From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 1615F1FDA97; Mon, 17 Mar 2025 16:54:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742230445; cv=none; b=rFVkaPZUjZ4U/PSBGkXrUhH+DhV00kK3a+x8IPP+ASfNIyjF4mqPPpumUiDJamFnG9HxMpN/bQPFJgU4Z2Up0uupYKi0zgA4v/JCy7TaKqI0VMULMZBjUObylakdbJCVM9CwoSioismkj2R8ED/KQypCZIDV/bZawBqYyn2UXHk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742230445; c=relaxed/simple; bh=KpU/PnNszW7hE8D8K45gNzAsaAMaaigdwtGIBChY8ds=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=E9ImK82Fj9SEhiMeCVTiRRed4Q2MuD7fCJvwPZQhFFcE8polwY2J0nQ6/4JE7zJqByD0hv1fkCdg33RgUADmoLe6TvTjKVAaBJ7sC+Q45WexjRUk1HBL5zHSsJjQmnVTec+AqBS6i4ASSEFL+wkxr2xriLAiYCMTrpEuypiKU1E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com; spf=none smtp.mailfrom=foss.arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=foss.arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 19B6913D5; Mon, 17 Mar 2025 09:54:11 -0700 (PDT) Received: from bogus (e133711.arm.com [10.1.196.55]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DF99A3F694; Mon, 17 Mar 2025 09:54:00 -0700 (PDT) Date: Mon, 17 Mar 2025 16:53:57 +0000 From: Sudeep Holla To: Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, Andre Przywara , Sudeep Holla , Herbert Xu , Jeff Johnson , linux-crypto@vger.kernel.org Subject: Re: [PATCH 2/9] hwrng: arm-smccc-trng - transition to the faux device interface Message-ID: References: <20250317-plat2faux_dev-v1-0-5fe67c085ad5@arm.com> <20250317-plat2faux_dev-v1-2-5fe67c085ad5@arm.com> <2025031748-deface-wasting-b635@gregkh> <2025031709-unmoved-carton-c130@gregkh> <2025031731-anyhow-askew-5731@gregkh> Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2025031731-anyhow-askew-5731@gregkh> On Mon, Mar 17, 2025 at 05:46:46PM +0100, Greg Kroah-Hartman wrote: > On Mon, Mar 17, 2025 at 02:43:21PM +0000, Sudeep Holla wrote: > > On Mon, Mar 17, 2025 at 03:30:15PM +0100, Greg Kroah-Hartman wrote: > > > On Mon, Mar 17, 2025 at 02:22:45PM +0000, Sudeep Holla wrote: > > > > On Mon, Mar 17, 2025 at 02:04:27PM +0100, Greg Kroah-Hartman wrote: > > > > > On Mon, Mar 17, 2025 at 10:13:14AM +0000, Sudeep Holla wrote: > > > > > > +MODULE_ALIAS("faux:smccc_trng"); > > > > > > > > > > Why do you need a branch new alias you just made up? Please don't add > > > > > that for these types of devices, that's not going to work at all (just > > > > > like the platform alias really doesn't work well. > > > > > > > > > > > > > Sure I will drop all of those alias. One question I have if the idea of > > > > creating a macro for this is good or bad ? I need this initial condition > > > > flag to make use of such a macro, so I didn't go for it, but it does > > > > remove some boiler-plate code. > > > > > > > > Let me know what do you think of it ? > > > > > > > > Regards, > > > > Sudeep > > > > > > > > -->8 > > > > diff --git i/include/linux/device/faux.h w/include/linux/device/faux.h > > > > index 9f43c0e46aa4..8af3eaef281a 100644 > > > > --- i/include/linux/device/faux.h > > > > +++ w/include/linux/device/faux.h > > > > @@ -66,4 +66,30 @@ static inline void faux_device_set_drvdata(struct faux_device *faux_dev, void *d > > > > dev_set_drvdata(&faux_dev->dev, data); > > > > } > > > > > > > > +#define module_faux_driver(name, tag, init_cond) \ > > > > +static struct faux_device_ops tag##_ops = { \ > > > > + .probe = tag##_probe, \ > > > > + .remove = tag##_remove, \ > > > > +}; \ > > > > + \ > > > > +static struct faux_device *tag##_dev; \ > > > > + \ > > > > +static int __init tag##_init(void) \ > > > > +{ \ > > > > + if (!(init_cond)) \ > > > > + return 0; \ > > > > + tag##_dev = faux_device_create(name, NULL, &tag##_ops); \ > > > > + if (!tag##_dev) \ > > > > + return -ENODEV; \ > > > > + \ > > > > + return 0; \ > > > > +} \ > > > > +module_init(tag##_init); \ > > > > + \ > > > > +static void __exit tag##_exit(void) \ > > > > +{ \ > > > > + faux_device_destroy(tag##_dev); \ > > > > +} \ > > > > +module_exit(tag##_exit); \ > > > > > > Yes, I see that some of your changes could be moved to use this, so I > > > think it is worth it. > > > > > > But why can't you use module_driver() here? Ah, that init_cond? And > > > the device. Hm, why not put the init_cond in the probe callback? That > > > should make this macro simpler. > > > > > > > I tried to keep the creation of the device itself conditional the way > > it is today. Deferring the check to probe means the device gets created > > unconditionally but won't be probed which is fine I guess. I was thinking > > that device shouldn't show up on the bus if the condition is not met to > > match the current scenario. I might be overthinking there. > > It will not show up anywhere if the probe call fails. Ah, nice. I somehow didn't realise that. Thanks for that info. > > > > And don't use "tag", that's an odd term here, just copy what > > > module_driver() does instead please. > > > > > > > Sure, I will not use it. It was just a name that came to my mind. > > > > Also creating the macro builds the dependency. Do you prefer to push the > > changes as is and the macro in one release and make use of the macro later. > > Let's see a series that adds the macro and uses it and we can figure it > out from there. If the macro is sane, I can just take that now for > 6.15-rc1 and then you can send the others to the different subsystems > after that shows up. > Sure, thanks again. -- Regards, Sudeep