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 9020E29CEB for ; Tue, 29 Jul 2025 11:28:18 +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=1753788500; cv=none; b=FV9dLt+/AkSbFD7lexccOyYmnFxlCgSB2vU0LzAjNIzNciQZSePFras4dDthhuI0O5ewAvTPVZHKYJvEYd3wTZWezzYRi4qmDbmJl1MJ9QCTn5mf7olwvmSql11Ja39FJdcd8CKeom4ReDfAHnRYsJ6fJ32dfb2FCooJOycWmUM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753788500; c=relaxed/simple; bh=+KY72cfKifK8T8HTWAJFTiEOR5uRUa+guTTo/8YTd78=; h=Mime-Version:Content-Type:Date:Message-Id:Subject:Cc:To:From: References:In-Reply-To; b=L5kUc/62dFK82lwnLmkfGm1P72ZgyVd1kRHbix9gez8FHizWG7HV+TeL4kMeqY1A1cCOPEZ6jX1t3ZyZbuRirSK3/0UxZEvFmbGM/UQIqotG+9bTybKZYC2FG/8W6FsYfy7qYuS5ByzcQn5EwsJw58gikZBeqoU+VOLrMBu3Ha4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=tqYYRXVP; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="tqYYRXVP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A3D59C4CEEF; Tue, 29 Jul 2025 11:28:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753788498; bh=+KY72cfKifK8T8HTWAJFTiEOR5uRUa+guTTo/8YTd78=; h=Date:Subject:Cc:To:From:References:In-Reply-To:From; b=tqYYRXVPGGH+T9F6KyHd7GMO8tCSFK+VKM5DgO3nGDRXBRpiml0OS6X+TSFxN7mPF 4AuhWFd1yCDaP2D8WzUSAVPc8y1T85RT2k2niSUCx7o0U0v53T56p9usfHqHQDlmSg e8J7RUly2xQOKnK2MPLn7BfqjYXUOfsAtqr5vBfFZSjktqHD0nxdGcY5JrJTmOOeFm TPOu1+HBfmFYAWwd29WASNw1NUmY9zoxtH+e/tBiehhCdDRtn/5jRI91Zp5vb1NJNL 7OnrRlRcOEUQO4xjfEbe/Ruj2mtCpzepQPwJDGaNS1Ycy6r6a/Y/BhbaDAI0/bYXh9 EGgwQS48rKSwA== Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Tue, 29 Jul 2025 13:28:14 +0200 Message-Id: Subject: Re: [PATCH] auxiliary: Automatically generate id Cc: "Sean Anderson" , "Greg Kroah-Hartman" , "Ira Weiny" , , "Rafael J . Wysocki" , "Dave Ertman" To: "Leon Romanovsky" From: "Danilo Krummrich" References: <20250728211022.9165-1-sean.anderson@linux.dev> <20250729100132.GH402218@unreal> <20250729111130.GI402218@unreal> In-Reply-To: <20250729111130.GI402218@unreal> On Tue Jul 29, 2025 at 1:11 PM CEST, Leon Romanovsky wrote: > On Tue, Jul 29, 2025 at 12:51:42PM +0200, Danilo Krummrich wrote: >> On Tue Jul 29, 2025 at 12:01 PM CEST, Leon Romanovsky wrote: >> > On Tue, Jul 29, 2025 at 11:36:27AM +0200, Danilo Krummrich wrote: >> >> On Mon Jul 28, 2025 at 11:10 PM CEST, Sean Anderson wrote: >> >> > As it turns out, ids are not allowed to have semantic meaning. Thei= r >> >> > only purpose is to prevent sysfs collisions. To simplify things, ju= st >> >> > generate a unique id for each auxiliary device. Remove all referenc= es to >> >> > filling in the id member of the device. >> >> > >> >> > Signed-off-by: Sean Anderson >> >> > --- >> >> > >> >> > drivers/base/auxiliary.c | 32 +++++++++++++++++++++++--------= - >> >> > include/linux/auxiliary_bus.h | 26 ++++++++------------------ >> >> > 2 files changed, 31 insertions(+), 27 deletions(-) >> >> > >> >> > diff --git a/drivers/base/auxiliary.c b/drivers/base/auxiliary.c >> >> > index dba7c8e13a53..f66067df03ad 100644 >> >> > --- a/drivers/base/auxiliary.c >> >> > +++ b/drivers/base/auxiliary.c >> >> > @@ -264,6 +264,8 @@ static const struct bus_type auxiliary_bus_type= =3D { >> >> > .pm =3D &auxiliary_dev_pm_ops, >> >> > }; >> >> > =20 >> >> > +static DEFINE_IDA(auxiliary_id); >> >>=20 >> >> I think this is the correct thing to do, even though the per device I= DA drivers >> >> typically went for so far produces IDs that are easier to handle when= debugging >> >> things. >> >>=20 >> >> > + >> >> > /** >> >> > * auxiliary_device_init - check auxiliary_device and initialize >> >> > * @auxdev: auxiliary device struct >> >> > @@ -331,20 +333,37 @@ int __auxiliary_device_add(struct auxiliary_d= evice *auxdev, const char *modname) >> >> > return -EINVAL; >> >> > } >> >> > =20 >> >> > + ret =3D ida_alloc(&auxiliary_id, GFP_KERNEL); >> >> > + if (ret < 0) { >> >> > + dev_err(dev, "auxiliary device id_alloc fauiled: %d\n", ret); >> >> > + return ret; >> >> > + } >> >> > + auxdev->id =3D ret; >> >>=20 >> >> This overwrites the ID number set by various drivers that (still) use= the >> >> auxiliary_device_init() and auxiliary_device_add() pair. >> >>=20 >> >> While I agree with the general intent, I think it's a very bad idea t= o just >> >> perform this change silently leaving drivers with their IDA instances= not >> >> knowing that the set ID numbers do not have an effect anymore. >> >>=20 >> >> I think this should be multiple steps: >> >>=20 >> >> (1) Remove the id parameter and force an internal ID only for >> >> auxiliary_device_create(). >> >>=20 >> >> (2) Convert applicable drivers (and the Rust abstraction) to use >> >> auxiliary_device_create() rather than auxiliary_device_init() a= nd >> >> auxiliary_device_add(). >> >>=20 >> >> (3) Treewide change to force an internal ID for all auxiliary devic= es >> >> considering this change in all affected drivers. >> > >> > I would suggest easier approach. >> > 1. Add to the proposal patch, the sed generated line which removes aux= dev->id >> > assignment in the drivers. >> > Something like this from mlx5: >> > - sf_dev->adev.id =3D id; >> > >> > 2. Add standalone patches to remove not used ida_alloc/ida_free calls >> > from the drivers. >>=20 >> I assume you suggest this as an alternative to (3) above? If so, that's = what I >> meant in (3), I should have written "treewide series" instead of "treewi= de >> change". > > I would say for all steps. Very important reason to use > auxiliary_device_init() and not auxiliary_device_create() is to bind > custom release callback, which is needed to release private data. > > In addition, complex devices embed struct auxiliary_device in their > internal struct to rely on container_of to access the data. > See mlx5_sf_dev_add() in drivers/net/ethernet/mellanox/mlx5/core/sf/dev/d= ev.c > as an example. That's why I said "*applicable* drivers" everywhere. :) The examples you mention don't fall under this category, but in general dri= vers that *can* use auxiliary_device_create() should do it. >> Technically (2) is orthogonal, yet I think it's a bit better to do the d= esired >> change right away. Otherwise we end up converting all applicable drivers= to >> implement the auxiliary device release callback (which we need for a com= mon >> ida_free()) first, just to remove it later on when we convert to >> auxiliary_device_create(). > > My expectation is to see extension of driver/base/core.c. Something like = that: > > diff --git a/drivers/base/core.c b/drivers/base/core.c > index cbc0099d8ef24..63847c84dbdc0 100644 > --- a/drivers/base/core.c > +++ b/drivers/base/core.c > @@ -2560,8 +2560,10 @@ static void device_release(struct kobject *kobj) > > kfree(dev->dma_range_map); > > - if (dev->release) > + if (dev->release) { > + dev->bus_specific_cleanup(dev); > dev->release(dev); > + } > else if (dev->type && dev->type->release) > dev->type->release(dev); > else if (dev->class && dev->class->dev_release) The common pattern is to have custom release callbacks for class or bus spe= cific device types. In this case drivers would set struct auxiliary_device::release. And the auxiliary bus would implement the underlying struct device::release to call= the driver provided struct auxiliary_device::release plus the additional cleanu= p. What you propose works as well, but it moves bus or class device specifics = into the generic struct device, where the normal inheritance pattern already sol= ves this.