From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex =?utf-8?Q?Benn=C3=A9e?= Subject: Re: [PATCH v4 20/28] arm64/sve: Add prctl controls for userspace vector length management Date: Mon, 30 Oct 2017 16:12:13 +0000 Message-ID: <87fua07gyq.fsf@linaro.org> References: <1509101470-7881-1-git-send-email-Dave.Martin@arm.com> <1509101470-7881-21-git-send-email-Dave.Martin@arm.com> <87r2toiikt.fsf@linaro.org> <20171028160506.GI19485@e103592.cambridge.arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Return-path: Received: from mail-wr0-f194.google.com ([209.85.128.194]:46158 "EHLO mail-wr0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752642AbdJ3QMQ (ORCPT ); Mon, 30 Oct 2017 12:12:16 -0400 Received: by mail-wr0-f194.google.com with SMTP id l1so13189546wrc.3 for ; Mon, 30 Oct 2017 09:12:15 -0700 (PDT) In-reply-to: <20171028160506.GI19485@e103592.cambridge.arm.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Dave Martin Cc: linux-arch@vger.kernel.org, Okamoto Takayuki , libc-alpha@sourceware.org, Ard Biesheuvel , Szabolcs Nagy , Catalin Marinas , Will Deacon , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Dave Martin writes: > On Fri, Oct 27, 2017 at 06:52:50PM +0100, Alex Benn=C3=A9e wrote: >> >> Dave Martin writes: >> >> > This patch adds two arm64-specific prctls, to permit userspace to >> > control its vector length: >> > >> > * PR_SVE_SET_VL: set the thread's SVE vector length and vector >> > length inheritance mode. >> > >> > * PR_SVE_GET_VL: get the same information. >> > >> > Although these prctls resemble instruction set features in the SVE >> > architecture, they provide additional control: the vector length >> > inheritance mode is Linux-specific and nothing to do with the >> > architecture, and the architecture does not permit EL0 to set its >> > own vector length directly. Both can be used in portable tools >> > without requiring the use of SVE instructions. >> > >> > Signed-off-by: Dave Martin >> > Reviewed-by: Catalin Marinas >> > Cc: Alex Benn=C3=A9e >> >> FYI there is a minor conflict applying this on current master. > > There are some trivial conflicts with one or two patches that already > went into arm64/for-next/core, so I based on that for this posting, not > torvalds/master. > > There's a note in the cover letter giving the precise commit I based > on, though the branch doesn't seem to have moved yet since I posted. Ahh probably those. It was only a few header file shuffles. I was rushing to apply before my flight back I failed to note the change in base commit. > > Otherwise, I don't see any conflict -- can you give details? Only that #endif _ASM_ had been dropped from the header file. > > Cheers > ---Dave From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f194.google.com ([209.85.128.194]:46158 "EHLO mail-wr0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752642AbdJ3QMQ (ORCPT ); Mon, 30 Oct 2017 12:12:16 -0400 Received: by mail-wr0-f194.google.com with SMTP id l1so13189546wrc.3 for ; Mon, 30 Oct 2017 09:12:15 -0700 (PDT) References: <1509101470-7881-1-git-send-email-Dave.Martin@arm.com> <1509101470-7881-21-git-send-email-Dave.Martin@arm.com> <87r2toiikt.fsf@linaro.org> <20171028160506.GI19485@e103592.cambridge.arm.com> From: Alex =?utf-8?Q?Benn=C3=A9e?= Subject: Re: [PATCH v4 20/28] arm64/sve: Add prctl controls for userspace vector length management In-reply-to: <20171028160506.GI19485@e103592.cambridge.arm.com> Date: Mon, 30 Oct 2017 16:12:13 +0000 Message-ID: <87fua07gyq.fsf@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Sender: linux-arch-owner@vger.kernel.org List-ID: To: Dave Martin Cc: linux-arch@vger.kernel.org, Okamoto Takayuki , libc-alpha@sourceware.org, Ard Biesheuvel , Szabolcs Nagy , Catalin Marinas , Will Deacon , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Message-ID: <20171030161213.jUvNSeHffu94TAUyoStSrKK5WZQVg_bV25wAioO6sf4@z> Dave Martin writes: > On Fri, Oct 27, 2017 at 06:52:50PM +0100, Alex Benn=C3=A9e wrote: >> >> Dave Martin writes: >> >> > This patch adds two arm64-specific prctls, to permit userspace to >> > control its vector length: >> > >> > * PR_SVE_SET_VL: set the thread's SVE vector length and vector >> > length inheritance mode. >> > >> > * PR_SVE_GET_VL: get the same information. >> > >> > Although these prctls resemble instruction set features in the SVE >> > architecture, they provide additional control: the vector length >> > inheritance mode is Linux-specific and nothing to do with the >> > architecture, and the architecture does not permit EL0 to set its >> > own vector length directly. Both can be used in portable tools >> > without requiring the use of SVE instructions. >> > >> > Signed-off-by: Dave Martin >> > Reviewed-by: Catalin Marinas >> > Cc: Alex Benn=C3=A9e >> >> FYI there is a minor conflict applying this on current master. > > There are some trivial conflicts with one or two patches that already > went into arm64/for-next/core, so I based on that for this posting, not > torvalds/master. > > There's a note in the cover letter giving the precise commit I based > on, though the branch doesn't seem to have moved yet since I posted. Ahh probably those. It was only a few header file shuffles. I was rushing to apply before my flight back I failed to note the change in base commit. > > Otherwise, I don't see any conflict -- can you give details? Only that #endif _ASM_ had been dropped from the header file. > > Cheers > ---Dave -- Alex Benn=C3=A9e