From 6d4e11c5e2e8cd54a035ba395bf8ccfa7e22cfd8 Mon Sep 17 00:00:00 2001 From: Robert Richter Date: Mon, 21 Sep 2015 22:58:35 +0200 Subject: irqchip/gicv3: Workaround for Cavium ThunderX erratum 23154 This patch implements Cavium ThunderX erratum 23154. The gicv3 of ThunderX requires a modified version for reading the IAR status to ensure data synchronization. Since this is in the fast-path and called with each interrupt, runtime patching is used using jump label patching for smallest overhead (no-op). This is the same technique as used for tracepoints. Signed-off-by: Robert Richter Reviewed-by: Marc Zygnier Acked-by: Catalin Marinas Cc: Tirumalesh Chalamarla Cc: linux-arm-kernel@lists.infradead.org Cc: Jason Cooper Cc: Will Deacon Link: http://lkml.kernel.org/r/1442869119-1814-3-git-send-email-rric@kernel.org Signed-off-by: Thomas Gleixner --- arch/arm64/Kconfig | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'arch/arm64/Kconfig') diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 07d1811aa03f..490df449377d 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -348,6 +348,16 @@ config ARM64_ERRATUM_843419 If unsure, say Y. +config CAVIUM_ERRATUM_23154 + bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed" + default y + help + The gicv3 of ThunderX requires a modified version for + reading the IAR status to ensure data synchronization + (access to icc_iar1_el1 is not sync'ed before and after). + + If unsure, say Y. + endmenu -- cgit v1.2.3