From patchwork Sat Nov 21 02:02:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Saravana Kannan X-Patchwork-Id: 330032 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 94114C8300E for ; Sat, 21 Nov 2020 02:03:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 56DE124124 for ; Sat, 21 Nov 2020 02:03:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Oy8wm9rw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727237AbgKUCDI (ORCPT ); Fri, 20 Nov 2020 21:03:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55420 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727229AbgKUCDI (ORCPT ); Fri, 20 Nov 2020 21:03:08 -0500 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 33C3AC061A47 for ; Fri, 20 Nov 2020 18:03:06 -0800 (PST) Received: by mail-yb1-xb49.google.com with SMTP id c137so14145175ybf.21 for ; Fri, 20 Nov 2020 18:03:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=x2gFsEGnt1hKBTrd9Sh3BTzH1tCcPBvDnEqJhrf0jZk=; b=Oy8wm9rwe1xVP8CflmSHV6kS8mZ8CgBwaFnQT3haVq3hQfhTNPB3Dt+DC1srIEOHnJ 00ReduJqDRDAQo4YVHy1qpCiEQz2PNiibjyIT3lltB9/N4XBvYtaxgJiErfIRrfc04LQ HK3VL6wPuPvyARgqpnwh7mKN6u6Cqa0Qqguc/PqLj0TgOesrnHZZ9yRhqVOBaT7kxpd3 dYu6ejbMVZYfjOzk9mfZ+HZZdv455G6CXO+PAnMkBmajLUc/z8awlvJ1DwSX5FWgZtuK wF8ckZS3fTtZQZbuZE/wXm3mJ8ohZofNG7tgMMkx/gVSlH7velqealMro7ClhtycjfVJ 32NA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=x2gFsEGnt1hKBTrd9Sh3BTzH1tCcPBvDnEqJhrf0jZk=; b=HRa0tsl3oyaLntHNsstdsSSCn9anBOp2u49tYi7pxFKRz05RBk+4qNGzdDxhzR0J4j nsrmlBr7eR3U0njPvpDEWQrZZTqZ2DQCL3vS9XXFb9tRtU7NI0eMDWfx6TEzcL6QxKoe c0Oi1BEOkh609OGl94fH4KvYH96W4dX5gQgMBWvSdCiBuvsEG8cRcVoXOwYZBmccbl8V 5MbipfatO53bCEo/yKHiBjzByrmFMzE+oyiLIHSdcmSDEyWBhPLDrgrKyvA0rSjnsI1d eGhktrn/w+eaCSYATBcikuMxAvqCzX3IImXzE9S6d03yTIX13GEs+lQsu3g4HeGvy4Xi 8qDA== X-Gm-Message-State: AOAM530gyRTy8aQizvIo51NH+RlYz8Hwrf4HiNKEZH7blo54so/oSIb9 xaN69at1BIPxB5HGMa5RmNppwoAVbulUQOQ= X-Google-Smtp-Source: ABdhPJw9Lk+TmjAMNEAUq1RSxqYyPt+9pEP3OOOGTSy7HY7WuXSKaV6EWWbJFhcTCdlhMAZY1adm2F1s03IEpYQ= Sender: "saravanak via sendgmr" X-Received: from saravanak.san.corp.google.com ([2620:15c:2d:3:7220:84ff:fe09:fedc]) (user=saravanak job=sendgmr) by 2002:a25:8446:: with SMTP id r6mr21337325ybm.442.1605924185419; Fri, 20 Nov 2020 18:03:05 -0800 (PST) Date: Fri, 20 Nov 2020 18:02:23 -0800 In-Reply-To: <20201121020232.908850-1-saravanak@google.com> Message-Id: <20201121020232.908850-9-saravanak@google.com> Mime-Version: 1.0 References: <20201121020232.908850-1-saravanak@google.com> X-Mailer: git-send-email 2.29.2.454.gaff20da3a2-goog Subject: [PATCH v2 08/17] driver core: Add fwnode link support From: Saravana Kannan To: "Rafael J. Wysocki" , "Rafael J. Wysocki" , Len Brown , Greg Kroah-Hartman , Ard Biesheuvel , Rob Herring , Frank Rowand , Marc Zyngier , Thomas Gleixner Cc: Saravana Kannan , Tomi Valkeinen , Laurent Pinchart , Grygorii Strashko , kernel-team@android.com, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, devicetree@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Add support for creating supplier-consumer links between fwnodes. It is intended for internal use the driver core and generic firmware support code (eg. Device Tree, ACPI), so it is simple by design and the API provided is limited. Signed-off-by: Saravana Kannan Acked-by: Rob Herring --- drivers/base/core.c | 98 ++++++++++++++++++++++++++++++++++++++++++ drivers/of/dynamic.c | 1 + include/linux/fwnode.h | 14 ++++++ 3 files changed, 113 insertions(+) diff --git a/drivers/base/core.c b/drivers/base/core.c index 401fa7e3505c..e2b246a44d1a 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -50,6 +50,104 @@ static LIST_HEAD(wait_for_suppliers); static DEFINE_MUTEX(wfs_lock); static LIST_HEAD(deferred_sync); static unsigned int defer_sync_state_count = 1; +static DEFINE_MUTEX(fwnode_link_lock); + +/** + * fwnode_link_add - Create a link between two fwnode_handles. + * @con: Consumer end of the link. + * @sup: Supplier end of the link. + * + * Create a fwnode link between fwnode handles @con and @sup. The fwnode link + * represents the detail that the firmware lists @sup fwnode as supplying a + * resource to @con. + * + * The driver core will use the fwnode link to create a device link between the + * two device objects corresponding to @con and @sup when they are created. The + * driver core will automatically delete the fwnode link between @con and @sup + * after doing that. + * + * 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) +{ + 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; + + link = kzalloc(sizeof(*link), GFP_KERNEL); + if (!link) { + ret = -ENOMEM; + goto out; + } + + link->supplier = sup; + INIT_LIST_HEAD(&link->s_hook); + link->consumer = con; + INIT_LIST_HEAD(&link->c_hook); + + list_add(&link->s_hook, &sup->consumers); + list_add(&link->c_hook, &con->suppliers); +out: + mutex_unlock(&fwnode_link_lock); + + return ret; +} + +/** + * fwnode_links_purge_suppliers - Delete all supplier links of fwnode_handle. + * @fwnode: fwnode whose supplier links need to be deleted + * + * Deletes all supplier links connecting directly to @fwnode. + */ +static void fwnode_links_purge_suppliers(struct fwnode_handle *fwnode) +{ + struct fwnode_link *link, *tmp; + + mutex_lock(&fwnode_link_lock); + list_for_each_entry_safe(link, tmp, &fwnode->suppliers, c_hook) { + list_del(&link->s_hook); + list_del(&link->c_hook); + kfree(link); + } + mutex_unlock(&fwnode_link_lock); +} + +/** + * fwnode_links_purge_consumers - Delete all consumer links of fwnode_handle. + * @fwnode: fwnode whose consumer links need to be deleted + * + * Deletes all consumer links connecting directly to @fwnode. + */ +static void fwnode_links_purge_consumers(struct fwnode_handle *fwnode) +{ + struct fwnode_link *link, *tmp; + + mutex_lock(&fwnode_link_lock); + list_for_each_entry_safe(link, tmp, &fwnode->consumers, s_hook) { + list_del(&link->s_hook); + list_del(&link->c_hook); + kfree(link); + } + mutex_unlock(&fwnode_link_lock); +} + +/** + * fwnode_links_purge - Delete all links connected to a fwnode_handle. + * @fwnode: fwnode whose links needs to be deleted + * + * Deletes all links connecting directly to a fwnode. + */ +void fwnode_links_purge(struct fwnode_handle *fwnode) +{ + fwnode_links_purge_suppliers(fwnode); + fwnode_links_purge_consumers(fwnode); +} #ifdef CONFIG_SRCU static DEFINE_MUTEX(device_links_lock); diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c index fe64430b438a..9a824decf61f 100644 --- a/drivers/of/dynamic.c +++ b/drivers/of/dynamic.c @@ -356,6 +356,7 @@ void of_node_release(struct kobject *kobj) property_list_free(node->properties); property_list_free(node->deadprops); + fwnode_links_purge(of_fwnode_handle(node)); kfree(node->full_name); kfree(node->data); diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h index 5589799708b5..b88365187347 100644 --- a/include/linux/fwnode.h +++ b/include/linux/fwnode.h @@ -10,6 +10,7 @@ #define _LINUX_FWNODE_H_ #include +#include struct fwnode_operations; struct device; @@ -18,6 +19,15 @@ struct fwnode_handle { struct fwnode_handle *secondary; const struct fwnode_operations *ops; struct device *dev; + struct list_head suppliers; + struct list_head consumers; +}; + +struct fwnode_link { + struct fwnode_handle *supplier; + struct list_head s_hook; + struct fwnode_handle *consumer; + struct list_head c_hook; }; /** @@ -174,8 +184,12 @@ static inline void fwnode_init(struct fwnode_handle *fwnode, const struct fwnode_operations *ops) { fwnode->ops = ops; + INIT_LIST_HEAD(&fwnode->consumers); + INIT_LIST_HEAD(&fwnode->suppliers); } extern u32 fw_devlink_get_flags(void); +int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup); +void fwnode_links_purge(struct fwnode_handle *fwnode); #endif