ArmMmuLib/ArmMmuPeiLib.inf new file mode 100644 index 000000000000..14ebf8de673d --- /dev/null +++ b/ArmPkg/Library/ArmMmuLib/ArmMmuPeiLib.inf @@ -0,0 +1,36 @@ +#/** @file +# +# Copyright (c) 2016 Linaro Ltd. 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. +# +# +#**/ + +[Defines] + INF_VERSION = 0x00010005 + BASE_NAME = ArmMmuPeiLib + FILE_GUID = b50d8d53-1ad1-44ea-9e69-8c89d4a6d08b + MODULE_TYPE = PEIM + VERSION_STRING = 1.0 + LIBRARY_CLASS = ArmMmuLib|PEIM + CONSTRUCTOR = ArmMmuPeiLibConstructor + +[Sources.AARCH64] + AArch64/ArmMmuLibCore.c + AArch64/ArmMmuPeiLibConstructor.c + AArch64/ArmMmuLibReplaceEntry.S + +[Packages] + ArmPkg/ArmPkg.dec + MdePkg/MdePkg.dec + +[LibraryClasses] + ArmLib + CacheMaintenanceLib + MemoryAllocationLib -- 2.7.4 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
