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authorPunit Agrawal <punit.agrawal@arm.com>2014-11-18 11:41:24 +0000
committerWill Deacon <will.deacon@arm.com>2014-11-20 16:33:53 +0000
commit587064b610c703f259317d00dc37bf6d40f4fc74 (patch)
tree4170a2e03c6d046c45811f22ab662b988d73ae48 /arch/arm64/Kconfig
parent0be0e44c182c4f13df13903fd1377671d157d7b7 (diff)
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arm64: Add framework for legacy instruction emulation
Typically, providing support for legacy instructions requires emulating the behaviour of instructions whose encodings have become undefined. If the instructions haven't been removed from the architecture, there maybe an option in the implementation to turn on/off the support for these instructions. Create common infrastructure to support legacy instruction emulation. In addition to emulation, also provide an option to support hardware execution when supported. The default execution mode (one of undef, emulate, hw exeuction) is dependent on the state of the instruction (deprecated or obsolete) in the architecture and can specified at the time of registering the instruction handlers. The runtime state of the emulation can be controlled by writing to individual nodes in sysctl. The expected default behaviour is documented as part of this patch. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/Kconfig')
-rw-r--r--arch/arm64/Kconfig18
1 files changed, 18 insertions, 0 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 1e0e4671dd25..aa8f4bea3738 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -164,6 +164,24 @@ config ARCH_XGENE
help
This enables support for AppliedMicro X-Gene SOC Family
+comment "Processor Features"
+
+menuconfig ARMV8_DEPRECATED
+ bool "Emulate deprecated/obsolete ARMv8 instructions"
+ depends on COMPAT
+ help
+ Legacy software support may require certain instructions
+ that have been deprecated or obsoleted in the architecture.
+
+ Enable this config to enable selective emulation of these
+ features.
+
+ If unsure, say Y
+
+if ARMV8_DEPRECATED
+
+endif
+
endmenu
menu "Bus support"