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 1BFF8E552; Sun, 3 Nov 2024 13:58:41 +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=1730642322; cv=none; b=ktDJxTysvazNOAIN81oArGydgVwhuvpTYyFruKfoK83/q9jg3Do1PbFocrFYm/1E/Zp1MqBbtyj4wONhFUAogvzLyS+hVe+Xeh8LTb9whYDe9iFq1tWAZVP2moFg3NzKxlNjzljdKSnEaDPzTNTM7gDbgmRnNWZedi62uLjBAHo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730642322; c=relaxed/simple; bh=b+RF7lm6Z+FCvqTFgFQeWEcA4ixEZihhp0KC6dDlaK0=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=EE2OtEsWonJf8tEAAydvAj6wXvmUxgQV1ReeZnQtdn5Cfvu7j7ZntH22BEfjl0fkZAZjzXa385aYUUGdm7ixXYoTbO9PtAXCmuEpK1aySlrRl6IIQyUuBbM4BdOXp6bnr6XgZJpNHqjxc8anCy3fiZPtJb6aq12srzXQ8oE/qoM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rAAG+Oa2; 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="rAAG+Oa2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 91E47C4CECD; Sun, 3 Nov 2024 13:58:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730642321; bh=b+RF7lm6Z+FCvqTFgFQeWEcA4ixEZihhp0KC6dDlaK0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=rAAG+Oa2ZJrDzl4OpS4oFv01B7VwCbJhH76WJxNefzhamcNgHbPty1p0119lJCChl y7So3fRyIejrH1zj8qOeyU8Mh2EeAm16VmTFTc8aORuoDZpGX3lxbRuh6hDJMKWjSg tjPPxkYVnrX3tfZ+GwZKTo2Lt1WYUn/TVWIK8NqfMBy1tsOVZtQceie/YAo03kYT3a LZZfHER+Z+blPlr6S1YsHyugH9YgzQYj1I6tcBYuUtycj9SsjdQs2WWY7XPUEv1AGO zi1Vjw30g7rSl6fGGOTaVcvpSBUI92dOj6V9f9Q3cCVBCudi5s+qjAr7if1/LfxRG3 +1L1aY9Pn88Bg== 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 1t7b7n-009Kpi-3B; Sun, 03 Nov 2024 13:58:39 +0000 Date: Sun, 03 Nov 2024 13:58:38 +0000 Message-ID: <86h68o1ks1.wl-maz@kernel.org> From: Marc Zyngier To: Frank Li Cc: Bjorn Helgaas , Richard Zhu , Lucas Stach , Lorenzo Pieralisi , Krzysztof =?UTF-8?B?V2lsY3p5xYRza2k=?= , 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, Frank.li@nxp.com, 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 v4 1/2] PCI: Add enable_device() and disable_device() callbacks for bridges In-Reply-To: <20241101-imx95_lut-v4-1-0fdf9a2fe754@nxp.com> References: <20241101-imx95_lut-v4-0-0fdf9a2fe754@nxp.com> <20241101-imx95_lut-v4-1-0fdf9a2fe754@nxp.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/29.4 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: linux-pci@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: 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, Frank.li@nxp.com, 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 Fri, 01 Nov 2024 21:04:39 +0000, 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. > > Acked-by: Bjorn Helgaas > Signed-off-by: Frank Li I converted the fruity PCIe controller over to this infrastructure, and things seem to work fine. FWIW: Reviewed-by: Marc Zyngier Tested-by: Marc Zyngier M. -- Without deviation from the norm, progress is not possible.