From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161281AbcA1Lax (ORCPT ); Thu, 28 Jan 2016 06:30:53 -0500 Received: from mail-ig0-f178.google.com ([209.85.213.178]:35857 "EHLO mail-ig0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161163AbcA1Lap (ORCPT ); Thu, 28 Jan 2016 06:30:45 -0500 MIME-Version: 1.0 In-Reply-To: <56A9FB15.1080203@arm.com> References: <1453936230-7305-1-git-send-email-dann.frazier@canonical.com> <20160128103441.GS14823@e104818-lin.cambridge.arm.com> <20160128110820.GE30928@arm.com> <56A9FB15.1080203@arm.com> Date: Thu, 28 Jan 2016 12:30:44 +0100 Message-ID: Subject: Re: [PATCH] arm64: Disallow combination of ARCH_XGENE and 16K page size From: Ard Biesheuvel To: "Suzuki K. Poulose" Cc: Will Deacon , Catalin Marinas , Feng Kan , dann frazier , Duc Dang , "linux-kernel@vger.kernel.org" , Loc Ho , Kumar Sankaran , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 28 January 2016 at 12:27, Suzuki K. Poulose wrote: > On 28/01/16 11:08, Will Deacon wrote: >> >> On Thu, Jan 28, 2016 at 10:34:41AM +0000, Catalin Marinas wrote: >>> >>> On Wed, Jan 27, 2016 at 04:10:30PM -0700, dann frazier wrote: >>>> >>>> 16K page size is an optional feature of the architecture, and is not >>>> supported by the X-Gene SoC family. > > > This enables support for AppliedMicro X-Gene SOC Family >>> >>> >>> This would be the case on Juno as well. But maybe at some point the >>> X-Gene family would gain a CPU with such support. >>> >>> Anyway, I would rather make 16K pages depend on EXPERT, make it a bit >>> harder to enable. We've had a few questions recently about enabling it >>> on CPUs that don't have such feature. >> >> >> I thought there was also a suggestion that we could fail gracefully in >> the EFI stub if we detected an unsupported page size? > > > Yes, there was. But then it was also recommended [1] to add a new stubbed > function > for both arm & arm64, where it got lost. May be we should revive it. > > https://lkml.org/lkml/2015/10/15/489 > I can pick this up -- Ard. From mboxrd@z Thu Jan 1 00:00:00 1970 From: ard.biesheuvel@linaro.org (Ard Biesheuvel) Date: Thu, 28 Jan 2016 12:30:44 +0100 Subject: [PATCH] arm64: Disallow combination of ARCH_XGENE and 16K page size In-Reply-To: <56A9FB15.1080203@arm.com> References: <1453936230-7305-1-git-send-email-dann.frazier@canonical.com> <20160128103441.GS14823@e104818-lin.cambridge.arm.com> <20160128110820.GE30928@arm.com> <56A9FB15.1080203@arm.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 28 January 2016 at 12:27, Suzuki K. Poulose wrote: > On 28/01/16 11:08, Will Deacon wrote: >> >> On Thu, Jan 28, 2016 at 10:34:41AM +0000, Catalin Marinas wrote: >>> >>> On Wed, Jan 27, 2016 at 04:10:30PM -0700, dann frazier wrote: >>>> >>>> 16K page size is an optional feature of the architecture, and is not >>>> supported by the X-Gene SoC family. > > > This enables support for AppliedMicro X-Gene SOC Family >>> >>> >>> This would be the case on Juno as well. But maybe at some point the >>> X-Gene family would gain a CPU with such support. >>> >>> Anyway, I would rather make 16K pages depend on EXPERT, make it a bit >>> harder to enable. We've had a few questions recently about enabling it >>> on CPUs that don't have such feature. >> >> >> I thought there was also a suggestion that we could fail gracefully in >> the EFI stub if we detected an unsupported page size? > > > Yes, there was. But then it was also recommended [1] to add a new stubbed > function > for both arm & arm64, where it got lost. May be we should revive it. > > https://lkml.org/lkml/2015/10/15/489 > I can pick this up -- Ard.