From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 09B533E1D13 for ; Thu, 21 May 2026 14:13:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779372782; cv=none; b=LBG6EFHWasmnfDIDN0U0NAefUwez2BbdMgIFJpi0yQjMxVwlm11QT4ohsNvsNvuwI09vOVO1Tq22nluvQP/jQzWDpjJtrFjn4juY5pCme+7639Mo6IXPxPUfn+en1tnMSsYvRpwvmAilkyFB/WuGOoi3KW0cgIw66fWO+M9Dq98= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779372782; c=relaxed/simple; bh=VHP7e6UawfJQJKJVkY1Uro//bDusGdDMvG+to9XrL/A=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=JJTwQCzIOvhgmNTe6iXzefmD7hZnhFXbMFuc0R0rkE5qBmT2ikGPszZG10+WE2d5Lqq1imuvsUuBzWRBSVUT2xlzC5JfHnKZl72J8M5cESUEOLJhhOP6QUH3knxfJdHqbma+FrDGtUxjhZOUEODgmaq84SAOAQ9+NYjhPu4JKLk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PvEZzZ16; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="PvEZzZ16" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BA34D1F000E9; Thu, 21 May 2026 14:12:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779372780; bh=MXq8TjfuRwBJDFmcjQaKf5Ac9Rz8xfKy5c9Zpo6weko=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=PvEZzZ1655FGmbd6zXJ6T/rMFb7CmhUfEtbJLoTjU4tmYnoX6+Tqswijm+UqlUu+8 ouyZbpZ1dwiKOU8M2Rmncv8jA2PnfKJhZcWGDR4432ZtareJ+vhZjDS9sNe1eymlb4 C5m+SRVzQDOkvlSnW5WAWS4rKl43pyPTozTbRuXJ3E5Kz7Lx1mcl3i5UCwQMEek6Zc XAWGv4rFOEhcUKSDFhPyU6BfRrxSczoaj21AiNDGVo6aHIQN3CdBIsGVVNzl2MvnFw juL43kkVxDrWvidYTzZ1IcfvvxXLYnZ49hcXZqzOvkfCdXyg4om6GUOED5oYQ9Jr24 +JU7LEVKranRg== Date: Thu, 21 May 2026 15:12:55 +0100 From: Conor Dooley To: Jonathan Cameron Cc: Srirangan Madhavan , catalin.marinas@arm.com, will@kernel.org, mark.rutland@arm.com, lpieralisi@kernel.org, sudeep.holla@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, vsethi@nvidia.com, jevans@nvidia.com, raghupathyk@nvidia.com, srikars@nvidia.com, nbenech@nvidia.com, alwilliamson@nvidia.com, Dan Williams Subject: Re: [RFC PATCH 2/2] arm64: mm: add SMCCC-backed cache invalidate provider Message-ID: <20260521-cried-unburned-b1bef70a7a69@spud> References: <20260521073047.320614-1-smadhavan@nvidia.com> <20260521073047.320614-3-smadhavan@nvidia.com> <20260521121812.2e4abd71@jic23-huawei> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="B3Dc7X1SeOCF54Ze" Content-Disposition: inline In-Reply-To: <20260521121812.2e4abd71@jic23-huawei> --B3Dc7X1SeOCF54Ze Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, May 21, 2026 at 12:18:12PM +0100, Jonathan Cameron wrote: > On Thu, 21 May 2026 07:30:47 +0000 > Srirangan Madhavan wrote: >=20 > > Add an arm64 cache maintenance backend that discovers SMCCC cache > > clean+invalidate support, queries attributes, handles transient BUSY and > > RATE_LIMITED responses with bounded retries, and registers with the gen= eric > > cache coherency framework. > >=20 > > Signed-off-by: Srirangan Madhavan > Hi Srirangan, >=20 > Other than the file location and Kconfig option comments, everything else > is really trivial. + some musings about maybe being worth more clever > fusing of ops in the future if it turns out to be useful. >=20 > > --- > > MAINTAINERS | 1 + > > arch/arm64/mm/Makefile | 1 + > > arch/arm64/mm/cache_maint.c | 180 ++++++++++++++++++++++++++++++++++++ >=20 > File location wise, this is a driver for a subsystem, be it one closely > coupled to arm. Arm maintainers, do you want it in there or in drivers/c= ache ? > My personal preference is always to keep drivers with subsystems but I do= n't > care that much. At the risk of stepping on Will's/Catalin's toes, I'll butt in here.. If this was on riscv, using an ecall into sbi firmware, I'd be asking for it to be put in drivers/cache. The mechanism for requesting the ops is arch-specific, but the actual execution of it is not, right? The actual execution is going to depend on the device-specific firmware that the smc is made to. That puts it in the same boat as clk-scmi to me, but I'm not really familiar with how these things break down on arm64 to be sure. > > 3 files changed, 182 insertions(+) > > create mode 100644 arch/arm64/mm/cache_maint.c > >=20 > > diff --git a/MAINTAINERS b/MAINTAINERS > > index 2fb1c75afd16..33c35f8e6e40 100644 > > --- a/MAINTAINERS > > +++ b/MAINTAINERS > > @@ -25383,6 +25383,7 @@ M: Jonathan Cameron > > S: Maintained > > T: git https://git.kernel.org/pub/scm/linux/kernel/git/conor/linux.git/ > > F: Documentation/devicetree/bindings/cache/ > > +F: arch/arm64/mm/cache_maint.c >=20 > I wonder if this should just have a separate maintainers entry?=20 > We did that for the hisi driver. >=20 > If not maybe add yourself as at least a Reviewer so that you get +CC'd > on relevant changes. >=20 > Conor, what do you think makes sense here. I think it is very weird to have an arch/arm64/mm file in this entry, implying that I would be applying patches for it, which I do not consider to be appropriate. If it gets moved to drivers/cache, then it I think a standalone maintainers entry for the driver is a good idea. Cheers, Conor. --B3Dc7X1SeOCF54Ze Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCag8S0QAKCRB4tDGHoIJi 0rO7AQDTYhq4WHwZ2SbzpeFW1Iak0z7hL6cFW6LeaPWHDMqiVQEA4bNnsd3mMhtD Lk8HFV8lYUn76z12P8ziDObCXHs8IAA= =NF1t -----END PGP SIGNATURE----- --B3Dc7X1SeOCF54Ze--