From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 3382D1A70E for ; Fri, 20 Oct 2023 13:02:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="TO+shwx8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 82E43C433C8; Fri, 20 Oct 2023 13:02:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1697806946; bh=XrtTOoK/79ng3GDfEJWxxSA/EXot0zFmqnMpJdl97B0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=TO+shwx8qZBPtRl4YUZE2O8zQWIAhmcsyZhMni6EGqFJ0KmdHXJOxV08qNvJ5Jkj8 stQ7Ld0G/obWjdleGuAvlC5tjIN2UNRmSSfy/QPENa78SYks95dLsQ2/HHng+k7DoP 64bPMq8GhfElvnoVlI1fF2iY/QC+SSwm40c5VMx0vaL11vHPgbr+JjbO8WJwrbAl/F FHS3SVADrgOceemJekTcr9qaJ8ioJl7fYv5nWt/z+uO4XQyT1ZHsbS9Ftzz63dJm7u oLqA3164ljEEjBj0a2kiBsCP4Q60AXIgJqgPj6x2buNKwpZsUP9K+qKh43QL0Lmzic i2QqmICcgcdGw== Received: from sofa.misterjones.org ([185.219.108.64] helo=wait-a-minute.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1qtp8x-0067s7-RQ; Fri, 20 Oct 2023 14:02:24 +0100 Date: Fri, 20 Oct 2023 14:02:22 +0100 Message-ID: <87v8b15twh.wl-maz@kernel.org> From: Marc Zyngier To: Ryan Roberts Cc: Catalin Marinas , Will Deacon , Oliver Upton , Suzuki K Poulose , James Morse , Zenghui Yu , Ard Biesheuvel , Anshuman Khandual , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev Subject: Re: [PATCH v4 01/12] arm64/mm: Update non-range tlb invalidation routines for FEAT_LPA2 In-Reply-To: <8a098442-4de8-42f1-9308-848a1d54f21a@arm.com> References: <20231009185008.3803879-1-ryan.roberts@arm.com> <20231009185008.3803879-2-ryan.roberts@arm.com> <87zg0f59ae.wl-maz@kernel.org> <86edhpn2gd.wl-maz@kernel.org> <8a098442-4de8-42f1-9308-848a1d54f21a@arm.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/28.2 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: ryan.roberts@arm.com, catalin.marinas@arm.com, will@kernel.org, oliver.upton@linux.dev, suzuki.poulose@arm.com, james.morse@arm.com, yuzenghui@huawei.com, ardb@kernel.org, anshuman.khandual@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Fri, 20 Oct 2023 13:39:47 +0100, Ryan Roberts wrote: > > On 20/10/2023 09:05, Marc Zyngier wrote: > > Maybe. There is something to be said about making the range rework > > (decreasing scale) an independent patch, as it is a significant change > > on its own. But maybe the rest of the plumbing can be grouped > > together. > > But that's effectively the split I have now, isn't it? The first patch > introduces TLBI_TTL_UNKNOWN to enable use of 0 as a ttl hint. Then the second > patch reworks the range stuff. I don't quite follow what you are suggesting. Not quite. What I'm proposing is that you pull the scale changes in their own patch, and preferably without any change to the external API (i.e. no change to the signature of the helper). They any extra change, such as the TTL rework can go separately. So while this is similar to your existing split, I'd like to see it without any churn around the calling convention. Which means turning the ordering around, and making use of a static key in the various helpers that need to know about LPA2. M. -- Without deviation from the norm, progress is not possible.