ArmPkg/ArmMmuLib ARM: Remove half baked large page support

Large page support on 32-bit ARM is essentially a glorified contiguous
bit where 16 consecutive entries describing a contiguous range with the
same attributes are presented in a way that permits the TLB to cache its
translation with a single entry.

This was never wired up completely, and does not add a lot of value in
EFI, where the page granularity is 4k and we expect to be able to set RO
and XP permissions on individual pages.

Given that large page support complicates the handling of the XN bit at
the page level (which is in a different place depending on whether the
page is small or large), let's just rip it out.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Leif Lindholm <quic_llindhol@quicinc.com>

3 files changed, 5 insertions, 6 deletions

diff --git a/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibConvert.c b/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibConvert.c
index bee8ad7028..6e2f08a7ce 100644
--- a/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibConvert.c
+++ b/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibConvert.c
@@ -15,16 +15,15 @@
 

 UINT32

 ConvertSectionAttributesToPageAttributes (

-  IN UINT32   SectionAttributes,

-  IN BOOLEAN  IsLargePage

+  IN UINT32  SectionAttributes

   )

 {

   UINT32  PageAttributes;

 

   PageAttributes  = 0;

-  PageAttributes |= TT_DESCRIPTOR_CONVERT_TO_PAGE_CACHE_POLICY (SectionAttributes, IsLargePage);

+  PageAttributes |= TT_DESCRIPTOR_CONVERT_TO_PAGE_CACHE_POLICY (SectionAttributes);

   PageAttributes |= TT_DESCRIPTOR_CONVERT_TO_PAGE_AP (SectionAttributes);

-  PageAttributes |= TT_DESCRIPTOR_CONVERT_TO_PAGE_XN (SectionAttributes, IsLargePage);

+  PageAttributes |= TT_DESCRIPTOR_CONVERT_TO_PAGE_XN (SectionAttributes);

   PageAttributes |= TT_DESCRIPTOR_CONVERT_TO_PAGE_NG (SectionAttributes);

   PageAttributes |= TT_DESCRIPTOR_CONVERT_TO_PAGE_S (SectionAttributes);

 

diff --git a/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibCore.c b/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibCore.c
index 9e304ea05e..28cc9b2fe0 100644
--- a/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibCore.c
+++ b/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibCore.c
@@ -145,7 +145,7 @@ PopulateLevel2PageTable (
                                   );

 

       // Translate the Section Descriptor into Page Descriptor

-      SectionDescriptor = TT_DESCRIPTOR_PAGE_TYPE_PAGE | ConvertSectionAttributesToPageAttributes (*SectionEntry, FALSE);

+      SectionDescriptor = TT_DESCRIPTOR_PAGE_TYPE_PAGE | ConvertSectionAttributesToPageAttributes (*SectionEntry);

 

       BaseSectionAddress = TT_DESCRIPTOR_SECTION_BASE_ADDRESS (*SectionEntry);

 

diff --git a/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibUpdate.c b/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibUpdate.c
index b402197ade..9ca00c976d 100644
--- a/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibUpdate.c
+++ b/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibUpdate.c
@@ -53,7 +53,7 @@ ConvertSectionToPages (
 

   // Get section attributes and convert to page attributes

   SectionDescriptor = FirstLevelTable[FirstLevelIdx];

-  PageDescriptor    = TT_DESCRIPTOR_PAGE_TYPE_PAGE | ConvertSectionAttributesToPageAttributes (SectionDescriptor, FALSE);

+  PageDescriptor    = TT_DESCRIPTOR_PAGE_TYPE_PAGE | ConvertSectionAttributesToPageAttributes (SectionDescriptor);

 

   // Allocate a page table for the 4KB entries (we use up a full page even though we only need 1KB)

   PageTable = (volatile ARM_PAGE_TABLE_ENTRY *)AllocatePages (1);