From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (bilbo.ozlabs.org [203.11.71.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 49L2MM35hszDqhK for ; Mon, 11 May 2020 10:47:11 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=ozlabs.org Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=ozlabs.org header.i=@ozlabs.org header.a=rsa-sha256 header.s=201707 header.b=VotOyfhZ; dkim-atps=neutral Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 49L2MK3RlZz9sNH; Mon, 11 May 2020 10:47:09 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ozlabs.org; s=201707; t=1589158030; bh=nW0qKAASREZcngQPCjdvhhZ6ixzlz4KDwsOx0W2evcU=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=VotOyfhZv9X+KyW7P1F6U9gHz4UF1l9LTanBUHINGtAhCMKXGMVItGQhuE+v/51mZ rbbwMrmVRvApvvQlZCC5G8rfbLyNgfn4bzXtmIgXdPon+lhg0dbePzwuJcMT0ym+bX L1tb9f6RzDNCqN86yb0zpO5L1Xyogp3KS4Jb4mBtxaMg9ipSgZQt0EdMyYXieHPvMF +AlmRwjK2joOJNoyv3eps3iAoRQW8zoJhPUa6Y3utg9pVlTn/ZS6OgwtIFAZfJLc6Y xoS6QQxCankH5Am0ZdGV6e3suAJLtrpNGXyYmZLjnk6rQ+AmJrN04muw5nVBoQLuP7 1DdOoxHtp5y1g== Message-ID: <840ea83777699177e2af8ba77c193c73e27feaca.camel@ozlabs.org> Subject: Re: How to use eSPI between Host and slave BMC in openbmc project From: Jeremy Kerr To: Andrew Jeffery , zhang_cy1989 , "openbmc@lists.ozlabs.org" Cc: James Feist Date: Mon, 11 May 2020 08:47:08 +0800 In-Reply-To: <775abd77-ce5b-4f1d-99e6-8f14b06114fa@www.fastmail.com> References: <50cce7b2.1057.171fdb24f4d.Coremail.zhang_cy1989@163.com> <775abd77-ce5b-4f1d-99e6-8f14b06114fa@www.fastmail.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.1 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: openbmc@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development list for OpenBMC List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 11 May 2020 00:47:11 -0000 Hi Felix, > 1 Are there some solutions to use eSPI interface in openbmc project? There are some platforms in development that use eSPI between the host and BMC, yes. > 2 Whether the Host side needs eSPI controler driver? I can't find any > info about eSPI in linux kernel for host os. Is eSPI transparent to > the Host side? For the host hardware I've seen, the eSPI channel doesn't need a driver - it's usually controlled entirely in hardware by the PCH. > 3 Whether the slave side（Ex BMC/EC） needs slave eSPI driver? I know > there are some registers descriptions of eSPIcontroller in the > ast2500 data sheet. Unfortunately, I don't find slave eSPI driver > either. For the BMC, we need some support in the kernel to handle eSPI behaviour. There is a prototype driver for the ast2500 eSPI slave around, but it hasn't made it upstream: https://lists.ozlabs.org/pipermail/openbmc/2018-February/010937.html > 4 which intel products include eSPI feature? I'm aware of the C62x series of PCH chipsets, there may be others too. > 5 eSPI interface can transmit io cycle and mem cycle， > but in which case or applications eSPI transfer mem cycle? I haven't seen anything specific, I don't think it'd be too useful in our architecture. Cheers, Jeremy