[RFC,v3,7/9] power: supply: core: add locking around extension access

Message ID	20240904-power-supply-extensions-v3-7-62efeb93f8ec@weissschuh.net (mailing list archive)
State	Handled Elsewhere, archived
Headers	show Received: from todd.t-8ch.de (todd.t-8ch.de [159.69.126.157]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D46AB1E7670; Wed, 4 Sep 2024 19:25:55 +0000 (UTC) From: =?utf-8?q?Thomas_Wei=C3=9Fschuh?= <linux@weissschuh.net> Date: Wed, 04 Sep 2024 21:25:40 +0200 Subject: [PATCH RFC v3 7/9] power: supply: core: add locking around extension access Precedence: bulk MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Message-Id: <20240904-power-supply-extensions-v3-7-62efeb93f8ec@weissschuh.net> References: <20240904-power-supply-extensions-v3-0-62efeb93f8ec@weissschuh.net> In-Reply-To: <20240904-power-supply-extensions-v3-0-62efeb93f8ec@weissschuh.net> To: Sebastian Reichel <sre@kernel.org>, Armin Wolf <W_Armin@gmx.de>, Hans de Goede <hdegoede@redhat.com> Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, =?utf-8?q?Thomas?= =?utf-8?q?_Wei=C3=9Fschuh?= <linux@weissschuh.net>
Series	power: supply: extension API \| expand [RFC,v3,0/9] power: supply: extension API [RFC,v3,1/9] power: supply: core: rename psy_has_property() to psy_desc_has_property() [RFC,v3,2/9] power: supply: core: register thermal zone for battery [RFC,v3,3/9] power: supply: hwmon: register battery properties [RFC,v3,4/9] power: supply: sysfs: register battery properties [RFC,v3,5/9] power: supply: sysfs: rework uevent property loop [RFC,v3,6/9] power: supply: core: implement extension API [RFC,v3,7/9] power: supply: core: add locking around extension access [RFC,v3,8/9] power: supply: test-power: implement a power supply extension [RFC,v3,9/9] power: supply: cros_charge-control: use power_supply extensions

diff --git a/drivers/power/supply/power_supply.h b/drivers/power/supply/power_supply.h index fb45f0717bd1..b8e14cc70fcf 100644 --- a/drivers/power/supply/power_supply.h +++ b/drivers/power/supply/power_supply.h @@ -9,6 +9,8 @@ * Modified: 2004, Oct Szabolcs Gyurko */ +#include <linux/lockdep.h> + struct device; struct device_type; struct power_supply; @@ -25,6 +27,7 @@ struct power_supply_ext_registration { }; #define power_supply_for_each_extension(pos, psy) \ + lockdep_assert_held(&(psy)->extensions_sem); \ list_for_each_entry(pos, &(psy)->extensions, list_head) diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c index db5e7af57e67..4839be25e6be 100644 --- a/drivers/power/supply/power_supply_core.c +++ b/drivers/power/supply/power_supply_core.c @@ -11,6 +11,7 @@ #include <linux/module.h> #include <linux/types.h> +#include <linux/cleanup.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/delay.h> @@ -80,6 +81,7 @@ static int __power_supply_changed_work(struct device *dev, void *data) static void power_supply_changed_work(struct work_struct *work) { + int ret; unsigned long flags; struct power_supply *psy = container_of(work, struct power_supply, changed_work); @@ -87,6 +89,16 @@ static void power_supply_changed_work(struct work_struct *work) dev_dbg(&psy->dev, "%s\n", __func__); spin_lock_irqsave(&psy->changed_lock, flags); + + if (unlikely(psy->update_groups)) { + psy->update_groups = false; + spin_unlock_irqrestore(&psy->changed_lock, flags); + ret = sysfs_update_groups(&psy->dev.kobj, power_supply_dev_type.groups); + if (ret) + dev_warn(&psy->dev, "failed to update sysfs groups: %pe\n", ERR_PTR(ret)); + spin_lock_irqsave(&psy->changed_lock, flags); + } + /* * Check 'changed' here to avoid issues due to race between * power_supply_changed() and this routine. In worst case @@ -1218,17 +1230,26 @@ bool power_supply_ext_has_property(const struct power_supply_ext *psy_ext, return found; } -bool power_supply_has_property(struct power_supply *psy, - enum power_supply_property psp) +static bool psy_has_property_no_ext(struct power_supply *psy, + enum power_supply_property psp) { - struct power_supply_ext_registration *reg; - if (psy_desc_has_property(psy->desc, psp)) return true; if (power_supply_battery_info_has_prop(psy->battery_info, psp)) return true; + return false; +} + +bool power_supply_has_property(struct power_supply *psy, + enum power_supply_property psp) +{ + struct power_supply_ext_registration *reg; + + if (psy_has_property_no_ext(psy, psp)) + return true; + power_supply_for_each_extension(reg, psy) if (power_supply_ext_has_property(reg->ext, psp)) return true; @@ -1329,11 +1350,14 @@ EXPORT_SYMBOL_GPL(power_supply_powers); static int power_supply_update_groups(struct power_supply *psy) { - int ret; + unsigned long flags; + + spin_lock_irqsave(&psy->changed_lock, flags); + psy->update_groups = true; + spin_unlock_irqrestore(&psy->changed_lock, flags); - ret = sysfs_update_groups(&psy->dev.kobj, power_supply_dev_type.groups); power_supply_changed(psy); - return ret; + return 0; } int power_supply_register_extension(struct power_supply *psy, const struct power_supply_ext *ext, @@ -1342,6 +1366,8 @@ int power_supply_register_extension(struct power_supply *psy, const struct power struct power_supply_ext_registration *reg; size_t i; + guard(rwsem_write)(&psy->extensions_sem); + for (i = 0; i < ext->num_properties; i++) { if (power_supply_has_property(psy, ext->properties[i])) return -EEXIST; @@ -1362,6 +1388,8 @@ void power_supply_unregister_extension(struct power_supply *psy, const struct po { struct power_supply_ext_registration *reg; + guard(rwsem_write)(&psy->extensions_sem); + power_supply_for_each_extension(reg, psy) { if (reg->ext == ext) { list_del(&reg->list_head); @@ -1405,6 +1433,7 @@ static int power_supply_read_temp(struct thermal_zone_device *tzd, WARN_ON(tzd == NULL); psy = thermal_zone_device_priv(tzd); + guard(rwsem_read)(&psy->extensions_sem); ret = power_supply_get_property(psy, POWER_SUPPLY_PROP_TEMP, &val); if (ret) return ret; @@ -1427,7 +1456,7 @@ static int psy_register_thermal(struct power_supply *psy) return 0; /* Register battery zone device psy reports temperature */ - if (power_supply_has_property(psy, POWER_SUPPLY_PROP_TEMP)) { + if (psy_has_property_no_ext(psy, POWER_SUPPLY_PROP_TEMP)) { /* Prefer our hwmon device and avoid duplicates */ struct thermal_zone_params tzp = { .no_hwmon = IS_ENABLED(CONFIG_POWER_SUPPLY_HWMON) @@ -1534,7 +1563,9 @@ __power_supply_register(struct device *parent, } spin_lock_init(&psy->changed_lock); + init_rwsem(&psy->extensions_sem); INIT_LIST_HEAD(&psy->extensions); + rc = device_add(dev); if (rc) goto device_add_failed; @@ -1547,6 +1578,8 @@ __power_supply_register(struct device *parent, if (rc) goto register_thermal_failed; + guard(rwsem_read)(&psy->extensions_sem); + rc = power_supply_create_triggers(psy); if (rc) goto create_triggers_failed; diff --git a/drivers/power/supply/power_supply_leds.c b/drivers/power/supply/power_supply_leds.c index f4a7e566bea1..09a6f3fe2f85 100644 --- a/drivers/power/supply/power_supply_leds.c +++ b/drivers/power/supply/power_supply_leds.c @@ -195,6 +195,8 @@ static void power_supply_remove_gen_triggers(struct power_supply *psy) void power_supply_update_leds(struct power_supply *psy) { + guard(rwsem_read)(&psy->extensions_sem); + if (psy->desc->type == POWER_SUPPLY_TYPE_BATTERY) power_supply_update_bat_leds(psy); else diff --git a/drivers/power/supply/power_supply_sysfs.c b/drivers/power/supply/power_supply_sysfs.c index e7c306afd846..b56e0bd424f5 100644 --- a/drivers/power/supply/power_supply_sysfs.c +++ b/drivers/power/supply/power_supply_sysfs.c @@ -371,6 +371,8 @@ static ssize_t power_supply_store_property(struct device *dev, value.intval = ret; + guard(rwsem_read)(&psy->extensions_sem); + ret = power_supply_set_property(psy, psp, &value); if (ret < 0) return ret; @@ -392,6 +394,8 @@ static umode_t power_supply_attr_is_visible(struct kobject *kobj, if (attrno == POWER_SUPPLY_PROP_TYPE) return mode; + guard(rwsem_read)(&psy->extensions_sem); + if (power_supply_has_property(psy, attrno)) { if (power_supply_property_is_writeable(psy, attrno) > 0) mode |= S_IWUSR; @@ -497,6 +501,8 @@ int power_supply_uevent(const struct device *dev, struct kobj_uevent_env *env) if (ret) goto out; + guard(rwsem_read)(&psy->extensions_sem); + for (j = 0; j < POWER_SUPPLY_ATTR_CNT; j++) { ret = add_prop_uevent(dev, env, j, prop_buf); if (ret) diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h index 51788faf1d66..87bc50698649 100644 --- a/include/linux/power_supply.h +++ b/include/linux/power_supply.h @@ -15,6 +15,7 @@ #include <linux/device.h> #include <linux/workqueue.h> #include <linux/leds.h> +#include <linux/rwsem.h> #include <linux/list.h> #include <linux/spinlock.h> #include <linux/notifier.h> @@ -322,10 +323,12 @@ struct power_supply { struct delayed_work deferred_register_work; spinlock_t changed_lock; bool changed; + bool update_groups; bool initialized; bool removing; atomic_t use_cnt; struct power_supply_battery_info *battery_info; + struct rw_semaphore extensions_sem; /* protects "extensions" */ struct list_head extensions; #ifdef CONFIG_THERMAL struct thermal_zone_device *tzd;

[RFC,v3,7/9] power: supply: core: add locking around extension access

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