From patchwork Sun Nov 18 21:56:17 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Osipenko X-Patchwork-Id: 999580 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-tegra-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="jC7BNa1Y"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 42ym5r71Qxz9s7T for ; Mon, 19 Nov 2018 08:57:04 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725979AbeKSISc (ORCPT ); Mon, 19 Nov 2018 03:18:32 -0500 Received: from mail-pg1-f196.google.com ([209.85.215.196]:42478 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725826AbeKSISb (ORCPT ); Mon, 19 Nov 2018 03:18:31 -0500 Received: by mail-pg1-f196.google.com with SMTP id d72so9455709pga.9; Sun, 18 Nov 2018 13:57:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=HC5HwkZmbWbDssTA5bO3q3vkro4goGPUNwKYVGKYDdo=; b=jC7BNa1Y0UMcQY2rBrAJrSGxqrXccGO5c5pZQqKOAo6yTov0xP9DTTD1btsx50sJcm lKxzUGpCDUoksXq2ZKPI2/sYEiMhX++LmNva2tKVYwgHl5lzYu7pQHmsjQS0n7WK3zkK M8r5diA67oCFV+8TisvqAdNa3sOMVm1fXXmOXZ56p6mKlKE5uwMVnqXKSSKMH/WipFDI dpcYgFGXPrupDym+U6vilggua9DWQMZnx+6dqLDPw1SO8JdPPus820yVbsg+Ue65zjfw oQdVfr+X/hL4XJfRngucDZXsNlQun5cSl8LmxLu0UBHeXY4g7YD5AZ/TkRm3ePIp/u/f BFjQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=HC5HwkZmbWbDssTA5bO3q3vkro4goGPUNwKYVGKYDdo=; b=pSK6YxYjRFUOAVF3lNVB87l4vJ10Dyj7H9uI5UF7Q5+C5ROWr7GJteynBXXWIvojrK PtG7tYlvTSEacqKNT1wr/KXDqTYE6az805JUcRCn6SjAs5eabzgRfoct23rsnmZi7CS/ u2AXtfCsIHmEJ5QXNbCNXrerCUOttegt8LVcXOT/RdKOXbPXF9elSy70vw0HbMLO1UhX brODsK+rjY/Htj1fvwiWmLvtBf/KvqiGhYZ+c3njEyMLPYb/EN4y1KpqAhI6P0NQdHFY Ju/4PpKD3VMKk2TQvcdMFpP1e/q8o7RplmEOI0kyoU7/M7LbEdKj/VQIHlM9csMTcQb4 bfDQ== X-Gm-Message-State: AGRZ1gLJ3h16UFkeDw8m65QoZ9ocOxkDnTCVzQTNcHHSTXXc5Y2PGBDI bgXs7pyQt/7A2QdEI1I1u64= X-Google-Smtp-Source: AJdET5cegUxADBFwJqCW1/Bbh3yONi6vORLaCy0hgf4XhTsjmnNJLEV8YpXZ+PGb3EoG2QsTZG9l1g== X-Received: by 2002:a62:f94b:: with SMTP id g11-v6mr20006654pfm.244.1542578221460; Sun, 18 Nov 2018 13:57:01 -0800 (PST) Received: from localhost.localdomain (ppp91-76-171-181.pppoe.mtu-net.ru. [91.76.171.181]) by smtp.gmail.com with ESMTPSA id j64-v6sm9733422pfc.43.2018.11.18.13.56.56 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 18 Nov 2018 13:57:00 -0800 (PST) From: Dmitry Osipenko To: Mark Brown , Rob Herring Cc: linux-tegra@vger.kernel.org, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/3] regulator: core: Use ww_mutex for regulators locking Date: Mon, 19 Nov 2018 00:56:17 +0300 Message-Id: <20181118215619.21518-3-digetx@gmail.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181118215619.21518-1-digetx@gmail.com> References: <20181118215619.21518-1-digetx@gmail.com> MIME-Version: 1.0 Sender: linux-tegra-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-tegra@vger.kernel.org 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 --- 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 730f23ca4aad..c58e76a37e5f 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]; @@ -242,11 +268,54 @@ 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); } /** @@ -283,13 +352,42 @@ static struct device_node *of_get_child_regulator(struct device_node *parent, /** * 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); } /** @@ -807,7 +905,7 @@ 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 @@ -2309,7 +2407,20 @@ 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)) @@ -2320,18 +2431,20 @@ 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 */ } @@ -2339,6 +2452,12 @@ 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; } /** @@ -2355,30 +2474,15 @@ 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; } @@ -2420,7 +2524,7 @@ 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))) @@ -2458,6 +2562,12 @@ 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; } @@ -2476,19 +2586,15 @@ 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; } @@ -2499,7 +2605,7 @@ 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); @@ -2532,14 +2638,15 @@ 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--) @@ -2553,9 +2660,10 @@ 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); @@ -2576,7 +2684,10 @@ 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++) { @@ -2687,9 +2798,9 @@ 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; } @@ -3303,7 +3414,7 @@ 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, @@ -3514,14 +3625,15 @@ 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; } @@ -3593,18 +3705,19 @@ 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; } @@ -3794,13 +3907,12 @@ 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; } @@ -4336,7 +4448,7 @@ 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; @@ -4704,7 +4816,7 @@ 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; @@ -5061,8 +5173,6 @@ 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, "", @@ -5119,8 +5229,101 @@ 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) @@ -5136,12 +5339,18 @@ 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