arm64: Enable and document ARM errata 1319367 and 1319537

Now that everything is in place, let's get the ball rolling
by allowing the corresponding config option to be selected.
Also add the required information to silicon_errata.rst.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

Documentation/arm64/silicon-errata.rst

@@ -70,8 +70,12 @@ stable kernels.
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-A57      | #834220         | ARM64_ERRATUM_834220        |
 +----------------+-----------------+-----------------+-----------------------------+
+| ARM            | Cortex-A57      | #1319537        | ARM64_ERRATUM_1319367       |
++----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-A72      | #853709         | N/A                         |
 +----------------+-----------------+-----------------+-----------------------------+
+| ARM            | Cortex-A72      | #1319367        | ARM64_ERRATUM_1319367       |
++----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-A73      | #858921         | ARM64_ERRATUM_858921        |
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-A55      | #1024718        | ARM64_ERRATUM_1024718       |

arch/arm64/Kconfig

@@ -538,6 +538,16 @@ config ARM64_ERRATUM_1286807
 	  invalidated has been observed by other observers. The
 	  workaround repeats the TLBI+DSB operation.
 
+config ARM64_ERRATUM_1319367
+	bool "Cortex-A57/A72: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
+	default y
+	help
+	  This option adds work arounds for ARM Cortex-A57 erratum 1319537
+	  and A72 erratum 1319367
+
+	  Cortex-A57 and A72 cores could end-up with corrupted TLBs by
+	  speculating an AT instruction during a guest context switch.
+
 	  If unsure, say Y.
 
 config ARM64_ERRATUM_1463225