From patchwork Tue Feb 7 01:41:53 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Saravana Kannan X-Patchwork-Id: 13130853 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 4DDD9C61DA4 for ; Tue, 7 Feb 2023 01:42:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230334AbjBGBm0 (ORCPT ); Mon, 6 Feb 2023 20:42:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40534 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230301AbjBGBmQ (ORCPT ); Mon, 6 Feb 2023 20:42:16 -0500 Received: from mail-pl1-x649.google.com (mail-pl1-x649.google.com [IPv6:2607:f8b0:4864:20::649]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 046E5113ED for ; Mon, 6 Feb 2023 17:42:13 -0800 (PST) Received: by mail-pl1-x649.google.com with SMTP id l1-20020a17090270c100b00198be135a14so7204408plt.9 for ; Mon, 06 Feb 2023 17:42:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=qilJcjCuMQ+UEcym7b4h9C92RRJ6Qj6pHG5dlY6nsNI=; b=W3xpeO/Rx34noJBz5nd6A4bxsUDyoqIhh7Cb2x3UmXZsoK8ED+AALcboiCZqoyinys 1toeCq44NyFwUzZ+gzQLgSl+KCNP+GEf6kLLEg+JXta1FpZzeLUU2keUV7ERvssI1FOu hpIoNUBWt2EucoDAErFvCDxGsmVEr2TJ6EKK7+n9BQxjio75CJwBibBIhOgfvSYZL/gy afaIUUJIivpS9OSgOyPy1/Ekhq88quTU3lpmMYtruya4C6g0GeUFX8y9KkixEga6+mtF BrJdWYEvqyNBme4s39lZ7YjVtDKbb6Vre9yguxW8VdqTPi5yoBdDTn8iTA1PZhhsB6Kx CwaQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=qilJcjCuMQ+UEcym7b4h9C92RRJ6Qj6pHG5dlY6nsNI=; b=Ae9NOiLjBdsk3XphS9avAOVsbR51SahLnov+r6NXUM34BcgF0BE1tjmmhQFWwjUGTW HRhMiXXwIW3cQHU9w9f1d10mhClCa7FFN2jookyDql+zy/ksq9rFmCXFSzZu5FB0rq4/ eSjEta5ytc5YFORN/f9W7BosFl2lnLyjkUW/uqORKyujaOFnJuVIe+luCRvQNWJ2XZ0N s+67J8CdTOfHxhNqYGt34jbwzJCu0oQOta9yKKzkq987FjI6QbVNmcNaHkXPHO14g6r+ B5ue1xYAztNp/EgaRvf1Xl43MTFr6OhoVM8CSjVJARSCKUX+vZiUxs21lgNVZ1iAqCLt 2GKg== X-Gm-Message-State: AO0yUKXAamPiJGUirfMjKKWHt82L+DyMwUWP+Kt/RetNc+Kz+cKbUvDp 5rPW4cNkdjqVEORBz4u9ByQBO/AeGYwtnq8= X-Google-Smtp-Source: AK7set9WA6uQ/1FNztyQpvzAT03IkHDfAC4BORG9y1kTW3w7tVvng8KdB/nV5PiGcKyoyrHyfOxaYgRn3+dBCkM= X-Received: from saravanak.san.corp.google.com ([2620:15c:2d:3:ae1:aba6:f21c:4a94]) (user=saravanak job=sendgmr) by 2002:a17:90a:bd04:b0:215:f80c:18e6 with SMTP id y4-20020a17090abd0400b00215f80c18e6mr4002191pjr.45.1675734133267; Mon, 06 Feb 2023 17:42:13 -0800 (PST) Date: Mon, 6 Feb 2023 17:41:53 -0800 In-Reply-To: <20230207014207.1678715-1-saravanak@google.com> Message-Id: <20230207014207.1678715-2-saravanak@google.com> Mime-Version: 1.0 References: <20230207014207.1678715-1-saravanak@google.com> X-Mailer: git-send-email 2.39.1.519.gcb327c4b5f-goog Subject: [PATCH v3 01/12] driver core: fw_devlink: Don't purge child fwnode's consumer links From: Saravana Kannan To: Greg Kroah-Hartman , "Rafael J. Wysocki" , Sudeep Holla , Cristian Marussi , Linus Walleij , Bartosz Golaszewski , Thomas Gleixner , Marc Zyngier , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , NXP Linux Team , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Rob Herring , Frank Rowand , Geert Uytterhoeven , Magnus Damm , Andy Shevchenko , Daniel Scally , Heikki Krogerus , Sakari Ailus , Len Brown , Saravana Kannan , " =?utf-8?b?UmFmYcWCIE1pxYJlY2tp?= " Cc: Abel Vesa , Alexander Stein , Tony Lindgren , Geert Uytterhoeven , John Stultz , Doug Anderson , Guenter Roeck , Dmitry Baryshkov , Maxim Kiselev , Maxim Kochetkov , Luca Weiss , Colin Foster , Martin Kepplinger , Jean-Philippe Brucker , Vladimir Oltean , kernel-team@android.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-gpio@vger.kernel.org, linux-mtd@lists.infradead.org, devicetree@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-acpi@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org When a device X is bound successfully to a driver, if it has a child firmware node Y that doesn't have a struct device created by then, we delete fwnode links where the child firmware node Y is the supplier. We did this to avoid blocking the consumers of the child firmware node Y from deferring probe indefinitely. While that a step in the right direction, it's better to make the consumers of the child firmware node Y to be consumers of the device X because device X is probably implementing whatever functionality is represented by child firmware node Y. By doing this, we capture the device dependencies more accurately and ensure better probe/suspend/resume ordering. Signed-off-by: Saravana Kannan Tested-by: Colin Foster Tested-by: Sudeep Holla --- drivers/base/core.c | 97 ++++++++++++++++++++++++++++++++++++--------- 1 file changed, 79 insertions(+), 18 deletions(-) diff --git a/drivers/base/core.c b/drivers/base/core.c index a3e14143ec0c..001e1914858d 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -54,11 +54,12 @@ static LIST_HEAD(deferred_sync); static unsigned int defer_sync_state_count = 1; static DEFINE_MUTEX(fwnode_link_lock); static bool fw_devlink_is_permissive(void); +static void __fw_devlink_link_to_consumers(struct device *dev); static bool fw_devlink_drv_reg_done; static bool fw_devlink_best_effort; /** - * fwnode_link_add - Create a link between two fwnode_handles. + * __fwnode_link_add - Create a link between two fwnode_handles. * @con: Consumer end of the link. * @sup: Supplier end of the link. * @@ -74,22 +75,18 @@ static bool fw_devlink_best_effort; * Attempts to create duplicate links between the same pair of fwnode handles * are ignored and there is no reference counting. */ -int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup) +static int __fwnode_link_add(struct fwnode_handle *con, + struct fwnode_handle *sup) { struct fwnode_link *link; - int ret = 0; - - mutex_lock(&fwnode_link_lock); list_for_each_entry(link, &sup->consumers, s_hook) if (link->consumer == con) - goto out; + return 0; link = kzalloc(sizeof(*link), GFP_KERNEL); - if (!link) { - ret = -ENOMEM; - goto out; - } + if (!link) + return -ENOMEM; link->supplier = sup; INIT_LIST_HEAD(&link->s_hook); @@ -100,9 +97,17 @@ int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup) list_add(&link->c_hook, &con->suppliers); pr_debug("%pfwP Linked as a fwnode consumer to %pfwP\n", con, sup); -out: - mutex_unlock(&fwnode_link_lock); + return 0; +} + +int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup) +{ + int ret; + + mutex_lock(&fwnode_link_lock); + ret = __fwnode_link_add(con, sup); + mutex_unlock(&fwnode_link_lock); return ret; } @@ -181,6 +186,51 @@ void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode) } EXPORT_SYMBOL_GPL(fw_devlink_purge_absent_suppliers); +/** + * __fwnode_links_move_consumers - Move consumer from @from to @to fwnode_handle + * @from: move consumers away from this fwnode + * @to: move consumers to this fwnode + * + * Move all consumer links from @from fwnode to @to fwnode. + */ +static void __fwnode_links_move_consumers(struct fwnode_handle *from, + struct fwnode_handle *to) +{ + struct fwnode_link *link, *tmp; + + list_for_each_entry_safe(link, tmp, &from->consumers, s_hook) { + __fwnode_link_add(link->consumer, to); + __fwnode_link_del(link); + } +} + +/** + * __fw_devlink_pickup_dangling_consumers - Pick up dangling consumers + * @fwnode: fwnode from which to pick up dangling consumers + * @new_sup: fwnode of new supplier + * + * If the @fwnode has a corresponding struct device and the device supports + * probing (that is, added to a bus), then we want to let fw_devlink create + * MANAGED device links to this device, so leave @fwnode and its descendant's + * fwnode links alone. + * + * Otherwise, move its consumers to the new supplier @new_sup. + */ +static void __fw_devlink_pickup_dangling_consumers(struct fwnode_handle *fwnode, + struct fwnode_handle *new_sup) +{ + struct fwnode_handle *child; + + if (fwnode->dev && fwnode->dev->bus) + return; + + fwnode->flags |= FWNODE_FLAG_NOT_DEVICE; + __fwnode_links_move_consumers(fwnode, new_sup); + + fwnode_for_each_available_child_node(fwnode, child) + __fw_devlink_pickup_dangling_consumers(child, new_sup); +} + #ifdef CONFIG_SRCU static DEFINE_MUTEX(device_links_lock); DEFINE_STATIC_SRCU(device_links_srcu); @@ -1267,16 +1317,23 @@ void device_links_driver_bound(struct device *dev) * them. So, fw_devlink no longer needs to create device links to any * of the device's suppliers. * - * Also, if a child firmware node of this bound device is not added as - * a device by now, assume it is never going to be added and make sure - * other devices don't defer probe indefinitely by waiting for such a - * child device. + * Also, if a child firmware node of this bound device is not added as a + * device by now, assume it is never going to be added. Make this bound + * device the fallback supplier to the dangling consumers of the child + * firmware node because this bound device is probably implementing the + * child firmware node functionality and we don't want the dangling + * consumers to defer probe indefinitely waiting for a device for the + * child firmware node. */ if (dev->fwnode && dev->fwnode->dev == dev) { struct fwnode_handle *child; fwnode_links_purge_suppliers(dev->fwnode); + mutex_lock(&fwnode_link_lock); fwnode_for_each_available_child_node(dev->fwnode, child) - fw_devlink_purge_absent_suppliers(child); + __fw_devlink_pickup_dangling_consumers(child, + dev->fwnode); + __fw_devlink_link_to_consumers(dev); + mutex_unlock(&fwnode_link_lock); } device_remove_file(dev, &dev_attr_waiting_for_supplier); @@ -1855,7 +1912,11 @@ static int fw_devlink_create_devlink(struct device *con, fwnode_is_ancestor_of(sup_handle, con->fwnode)) return -EINVAL; - sup_dev = get_dev_from_fwnode(sup_handle); + if (sup_handle->flags & FWNODE_FLAG_NOT_DEVICE) + sup_dev = fwnode_get_next_parent_dev(sup_handle); + else + sup_dev = get_dev_from_fwnode(sup_handle); + if (sup_dev) { /* * If it's one of those drivers that don't actually bind to