From b92a66a65cb4480774066d9a3080c77eb34b7232 Mon Sep 17 00:00:00 2001 From: Michael Neuling Date: Mon, 10 Sep 2012 00:35:26 +0000 Subject: powerpc: Add denormalisation exception handling for POWER6/7 On POWER6 and POWER7 if the input operand to an instruction is a denormalised single precision binary floating point value we can take a denormalisation exception where it's expected that the hypervisor (HV=1) will fix up the inputs before the instruction is run. This adds code to handle this denormalisation exception for POWER6 and POWER7. It also add a CONFIG_PPC_DENORMALISATION option and sets it in pseries/ppc64_defconfig. This is useful on bare metal systems only. Based on patch from Milton Miller. Signed-off-by: Michael Neuling Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/Kconfig | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'arch/powerpc/Kconfig') diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 98e513b6270..748ccaa3b4b 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -560,6 +560,14 @@ config SCHED_SMT when dealing with POWER5 cpus at a cost of slightly increased overhead in some places. If unsure say N here. +config PPC_DENORMALISATION + bool "PowerPC denormalisation exception handling" + depends on PPC_BOOK3S_64 + default "n" + ---help--- + Add support for handling denormalisation of single precision + values. Useful for bare metal only. If unsure say Y here. + config CMDLINE_BOOL bool "Default bootloader kernel arguments" -- cgit v1.2.3