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 3650F1CDA27; Fri, 1 Nov 2024 16:58:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730480309; cv=none; b=Rw0a2z+qtg1CIRawBejPDr8dnBoNVF0KF/RpuLOLs3xtpI0by3Y7WCPevkEOJAdvg5gWab0l540MjB+bka92tN1nZ14qCWH1sR4e/+++NUG8+26tYpr+Vl+aQ4zGxSVzfwYsAKCXhINhRESLHxdr8L3/kouKvtrorG9HQ06kymI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730480309; c=relaxed/simple; bh=GVPNqWb/dknPmd6p+uZIGZMEUGgcHP7E/AKSLlgyl/E=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=plN5s63EiTerjhrAB312h4WoPZyF1pRa0GFV/Ih/Em+4IJ36Eo0T0hOfKMqiA6tfWAnjUiZopYGVvj2rv9YcAgrJKtLh4Jo7TesQPhbiXzSKo3rCYgmTYyv+xKsOrcwXTsnZxNy1uV/Wwb7/u5ZSewCguWIKvbgK6Xkx/mPM73Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=K9Ar2Dcf; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="K9Ar2Dcf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8B7C1C4CED5; Fri, 1 Nov 2024 16:58:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730480308; bh=GVPNqWb/dknPmd6p+uZIGZMEUGgcHP7E/AKSLlgyl/E=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=K9Ar2Dcf0WfbH4pBzF8hWpplM6RzTAXWgzy0ylB018g4CzZFpaSNTJk6EOzZdDyaN d998mKDc3DDzrOEviXB6UF5p2ucgmSxnz21UpVMy9By7DaASKlvs/zG0TDiY4gJZXu T7LMparyz0S+6yfu3VWIGfZFB1OgXldJejdaWUyAzqEzk5o7YuhrxRtGdIlWrLHjGE yWWCMZKzibotcjJf628ub5i8+Y9yFCiGG2RLsgkkUBGuT+JAOc6d26S86yLdu8tev4 2giPsnN1WcTxGWLTsSULAGYLInqh29lYHyJ5qVoKTVLHSnwv5JkuZwuKtzDoWFIwVr LTZPKmhyfRDVw== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.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 1t6uyg-008vzw-Fr; Fri, 01 Nov 2024 16:58:26 +0000 Date: Fri, 01 Nov 2024 16:58:26 +0000 Message-ID: <86ldy228nh.wl-maz@kernel.org> From: Marc Zyngier To: Bjorn Helgaas Cc: Frank Li , Bjorn Helgaas , Richard Zhu , Lucas Stach , Lorenzo Pieralisi , Krzysztof =?UTF-8?B?V2lsY3p5?= =?UTF-8?B?xYRza2k=?= , Manivannan Sadhasivam , Rob Herring , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, imx@lists.linux.dev, alyssa@rosenzweig.io, bpf@vger.kernel.org, broonie@kernel.org, jgg@ziepe.ca, joro@8bytes.org, lgirdwood@gmail.com, p.zabel@pengutronix.de, robin.murphy@arm.com, will@kernel.org Subject: Re: [PATCH v3 1/2] PCI: Add enable_device() and disable_device() callbacks for bridges In-Reply-To: <20241030210043.GA1219525@bhelgaas> References: <20241024-imx95_lut-v3-1-7509c9bbab86@nxp.com> <20241030210043.GA1219525@bhelgaas> 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/29.4 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org 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: helgaas@kernel.org, Frank.Li@nxp.com, bhelgaas@google.com, hongxing.zhu@nxp.com, l.stach@pengutronix.de, lpieralisi@kernel.org, kw@linux.com, manivannan.sadhasivam@linaro.org, robh@kernel.org, shawnguo@kernel.org, s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, imx@lists.linux.dev, alyssa@rosenzweig.io, bpf@vger.kernel.org, broonie@kernel.org, jgg@ziepe.ca, joro@8bytes.org, lgirdwood@gmail.com, p.zabel@pengutronix.de, robin.murphy@arm.com, will@kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Wed, 30 Oct 2024 21:00:43 +0000, Bjorn Helgaas wrote: > > On Thu, Oct 24, 2024 at 06:34:44PM -0400, Frank Li wrote: > > Some PCIe host bridges require special handling when enabling or disabling > > PCIe Endpoints. For example, the i.MX95 platform has a lookup table to map > > Requester IDs to StreamIDs, which are used by the SMMU and MSI controller > > to identify the source of DMA accesses. > > > > Without this mapping, DMA accesses may target unintended memory, which > > would corrupt memory or read the wrong data. > > > > Add a host bridge .enable_device() hook the imx6 driver can use to > > configure the Requester ID to StreamID mapping. The hardware table isn't > > big enough to map all possible Requester IDs, so this hook may fail if no > > table space is available. In that case, return failure from > > pci_enable_device(). > > > > It might make more sense to make pci_set_master() decline to enable bus > > mastering and return failure, but it currently doesn't have a way to return > > failure. > > > > Signed-off-by: Frank Li > > Acked-by: Bjorn Helgaas > > Merge along with the imx6 change. It'd be good to have this on a stable branch somewhere so that I can refer to it when posting the conversion for the Apple driver to that infrastructure, removing the need for a bus notifier. Otherwise, I'll just cherry-pick that patch and post the whole thing. Thanks, M. -- Without deviation from the norm, progress is not possible.