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 40298EAC7; Sun, 9 Mar 2025 09:39:11 +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=1741513152; cv=none; b=Q7ktrDMnSM8mJj7T3X05bfTVOs9UZhmqj8P1YLu3PKI7JBTn1NFVX/bYYdeiDY6bwuHBkMGtCCCJCEcyD97anwVyMQF4jCfTKqa4m5VumRu0bbodKxM36LIKVpC+Dmglv4atTaE0Ipv/ctkP0Ryqt4LVyhKVm6wS2oyBYclj3wk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741513152; c=relaxed/simple; bh=30EPtgIO0gOgovBW9OPvD/glEOOua8MuO2Ju4ocSWCg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XgktOj7ZZpDlBTcDddzwdJ2oy7iK7rDQLyfwWqPrvMfL+rbDEXX4nYfbqRyyQePdifgqUY9i0JrWFQhMCB+ICwpdVP4sO1i1JkRCUJ7s0K69cK6ry6j3euDC2d0QuO2vaF5YJBnAsvT7V1X0/EKEHjfjHtptQJig39u2V2+us8U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=k4IQdwkP; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="k4IQdwkP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1F777C4CEE5; Sun, 9 Mar 2025 09:39:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741513151; bh=30EPtgIO0gOgovBW9OPvD/glEOOua8MuO2Ju4ocSWCg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=k4IQdwkP9FwJ74xa28X0TJT483QmWn1Y5f/vdayKfrVldDuYLn51c4PZDuM1hYm2G tF4Bqf4LiJbRYB9LWIm1Qv/HWCBOxUQwomM3KXl4RffZXmQpy0v6irqqvZZgw3fDSC obO33AfCuYPK44b3Y3kPaqoY8AWKZnlmhw3Uibms= Date: Sun, 9 Mar 2025 10:37:55 +0100 From: "gregkh@linuxfoundation.org" To: Aditya Garg Cc: "bhelgaas@google.com" , "joro@8bytes.org" , "will@kernel.org" , "robin.murphy@arm.com" , "andriy.shevchenko@linux.intel.com" , "linux-staging@lists.linux.dev" , Linux Kernel Mailing List , "linux-pci@vger.kernel.org" , "iommu@lists.linux.dev" , Aun-Ali Zaidi , "paul@mrarm.io" , Orlando Chamberlain Subject: Re: [PATCH RFC] staging: Add driver to communicate with the T2 Security Chip Message-ID: <2025030935-contently-handbrake-9239@gregkh> References: <1A12CB39-B4FD-4859-9CD7-115314D97C75@live.com> <2025030931-tattoo-patriarch-006d@gregkh> <2025030937-antihero-sandblast-7c87@gregkh> Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Sun, Mar 09, 2025 at 09:28:01AM +0000, Aditya Garg wrote: > > > > On 9 Mar 2025, at 2:46 PM, gregkh@linuxfoundation.org wrote: > > > > On Sun, Mar 09, 2025 at 09:03:29AM +0000, Aditya Garg wrote: > >> > >> > >>>> On 9 Mar 2025, at 2:24 PM, gregkh@linuxfoundation.org wrote: > >>> > >>> On Sun, Mar 09, 2025 at 08:40:31AM +0000, Aditya Garg wrote: > >>>> From: Paul Pawlowski > >>>> > >>>> This patch adds a driver named apple-bce, to add support for the T2 > >>>> Security Chip found on certain Macs. > >>>> > >>>> The driver has 3 main components: > >>>> > >>>> BCE (Buffer Copy Engine) - this is what the files in the root directory > >>>> are for. This estabilishes a basic communication channel with the T2. > >>>> VHCI and Audio both require this component. > >>> > >>> So this is a new "bus" type? Or a platform resource? Or something > >>> else? > >> > >> It's a PCI device > > > > Great, but then is the resources split up into smaller drivers that then > > bind to it? How does the other devices talk to this? > > We technically can split up these 3 into separate drivers and put then into their own trees. That's fine, but you say that the bce code is used by the other drivers, right? So there is some sort of "tie" between these, and that needs to be properly conveyed in the device tree in sysfs as that will be required for proper resource management. thanks, greg k-h