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 X-Spam-Level: X-Spam-Status: No, score=-11.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED 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 9D8C5C43441 for ; Mon, 19 Nov 2018 13:10:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3CBCD208E3 for ; Mon, 19 Nov 2018 13:10:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=sirena.org.uk header.i=@sirena.org.uk header.b="liG0lQtu" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3CBCD208E3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729304AbeKSXeD (ORCPT ); Mon, 19 Nov 2018 18:34:03 -0500 Received: from heliosphere.sirena.org.uk ([172.104.155.198]:49808 "EHLO heliosphere.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729292AbeKSXeC (ORCPT ); Mon, 19 Nov 2018 18:34:02 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sirena.org.uk; s=20170815-heliosphere; h=Date:Message-Id:In-Reply-To: Subject:Cc:To:From:Sender:Reply-To:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:References: List-Id:List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner: List-Archive; bh=v8qsaQRECOxS/mgwoSHd9TcSa61ZC9Yig1dFpARAg6M=; b=liG0lQtuTupI bIH6mf6MZqPMjoiqDbXGUdBXEwxKhImYFAvoibvEsS32jEatsjt9CRE95ut1gh/m1UlU3AdxXh3/0 l/ZSvS7+nX6iSGq9znbebLjsBZ2qS5lhhfqFn41CmiApPYPpq284kq/PfVcxWp9K/MlwaaJhsOElr LCsw0=; Received: from cpc102320-sgyl38-2-0-cust46.18-2.cable.virginm.net ([82.37.168.47] helo=debutante.sirena.org.uk) by heliosphere.sirena.org.uk with esmtpa (Exim 4.89) (envelope-from ) id 1gOjJo-0000AH-Lk; Mon, 19 Nov 2018 13:10:24 +0000 Received: by debutante.sirena.org.uk (Postfix, from userid 1000) id 577A01125031; Mon, 19 Nov 2018 13:10:24 +0000 (GMT) From: Mark Brown To: Dmitry Osipenko Cc: Mark Brown , linux-kernel@vger.kernel.org Subject: Applied "regulator: core: Use ww_mutex for regulators locking" to the regulator tree In-Reply-To: Message-Id: <20181119131024.577A01125031@debutante.sirena.org.uk> Date: Mon, 19 Nov 2018 13:10:24 +0000 (GMT) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The patch regulator: core: Use ww_mutex for regulators locking has been applied to the regulator tree at https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark >From f8702f9e4aa7b45131af3df5531d6e3835269141 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Mon, 19 Nov 2018 00:56:17 +0300 Subject: [PATCH] regulator: core: Use ww_mutex for regulators locking Wait/wound mutex shall be used in order to avoid lockups on locking of coupled regulators. Signed-off-by: Dmitry Osipenko Suggested-by: Lucas Stach Signed-off-by: Mark Brown --- drivers/regulator/core.c | 403 +++++++++++++++++++------- drivers/regulator/da9210-regulator.c | 4 +- drivers/regulator/stpmic1_regulator.c | 4 +- drivers/regulator/wm8350-regulator.c | 4 +- include/linux/regulator/driver.h | 6 +- 5 files changed, 317 insertions(+), 104 deletions(-) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 783ec9c74104..47ccd35c7965 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -50,6 +50,8 @@ #define rdev_dbg(rdev, fmt, ...) \ pr_debug("%s: " fmt, rdev_get_name(rdev), ##__VA_ARGS__) +static DEFINE_WW_CLASS(regulator_ww_class); +static DEFINE_MUTEX(regulator_nesting_mutex); static DEFINE_MUTEX(regulator_list_mutex); static LIST_HEAD(regulator_map_list); static LIST_HEAD(regulator_ena_gpio_list); @@ -154,7 +156,7 @@ static inline struct regulator_dev *rdev_get_supply(struct regulator_dev *rdev) /** * regulator_lock_nested - lock a single regulator * @rdev: regulator source - * @subclass: mutex subclass used for lockdep + * @ww_ctx: w/w mutex acquire context * * This function can be called many times by one task on * a single regulator and its mutex will be locked only @@ -162,24 +164,52 @@ static inline struct regulator_dev *rdev_get_supply(struct regulator_dev *rdev) * than the one, which initially locked the mutex, it will * wait on mutex. */ -static void regulator_lock_nested(struct regulator_dev *rdev, - unsigned int subclass) +static inline int regulator_lock_nested(struct regulator_dev *rdev, + struct ww_acquire_ctx *ww_ctx) { - if (!mutex_trylock(&rdev->mutex)) { - if (rdev->mutex_owner == current) { + bool lock = false; + int ret = 0; + + mutex_lock(®ulator_nesting_mutex); + + if (ww_ctx || !ww_mutex_trylock(&rdev->mutex)) { + if (rdev->mutex_owner == current) rdev->ref_cnt++; - return; + else + lock = true; + + if (lock) { + mutex_unlock(®ulator_nesting_mutex); + ret = ww_mutex_lock(&rdev->mutex, ww_ctx); + mutex_lock(®ulator_nesting_mutex); } - mutex_lock_nested(&rdev->mutex, subclass); + } else { + lock = true; } - rdev->ref_cnt = 1; - rdev->mutex_owner = current; + if (lock && ret != -EDEADLK) { + rdev->ref_cnt++; + rdev->mutex_owner = current; + } + + mutex_unlock(®ulator_nesting_mutex); + + return ret; } -static inline void regulator_lock(struct regulator_dev *rdev) +/** + * regulator_lock - lock a single regulator + * @rdev: regulator source + * + * This function can be called many times by one task on + * a single regulator and its mutex will be locked only + * once. If a task, which is calling this function is other + * than the one, which initially locked the mutex, it will + * wait on mutex. + */ +void regulator_lock(struct regulator_dev *rdev) { - regulator_lock_nested(rdev, 0); + regulator_lock_nested(rdev, NULL); } /** @@ -189,52 +219,48 @@ static inline void regulator_lock(struct regulator_dev *rdev) * This function unlocks the mutex when the * reference counter reaches 0. */ -static void regulator_unlock(struct regulator_dev *rdev) +void regulator_unlock(struct regulator_dev *rdev) { - if (rdev->ref_cnt != 0) { - rdev->ref_cnt--; + mutex_lock(®ulator_nesting_mutex); - if (!rdev->ref_cnt) { - rdev->mutex_owner = NULL; - mutex_unlock(&rdev->mutex); - } + if (--rdev->ref_cnt == 0) { + rdev->mutex_owner = NULL; + ww_mutex_unlock(&rdev->mutex); } + + WARN_ON_ONCE(rdev->ref_cnt < 0); + + mutex_unlock(®ulator_nesting_mutex); } -static int regulator_lock_recursive(struct regulator_dev *rdev, - unsigned int subclass) +static void regulator_unlock_recursive(struct regulator_dev *rdev, + unsigned int n_coupled) { struct regulator_dev *c_rdev; int i; - for (i = 0; i < rdev->coupling_desc.n_coupled; i++) { - c_rdev = rdev->coupling_desc.coupled_rdevs[i]; + for (i = n_coupled; i > 0; i--) { + c_rdev = rdev->coupling_desc.coupled_rdevs[i - 1]; if (!c_rdev) continue; - regulator_lock_nested(c_rdev, subclass++); - if (c_rdev->supply) - subclass = - regulator_lock_recursive(c_rdev->supply->rdev, - subclass); - } + regulator_unlock_recursive( + c_rdev->supply->rdev, + c_rdev->coupling_desc.n_coupled); - return subclass; + regulator_unlock(c_rdev); + } } -/** - * regulator_unlock_dependent - unlock regulator's suppliers and coupled - * regulators - * @rdev: regulator source - * - * Unlock all regulators related with rdev by coupling or suppling. - */ -static void regulator_unlock_dependent(struct regulator_dev *rdev) +static int regulator_lock_recursive(struct regulator_dev *rdev, + struct regulator_dev **new_contended_rdev, + struct regulator_dev **old_contended_rdev, + struct ww_acquire_ctx *ww_ctx) { struct regulator_dev *c_rdev; - int i; + int i, err; for (i = 0; i < rdev->coupling_desc.n_coupled; i++) { c_rdev = rdev->coupling_desc.coupled_rdevs[i]; @@ -242,23 +268,95 @@ static void regulator_unlock_dependent(struct regulator_dev *rdev) if (!c_rdev) continue; - regulator_unlock(c_rdev); + if (c_rdev != *old_contended_rdev) { + err = regulator_lock_nested(c_rdev, ww_ctx); + if (err) { + if (err == -EDEADLK) { + *new_contended_rdev = c_rdev; + goto err_unlock; + } - if (c_rdev->supply) - regulator_unlock_dependent(c_rdev->supply->rdev); + /* shouldn't happen */ + WARN_ON_ONCE(err != -EALREADY); + } + } else { + *old_contended_rdev = NULL; + } + + if (c_rdev->supply) { + err = regulator_lock_recursive(c_rdev->supply->rdev, + new_contended_rdev, + old_contended_rdev, + ww_ctx); + if (err) { + regulator_unlock(c_rdev); + goto err_unlock; + } + } } + + return 0; + +err_unlock: + regulator_unlock_recursive(rdev, i); + + return err; +} + +/** + * regulator_unlock_dependent - unlock regulator's suppliers and coupled + * regulators + * @rdev: regulator source + * @ww_ctx: w/w mutex acquire context + * + * Unlock all regulators related with rdev by coupling or suppling. + */ +static void regulator_unlock_dependent(struct regulator_dev *rdev, + struct ww_acquire_ctx *ww_ctx) +{ + regulator_unlock_recursive(rdev, rdev->coupling_desc.n_coupled); + ww_acquire_fini(ww_ctx); } /** * regulator_lock_dependent - lock regulator's suppliers and coupled regulators * @rdev: regulator source + * @ww_ctx: w/w mutex acquire context * * This function as a wrapper on regulator_lock_recursive(), which locks * all regulators related with rdev by coupling or suppling. */ -static inline void regulator_lock_dependent(struct regulator_dev *rdev) +static void regulator_lock_dependent(struct regulator_dev *rdev, + struct ww_acquire_ctx *ww_ctx) { - regulator_lock_recursive(rdev, 0); + struct regulator_dev *new_contended_rdev = NULL; + struct regulator_dev *old_contended_rdev = NULL; + int err; + + mutex_lock(®ulator_list_mutex); + + ww_acquire_init(ww_ctx, ®ulator_ww_class); + + do { + if (new_contended_rdev) { + ww_mutex_lock_slow(&new_contended_rdev->mutex, ww_ctx); + old_contended_rdev = new_contended_rdev; + old_contended_rdev->ref_cnt++; + } + + err = regulator_lock_recursive(rdev, + &new_contended_rdev, + &old_contended_rdev, + ww_ctx); + + if (old_contended_rdev) + regulator_unlock(old_contended_rdev); + + } while (err == -EDEADLK); + + ww_acquire_done(ww_ctx); + + mutex_unlock(®ulator_list_mutex); } /** @@ -772,7 +870,7 @@ static int drms_uA_update(struct regulator_dev *rdev) int current_uA = 0, output_uV, input_uV, err; unsigned int mode; - lockdep_assert_held_once(&rdev->mutex); + lockdep_assert_held_once(&rdev->mutex.base); /* * first check to see if we can set modes at all, otherwise just @@ -2274,7 +2372,20 @@ static int _regulator_enable(struct regulator_dev *rdev) { int ret; - lockdep_assert_held_once(&rdev->mutex); + lockdep_assert_held_once(&rdev->mutex.base); + + if (rdev->supply) { + ret = _regulator_enable(rdev->supply->rdev); + if (ret < 0) + return ret; + } + + /* balance only if there are regulators coupled */ + if (rdev->coupling_desc.n_coupled > 1) { + ret = regulator_balance_voltage(rdev, PM_SUSPEND_ON); + if (ret < 0) + goto err_disable_supply; + } /* check voltage and requested load before enabling */ if (regulator_ops_is_valid(rdev, REGULATOR_CHANGE_DRMS)) @@ -2285,18 +2396,20 @@ static int _regulator_enable(struct regulator_dev *rdev) ret = _regulator_is_enabled(rdev); if (ret == -EINVAL || ret == 0) { if (!regulator_ops_is_valid(rdev, - REGULATOR_CHANGE_STATUS)) - return -EPERM; + REGULATOR_CHANGE_STATUS)) { + ret = -EPERM; + goto err_disable_supply; + } ret = _regulator_do_enable(rdev); if (ret < 0) - return ret; + goto err_disable_supply; _notifier_call_chain(rdev, REGULATOR_EVENT_ENABLE, NULL); } else if (ret < 0) { rdev_err(rdev, "is_enabled() failed: %d\n", ret); - return ret; + goto err_disable_supply; } /* Fallthrough on positive return values - already enabled */ } @@ -2304,6 +2417,12 @@ static int _regulator_enable(struct regulator_dev *rdev) rdev->use_count++; return 0; + +err_disable_supply: + if (rdev->supply) + _regulator_disable(rdev->supply->rdev); + + return ret; } /** @@ -2320,30 +2439,15 @@ static int _regulator_enable(struct regulator_dev *rdev) int regulator_enable(struct regulator *regulator) { struct regulator_dev *rdev = regulator->rdev; + struct ww_acquire_ctx ww_ctx; int ret = 0; if (regulator->always_on) return 0; - if (rdev->supply) { - ret = regulator_enable(rdev->supply); - if (ret != 0) - return ret; - } - - regulator_lock_dependent(rdev); - /* balance only if there are regulators coupled */ - if (rdev->coupling_desc.n_coupled > 1) { - ret = regulator_balance_voltage(rdev, PM_SUSPEND_ON); - if (ret != 0) - goto unlock; - } + regulator_lock_dependent(rdev, &ww_ctx); ret = _regulator_enable(rdev); -unlock: - regulator_unlock_dependent(rdev); - - if (ret != 0 && rdev->supply) - regulator_disable(rdev->supply); + regulator_unlock_dependent(rdev, &ww_ctx); return ret; } @@ -2385,7 +2489,7 @@ static int _regulator_disable(struct regulator_dev *rdev) { int ret = 0; - lockdep_assert_held_once(&rdev->mutex); + lockdep_assert_held_once(&rdev->mutex.base); if (WARN(rdev->use_count <= 0, "unbalanced disables for %s\n", rdev_get_name(rdev))) @@ -2423,6 +2527,12 @@ static int _regulator_disable(struct regulator_dev *rdev) rdev->use_count--; } + if (ret == 0 && rdev->coupling_desc.n_coupled > 1) + ret = regulator_balance_voltage(rdev, PM_SUSPEND_ON); + + if (ret == 0 && rdev->supply) + ret = _regulator_disable(rdev->supply->rdev); + return ret; } @@ -2441,19 +2551,15 @@ static int _regulator_disable(struct regulator_dev *rdev) int regulator_disable(struct regulator *regulator) { struct regulator_dev *rdev = regulator->rdev; + struct ww_acquire_ctx ww_ctx; int ret = 0; if (regulator->always_on) return 0; - regulator_lock_dependent(rdev); + regulator_lock_dependent(rdev, &ww_ctx); ret = _regulator_disable(rdev); - if (rdev->coupling_desc.n_coupled > 1) - regulator_balance_voltage(rdev, PM_SUSPEND_ON); - regulator_unlock_dependent(rdev); - - if (ret == 0 && rdev->supply) - regulator_disable(rdev->supply); + regulator_unlock_dependent(rdev, &ww_ctx); return ret; } @@ -2464,7 +2570,7 @@ static int _regulator_force_disable(struct regulator_dev *rdev) { int ret = 0; - lockdep_assert_held_once(&rdev->mutex); + lockdep_assert_held_once(&rdev->mutex.base); ret = _notifier_call_chain(rdev, REGULATOR_EVENT_FORCE_DISABLE | REGULATOR_EVENT_PRE_DISABLE, NULL); @@ -2497,14 +2603,15 @@ static int _regulator_force_disable(struct regulator_dev *rdev) int regulator_force_disable(struct regulator *regulator) { struct regulator_dev *rdev = regulator->rdev; + struct ww_acquire_ctx ww_ctx; int ret; - regulator_lock_dependent(rdev); + regulator_lock_dependent(rdev, &ww_ctx); regulator->uA_load = 0; ret = _regulator_force_disable(regulator->rdev); if (rdev->coupling_desc.n_coupled > 1) regulator_balance_voltage(rdev, PM_SUSPEND_ON); - regulator_unlock_dependent(rdev); + regulator_unlock_dependent(rdev, &ww_ctx); if (rdev->supply) while (rdev->open_count--) @@ -2518,9 +2625,10 @@ static void regulator_disable_work(struct work_struct *work) { struct regulator_dev *rdev = container_of(work, struct regulator_dev, disable_work.work); + struct ww_acquire_ctx ww_ctx; int count, i, ret; - regulator_lock(rdev); + regulator_lock_dependent(rdev, &ww_ctx); BUG_ON(!rdev->deferred_disables); @@ -2541,7 +2649,10 @@ static void regulator_disable_work(struct work_struct *work) rdev_err(rdev, "Deferred disable failed: %d\n", ret); } - regulator_unlock(rdev); + if (rdev->coupling_desc.n_coupled > 1) + regulator_balance_voltage(rdev, PM_SUSPEND_ON); + + regulator_unlock_dependent(rdev, &ww_ctx); if (rdev->supply) { for (i = 0; i < count; i++) { @@ -2652,9 +2763,9 @@ int regulator_is_enabled(struct regulator *regulator) if (regulator->always_on) return 1; - regulator_lock_dependent(regulator->rdev); + regulator_lock(regulator->rdev); ret = _regulator_is_enabled(regulator->rdev); - regulator_unlock_dependent(regulator->rdev); + regulator_unlock(regulator->rdev); return ret; } @@ -3268,7 +3379,7 @@ static int regulator_get_optimal_voltage(struct regulator_dev *rdev, int tmp_min = 0; int tmp_max = INT_MAX; - lockdep_assert_held_once(&c_rdevs[i]->mutex); + lockdep_assert_held_once(&c_rdevs[i]->mutex.base); ret = regulator_check_consumers(c_rdevs[i], &tmp_min, @@ -3479,14 +3590,15 @@ static int regulator_balance_voltage(struct regulator_dev *rdev, */ int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV) { - int ret = 0; + struct ww_acquire_ctx ww_ctx; + int ret; - regulator_lock_dependent(regulator->rdev); + regulator_lock_dependent(regulator->rdev, &ww_ctx); ret = regulator_set_voltage_unlocked(regulator, min_uV, max_uV, PM_SUSPEND_ON); - regulator_unlock_dependent(regulator->rdev); + regulator_unlock_dependent(regulator->rdev, &ww_ctx); return ret; } @@ -3558,18 +3670,19 @@ static int _regulator_set_suspend_voltage(struct regulator *regulator, int regulator_set_suspend_voltage(struct regulator *regulator, int min_uV, int max_uV, suspend_state_t state) { - int ret = 0; + struct ww_acquire_ctx ww_ctx; + int ret; /* PM_SUSPEND_ON is handled by regulator_set_voltage() */ if (regulator_check_states(state) || state == PM_SUSPEND_ON) return -EINVAL; - regulator_lock_dependent(regulator->rdev); + regulator_lock_dependent(regulator->rdev, &ww_ctx); ret = _regulator_set_suspend_voltage(regulator, min_uV, max_uV, state); - regulator_unlock_dependent(regulator->rdev); + regulator_unlock_dependent(regulator->rdev, &ww_ctx); return ret; } @@ -3759,13 +3872,12 @@ static int _regulator_get_voltage(struct regulator_dev *rdev) */ int regulator_get_voltage(struct regulator *regulator) { + struct ww_acquire_ctx ww_ctx; int ret; - regulator_lock_dependent(regulator->rdev); - + regulator_lock_dependent(regulator->rdev, &ww_ctx); ret = _regulator_get_voltage(regulator->rdev); - - regulator_unlock_dependent(regulator->rdev); + regulator_unlock_dependent(regulator->rdev, &ww_ctx); return ret; } @@ -4301,7 +4413,7 @@ EXPORT_SYMBOL_GPL(regulator_bulk_free); int regulator_notifier_call_chain(struct regulator_dev *rdev, unsigned long event, void *data) { - lockdep_assert_held_once(&rdev->mutex); + lockdep_assert_held_once(&rdev->mutex.base); _notifier_call_chain(rdev, event, data); return NOTIFY_DONE; @@ -4669,7 +4781,7 @@ regulator_register(const struct regulator_desc *regulator_desc, rdev->dev.of_node = of_node_get(config->of_node); } - mutex_init(&rdev->mutex); + ww_mutex_init(&rdev->mutex, ®ulator_ww_class); rdev->reg_data = config->driver_data; rdev->owner = regulator_desc->owner; rdev->desc = regulator_desc; @@ -5026,8 +5138,6 @@ static void regulator_summary_show_subtree(struct seq_file *s, if (!rdev) return; - regulator_lock_nested(rdev, level); - opmode = _regulator_get_mode_unlocked(rdev); seq_printf(s, "%*s%-*s %3d %4d %6d %7s ", level * 3 + 1, "", @@ -5084,8 +5194,101 @@ static void regulator_summary_show_subtree(struct seq_file *s, class_for_each_device(®ulator_class, NULL, &summary_data, regulator_summary_show_children); +} + +struct summary_lock_data { + struct ww_acquire_ctx *ww_ctx; + struct regulator_dev **new_contended_rdev; + struct regulator_dev **old_contended_rdev; +}; + +static int regulator_summary_lock_one(struct device *dev, void *data) +{ + struct regulator_dev *rdev = dev_to_rdev(dev); + struct summary_lock_data *lock_data = data; + int ret = 0; + + if (rdev != *lock_data->old_contended_rdev) { + ret = regulator_lock_nested(rdev, lock_data->ww_ctx); + + if (ret == -EDEADLK) + *lock_data->new_contended_rdev = rdev; + else + WARN_ON_ONCE(ret); + } else { + *lock_data->old_contended_rdev = NULL; + } + + return ret; +} + +static int regulator_summary_unlock_one(struct device *dev, void *data) +{ + struct regulator_dev *rdev = dev_to_rdev(dev); + struct summary_lock_data *lock_data = data; + + if (lock_data) { + if (rdev == *lock_data->new_contended_rdev) + return -EDEADLK; + } regulator_unlock(rdev); + + return 0; +} + +static int regulator_summary_lock_all(struct ww_acquire_ctx *ww_ctx, + struct regulator_dev **new_contended_rdev, + struct regulator_dev **old_contended_rdev) +{ + struct summary_lock_data lock_data; + int ret; + + lock_data.ww_ctx = ww_ctx; + lock_data.new_contended_rdev = new_contended_rdev; + lock_data.old_contended_rdev = old_contended_rdev; + + ret = class_for_each_device(®ulator_class, NULL, &lock_data, + regulator_summary_lock_one); + if (ret) + class_for_each_device(®ulator_class, NULL, &lock_data, + regulator_summary_unlock_one); + + return ret; +} + +static void regulator_summary_lock(struct ww_acquire_ctx *ww_ctx) +{ + struct regulator_dev *new_contended_rdev = NULL; + struct regulator_dev *old_contended_rdev = NULL; + int err; + + ww_acquire_init(ww_ctx, ®ulator_ww_class); + + do { + if (new_contended_rdev) { + ww_mutex_lock_slow(&new_contended_rdev->mutex, ww_ctx); + old_contended_rdev = new_contended_rdev; + old_contended_rdev->ref_cnt++; + } + + err = regulator_summary_lock_all(ww_ctx, + &new_contended_rdev, + &old_contended_rdev); + + if (old_contended_rdev) + regulator_unlock(old_contended_rdev); + + } while (err == -EDEADLK); + + ww_acquire_done(ww_ctx); +} + +static void regulator_summary_unlock(struct ww_acquire_ctx *ww_ctx) +{ + class_for_each_device(®ulator_class, NULL, NULL, + regulator_summary_unlock_one); + ww_acquire_fini(ww_ctx); } static int regulator_summary_show_roots(struct device *dev, void *data) @@ -5101,12 +5304,18 @@ static int regulator_summary_show_roots(struct device *dev, void *data) static int regulator_summary_show(struct seq_file *s, void *data) { + struct ww_acquire_ctx ww_ctx; + seq_puts(s, " regulator use open bypass opmode voltage current min max\n"); seq_puts(s, "---------------------------------------------------------------------------------------\n"); + regulator_summary_lock(&ww_ctx); + class_for_each_device(®ulator_class, NULL, s, regulator_summary_show_roots); + regulator_summary_unlock(&ww_ctx); + return 0; } diff --git a/drivers/regulator/da9210-regulator.c b/drivers/regulator/da9210-regulator.c index d0496d6b0934..84dba64ed11e 100644 --- a/drivers/regulator/da9210-regulator.c +++ b/drivers/regulator/da9210-regulator.c @@ -131,7 +131,7 @@ static irqreturn_t da9210_irq_handler(int irq, void *data) if (error < 0) goto error_i2c; - mutex_lock(&chip->rdev->mutex); + regulator_lock(chip->rdev); if (val & DA9210_E_OVCURR) { regulator_notifier_call_chain(chip->rdev, @@ -157,7 +157,7 @@ static irqreturn_t da9210_irq_handler(int irq, void *data) handled |= DA9210_E_VMAX; } - mutex_unlock(&chip->rdev->mutex); + regulator_unlock(chip->rdev); if (handled) { /* Clear handled events */ diff --git a/drivers/regulator/stpmic1_regulator.c b/drivers/regulator/stpmic1_regulator.c index e15634edb8ce..eac0848a78c7 100644 --- a/drivers/regulator/stpmic1_regulator.c +++ b/drivers/regulator/stpmic1_regulator.c @@ -489,14 +489,14 @@ static irqreturn_t stpmic1_curlim_irq_handler(int irq, void *data) { struct regulator_dev *rdev = (struct regulator_dev *)data; - mutex_lock(&rdev->mutex); + regulator_lock(rdev, NULL); /* Send an overcurrent notification */ regulator_notifier_call_chain(rdev, REGULATOR_EVENT_OVER_CURRENT, NULL); - mutex_unlock(&rdev->mutex); + regulator_unlock(rdev); return IRQ_HANDLED; } diff --git a/drivers/regulator/wm8350-regulator.c b/drivers/regulator/wm8350-regulator.c index 8ad11b074b49..a1c7dfee5c37 100644 --- a/drivers/regulator/wm8350-regulator.c +++ b/drivers/regulator/wm8350-regulator.c @@ -1153,7 +1153,7 @@ static irqreturn_t pmic_uv_handler(int irq, void *data) { struct regulator_dev *rdev = (struct regulator_dev *)data; - mutex_lock(&rdev->mutex); + regulator_lock(rdev); if (irq == WM8350_IRQ_CS1 || irq == WM8350_IRQ_CS2) regulator_notifier_call_chain(rdev, REGULATOR_EVENT_REGULATION_OUT, @@ -1162,7 +1162,7 @@ static irqreturn_t pmic_uv_handler(int irq, void *data) regulator_notifier_call_chain(rdev, REGULATOR_EVENT_UNDER_VOLTAGE, NULL); - mutex_unlock(&rdev->mutex); + regulator_unlock(rdev); return IRQ_HANDLED; } diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h index a05d37d0efa1..7065031f0846 100644 --- a/include/linux/regulator/driver.h +++ b/include/linux/regulator/driver.h @@ -20,6 +20,7 @@ #include #include #include +#include struct gpio_desc; struct regmap; @@ -462,7 +463,7 @@ struct regulator_dev { struct coupling_desc coupling_desc; struct blocking_notifier_head notifier; - struct mutex mutex; /* consumer lock */ + struct ww_mutex mutex; /* consumer lock */ struct task_struct *mutex_owner; int ref_cnt; struct module *owner; @@ -545,4 +546,7 @@ int regulator_set_active_discharge_regmap(struct regulator_dev *rdev, bool enable); void *regulator_get_init_drvdata(struct regulator_init_data *reg_init_data); +void regulator_lock(struct regulator_dev *rdev); +void regulator_unlock(struct regulator_dev *rdev); + #endif -- 2.19.0.rc2