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 X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C8590C282CE for ; Tue, 4 Jun 2019 17:16:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A82B82075B for ; Tue, 4 Jun 2019 17:16:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726211AbfFDRQS (ORCPT ); Tue, 4 Jun 2019 13:16:18 -0400 Received: from mga17.intel.com ([192.55.52.151]:2047 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725267AbfFDRQS (ORCPT ); Tue, 4 Jun 2019 13:16:18 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 04 Jun 2019 10:16:17 -0700 X-ExtLoop1: 1 Received: from smile.fi.intel.com (HELO smile) ([10.237.68.145]) by orsmga006.jf.intel.com with ESMTP; 04 Jun 2019 10:16:11 -0700 Received: from andy by smile with local (Exim 4.92) (envelope-from ) id 1hYD2h-0001Jc-6c; Tue, 04 Jun 2019 20:16:11 +0300 Date: Tue, 4 Jun 2019 20:16:11 +0300 From: Andy Shevchenko To: Eduardo Valentin Cc: Wolfram Sang , Haiyue Wang , jarkko.nikula@linux.intel.com, brendanhiggins@google.com, Rob Herring , Mark Rutland , linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/3] i2c: slave-mqueue: add a slave backend to receive and queue messages Message-ID: <20190604171611.GS9224@smile.fi.intel.com> References: <20190531043347.4196-1-eduval@amazon.com> <20190531043347.4196-3-eduval@amazon.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190531043347.4196-3-eduval@amazon.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 30, 2019 at 09:33:46PM -0700, Eduardo Valentin wrote: > From: Haiyue Wang > > Some protocols over I2C are designed for bi-directional transferring > messages by using I2C Master Write protocol. Like the MCTP (Management > Component Transport Protocol) and IPMB (Intelligent Platform Management > Bus), they both require that the userspace can receive messages from > I2C dirvers under slave mode. > > This new slave mqueue backend is used to receive and queue messages, it > will exposes these messages to userspace by sysfs bin file. > > Note: DT interface and a couple of minor fixes here and there > by Eduardo, so I kept the original authorship here. > +#define MQ_MSGBUF_SIZE CONFIG_I2C_SLAVE_MQUEUE_MESSAGE_SIZE > +#define MQ_QUEUE_SIZE CONFIG_I2C_SLAVE_MQUEUE_QUEUE_SIZE > +#define MQ_QUEUE_NEXT(x) (((x) + 1) & (MQ_QUEUE_SIZE - 1)) Also possible ((x + 1) % ..._SIZE) > + mq = dev_get_drvdata(container_of(kobj, struct device, kobj)); kobj_to_dev() > +static int i2c_slave_mqueue_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + struct device *dev = &client->dev; > + struct mq_queue *mq; > + int ret, i; > + void *buf; > + > + mq = devm_kzalloc(dev, sizeof(*mq), GFP_KERNEL); > + if (!mq) > + return -ENOMEM; > + > + BUILD_BUG_ON(!is_power_of_2(MQ_QUEUE_SIZE)); Perhaps start function with this kind of assertions? > + > + buf = devm_kmalloc_array(dev, MQ_QUEUE_SIZE, MQ_MSGBUF_SIZE, > + GFP_KERNEL); > + if (!buf) > + return -ENOMEM; > + > + for (i = 0; i < MQ_QUEUE_SIZE; i++) > + mq->queue[i].buf = buf + i * MQ_MSGBUF_SIZE; Just wondering if kfifo API can bring an advantage here? > + return 0; > +} > +static const struct of_device_id i2c_slave_mqueue_of_match[] = { > + { > + .compatible = "i2c-slave-mqueue", > + }, > + { }, No need for comma here. > +}; > + > +static struct i2c_driver i2c_slave_mqueue_driver = { > + .driver = { > + .name = "i2c-slave-mqueue", > + .of_match_table = of_match_ptr(i2c_slave_mqueue_of_match), Wouldn't compiler warn you due to unused data? Perhaps drop of_match_ptr() for good... > + }, > + .probe = i2c_slave_mqueue_probe, > + .remove = i2c_slave_mqueue_remove, > + .id_table = i2c_slave_mqueue_id, > +}; -- With Best Regards, Andy Shevchenko