arm64: Allow CAVIUM_TX2_ERRATUM_219 to be selected

Allow the user to select the workaround for TX2-219, and update
the silicon-errata.rst file to reflect this.

Cc: <stable@vger.kernel.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/Documentation/arm64/silicon-errata.rst b/Documentation/arm64/silicon-errata.rst
index 17ea3fecddaa50ac1a1e8af59f222105622b1720..ab7ed2fd072f34a83eb551558ea8b0b5e36db2d4 100644 (file)
--- a/Documentation/arm64/silicon-errata.rst
+++ b/Documentation/arm64/silicon-errata.rst
@@ -107,6 +107,8 @@ stable kernels.
 +----------------+-----------------+-----------------+-----------------------------+
 | Cavium         | ThunderX2 SMMUv3| #126            | N/A                         |
 +----------------+-----------------+-----------------+-----------------------------+
+| Cavium         | ThunderX2 Core  | #219            | CAVIUM_TX2_ERRATUM_219      |
++----------------+-----------------+-----------------+-----------------------------+
 +----------------+-----------------+-----------------+-----------------------------+
 | Freescale/NXP  | LS2080A/LS1043A | A-008585        | FSL_ERRATUM_A008585         |
 +----------------+-----------------+-----------------+-----------------------------+

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 41a9b4257b727710bcd4be1e9bcf47e6739a908d..7d36fd95ae5a603b0a69eef5712ebca1c7822ef2 100644 (file)
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -617,6 +617,23 @@ config CAVIUM_ERRATUM_30115
 
          If unsure, say Y.
 
+config CAVIUM_TX2_ERRATUM_219
+       bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
+       default y
+       help
+         On Cavium ThunderX2, a load, store or prefetch instruction between a
+         TTBR update and the corresponding context synchronizing operation can
+         cause a spurious Data Abort to be delivered to any hardware thread in
+         the CPU core.
+
+         Work around the issue by avoiding the problematic code sequence and
+         trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
+         trap handler performs the corresponding register access, skips the
+         instruction and ensures context synchronization by virtue of the
+         exception return.
+
+         If unsure, say Y.
+
 config QCOM_FALKOR_ERRATUM_1003
        bool "Falkor E1003: Incorrect translation due to ASID change"
        default y