The relations between T0SZ, the number of translation levels and the size/alignment of the root table can be expressed in simple arithmetic expressions, so get rid of the lookup table.
Note that this disregards the fact that the maximum value of T0SZ is 39 not 42 (as one would expect for the smallest VA size using 2 levels) but since this corresponds to a VA size of 32 MB and 4 MB, respectively, neither of which are sufficient to run UEFI, we can safely ignore the distinction. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel <[email protected]> --- ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c | 35 +++----------------- 1 file changed, 4 insertions(+), 31 deletions(-) diff --git a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c index 6e05e6085011..84a689af7c8a 100644 --- a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c +++ b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c @@ -121,20 +121,8 @@ GcdAttributeToArmAttribute ( } } -// Describe the T0SZ values for each translation table level -typedef struct { - UINTN MinT0SZ; - UINTN MaxT0SZ; - UINTN LargestT0SZ; // Generally (MaxT0SZ == LargestT0SZ) but at the Level3 Table - // the MaxT0SZ is not at the boundary of the table -} T0SZ_DESCRIPTION_PER_LEVEL; - -// Map table for the corresponding Level of Table -STATIC CONST T0SZ_DESCRIPTION_PER_LEVEL T0SZPerTableLevel[] = { - { 16, 24, 24 }, // Table Level 0 - { 25, 33, 33 }, // Table Level 1 - { 34, 39, 42 } // Table Level 2 -}; +#define MIN_T0SZ 16 +#define BITS_PER_LEVEL 9 VOID GetRootTranslationTableInfo ( @@ -143,28 +131,13 @@ GetRootTranslationTableInfo ( OUT UINTN *TableEntryCount ) { - UINTN Index; - - // Identify the level of the root table from the given T0SZ - for (Index = 0; Index < sizeof (T0SZPerTableLevel) / sizeof (T0SZ_DESCRIPTION_PER_LEVEL); Index++) { - if (T0SZ <= T0SZPerTableLevel[Index].MaxT0SZ) { - break; - } - } - - // If we have not found the corresponding maximum T0SZ then we use the last one - if (Index == sizeof (T0SZPerTableLevel) / sizeof (T0SZ_DESCRIPTION_PER_LEVEL)) { - Index--; - } - // Get the level of the root table if (TableLevel) { - *TableLevel = Index; + *TableLevel = (T0SZ - MIN_T0SZ) / BITS_PER_LEVEL; } - // The Size of the Table is 2^(T0SZ-LargestT0SZ) if (TableEntryCount) { - *TableEntryCount = 1 << (T0SZPerTableLevel[Index].LargestT0SZ - T0SZ + 1); + *TableEntryCount = 1UL << (BITS_PER_LEVEL - (T0SZ - MIN_T0SZ) % BITS_PER_LEVEL); } } -- 2.7.4 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
