Revision: 18897
http://sourceforge.net/p/edk2/code/18897
Author: abiesheuvel
Date: 2015-11-18 15:59:22 +0000 (Wed, 18 Nov 2015)
Log Message:
-----------
ArmPkg/ArmV7Mmu: introduce feature PCD to map normal memory non-shareable
Even though mapping normal memory (inner) shareable is usually the
correct choice on coherent systems, it may be desirable in some cases
to use non-shareable mappings for normal memory, e.g., when hardware
managed coherency is not required and the memory system is not fully
configured yet. So introduce a PCD PcdNormalMemoryNonshareableOverride
that makes cacheable mappings of normal memory non-shareable.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <[email protected]>
Reviewed-by: Leif Lindholm <[email protected]>
Modified Paths:
--------------
trunk/edk2/ArmPkg/ArmPkg.dec
trunk/edk2/ArmPkg/Library/ArmLib/ArmV7/ArmV7Lib.inf
trunk/edk2/ArmPkg/Library/ArmLib/ArmV7/ArmV7LibPrePi.inf
trunk/edk2/ArmPkg/Library/ArmLib/ArmV7/ArmV7Mmu.c
Modified: trunk/edk2/ArmPkg/ArmPkg.dec
===================================================================
--- trunk/edk2/ArmPkg/ArmPkg.dec 2015-11-18 15:59:04 UTC (rev 18896)
+++ trunk/edk2/ArmPkg/ArmPkg.dec 2015-11-18 15:59:22 UTC (rev 18897)
@@ -73,6 +73,12 @@
# Define if the GICv3 controller should use the GICv2 legacy
gArmTokenSpaceGuid.PcdArmGicV3WithV2Legacy|FALSE|BOOLEAN|0x00000042
+[PcdsFeatureFlag.ARM]
+ # Whether to map normal memory as non-shareable. FALSE is the safe choice,
but
+ # TRUE may be appropriate to fix performance problems if you don't care about
+ # hardware coherency (i.e., no virtualization or cache coherent DMA)
+
gArmTokenSpaceGuid.PcdNormalMemoryNonshareableOverride|FALSE|BOOLEAN|0x00000043
+
[PcdsFixedAtBuild.common]
gArmTokenSpaceGuid.PcdTrustzoneSupport|FALSE|BOOLEAN|0x00000006
Modified: trunk/edk2/ArmPkg/Library/ArmLib/ArmV7/ArmV7Lib.inf
===================================================================
--- trunk/edk2/ArmPkg/Library/ArmLib/ArmV7/ArmV7Lib.inf 2015-11-18 15:59:04 UTC
(rev 18896)
+++ trunk/edk2/ArmPkg/Library/ArmLib/ArmV7/ArmV7Lib.inf 2015-11-18 15:59:22 UTC
(rev 18897)
@@ -48,3 +48,6 @@
[Protocols]
gEfiCpuArchProtocolGuid
+
+[FeaturePcd.ARM]
+ gArmTokenSpaceGuid.PcdNormalMemoryNonshareableOverride
Modified: trunk/edk2/ArmPkg/Library/ArmLib/ArmV7/ArmV7LibPrePi.inf
===================================================================
--- trunk/edk2/ArmPkg/Library/ArmLib/ArmV7/ArmV7LibPrePi.inf 2015-11-18
15:59:04 UTC (rev 18896)
+++ trunk/edk2/ArmPkg/Library/ArmLib/ArmV7/ArmV7LibPrePi.inf 2015-11-18
15:59:22 UTC (rev 18897)
@@ -48,3 +48,6 @@
[Protocols]
gEfiCpuArchProtocolGuid
+
+[FeaturePcd.ARM]
+ gArmTokenSpaceGuid.PcdNormalMemoryNonshareableOverride
Modified: trunk/edk2/ArmPkg/Library/ArmLib/ArmV7/ArmV7Mmu.c
===================================================================
--- trunk/edk2/ArmPkg/Library/ArmLib/ArmV7/ArmV7Mmu.c 2015-11-18 15:59:04 UTC
(rev 18896)
+++ trunk/edk2/ArmPkg/Library/ArmLib/ArmV7/ArmV7Mmu.c 2015-11-18 15:59:22 UTC
(rev 18897)
@@ -80,6 +80,10 @@
break;
}
+ if (FeaturePcdGet(PcdNormalMemoryNonshareableOverride)) {
+ PageAttributes &= ~TT_DESCRIPTOR_PAGE_S_SHARED;
+ }
+
// Check if the Section Entry has already been populated. Otherwise attach a
// Level 2 Translation Table to it
if (*SectionEntry != 0) {
@@ -178,6 +182,10 @@
break;
}
+ if (FeaturePcdGet(PcdNormalMemoryNonshareableOverride)) {
+ Attributes &= ~TT_DESCRIPTOR_SECTION_S_SHARED;
+ }
+
// Get the first section entry for this mapping
SectionEntry =
TRANSLATION_TABLE_ENTRY_FOR_VIRTUAL_ADDRESS(TranslationTable,
MemoryRegion->VirtualBase);
@@ -266,15 +274,19 @@
}
if (TTBRAttributes & TTBR_SHAREABLE) {
- //
- // Unlike the S bit in the short descriptors, which implies inner shareable
- // on an implementation that supports two levels, the meaning of the S bit
- // in the TTBR depends on the NOS bit, which defaults to Outer Shareable.
- // However, we should only set this bit after we have confirmed that the
- // implementation supports multiple levels, or else the NOS bit is UNK/SBZP
- //
- if (((ArmReadIdMmfr0 () >> 12) & 0xf) != 0) {
- TTBRAttributes |= TTBR_NOT_OUTER_SHAREABLE;
+ if (FeaturePcdGet(PcdNormalMemoryNonshareableOverride)) {
+ TTBRAttributes ^= TTBR_SHAREABLE;
+ } else {
+ //
+ // Unlike the S bit in the short descriptors, which implies inner
shareable
+ // on an implementation that supports two levels, the meaning of the S
bit
+ // in the TTBR depends on the NOS bit, which defaults to Outer Shareable.
+ // However, we should only set this bit after we have confirmed that the
+ // implementation supports multiple levels, or else the NOS bit is
UNK/SBZP
+ //
+ if (((ArmReadIdMmfr0 () >> 12) & 0xf) != 0) {
+ TTBRAttributes |= TTBR_NOT_OUTER_SHAREABLE;
+ }
}
}
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