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: 1404269 Return-Path: X-Original-To: incoming-dt@patchwork.ozlabs.org Delivered-To: patchwork-incoming-dt@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=devicetree-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20161025 header.b=Oy8wm9rw; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4CdGtQ3PLGz9sVp for ; Sat, 21 Nov 2020 13:03:58 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727534AbgKUCDq (ORCPT ); Fri, 20 Nov 2020 21:03:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55422 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726398AbgKUCDJ (ORCPT ); Fri, 20 Nov 2020 21:03:09 -0500 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 34846C061A48 for ; Fri, 20 Nov 2020 18:03:06 -0800 (PST) Received: by mail-yb1-xb4a.google.com with SMTP id m186so14132104ybm.22 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=Hvl5e8JGuTFI49z9S5N5ddmr26D3IWviTeUsCCnZ/gdPM18bRl0yxtuqKU7NA5bms2 13LNz5DWh2klN+dm4Lur7o420gp9nkaEciFcM3U2kRGkDb5n9wg6web0GMD4/3VZ1Brc uIQ1mWtiEGIMX93yKi8iUPFIGBgiRbm2KrzVQgeigxFkkIa46FSfbVHTeUyMdLxxjt04 gfKgpxVG3y8lGUercOVAUfZJfQCu7wb2dSCjNdTf46KkcNDOhdVGqAFomdzO7F1/6vnr U/dZCiNzxEz+PWtD1ZCbqqNN56pr3os0QtjFm4OORKAjGLmB78L8F78iNevhzE/flFiG 1IrA== X-Gm-Message-State: AOAM531CP4W6UqgQV7oedu2uvgKb81s9kxi49syL0vhevrKaRyT/S8GE s0O34cr9+0BQev01UU27wA+yRfdmR0roBzw= 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: devicetree@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