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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3F773C636CC for ; Wed, 8 Feb 2023 11:14:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229972AbjBHLOE (ORCPT ); Wed, 8 Feb 2023 06:14:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41968 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230361AbjBHLNx (ORCPT ); Wed, 8 Feb 2023 06:13:53 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4894B2659D for ; Wed, 8 Feb 2023 03:13:43 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D881F61156 for ; Wed, 8 Feb 2023 11:13:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E126FC433D2; Wed, 8 Feb 2023 11:13:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1675854822; bh=T46tXjAqJt8qFrwAGWcwbQFneNO1ZDw3Sb9SGT5jx1k=; h=From:To:Cc:Subject:Date:From; b=2nneWM/zymBt8y5CJT8DMCX7ttceR/AxxAkqOW6/2iPKpAZkzu5SsSi9zJud3hfTo PllcibCsgo7Z2BW4R5hEUoJLI5sV4JnbJ8HhICW2m9CgIH7u9NqlQWzl4QqpQ0qnTq qG1z0k6v+fyl5hypFfNHT5jF+tnbv3CNPhB6lfGw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , "Rafael J. Wysocki" Subject: [PATCH 00/21] driver core: bus: remove private "backpointer" from struct bus_type Date: Wed, 8 Feb 2023 12:13:09 +0100 Message-Id: <20230208111330.439504-1-gregkh@linuxfoundation.org> X-Mailer: git-send-email 2.39.1 MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2989; i=gregkh@linuxfoundation.org; h=from:subject; bh=T46tXjAqJt8qFrwAGWcwbQFneNO1ZDw3Sb9SGT5jx1k=; b=owGbwMvMwCRo6H6F97bub03G02pJDMmPm6849r0re1Alv2fB3TvZ+f07OG92sAR+kJZxOrSE91G6 SvG7jlgWBkEmBlkxRZYv23iO7q84pOhlaHsaZg4rE8gQBi5OAZhI6nWGBVOPMIR+sZAuXS+1OmpT+s Xn0V6/6hjmysz26fw/baGD8L1e2y9dgb4vzllcAgA= X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In the quest to make all struct bus_type constant in the kernel, allowing them to move into read-only memory, this patch series goes through the steps in getting rid of the "private" pointer in struct bus_type. It does so primarily by relying on the already-present list of subsystems in the driver core and looking up the struct bus_type from that list when needed, or looking up the private structure from the bus pointer, depending on what is needed. Overall, more lines of code are added, but we now have the additional safely that the internal subsystem private type is properly reference counted. We "got away" with not incrementing reference counts because we relied on the caller of functions to have a valid reference when calling into the core. That's not really the proper way to handle reference counts, so as part of the conversion, reference counts are now correctly handled. There are still some remaining steps to be able to have bus_type be constant everywhere in the kernel, but this series is a great first step and is the "hard part" of the work. The rest involves changing the callback sysfs file functions and handling the dev_root pointer properly. Those changes will be forthcoming after these as they involve lots more minor driver changes all over the kernel. This has been build-tested by the 0-day bot for a while, and is being used by me right now to send this series out, so it "works for me!" This series is based against my current driver-core-next branch that is in linux-next. Greg Kroah-Hartman (21): driver core: add local subsys_get and subsys_put functions driver core: bus: implement bus_get/put() without the private pointer driver core: bus: constantify the bus_find_* functions driver core: bus: convert bus_create/remove_file to be constant driver core: bus: sysfs function cleanups driver core: bus: bus_add/probe/remove_device() cleanups driver core: bus: bus_register/unregister() cleanups driver core: bus: subsys_interface_register/unregister() cleanups driver core: bus: bus_get_kset() cleanup driver core: bus: bus_register/unregister_notifier() cleanups driver core: bus: bus_add/remove_driver() cleanups driver core: bus: bus iterator cleanups driver core: bus: clean up bus_sort_breadthfirst() driver core: move driver_find() to bus.c driver core: bus: clean up driver_find() driver core: create bus_is_registered() driver core: remove private pointer from struct bus_type driver core: bus: constify bus_register/unregister_notifier() driver core: bus: constify bus_get_kset() driver core: bus: constify some internal functions driver core: bus: constify bus_unregister() drivers/base/base.h | 14 ++ drivers/base/bus.c | 491 ++++++++++++++++++++++++++----------- drivers/base/driver.c | 29 +-- include/linux/device/bus.h | 37 ++- 4 files changed, 375 insertions(+), 196 deletions(-) -- 2.39.1