Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Wed, 23 Nov 2022 12:25:32 -0400
From:   Jason Gunthorpe <jgg@ziepe.ca>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Matthew Wilcox <willy@infradead.org>,
        Maximilian Luz <luzmaximilian@gmail.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        linux-kernel@vger.kernel.org, Jens Axboe <axboe@kernel.dk>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Len Brown <lenb@kernel.org>,
        Stefan Richter <stefanr@s5r6.in-berlin.de>,
        Wolfram Sang <wsa@kernel.org>,
        Alexandre Belloni <alexandre.belloni@bootlin.com>,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        Sean Young <sean@mess.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Frank Rowand <frowand.list@gmail.com>,
        Hans de Goede <hdegoede@redhat.com>,
        Mark Gross <markgross@kernel.org>,
        Vinod Koul <vkoul@kernel.org>,
        Bard Liao <yung-chuan.liao@linux.intel.com>,
        Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>,
        Sanyog Kale <sanyog.r.kale@intel.com>,
        Andreas Noever <andreas.noever@gmail.com>,
        Michael Jamet <michael.jamet@intel.com>,
        Mika Westerberg <mika.westerberg@linux.intel.com>,
        Yehezkel Bernat <YehezkelShB@gmail.com>,
        Jiri Slaby <jirislaby@kernel.org>,
        Heikki Krogerus <heikki.krogerus@linux.intel.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Chaitanya Kulkarni <kch@nvidia.com>,
        Ming Lei <ming.lei@redhat.com>,
        Jilin Yuan <yuanjilin@cdjrlc.com>,
        Alan Stern <stern@rowland.harvard.edu>,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ira Weiny <ira.weiny@intel.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Won Chung <wonchung@google.com>, alsa-devel@alsa-project.org,
        devicetree@vger.kernel.org, linux-acpi@vger.kernel.org,
        linux-block@vger.kernel.org, linux-i2c@vger.kernel.org,
        linux-i3c@lists.infradead.org, linux-input@vger.kernel.org,
        linux-media@vger.kernel.org, linux-serial@vger.kernel.org,
        linux-usb@vger.kernel.org, linux1394-devel@lists.sourceforge.net,
        platform-driver-x86@vger.kernel.org
Subject: Re: [PATCH 3/5] driver core: make struct device_type.uevent() take a
 const *
Message-ID: <Y35JfNJDppRp5bLX@ziepe.ca>
References: <20221123122523.1332370-1-gregkh@linuxfoundation.org>
 <20221123122523.1332370-3-gregkh@linuxfoundation.org>
 <711d5275-7e80-c00d-0cdc-0f3d52175361@gmail.com>
 <Y34hgIW8p1RlQTBB@smile.fi.intel.com>
 <97be39ed-3cea-d55a-caa6-c2652baef399@gmail.com>
 <Y34zyzdbRUdyOSkA@casper.infradead.org>
 <Y34+V2bCDdqujBDk@kroah.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <Y34+V2bCDdqujBDk@kroah.com>
Precedence: bulk

On Wed, Nov 23, 2022 at 04:37:59PM +0100, Greg Kroah-Hartman wrote:
> static inline struct device *__kobj_to_dev(struct kobject *kobj)
> {
>         return container_of(kobj, struct device, kobj);
> }
> 
> static inline const struct device *__kobj_to_dev_const(const struct kobject *kobj)
> {
>         return container_of(kobj, const struct device, kobj);
> }
> 
> /*
>  * container_of() will happily take a const * and spit back a non-const * as it
>  * is just doing pointer math.  But we want to be a bit more careful in the
>  * driver code, so manually force any const * of a kobject to also be a const *
>  * to a device.
>  */
> #define kobj_to_dev(kobj)                                       \
>         _Generic((kobj),                                        \
>                  const struct kobject *: __kobj_to_dev_const,   \
>                  struct kobject *: __kobj_to_dev)(kobj)
> 
> 
> Want me to do the same thing here as well?

It would be nice to have a shared macro code gen all of the above
instead of copy and pasting it. Then maybe other cases beyond struct
device could adopt const too..

Jason