As it turns out, ARMv8 (DDI 0487E.a D4.4.5) also permits accesses made with the MMU and caches off to hit in the caches, so to ensure that any modifications we make before enabling the MMU are visible afterwards as well, we should invalidate page tables right after allocation like we do now on ARM, if the MMU is still disabled at that point.
Signed-off-by: Ard Biesheuvel <[email protected]> --- ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c | 25 ++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c index 204e33c75f95..b5d6b66806f8 100644 --- a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c +++ b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c @@ -282,6 +282,15 @@ GetBlockEntryListFromAddress ( return NULL; } + if (!ArmMmuEnabled ()) { + // + // Make sure we are not inadvertently hitting in the caches + // when populating the page tables. + // + InvalidateDataCacheRange (TranslationTable, + TT_ENTRY_COUNT * sizeof(UINT64)); + } + // Populate the newly created lower level table SubTableBlockEntry = TranslationTable; for (Index = 0; Index < TT_ENTRY_COUNT; Index++) { @@ -306,6 +315,14 @@ GetBlockEntryListFromAddress ( return NULL; } + if (!ArmMmuEnabled ()) { + // + // Make sure we are not inadvertently hitting in the caches + // when populating the page tables. + // + InvalidateDataCacheRange (TranslationTable, + TT_ENTRY_COUNT * sizeof(UINT64)); + } ZeroMem (TranslationTable, TT_ENTRY_COUNT * sizeof(UINT64)); // Fill the new BlockEntry with the TranslationTable @@ -697,6 +714,14 @@ ArmConfigureMmu ( *TranslationTableSize = RootTableEntryCount * sizeof(UINT64); } + if (!ArmMmuEnabled ()) { + // + // Make sure we are not inadvertently hitting in the caches + // when populating the page tables. + // + InvalidateDataCacheRange (TranslationTable, + RootTableEntryCount * sizeof(UINT64)); + } ZeroMem (TranslationTable, RootTableEntryCount * sizeof(UINT64)); TranslationTableAttribute = TT_ATTR_INDX_INVALID; -- 2.17.1 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#55555): https://edk2.groups.io/g/devel/message/55555 Mute This Topic: https://groups.io/mt/71759645/21656 Group Owner: [email protected] Unsubscribe: https://edk2.groups.io/g/devel/unsub [[email protected]] -=-=-=-=-=-=-=-=-=-=-=-
