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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1C49DEFCD99 for ; Mon, 9 Mar 2026 11:50:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Subject:CC:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=vQGsm/7WyWfrczKkUG7EwZyVp3H8TpwX98GqbdoVhBM=; b=R1yApzIpKbv/s4d///Yuncwi5X XrV08ZqRZt2gL3CndXHzABXFid100o9fMR3rAM6RJgqgv7Q4QT5low8jkSw2sbZM/daxyy7bOIwoX cJw60vrGegqCaclEdYhjD19ORqF14+bX7unoTsn7Ys4FF0ogcVtlopzAh+jQ0f0oRfNcZJB8gSDpo k3Chc36evVt4fzyUPjhVZVYS3KSenatrquqAq9xa2GpECL8i/L1QRhxjUhci6AWAh5z+4k6jMJioo gT4M1STg+2p8KGVTPD0MMLZnYM08Ys+Jt+PG1vp/VH9zhlxdlTvmYvtqwknXSsXn+yymQhQJo3vsU cW+Cduig==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vzZ7n-00000007EBi-0Qhr; Mon, 09 Mar 2026 11:50:15 +0000 Received: from frasgout.his.huawei.com ([185.176.79.56]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vzZ7j-00000007EB8-1WQp for linux-arm-kernel@lists.infradead.org; Mon, 09 Mar 2026 11:50:13 +0000 Received: from mail.maildlp.com (unknown [172.18.224.107]) by frasgout.his.huawei.com (SkyGuard) with ESMTPS id 4fTwKL3ygXzJ46C2; Mon, 9 Mar 2026 19:49:26 +0800 (CST) Received: from dubpeml500005.china.huawei.com (unknown [7.214.145.207]) by mail.maildlp.com (Postfix) with ESMTPS id 69ABF40584; Mon, 9 Mar 2026 19:50:09 +0800 (CST) Received: from localhost (10.203.177.15) by dubpeml500005.china.huawei.com (7.214.145.207) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Mon, 9 Mar 2026 11:50:08 +0000 Date: Mon, 9 Mar 2026 11:50:07 +0000 From: Jonathan Cameron To: Nicolin Chen CC: , , , , , , , , , , , , , , , Subject: Re: [PATCH v3 2/3] PCI: Allow ATS to be always on for pre-CXL devices Message-ID: <20260309115007.00005442@huawei.com> In-Reply-To: References: X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.203.177.15] X-ClientProxiedBy: lhrpeml500012.china.huawei.com (7.191.174.4) To dubpeml500005.china.huawei.com (7.214.145.207) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260309_045012_808901_A2ED5771 X-CRM114-Status: UNSURE ( 7.83 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, 6 Mar 2026 15:41:16 -0800 Nicolin Chen wrote: > Some NVIDIA GPU/NIC devices, although don't implement the CXL config space, > they have many CXL-like properties. Call this kind "pre-CXL". > > Similar to CXL.cache capaiblity, these pre-CXL devices also require the ATS > function even when their RIDs are IOMMU bypassed, i.e. keep ATS "always on" > v.s. "on demand" when a non-zero PASID line gets enabled in SVA use cases. > > Introduce pci_dev_specific_ats_always_on() quirk function to scan a list of > IDs for these device. Then, include it pci_ats_always_on(). > > Suggested-by: Jason Gunthorpe > Signed-off-by: Nicolin Chen Seems like a reasonably tidy quirk. Reviewed-by: Jonathan Cameron