From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0A47FC3A59C for ; Fri, 16 Aug 2019 01:42:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CF50F206C1 for ; Fri, 16 Aug 2019 01:42:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726497AbfHPBma (ORCPT ); Thu, 15 Aug 2019 21:42:30 -0400 Received: from ozlabs.org ([203.11.71.1]:49931 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726357AbfHPBma (ORCPT ); Thu, 15 Aug 2019 21:42:30 -0400 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 468mKG2TSzz9sN6; Fri, 16 Aug 2019 11:42:26 +1000 (AEST) From: Michael Ellerman To: Greg Kroah-Hartman , Alastair D'Silva Cc: alastair@d-silva.org, stable@vger.kernel.org, Benjamin Herrenschmidt , Paul Mackerras , Allison Randal , Thomas Gleixner , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] powerpc: Allow flush_(inval_)dcache_range to work across ranges >4GB In-Reply-To: <20190815071924.GA26670@kroah.com> References: <20190815045543.16325-1-alastair@au1.ibm.com> <20190815071924.GA26670@kroah.com> Date: Fri, 16 Aug 2019 11:42:22 +1000 Message-ID: <87mug97uo1.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Greg Kroah-Hartman writes: > On Thu, Aug 15, 2019 at 02:55:42PM +1000, Alastair D'Silva wrote: >> From: Alastair D'Silva >> >> Heads Up: This patch cannot be submitted to Linus's tree, as the affected >> assembler functions have already been converted to C. That was done in upstream commit: 22e9c88d486a ("powerpc/64: reuse PPC32 static inline flush_dcache_range()") Which is a larger change that we don't want to backport. This patch is a minimal fix for stable trees. >> When calling flush_(inval_)dcache_range with a size >4GB, we were masking >> off the upper 32 bits, so we would incorrectly flush a range smaller >> than intended. >> >> This patch replaces the 32 bit shifts with 64 bit ones, so that >> the full size is accounted for. >> >> Signed-off-by: Alastair D'Silva >> --- >> arch/powerpc/kernel/misc_64.S | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) Acked-by: Michael Ellerman > > > This is not the correct way to submit patches for inclusion in the > stable kernel tree. Please read: > https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html > for how to do this properly. > > Hi Greg, This is "option 3", submit the patch directly, and the patch "deviates from the original upstream patch" because the upstream patch was a wholesale conversion from asm to C. This patch applies cleanly to v4.14 and v4.19. The change log should have mentioned which upstream patch it is not a backport of, is there anything else we should have done differently to avoid the formletter bot :) cheers