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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EDE5BC61DA4 for ; Mon, 6 Mar 2023 10:45:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229636AbjCFKpf (ORCPT ); Mon, 6 Mar 2023 05:45:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53960 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229558AbjCFKpe (ORCPT ); Mon, 6 Mar 2023 05:45:34 -0500 X-Greylist: delayed 539 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Mon, 06 Mar 2023 02:45:33 PST Received: from dvalin.narfation.org (dvalin.narfation.org [213.160.73.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1F3C91C5BE for ; Mon, 6 Mar 2023 02:45:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=narfation.org; s=20121; t=1678098974; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=u4rIRxinr1EJC64oGURBJXPpjgsfhmHhuJGOQcUl8tE=; b=O6sxW8F4mUPaIGrSkpZsODy4dqTQN3fPoJdipaKwVFn/+3IQ3thkANTcKlNUFuoBoC1yNU VeBvmQvLwMBGvGaUMFtjvkOVOeRYO4vZQp8BbaY46fGw+CCEgcwF0Y0HhijMfgf8wXKujM IH3fh3WKAy+7XEpuALN2SrNUSvGr2NQ= X-Mailbox-Line: From sven@narfation.org Mon Mar 06 10:28:15 2023 From: Sven Eckelmann To: linux-mips@linux-mips.org, Ralf Baechle , Paul Burton Cc: Paul Burton , James Hogan , Joshua Kinard , Paul Gortmaker , linux-kernel@vger.kernel.org, "Maciej W. Rozycki" , Markos Chandras , "Kirill A. Shutemov" , David Bauer Subject: Re: [PATCH 1/2] MIPS: Add barriers between dcache & icache flushes Date: Mon, 06 Mar 2023 11:28:15 +0100 Message-ID: <4818332.31r3eYUQgx@ripper> X-KMail-Identity: 80820071 X-KMail-Transport: 1618418458 X-KMail-Fcc: 108 X-KMail-Identity-Name: Sven Eckelmann X-KMail-Transport-Name: narfation.org In-Reply-To: <1456164585-26910-1-git-send-email-paul.burton@imgtec.com> References: <1456164585-26910-1-git-send-email-paul.burton@imgtec.com> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart4473054.LvFx2qVVIh"; micalg="pgp-sha512"; protocol="application/pgp-signature" Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org --nextPart4473054.LvFx2qVVIh Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii"; protected-headers="v1" From: Sven Eckelmann Date: Mon, 06 Mar 2023 11:28:15 +0100 Message-ID: <4818332.31r3eYUQgx@ripper> References: <1456164585-26910-1-git-send-email-paul.burton@imgtec.com> MIME-Version: 1.0 On Monday, 22 February 2016 19:09:44 CET Paul Burton wrote: > Index-based cache operations may be arbitrarily reordered by out of > order CPUs. Thus code which writes back the dcache & then invalidates > the icache using indexed cache ops must include a barrier between > operating on the 2 caches in order to prevent the scenario in which: > > - icache invalidation occurs. > > - icache fetch occurs, due to speculation. > > - dcache writeback occurs. > > If the above were allowed to happen then the icache would contain stale > data. Forcing the dcache writeback to complete before the icache > invalidation avoids this. > > Signed-off-by: Paul Burton > Cc: James Hogan > --- What happened to this patch? Because it seems like it is required for some 74kc devices to get them booting (instead of being stuck in an endless tlbmiss_handler_setup_pgd loop): * https://github.com/freifunk-gluon/gluon/issues/2784 * https://github.com/openwrt/openwrt/commit/ea6fb9c16dfb9763ea681803db65644b68bae873 * https://github.com/freifunk-gluon/gluon/pull/2810 Kind regards, Sven --nextPart4473054.LvFx2qVVIh Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part. Content-Transfer-Encoding: 7Bit -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEF10rh2Elc9zjMuACXYcKB8Eme0YFAmQFwD8ACgkQXYcKB8Em e0bR3Q//Riq/B7nemvF/RQ63b4IjVgBkq81+RlQ6xLBdaDEnFr8phcT8RnSJ74tb ljc8OkXvqL56Ddt9svcyBRHma4gu3UbowdxJCMw4xgv6SV0Fa8yd0Yk5NSlvOsv2 dlg21L+515rYEz9Ow/FcvC1x60CIOTZLMIw87qu2lOgQY7SdG0QB4z/GZWg6xubR J3iHMB1b0JGdZRLA+u5GK0235oZXU0zbMk8ZOovu111E7AMULcnwCmbUvPEbr21k Gw1BPAuYYpb8h3dk3lkY3GxkwGyeZrblFiOav8pd2y73hDdWgo4da8t+BCAUV4oM Ks7DabVTGZyAFlXcrQZ0RczK3C6MZF6Z1KXSuJxI2NiTNvl78OUbfek9DDVYgA8g nLcjXNZtoOVoF5/1I8+7bCcNnXwfhaEHidO0IkY9RkezYoQWeFeIeLfaV2BFFwG7 RllYLH/NJGVAWJJrmcZEWF6v9Q6w/G/QySO+OjJ007Ph9HyjWLmiHGrizOkkTj0z KozMR8iRY6bpT6B+t2Zm0xmN9JRDpHRgCVkqZcE4BF2fptwcB/7GsfiogJ7heiIL OyDLNNoUmE7I6eJDCR/bHL4yLHp/8SctrD/wB7nk9NEouhXeCtqw/xg5e2elOBGw 7K3T3F5lICq0FXFZg5dM863XK7sCeIVzObj2O9CBuS3BGZhwDL4= =WpWD -----END PGP SIGNATURE----- --nextPart4473054.LvFx2qVVIh--