Merge tag 'lsk-v3.10-15.05-android' into develop-3.10

[firefly-linux-kernel-4.4.55.git] / arch / arm64 / Kconfig

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 72b758667ae462dbcc54dd14ea68c3badd74e372..135f9ca7874c28a411a7d3af232a19c3be8a46ff 100644 (file)
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -168,6 +168,32 @@ endmenu
 
 menu "Kernel Features"
 
+menu "ARM errata workarounds"
+
+config ARM64_ERRATUM_845719
+       bool "Cortex-A53: 845719: a load might read incorrect data"
+       depends on COMPAT
+       default n
+       help
+         This option adds an alternative code sequence to work around ARM
+         erratum 845719 on Cortex-A53 parts up to r0p4.
+
+         When running a compat (AArch32) userspace on an affected Cortex-A53
+         part, a load at EL0 from a virtual address that matches the bottom 32
+         bits of the virtual address used by a recent load at (AArch64) EL1
+         might return incorrect data.
+
+         The workaround is to write the contextidr_el1 register on exception
+         return to a 32-bit task.
+         Please note that this does not necessarily enable the workaround,
+         as it depends on the alternative framework, which will only patch
+         the kernel if an affected CPU is detected.
+
+         If unsure, say Y.
+
+endmenu
+
+
 config ARM64_64K_PAGES
        bool "Enable 64KB pages support"
        help