From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id F3B74B6F7A for ; Tue, 12 Jul 2011 13:51:51 +1000 (EST) Subject: Re: [PATCH] powerpc: add denormalisation exception handling for POWER6/7 Mime-Version: 1.0 (Apple Message framework v1084) Content-Type: text/plain; charset=us-ascii From: Kumar Gala In-Reply-To: <11738.1310363538@neuling.org> Date: Mon, 11 Jul 2011 22:51:33 -0500 Message-Id: <9875FD87-1762-4CCE-8A34-7BAC2C42E9A6@kernel.crashing.org> References: <11738.1310363538@neuling.org> To: Michael Neuling Cc: Paul Mackerras , miltonm@bga.com, linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Jul 11, 2011, at 12:52 AM, Michael Neuling wrote: > On POWER6 and POWER7 if the input operand to an instruction is a > denormalised single precision binary floating we can take a > denormalisation exception where it's expected that the hypervisor = (HV=3D1) > will fix up the inputs before the instruction is run. >=20 > This adds code to handle this denormalisation exception for POWER6 and > POWER7. >=20 > It also add a CONFIG_PPC_DENORMALISATION option and sets it in > pseries/ppc64_defconfig.=20 >=20 > This is useful on bare metal systems only. Based on patch from Milton > Miller. >=20 > Signed-off-by: Michael Neuling >=20 > --- > arch/powerpc/Kconfig | 7 + > arch/powerpc/configs/ppc64_defconfig | 1=20 > arch/powerpc/configs/pseries_defconfig | 1=20 > arch/powerpc/include/asm/ppc-opcode.h | 2=20 > arch/powerpc/include/asm/reg.h | 1=20 > arch/powerpc/kernel/exceptions-64s.S | 125 = +++++++++++++++++++++++++++++++++ > 6 files changed, 137 insertions(+) Is it possible to run POWER6/7 systems in baremetal if you are not IBM? Just wondering if this is useful to anyone but IBM. - k=