External email: Use caution opening links or att= achments

Given how the meaning of the attribute bits for page table entry types is slightly awkward, and changes between levels, add some helpers to
abstract from this.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif@nuviainc.com>
---
ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c | 40 ++= 3;++++++++++++++-= --
1 file changed, 35 insertions(+), 5 deletions(-)

diff --git a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c b/ArmPkg/Li= brary/ArmMmuLib/AArch64/ArmMmuLibCore.c
index d78918cf7ba8..0680ba36d907 100644
--- a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
+++ b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
@@ -162,6 +162,36 @@ FreePageTablesRecursive (
   FreePages (TranslationTable, 1);
}

+STATIC
+BOOLEAN
+IsBlockEntry (
+ IN UINT64 Entry,
+ IN UINTN   Level
+ )
+{
+ if (Level =3D=3D 3) {
+    return (Entry & TT_TYPE_MASK) =3D=3D TT_TYPE_= BLOCK_ENTRY_LEVEL3;
+ }
+ return (Entry & TT_TYPE_MASK) =3D=3D TT_TYPE_BLOCK_ENTRY;=
+}
+
+STATIC
+BOOLEAN
+IsTableEntry (
+ IN UINT64 Entry,
+ IN UINTN   Level
+ )
+{
+ if (Level =3D=3D 3) {
+    //
+    // TT_TYPE_TABLE_ENTRY aliases TT_TYPE_BLOCK_ENTR= Y_LEVEL3
+    // so we need to take the level into account as w= ell.
+    //
+    return FALSE;
+ }
+ return (Entry & TT_TYPE_MASK) =3D=3D TT_TYPE_TABLE_ENTRY;=
+}
+
STATIC
EFI_STATUS
UpdateRegionMappingRecursive (
@@ -203,7 +233,7 @@ UpdateRegionMappingRecursive (
     if (Level =3D=3D 0 || ((RegionStart | BlockEnd) = & BlockMask) !=3D 0) {
       ASSERT (Level < 3);

-      if ((*Entry & TT_TYPE_MASK) !=3D TT_T= YPE_TABLE_ENTRY) {
+      if (!IsTableEntry (*Entry, Level)) {<= br>          //
         // No table entry exists= =20yet, so we need to allocate a page table
         // for the next level. @@ -221,7 +251,7 @@ UpdateRegionMappingRecursive (
           InvalidateDa= taCacheRange (TranslationTable, EFI_PAGE_SIZE);
         }

-        if ((*Entry & TT_TYPE_MAS= K) =3D=3D TT_TYPE_BLOCK_ENTRY) {
+        if (IsBlockEntry (*Entry,= =20Level)) {
           //
           // We are sp= litting an existing block entry, so we have to populate
           // the new t= able with the attributes of the block entry it replaces.
@@ -252,7 +282,7 @@ UpdateRegionMappingRecursive (
            &= nbsp;     AttributeSetMask, AttributeClearMask, Trans= lationTable,
            &= nbsp;     Level + 1);
       if (EFI_ERROR (Status)) {
-        if ((*Entry & TT_TYPE_MAS= K) !=3D TT_TYPE_TABLE_ENTRY) {
+        if (!IsTableEntry (*Entry= , Level)) {
           //
           // We are cr= eating a new table entry, so on failure, we can free all
           // allocatio= ns we made recursively, given that the whole subhierarchy
@@ -265,10 +295,10 @@ UpdateRegionMappingRecursive (
         return Status;
       }

-      if ((*Entry & TT_TYPE_MASK) !=3D TT_T= YPE_TABLE_ENTRY) {
+      if (!IsTableEntry (*Entry, Level)) {<= br>          EntryValue =3D (UINTN)Tr= anslationTable | TT_TYPE_TABLE_ENTRY;
         ReplaceTableEntry (Entry= , EntryValue, RegionStart,
-            =             &= nbsp; (*Entry & TT_TYPE_MASK) =3D=3D TT_TYPE_BLOCK_ENTRY);
+          IsBlockEntry = (*Entry, Level));
       }
     } else {
       EntryValue =3D (*Entry & Attribu= teClearMask) | AttributeSetMask;
--
2.17.1