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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A4EB3CCD1BE for ; Wed, 22 Oct 2025 20:47:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 143F08E0010; Wed, 22 Oct 2025 16:47:31 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0F52F8E0002; Wed, 22 Oct 2025 16:47:31 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0318E8E0010; Wed, 22 Oct 2025 16:47:30 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id E60908E0002 for ; Wed, 22 Oct 2025 16:47:30 -0400 (EDT) Received: from smtpin11.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 8FEC616096D for ; Wed, 22 Oct 2025 20:47:30 +0000 (UTC) X-FDA: 84026935860.11.346F242 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf02.hostedemail.com (Postfix) with ESMTP id DBFAE80002 for ; Wed, 22 Oct 2025 20:47:28 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=eMDWLrfV; spf=pass (imf02.hostedemail.com: domain of conor@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=conor@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1761166049; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=amyp0bQQLpeK8dKZTAb4WHpNFpX9yDj0u1UHnTXihyk=; b=8RNW44xF7Upibpl6Gs9eRnXrjkxMsNwKF3V9Jj8LDrSZY2YSH1FBi/jqBrZHrHGBBrXvtF gOGyCbF4V8zznXovvV+lLyJ4j2ejUTD4Kf+N883rrjsauTuo5rOT8eOTdmXDnPx6Mc9bB7 zleiXs0EAi9r1vrHTBUA2eWz0jEZf2w= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=eMDWLrfV; spf=pass (imf02.hostedemail.com: domain of conor@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=conor@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1761166049; a=rsa-sha256; cv=none; b=PDdEFofNwdEBJfGLf/AFPxrj/K2bMrDveqMdrjpmU7BrEm4imlcJhid6K79fg23FVZbKIN xef87WXgyLE3kR1lX6ktx4eelaRMCfATuiaG1tkRke9ECehrwB09rBw5bUy6W9C9N80YTT J8StloD+JY7klUa9uPgXQpeeynBo184= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id D513A4533F; Wed, 22 Oct 2025 20:47:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6F71BC4CEE7; Wed, 22 Oct 2025 20:47:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761166047; bh=e4wpAeuwnWxwPsv6xR22bTAFdrGhHjpoATj1khsZ/3E=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=eMDWLrfV+vZznUoPf7CPswB3dBThpbX2cO+2bWvkQ50o2TCrvoCdE1Cd8xXrUFRoi 4RQOPMKhr+0tnSOK+DiKcMtj1oDkCTxPA4mHmnI44BotWVAjb9ldTnLMyTQjyS1Glb ijl24xdpzSdzrCZEKhn++IHDQPpZbUdTkCvlJsrAxJb/YRqToadM7K56X3TBjl4HEM Kyj7DofAye5roHM4RI4hcbcHBS9HAWzaMufkLYbmgqUo5c4mw2HV49+ecHPYhV766I BEuFIsEhcM7FbKPeKnO/YdST5KXQbtfPvLsfWmyESS1GnxaOKoG42xaOoXjHPKwp4J 2Yalv6aXeJwRQ== Date: Wed, 22 Oct 2025 21:47:21 +0100 From: Conor Dooley To: Andrew Morton Cc: Jonathan Cameron , Catalin Marinas , linux-cxl@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, Dan Williams , "H . Peter Anvin" , Peter Zijlstra , james.morse@arm.com, Will Deacon , Davidlohr Bueso , linuxarm@huawei.com, Yushan Wang , Lorenzo Pieralisi , Mark Rutland , Dave Hansen , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, Andy Lutomirski , Dave Jiang Subject: Re: [PATCH v4 0/6] Cache coherency management subsystem Message-ID: <20251022-harsh-juggling-2d4778b0649e@spud> References: <20251022113349.1711388-1-Jonathan.Cameron@huawei.com> <20251022122241.d2aa0d7864f67112aa7691bf@linux-foundation.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="S6HWZzkHmuKfgcDz" Content-Disposition: inline In-Reply-To: <20251022122241.d2aa0d7864f67112aa7691bf@linux-foundation.org> X-Rspamd-Queue-Id: DBFAE80002 X-Rspamd-Server: rspam11 X-Rspam-User: X-Stat-Signature: ozapq69rxb5u79ydnfguxmmxjxwr8qdm X-HE-Tag: 1761166048-211490 X-HE-Meta: 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 NluTBfBy 8rpj+JQjRCZI4qRsF0P6sFmqYu+kcfnCt37lDpb8Dm/cRxZ0AZNJbyLqeMDrCL/soARjbyER+u66q6pAYqQa9TXF9h3ZF4B9nscOjFlmAXWctw/19cSaMZOQwDWLtXbwmry0KlZK71XAbMSJ8qO8peX+9QUh92EAkYDvPh5YA0485l2JItWcXCInmB5D3Z+OBlj5tC6v1adrEdeIeKCvEoWE+uL3CPavBhIFQ5TvuEF4w/gPeJ2ny/6jnWHS6rQ4jfZwdeE8cc94svKNfetjDLSqrfPt4fbbYtum2cB8L9KA4RMQEnHBDCjSaiA8btMdTxrxW3Q6bHkn8vFy/STwefb254Ut0iXPe+KEigpva7W8ueLz4WVScXjfvJRejg87h5GCU X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: --S6HWZzkHmuKfgcDz Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Oct 22, 2025 at 12:22:41PM -0700, Andrew Morton wrote: > On Wed, 22 Oct 2025 12:33:43 +0100 Jonathan Cameron wrote: >=20 > > Support system level interfaces for cache maintenance as found on some > > ARM64 systems. This is needed for correct functionality during various > > forms of memory hotplug (e.g. CXL). Typical hardware has MMIO interface > > found via ACPI DSDT. > >=20 > > Includes parameter changes to cpu_cache_invalidate_memregion() but no > > functional changes for architectures that already support this call. >=20 > I see additions to lib/ so presumably there is an expectation that > other architectures might use this. >=20 > Please expand on this. Any particular architectures in mind? Any > words of wisdom which maintainers of those architectures might benefit > from? It seems fairly probable that we're gonna end up with riscv systems where drivers are being used for both this and the existing non-standard cache ops stuff. > > How to merge? When this is ready to proceed (so subject to review > > feedback on this version), I'm not sure what the best route into the > > kernel is. Conor could take the lot via his tree for drivers/cache but > > the generic changes perhaps suggest it might be better if Andrew > > handles this? Any merge conflicts in drivers/cache will be trivial > > build file stuff. Or maybe even take it throug one of the affected > > trees such as CXL. >=20 > Let's not split the series up. Either CXL or COnor's tree is fine my > me. CXL is fine by me, greater volume there probably by orders of magnitude. --S6HWZzkHmuKfgcDz Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCaPlC2QAKCRB4tDGHoIJi 0tdvAQDJHGwCvxYrXGJs6nPPk7w5pV6+UajlzpKhldIVtCgm2QD/XrQK+qDLbAJA ymsJdZLdZoCSVVQ542yRJc4RjGzDnA8= =4U3B -----END PGP SIGNATURE----- --S6HWZzkHmuKfgcDz--