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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E9EE7C433EF for ; Sat, 9 Oct 2021 00:04:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CB73760FC2 for ; Sat, 9 Oct 2021 00:04:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243945AbhJIAGw (ORCPT ); Fri, 8 Oct 2021 20:06:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38252 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243850AbhJIAGv (ORCPT ); Fri, 8 Oct 2021 20:06:51 -0400 Received: from mail-oi1-x234.google.com (mail-oi1-x234.google.com [IPv6:2607:f8b0:4864:20::234]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 87EBFC061755 for ; Fri, 8 Oct 2021 17:04:55 -0700 (PDT) Received: by mail-oi1-x234.google.com with SMTP id a3so15808538oid.6 for ; Fri, 08 Oct 2021 17:04:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=9N6N5ZTR9CIN4xom+ZlVChwK9wG/IG6oiW3V0bEVeE0=; b=pnxjmjuB6yVd7ZXZnO/+xjCpCQiPZPzLM+yHPuwW4K98MFNX8Zlp9l5ZhU6MNa35Xq DpTBfPXSsPYedCt2+dphpLoLh76LXhwMOaQ4j+vLc2LVfSe/5YxWWcjjkoeAXVhg/W69 3Vm3tJanr3Dr5cwiAYiJptcQbl/RNloGTul82Wm4CB/vu+BjsZHEBeNk7r4lUhf1oMUi GKw7U2V6A2vpfgvlTGkExT1cEfiyb0/mp95ErxQFH6d9FKCvz1iEYKhs/N8p4YhLS/4s s8JIzGE2wWjlSSnhBSeTqQp/TCLCg0k911f3jlbl4HjaH805QWDVZTXJXHKOUB2ya4k2 5WoA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=9N6N5ZTR9CIN4xom+ZlVChwK9wG/IG6oiW3V0bEVeE0=; b=Kfxqu9nw9boop8Ukza/aRxhK3/e+agHU8A+2RoifB2JFHQ7o5FMQryOCGjV5GoX6Rv ioZsDQGfsnO6FypgyNRo1aW/X0Vg4R+NS5fR4HRkN407V+O1EeCTd9d/QwBfew+hdLrM tw+mJTTMDnD6fDscLGlL7CD2SVwlrvekD9bmvPPfQbM73FIZ3MAOb7GQGbrmzjJupjjY PrqP4c+fvPOr9YdFXfRw31WNjqFFcvlvFIu084RJL+BWQ+27PdCTOWSh/utE3RSELTQe uNfxviJnDBlp/F4Wzuvmz4xFgxCZuSoEUsSik74V4ZKdR1rI9cf0djFnCE9majNh8lTa 3CTg== X-Gm-Message-State: AOAM530D99hfZ++vaHaLob9OgB3y2qYv0mWLmmgosf9DZONRli2vStgP W1VrQaJruJdpUY2TS7GN3+w5BnUTwaTK9w== X-Google-Smtp-Source: ABdhPJxnYVoBlj5hRyP6LkDot6B3z6O7w8iCB/+04vuWpx5srscRpG1TfqpTbY3LQw+aE/sAB1Fb8A== X-Received: by 2002:a54:4f0e:: with SMTP id e14mr10134624oiy.73.1633737894759; Fri, 08 Oct 2021 17:04:54 -0700 (PDT) Received: from ripper ([2600:1700:a0:3dc8:205:1bff:fec0:b9b3]) by smtp.gmail.com with ESMTPSA id c17sm237599oiw.10.2021.10.08.17.04.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 08 Oct 2021 17:04:54 -0700 (PDT) Date: Fri, 8 Oct 2021 17:06:32 -0700 From: Bjorn Andersson To: Arnaud Pouliquen Cc: Ohad Ben-Cohen , Mathieu Poirier , linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, julien.massot@iot.bzh Subject: Re: [PATCH v4 4/4] rpmsg: char: Introduce the "rpmsg-raw" channel Message-ID: References: <20210712131900.24752-1-arnaud.pouliquen@foss.st.com> <20210712131900.24752-5-arnaud.pouliquen@foss.st.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210712131900.24752-5-arnaud.pouliquen@foss.st.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 12 Jul 06:19 PDT 2021, Arnaud Pouliquen wrote: > Allows to probe the endpoint device on a remote name service announcement, > by registering a rpmsg_driverfor the "rpmsg-raw" channel. > > With this patch the /dev/rpmsgX interface can be instantiated by the remote > firmware. > > Signed-off-by: Arnaud Pouliquen > Reviewed-by: Mathieu Poirier > Tested-by: Julien Massot > --- > drivers/rpmsg/rpmsg_char.c | 75 +++++++++++++++++++++++++++++++++++++- > 1 file changed, 73 insertions(+), 2 deletions(-) > > diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c > index bd728d90ba4c..1b7b610e113d 100644 > --- a/drivers/rpmsg/rpmsg_char.c > +++ b/drivers/rpmsg/rpmsg_char.c > @@ -25,6 +25,8 @@ > > #include "rpmsg_char.h" > > +#define RPMSG_CHAR_DEVNAME "rpmsg-raw" > + > static dev_t rpmsg_major; > static struct class *rpmsg_class; > > @@ -421,6 +423,61 @@ int rpmsg_chrdev_eptdev_create(struct rpmsg_device *rpdev, struct device *parent > } > EXPORT_SYMBOL(rpmsg_chrdev_eptdev_create); > > +static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev) > +{ > + struct rpmsg_channel_info chinfo; > + struct rpmsg_eptdev *eptdev; > + struct rpmsg_endpoint *ept; > + > + memcpy(chinfo.name, RPMSG_CHAR_DEVNAME, sizeof(RPMSG_CHAR_DEVNAME)); The length should relate to the size of the destination buffer. This looks like an excellent job for strscpy_pad() > + chinfo.src = rpdev->src; > + chinfo.dst = rpdev->dst; > + > + eptdev = __rpmsg_chrdev_eptdev_create(rpdev, &rpdev->dev, chinfo); Note that this creates a new endpoint device as a child of the rpdev, while new endpoints created by RPMSG_CREATE_EPT_IOCTL are parented by the rpmsg_ctrl device. So it is possible to create two /dev/rpmsgN nodes for the same endpoint, I believe with the outcome that this one will be open but __rpmsg_create_ept() in virtio_rpmsg_bus should return NULL if the user tries to open the other one. > + if (IS_ERR(eptdev)) > + return PTR_ERR(eptdev); > + > + /* > + * Create the default endpoint associated to the rpmsg device and provide rpmsg_eptdev > + * structure as callback private data. > + */ > + ept = rpmsg_create_default_ept(rpdev, rpmsg_ept_cb, eptdev, eptdev->chinfo); Why don't you just set rpdev->priv to eptdev and make rpmsg_ept_cb the callback of your rpmsg_driver? > + if (!ept) { > + dev_err(&rpdev->dev, "failed to create %s\n", eptdev->chinfo.name); > + put_device(&eptdev->dev); > + return -EINVAL; > + } > + > + /* > + * Do not allow the creation and release of an endpoint on /dev/rpmsgX open and close, > + * reuse the default endpoint instead > + */ What happens when __rpmsg_chrdev_eptdev_create() delivers a uevent and user space quickly calls open() on the newly created /dev/rpmsgN, before the next line? > + eptdev->static_ept = true; > + > + return 0; > +} > + > +static void rpmsg_chrdev_remove(struct rpmsg_device *rpdev) > +{ > + int ret; > + > + ret = device_for_each_child(&rpdev->dev, NULL, rpmsg_chrdev_eptdev_destroy); > + if (ret) > + dev_warn(&rpdev->dev, "failed to destroy endpoints: %d\n", ret); > +} > + > +static struct rpmsg_device_id rpmsg_chrdev_id_table[] = { > + { .name = RPMSG_CHAR_DEVNAME }, I would expect that this list would grow, but you hard coded RPMSG_CHAR_DEVNAME in probe, so that won't work. Regards, Bjorn > + { }, > +}; > + > +static struct rpmsg_driver rpmsg_chrdev_driver = { > + .probe = rpmsg_chrdev_probe, > + .remove = rpmsg_chrdev_remove, > + .id_table = rpmsg_chrdev_id_table, > + .drv.name = "rpmsg_chrdev", > +}; > + > static int rpmsg_chrdev_init(void) > { > int ret; > @@ -434,16 +491,30 @@ static int rpmsg_chrdev_init(void) > rpmsg_class = class_create(THIS_MODULE, "rpmsg"); > if (IS_ERR(rpmsg_class)) { > pr_err("failed to create rpmsg class\n"); > - unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); > - return PTR_ERR(rpmsg_class); > + ret = PTR_ERR(rpmsg_class); > + goto free_region; > + } > + > + ret = register_rpmsg_driver(&rpmsg_chrdev_driver); > + if (ret < 0) { > + pr_err("rpmsg: failed to register rpmsg raw driver\n"); > + goto free_class; > } > > return 0; > + > +free_class: > + class_destroy(rpmsg_class); > +free_region: > + unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); > + > + return ret; > } > postcore_initcall(rpmsg_chrdev_init); > > static void rpmsg_chrdev_exit(void) > { > + unregister_rpmsg_driver(&rpmsg_chrdev_driver); > class_destroy(rpmsg_class); > unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); > } > -- > 2.17.1 >