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 7F735C369A2 for ; Thu, 10 Apr 2025 16:08:18 +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:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=b/USx7FyrAAP0KVFJIR3S9nGQoNXd7rpnvG6sRwEcjk=; b=iiZ8LGpXU3Vq6o2fDUtuWXLA54 L5xPKS7V3MiszBFnsNS80e/JHKqt+8XJa7kY2m5dWG0iYCmdF9YsB8rFZzcDRIRF2aVVkJrfsV5Cg KFjtx2FlOcN6wjIAhSab/6x/Qwc6ugs4kpMtQ6tuDQc6S3X0TLKzDeBhpcXL6OadtFLkVs7lEmi8b y+k5P1Jk8FAAdd3DpECVamBsmiUhEaeHS0gSz7hn+2yR8xT9IibkfB/6Ti3Zmr9W2rs84BMubavax 4I3lV7u6k8wPutPu5wxRaqZ/mJIDmI3OaHebSxEN99LK125Tw7UDc6NkVyaNQS2CCvXgmwbtlD+Jy pAyf53/w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1u2uRf-0000000B88V-40aL; Thu, 10 Apr 2025 16:08:03 +0000 Received: from linux.microsoft.com ([13.77.154.182]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1u2tdK-0000000AysB-3yw5 for linux-arm-kernel@lists.infradead.org; Thu, 10 Apr 2025 15:16:08 +0000 Received: from [10.137.184.60] (unknown [131.107.159.188]) by linux.microsoft.com (Postfix) with ESMTPSA id EA497203B86C; Thu, 10 Apr 2025 08:16:00 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com EA497203B86C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1744298161; bh=b/USx7FyrAAP0KVFJIR3S9nGQoNXd7rpnvG6sRwEcjk=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=pPUwqlOBrIErhRnMenQuuETY6McFAU1X0L10gqqB+/k7VCThivMB270N9MVPVqKZv OKxIXSvIKMZxOqZulERNSc4wZJRTLL80Ml0pDUeMCwWwOhmkq4niN8+MWNU6gCLoNP iRC71M6wjwxVnS1zZO8WpZAJaxORmPm0mctceOLU= Message-ID: Date: Thu, 10 Apr 2025 08:16:00 -0700 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH hyperv-next 5/6] arch, drivers: Add device struct bitfield to not bounce-buffer To: Christoph Hellwig Cc: Robin Murphy , aleksander.lobakin@intel.com, andriy.shevchenko@linux.intel.com, arnd@arndb.de, bp@alien8.de, catalin.marinas@arm.com, corbet@lwn.net, dakr@kernel.org, dan.j.williams@intel.com, dave.hansen@linux.intel.com, decui@microsoft.com, gregkh@linuxfoundation.org, haiyangz@microsoft.com, hpa@zytor.com, James.Bottomley@HansenPartnership.com, Jonathan.Cameron@huawei.com, kys@microsoft.com, leon@kernel.org, lukas@wunner.de, luto@kernel.org, m.szyprowski@samsung.com, martin.petersen@oracle.com, mingo@redhat.com, peterz@infradead.org, quic_zijuhu@quicinc.com, tglx@linutronix.de, wei.liu@kernel.org, will@kernel.org, iommu@lists.linux.dev, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, x86@kernel.org, apais@microsoft.com, benhill@microsoft.com, bperkins@microsoft.com, sunilmut@microsoft.com, Suzuki K Poulose References: <20250409000835.285105-1-romank@linux.microsoft.com> <20250409000835.285105-6-romank@linux.microsoft.com> <0eb87302-fae8-4708-aaf8-d16e836e727f@arm.com> <0ab2849a-5c03-4a8c-891e-3cb89b20b0e4@linux.microsoft.com> <20250410072150.GA32563@lst.de> Content-Language: en-US From: Roman Kisel In-Reply-To: <20250410072150.GA32563@lst.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250410_081603_026131_C8760111 X-CRM114-Status: GOOD ( 11.18 ) 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 4/10/2025 12:21 AM, Christoph Hellwig wrote: > On Wed, Apr 09, 2025 at 09:44:03AM -0700, Roman Kisel wrote: >> Do you feel this is shoehorned in `struct device`? I couldn't find an >> appropriate private (== opaque pointer) part in the structure to store >> that bit (`struct device_private` wouldn't fit the bill) and looked like >> adding it to the struct itself would do no harm. However, my read of the >> room is that folks see that as dubious :) > > We'll need per-device information. But it is much higher level than a > need bounce buffer flag. > I see, thanks for the explanation! -- Thank you, Roman