From 00ce3873f730fb24c657854ec04374358e711838 Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski Date: Wed, 4 May 2022 10:17:32 +0200 Subject: opp: Add apis to retrieve opps with interconnect bandwidth Add dev_pm_opp_find_bw_ceil and dev_pm_opp_find_bw_floor to retrieve opps based on interconnect associated with the opp and bandwidth. The index variable is the index of the interconnect as specified in the opp table in Devicetree. Co-developed-by: Thara Gopinath Signed-off-by: Thara Gopinath Signed-off-by: Krzysztof Kozlowski Signed-off-by: Viresh Kumar --- include/linux/pm_opp.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'include/linux') diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h index 0d85a63a1f78..dcea178868c9 100644 --- a/include/linux/pm_opp.h +++ b/include/linux/pm_opp.h @@ -129,6 +129,13 @@ struct dev_pm_opp *dev_pm_opp_find_freq_ceil_by_volt(struct device *dev, struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev, unsigned long *freq); + +struct dev_pm_opp *dev_pm_opp_find_bw_ceil(struct device *dev, + unsigned int *bw, int index); + +struct dev_pm_opp *dev_pm_opp_find_bw_floor(struct device *dev, + unsigned int *bw, int index); + void dev_pm_opp_put(struct dev_pm_opp *opp); int dev_pm_opp_add(struct device *dev, unsigned long freq, @@ -279,6 +286,18 @@ static inline struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev, return ERR_PTR(-EOPNOTSUPP); } +static inline struct dev_pm_opp *dev_pm_opp_find_bw_ceil(struct device *dev, + unsigned int *bw, int index) +{ + return ERR_PTR(-EOPNOTSUPP); +} + +static inline struct dev_pm_opp *dev_pm_opp_find_bw_floor(struct device *dev, + unsigned int *bw, int index) +{ + return ERR_PTR(-EOPNOTSUPP); +} + static inline void dev_pm_opp_put(struct dev_pm_opp *opp) {} static inline int dev_pm_opp_add(struct device *dev, unsigned long freq, -- cgit v1.3-15-g9ac1 From 22079af7df5a5dfef1c4d160abfd43035211759e Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Wed, 4 May 2022 15:40:22 +0530 Subject: opp: Reorder definition of ceil/floor helpers Reorder the helpers to keep all freq specific ones, followed by level and bw. No functional change. Signed-off-by: Viresh Kumar --- drivers/opp/core.c | 194 ++++++++++++++++++++++++------------------------- include/linux/pm_opp.h | 22 +++--- 2 files changed, 108 insertions(+), 108 deletions(-) (limited to 'include/linux') diff --git a/drivers/opp/core.c b/drivers/opp/core.c index 48606f52759d..84063eaebb91 100644 --- a/drivers/opp/core.c +++ b/drivers/opp/core.c @@ -456,103 +456,6 @@ struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev, } EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_exact); -/** - * dev_pm_opp_find_level_exact() - search for an exact level - * @dev: device for which we do this operation - * @level: level to search for - * - * Return: Searches for exact match in the opp table and returns pointer to the - * matching opp if found, else returns ERR_PTR in case of error and should - * be handled using IS_ERR. Error return values can be: - * EINVAL: for bad pointer - * ERANGE: no match found for search - * ENODEV: if device not found in list of registered devices - * - * The callers are required to call dev_pm_opp_put() for the returned OPP after - * use. - */ -struct dev_pm_opp *dev_pm_opp_find_level_exact(struct device *dev, - unsigned int level) -{ - struct opp_table *opp_table; - struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE); - - opp_table = _find_opp_table(dev); - if (IS_ERR(opp_table)) { - int r = PTR_ERR(opp_table); - - dev_err(dev, "%s: OPP table not found (%d)\n", __func__, r); - return ERR_PTR(r); - } - - mutex_lock(&opp_table->lock); - - list_for_each_entry(temp_opp, &opp_table->opp_list, node) { - if (temp_opp->level == level) { - opp = temp_opp; - - /* Increment the reference count of OPP */ - dev_pm_opp_get(opp); - break; - } - } - - mutex_unlock(&opp_table->lock); - dev_pm_opp_put_opp_table(opp_table); - - return opp; -} -EXPORT_SYMBOL_GPL(dev_pm_opp_find_level_exact); - -/** - * dev_pm_opp_find_level_ceil() - search for an rounded up level - * @dev: device for which we do this operation - * @level: level to search for - * - * Return: Searches for rounded up match in the opp table and returns pointer - * to the matching opp if found, else returns ERR_PTR in case of error and - * should be handled using IS_ERR. Error return values can be: - * EINVAL: for bad pointer - * ERANGE: no match found for search - * ENODEV: if device not found in list of registered devices - * - * The callers are required to call dev_pm_opp_put() for the returned OPP after - * use. - */ -struct dev_pm_opp *dev_pm_opp_find_level_ceil(struct device *dev, - unsigned int *level) -{ - struct opp_table *opp_table; - struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE); - - opp_table = _find_opp_table(dev); - if (IS_ERR(opp_table)) { - int r = PTR_ERR(opp_table); - - dev_err(dev, "%s: OPP table not found (%d)\n", __func__, r); - return ERR_PTR(r); - } - - mutex_lock(&opp_table->lock); - - list_for_each_entry(temp_opp, &opp_table->opp_list, node) { - if (temp_opp->available && temp_opp->level >= *level) { - opp = temp_opp; - *level = opp->level; - - /* Increment the reference count of OPP */ - dev_pm_opp_get(opp); - break; - } - } - - mutex_unlock(&opp_table->lock); - dev_pm_opp_put_opp_table(opp_table); - - return opp; -} -EXPORT_SYMBOL_GPL(dev_pm_opp_find_level_ceil); - static noinline struct dev_pm_opp *_find_freq_ceil(struct opp_table *opp_table, unsigned long *freq) { @@ -729,6 +632,103 @@ struct dev_pm_opp *dev_pm_opp_find_freq_ceil_by_volt(struct device *dev, } EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_ceil_by_volt); +/** + * dev_pm_opp_find_level_exact() - search for an exact level + * @dev: device for which we do this operation + * @level: level to search for + * + * Return: Searches for exact match in the opp table and returns pointer to the + * matching opp if found, else returns ERR_PTR in case of error and should + * be handled using IS_ERR. Error return values can be: + * EINVAL: for bad pointer + * ERANGE: no match found for search + * ENODEV: if device not found in list of registered devices + * + * The callers are required to call dev_pm_opp_put() for the returned OPP after + * use. + */ +struct dev_pm_opp *dev_pm_opp_find_level_exact(struct device *dev, + unsigned int level) +{ + struct opp_table *opp_table; + struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE); + + opp_table = _find_opp_table(dev); + if (IS_ERR(opp_table)) { + int r = PTR_ERR(opp_table); + + dev_err(dev, "%s: OPP table not found (%d)\n", __func__, r); + return ERR_PTR(r); + } + + mutex_lock(&opp_table->lock); + + list_for_each_entry(temp_opp, &opp_table->opp_list, node) { + if (temp_opp->level == level) { + opp = temp_opp; + + /* Increment the reference count of OPP */ + dev_pm_opp_get(opp); + break; + } + } + + mutex_unlock(&opp_table->lock); + dev_pm_opp_put_opp_table(opp_table); + + return opp; +} +EXPORT_SYMBOL_GPL(dev_pm_opp_find_level_exact); + +/** + * dev_pm_opp_find_level_ceil() - search for an rounded up level + * @dev: device for which we do this operation + * @level: level to search for + * + * Return: Searches for rounded up match in the opp table and returns pointer + * to the matching opp if found, else returns ERR_PTR in case of error and + * should be handled using IS_ERR. Error return values can be: + * EINVAL: for bad pointer + * ERANGE: no match found for search + * ENODEV: if device not found in list of registered devices + * + * The callers are required to call dev_pm_opp_put() for the returned OPP after + * use. + */ +struct dev_pm_opp *dev_pm_opp_find_level_ceil(struct device *dev, + unsigned int *level) +{ + struct opp_table *opp_table; + struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE); + + opp_table = _find_opp_table(dev); + if (IS_ERR(opp_table)) { + int r = PTR_ERR(opp_table); + + dev_err(dev, "%s: OPP table not found (%d)\n", __func__, r); + return ERR_PTR(r); + } + + mutex_lock(&opp_table->lock); + + list_for_each_entry(temp_opp, &opp_table->opp_list, node) { + if (temp_opp->available && temp_opp->level >= *level) { + opp = temp_opp; + *level = opp->level; + + /* Increment the reference count of OPP */ + dev_pm_opp_get(opp); + break; + } + } + + mutex_unlock(&opp_table->lock); + dev_pm_opp_put_opp_table(opp_table); + + return opp; +} +EXPORT_SYMBOL_GPL(dev_pm_opp_find_level_ceil); + /** * dev_pm_opp_find_bw_ceil() - Search for a rounded ceil bandwidth * @dev: device for which we do this operation diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h index dcea178868c9..6708b4ec244d 100644 --- a/include/linux/pm_opp.h +++ b/include/linux/pm_opp.h @@ -117,16 +117,16 @@ unsigned long dev_pm_opp_get_suspend_opp_freq(struct device *dev); struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev, unsigned long freq, bool available); -struct dev_pm_opp *dev_pm_opp_find_level_exact(struct device *dev, - unsigned int level); -struct dev_pm_opp *dev_pm_opp_find_level_ceil(struct device *dev, - unsigned int *level); - struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev, unsigned long *freq); struct dev_pm_opp *dev_pm_opp_find_freq_ceil_by_volt(struct device *dev, unsigned long u_volt); +struct dev_pm_opp *dev_pm_opp_find_level_exact(struct device *dev, + unsigned int level); +struct dev_pm_opp *dev_pm_opp_find_level_ceil(struct device *dev, + unsigned int *level); + struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev, unsigned long *freq); @@ -250,12 +250,6 @@ static inline unsigned long dev_pm_opp_get_suspend_opp_freq(struct device *dev) return 0; } -static inline struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev, - unsigned long freq, bool available) -{ - return ERR_PTR(-EOPNOTSUPP); -} - static inline struct dev_pm_opp *dev_pm_opp_find_level_exact(struct device *dev, unsigned int level) { @@ -268,6 +262,12 @@ static inline struct dev_pm_opp *dev_pm_opp_find_level_ceil(struct device *dev, return ERR_PTR(-EOPNOTSUPP); } +static inline struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev, + unsigned long freq, bool available) +{ + return ERR_PTR(-EOPNOTSUPP); +} + static inline struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev, unsigned long *freq) { -- cgit v1.3-15-g9ac1 From 13dfd97a341a5cf9d15f415dd469f45e971ef12a Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Thu, 19 May 2022 14:02:32 +0300 Subject: notifier: Add atomic_notifier_call_chain_is_empty() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add atomic_notifier_call_chain_is_empty() that returns true if given atomic call chain is empty. The first user of this new notifier API function will be the kernel power-off core code that will support power-off call chains. The core code will need to check whether there is a power-off handler registered at all in order to decide whether to halt machine or power it off. Reviewed-by: Michał Mirosław Signed-off-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki --- include/linux/notifier.h | 2 ++ kernel/notifier.c | 13 +++++++++++++ 2 files changed, 15 insertions(+) (limited to 'include/linux') diff --git a/include/linux/notifier.h b/include/linux/notifier.h index 87069b8459af..95e2440037de 100644 --- a/include/linux/notifier.h +++ b/include/linux/notifier.h @@ -173,6 +173,8 @@ extern int blocking_notifier_call_chain_robust(struct blocking_notifier_head *nh extern int raw_notifier_call_chain_robust(struct raw_notifier_head *nh, unsigned long val_up, unsigned long val_down, void *v); +extern bool atomic_notifier_call_chain_is_empty(struct atomic_notifier_head *nh); + #define NOTIFY_DONE 0x0000 /* Don't care */ #define NOTIFY_OK 0x0001 /* Suits me */ #define NOTIFY_STOP_MASK 0x8000 /* Don't call further */ diff --git a/kernel/notifier.c b/kernel/notifier.c index ba005ebf4730..137b902c985b 100644 --- a/kernel/notifier.c +++ b/kernel/notifier.c @@ -204,6 +204,19 @@ int atomic_notifier_call_chain(struct atomic_notifier_head *nh, EXPORT_SYMBOL_GPL(atomic_notifier_call_chain); NOKPROBE_SYMBOL(atomic_notifier_call_chain); +/** + * atomic_notifier_call_chain_is_empty - Check whether notifier chain is empty + * @nh: Pointer to head of the atomic notifier chain + * + * Checks whether notifier chain is empty. + * + * Returns true is notifier chain is empty, false otherwise. + */ +bool atomic_notifier_call_chain_is_empty(struct atomic_notifier_head *nh) +{ + return !rcu_access_pointer(nh->head); +} + /* * Blocking notifier chain routines. All access to the chain is * synchronized by an rwsem. -- cgit v1.3-15-g9ac1 From c82f898d873ce10d88f8d60b38c8dd19f1ed7c66 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Tue, 10 May 2022 02:32:10 +0300 Subject: notifier: Add blocking/atomic_notifier_chain_register_unique_prio() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add variant of blocking/atomic_notifier_chain_register() functions that allow registration of a notifier only if it has unique priority, otherwise -EBUSY error code is returned by the new functions. Reviewed-by: Michał Mirosław Signed-off-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki --- include/linux/notifier.h | 5 +++ kernel/notifier.c | 88 +++++++++++++++++++++++++++++++++++++----------- 2 files changed, 74 insertions(+), 19 deletions(-) (limited to 'include/linux') diff --git a/include/linux/notifier.h b/include/linux/notifier.h index 95e2440037de..aef88c2d1173 100644 --- a/include/linux/notifier.h +++ b/include/linux/notifier.h @@ -150,6 +150,11 @@ extern int raw_notifier_chain_register(struct raw_notifier_head *nh, extern int srcu_notifier_chain_register(struct srcu_notifier_head *nh, struct notifier_block *nb); +extern int atomic_notifier_chain_register_unique_prio( + struct atomic_notifier_head *nh, struct notifier_block *nb); +extern int blocking_notifier_chain_register_unique_prio( + struct blocking_notifier_head *nh, struct notifier_block *nb); + extern int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh, struct notifier_block *nb); extern int blocking_notifier_chain_unregister(struct blocking_notifier_head *nh, diff --git a/kernel/notifier.c b/kernel/notifier.c index 137b902c985b..0d5bd62c480e 100644 --- a/kernel/notifier.c +++ b/kernel/notifier.c @@ -20,7 +20,8 @@ BLOCKING_NOTIFIER_HEAD(reboot_notifier_list); */ static int notifier_chain_register(struct notifier_block **nl, - struct notifier_block *n) + struct notifier_block *n, + bool unique_priority) { while ((*nl) != NULL) { if (unlikely((*nl) == n)) { @@ -30,6 +31,8 @@ static int notifier_chain_register(struct notifier_block **nl, } if (n->priority > (*nl)->priority) break; + if (n->priority == (*nl)->priority && unique_priority) + return -EBUSY; nl = &((*nl)->next); } n->next = *nl; @@ -144,12 +147,35 @@ int atomic_notifier_chain_register(struct atomic_notifier_head *nh, int ret; spin_lock_irqsave(&nh->lock, flags); - ret = notifier_chain_register(&nh->head, n); + ret = notifier_chain_register(&nh->head, n, false); spin_unlock_irqrestore(&nh->lock, flags); return ret; } EXPORT_SYMBOL_GPL(atomic_notifier_chain_register); +/** + * atomic_notifier_chain_register_unique_prio - Add notifier to an atomic notifier chain + * @nh: Pointer to head of the atomic notifier chain + * @n: New entry in notifier chain + * + * Adds a notifier to an atomic notifier chain if there is no other + * notifier registered using the same priority. + * + * Returns 0 on success, %-EEXIST or %-EBUSY on error. + */ +int atomic_notifier_chain_register_unique_prio(struct atomic_notifier_head *nh, + struct notifier_block *n) +{ + unsigned long flags; + int ret; + + spin_lock_irqsave(&nh->lock, flags); + ret = notifier_chain_register(&nh->head, n, true); + spin_unlock_irqrestore(&nh->lock, flags); + return ret; +} +EXPORT_SYMBOL_GPL(atomic_notifier_chain_register_unique_prio); + /** * atomic_notifier_chain_unregister - Remove notifier from an atomic notifier chain * @nh: Pointer to head of the atomic notifier chain @@ -222,18 +248,9 @@ bool atomic_notifier_call_chain_is_empty(struct atomic_notifier_head *nh) * synchronized by an rwsem. */ -/** - * blocking_notifier_chain_register - Add notifier to a blocking notifier chain - * @nh: Pointer to head of the blocking notifier chain - * @n: New entry in notifier chain - * - * Adds a notifier to a blocking notifier chain. - * Must be called in process context. - * - * Returns 0 on success, %-EEXIST on error. - */ -int blocking_notifier_chain_register(struct blocking_notifier_head *nh, - struct notifier_block *n) +static int __blocking_notifier_chain_register(struct blocking_notifier_head *nh, + struct notifier_block *n, + bool unique_priority) { int ret; @@ -243,15 +260,48 @@ int blocking_notifier_chain_register(struct blocking_notifier_head *nh, * such times we must not call down_write(). */ if (unlikely(system_state == SYSTEM_BOOTING)) - return notifier_chain_register(&nh->head, n); + return notifier_chain_register(&nh->head, n, unique_priority); down_write(&nh->rwsem); - ret = notifier_chain_register(&nh->head, n); + ret = notifier_chain_register(&nh->head, n, unique_priority); up_write(&nh->rwsem); return ret; } + +/** + * blocking_notifier_chain_register - Add notifier to a blocking notifier chain + * @nh: Pointer to head of the blocking notifier chain + * @n: New entry in notifier chain + * + * Adds a notifier to a blocking notifier chain. + * Must be called in process context. + * + * Returns 0 on success, %-EEXIST on error. + */ +int blocking_notifier_chain_register(struct blocking_notifier_head *nh, + struct notifier_block *n) +{ + return __blocking_notifier_chain_register(nh, n, false); +} EXPORT_SYMBOL_GPL(blocking_notifier_chain_register); +/** + * blocking_notifier_chain_register_unique_prio - Add notifier to a blocking notifier chain + * @nh: Pointer to head of the blocking notifier chain + * @n: New entry in notifier chain + * + * Adds a notifier to an blocking notifier chain if there is no other + * notifier registered using the same priority. + * + * Returns 0 on success, %-EEXIST or %-EBUSY on error. + */ +int blocking_notifier_chain_register_unique_prio(struct blocking_notifier_head *nh, + struct notifier_block *n) +{ + return __blocking_notifier_chain_register(nh, n, true); +} +EXPORT_SYMBOL_GPL(blocking_notifier_chain_register_unique_prio); + /** * blocking_notifier_chain_unregister - Remove notifier from a blocking notifier chain * @nh: Pointer to head of the blocking notifier chain @@ -354,7 +404,7 @@ EXPORT_SYMBOL_GPL(blocking_notifier_call_chain); int raw_notifier_chain_register(struct raw_notifier_head *nh, struct notifier_block *n) { - return notifier_chain_register(&nh->head, n); + return notifier_chain_register(&nh->head, n, false); } EXPORT_SYMBOL_GPL(raw_notifier_chain_register); @@ -433,10 +483,10 @@ int srcu_notifier_chain_register(struct srcu_notifier_head *nh, * such times we must not call mutex_lock(). */ if (unlikely(system_state == SYSTEM_BOOTING)) - return notifier_chain_register(&nh->head, n); + return notifier_chain_register(&nh->head, n, false); mutex_lock(&nh->mutex); - ret = notifier_chain_register(&nh->head, n); + ret = notifier_chain_register(&nh->head, n, false); mutex_unlock(&nh->mutex); return ret; } -- cgit v1.3-15-g9ac1 From 232edc2f72f5beda3586360de6254d443820050a Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Tue, 10 May 2022 02:32:11 +0300 Subject: kernel/reboot: Introduce sys-off handler API In order to support power-off chaining we need to get rid of the global pm_* variables, replacing them with the new kernel API functions that support chaining. Introduce new generic sys-off handler API that brings the following features: 1. Power-off and restart handlers are registered using same API function that supports chaining, hence all power-off and restart modes will support chaining using this unified function. 2. Prevents notifier priority collisions by disallowing registration of multiple handlers at the non-default priority level. 3. Supports passing opaque user argument to callback, which allows us to remove global variables from drivers. This patch adds support of the following sys-off modes: - SYS_OFF_MODE_POWER_OFF_PREPARE that replaces global pm_power_off_prepare variable and provides chaining support for power-off-prepare handlers. - SYS_OFF_MODE_POWER_OFF that replaces global pm_power_off variable and provides chaining support for power-off handlers. - SYS_OFF_MODE_RESTART that provides a better restart API, removing a need from drivers to have a global scratch variable by utilizing the opaque callback argument. Signed-off-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki --- include/linux/reboot.h | 77 +++++++++++++++++++++ kernel/reboot.c | 182 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 259 insertions(+) (limited to 'include/linux') diff --git a/include/linux/reboot.h b/include/linux/reboot.h index af907a3d68d1..b79f8942ea5f 100644 --- a/include/linux/reboot.h +++ b/include/linux/reboot.h @@ -7,6 +7,7 @@ #include struct device; +struct sys_off_handler; #define SYS_DOWN 0x0001 /* Notify of system down */ #define SYS_RESTART SYS_DOWN @@ -62,6 +63,82 @@ extern void machine_shutdown(void); struct pt_regs; extern void machine_crash_shutdown(struct pt_regs *); +/* + * sys-off handler API. + */ + +/* + * Standard sys-off priority levels. Users are expected to set priorities + * relative to the standard levels. + * + * SYS_OFF_PRIO_PLATFORM: Use this for platform-level handlers. + * + * SYS_OFF_PRIO_LOW: Use this for handler of last resort. + * + * SYS_OFF_PRIO_DEFAULT: Use this for normal handlers. + * + * SYS_OFF_PRIO_HIGH: Use this for higher priority handlers. + * + * SYS_OFF_PRIO_FIRMWARE: Use this if handler uses firmware call. + */ +#define SYS_OFF_PRIO_PLATFORM -256 +#define SYS_OFF_PRIO_LOW -128 +#define SYS_OFF_PRIO_DEFAULT 0 +#define SYS_OFF_PRIO_HIGH 192 +#define SYS_OFF_PRIO_FIRMWARE 224 + +enum sys_off_mode { + /** + * @SYS_OFF_MODE_POWER_OFF_PREPARE: + * + * Handlers prepare system to be powered off. Handlers are + * allowed to sleep. + */ + SYS_OFF_MODE_POWER_OFF_PREPARE, + + /** + * @SYS_OFF_MODE_POWER_OFF: + * + * Handlers power-off system. Handlers are disallowed to sleep. + */ + SYS_OFF_MODE_POWER_OFF, + + /** + * @SYS_OFF_MODE_RESTART: + * + * Handlers restart system. Handlers are disallowed to sleep. + */ + SYS_OFF_MODE_RESTART, +}; + +/** + * struct sys_off_data - sys-off callback argument + * + * @mode: Mode ID. Currently used only by the sys-off restart mode, + * see enum reboot_mode for the available modes. + * @cb_data: User's callback data. + * @cmd: Command string. Currently used only by the sys-off restart mode, + * NULL otherwise. + */ +struct sys_off_data { + int mode; + void *cb_data; + const char *cmd; +}; + +struct sys_off_handler * +register_sys_off_handler(enum sys_off_mode mode, + int priority, + int (*callback)(struct sys_off_data *data), + void *cb_data); +void unregister_sys_off_handler(struct sys_off_handler *handler); + +int devm_register_sys_off_handler(struct device *dev, + enum sys_off_mode mode, + int priority, + int (*callback)(struct sys_off_data *data), + void *cb_data); + /* * Architecture independent implemenations of sys_reboot commands. */ diff --git a/kernel/reboot.c b/kernel/reboot.c index 6bcc5d6a6572..3e6867ee61e0 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -48,6 +48,15 @@ int reboot_cpu; enum reboot_type reboot_type = BOOT_ACPI; int reboot_force; +struct sys_off_handler { + struct notifier_block nb; + int (*sys_off_cb)(struct sys_off_data *data); + void *cb_data; + enum sys_off_mode mode; + bool blocking; + void *list; +}; + /* * If set, this is used for preparing the system to power off. */ @@ -281,6 +290,179 @@ void kernel_halt(void) } EXPORT_SYMBOL_GPL(kernel_halt); +/* + * Notifier list for kernel code which wants to be called + * to prepare system for power off. + */ +static BLOCKING_NOTIFIER_HEAD(power_off_prep_handler_list); + +/* + * Notifier list for kernel code which wants to be called + * to power off system. + */ +static ATOMIC_NOTIFIER_HEAD(power_off_handler_list); + +static int sys_off_notify(struct notifier_block *nb, + unsigned long mode, void *cmd) +{ + struct sys_off_handler *handler; + struct sys_off_data data = {}; + + handler = container_of(nb, struct sys_off_handler, nb); + data.cb_data = handler->cb_data; + data.mode = mode; + data.cmd = cmd; + + return handler->sys_off_cb(&data); +} + +/** + * register_sys_off_handler - Register sys-off handler + * @mode: Sys-off mode + * @priority: Handler priority + * @callback: Callback function + * @cb_data: Callback argument + * + * Registers system power-off or restart handler that will be invoked + * at the step corresponding to the given sys-off mode. Handler's callback + * should return NOTIFY_DONE to permit execution of the next handler in + * the call chain or NOTIFY_STOP to break the chain (in error case for + * example). + * + * Multiple handlers can be registered at the default priority level. + * + * Only one handler can be registered at the non-default priority level, + * otherwise ERR_PTR(-EBUSY) is returned. + * + * Returns a new instance of struct sys_off_handler on success, or + * an ERR_PTR()-encoded error code otherwise. + */ +struct sys_off_handler * +register_sys_off_handler(enum sys_off_mode mode, + int priority, + int (*callback)(struct sys_off_data *data), + void *cb_data) +{ + struct sys_off_handler *handler; + int err; + + handler = kzalloc(sizeof(*handler), GFP_KERNEL); + if (!handler) + return ERR_PTR(-ENOMEM); + + switch (mode) { + case SYS_OFF_MODE_POWER_OFF_PREPARE: + handler->list = &power_off_prep_handler_list; + handler->blocking = true; + break; + + case SYS_OFF_MODE_POWER_OFF: + handler->list = &power_off_handler_list; + break; + + case SYS_OFF_MODE_RESTART: + handler->list = &restart_handler_list; + break; + + default: + kfree(handler); + return ERR_PTR(-EINVAL); + } + + handler->nb.notifier_call = sys_off_notify; + handler->nb.priority = priority; + handler->sys_off_cb = callback; + handler->cb_data = cb_data; + handler->mode = mode; + + if (handler->blocking) { + if (priority == SYS_OFF_PRIO_DEFAULT) + err = blocking_notifier_chain_register(handler->list, + &handler->nb); + else + err = blocking_notifier_chain_register_unique_prio(handler->list, + &handler->nb); + } else { + if (priority == SYS_OFF_PRIO_DEFAULT) + err = atomic_notifier_chain_register(handler->list, + &handler->nb); + else + err = atomic_notifier_chain_register_unique_prio(handler->list, + &handler->nb); + } + + if (err) { + kfree(handler); + return ERR_PTR(err); + } + + return handler; +} +EXPORT_SYMBOL_GPL(register_sys_off_handler); + +/** + * unregister_sys_off_handler - Unregister sys-off handler + * @handler: Sys-off handler + * + * Unregisters given sys-off handler. + */ +void unregister_sys_off_handler(struct sys_off_handler *handler) +{ + int err; + + if (!handler) + return; + + if (handler->blocking) + err = blocking_notifier_chain_unregister(handler->list, + &handler->nb); + else + err = atomic_notifier_chain_unregister(handler->list, + &handler->nb); + + /* sanity check, shall never happen */ + WARN_ON(err); + + kfree(handler); +} +EXPORT_SYMBOL_GPL(unregister_sys_off_handler); + +static void devm_unregister_sys_off_handler(void *data) +{ + struct sys_off_handler *handler = data; + + unregister_sys_off_handler(handler); +} + +/** + * devm_register_sys_off_handler - Register sys-off handler + * @dev: Device that registers handler + * @mode: Sys-off mode + * @priority: Handler priority + * @callback: Callback function + * @cb_data: Callback argument + * + * Registers resource-managed sys-off handler. + * + * Returns zero on success, or error code on failure. + */ +int devm_register_sys_off_handler(struct device *dev, + enum sys_off_mode mode, + int priority, + int (*callback)(struct sys_off_data *data), + void *cb_data) +{ + struct sys_off_handler *handler; + + handler = register_sys_off_handler(mode, priority, callback, cb_data); + if (IS_ERR(handler)) + return PTR_ERR(handler); + + return devm_add_action_or_reset(dev, devm_unregister_sys_off_handler, + handler); +} +EXPORT_SYMBOL_GPL(devm_register_sys_off_handler); + /** * kernel_power_off - power_off the system * -- cgit v1.3-15-g9ac1 From 2b6aa7332f8020dfdaffe340ff038aac4df35238 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Tue, 10 May 2022 02:32:13 +0300 Subject: kernel/reboot: Add do_kernel_power_off() Add do_kernel_power_off() helper that will remove open-coded pm_power_off invocations from the architecture code. This is the first step on the way to remove the global pm_power_off variable, which will allow us to implement consistent power-off chaining support. Signed-off-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki --- include/linux/reboot.h | 2 ++ kernel/reboot.c | 13 +++++++++++++ 2 files changed, 15 insertions(+) (limited to 'include/linux') diff --git a/include/linux/reboot.h b/include/linux/reboot.h index b79f8942ea5f..99a9753e77bc 100644 --- a/include/linux/reboot.h +++ b/include/linux/reboot.h @@ -63,6 +63,8 @@ extern void machine_shutdown(void); struct pt_regs; extern void machine_crash_shutdown(struct pt_regs *); +void do_kernel_power_off(void); + /* * sys-off handler API. */ diff --git a/kernel/reboot.c b/kernel/reboot.c index 96f681f7b20c..892d25aa12df 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -504,6 +504,19 @@ static void do_kernel_power_off_prepare(void) blocking_notifier_call_chain(&power_off_prep_handler_list, 0, NULL); } +/** + * do_kernel_power_off - Execute kernel power-off handler call chain + * + * Expected to be called as last step of the power-off sequence. + * + * Powers off the system immediately if a power-off handler function has + * been registered. Otherwise does nothing. + */ +void do_kernel_power_off(void) +{ + atomic_notifier_call_chain(&power_off_handler_list, 0, NULL); +} + /** * kernel_power_off - power_off the system * -- cgit v1.3-15-g9ac1 From 0e2110d2e910e44cc7cf23fce14613e232602602 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Tue, 10 May 2022 02:32:15 +0300 Subject: kernel/reboot: Add kernel_can_power_off() Add kernel_can_power_off() helper that replaces open-coded checks of the global pm_power_off variable. This is a necessary step towards supporting chained power-off handlers. Signed-off-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki --- include/linux/reboot.h | 1 + kernel/reboot.c | 14 +++++++++++++- 2 files changed, 14 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/reboot.h b/include/linux/reboot.h index 99a9753e77bc..5837c6c2fb40 100644 --- a/include/linux/reboot.h +++ b/include/linux/reboot.h @@ -149,6 +149,7 @@ extern void kernel_restart_prepare(char *cmd); extern void kernel_restart(char *cmd); extern void kernel_halt(void); extern void kernel_power_off(void); +extern bool kernel_can_power_off(void); extern int C_A_D; /* for sysctl */ void ctrl_alt_del(void); diff --git a/kernel/reboot.c b/kernel/reboot.c index 7723aff4d09b..fb3f49350927 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -523,6 +523,18 @@ void do_kernel_power_off(void) atomic_notifier_call_chain(&power_off_handler_list, 0, NULL); } +/** + * kernel_can_power_off - check whether system can be powered off + * + * Returns true if power-off handler is registered and system can be + * powered off, false otherwise. + */ +bool kernel_can_power_off(void) +{ + return !atomic_notifier_call_chain_is_empty(&power_off_handler_list); +} +EXPORT_SYMBOL_GPL(kernel_can_power_off); + /** * kernel_power_off - power_off the system * @@ -581,7 +593,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, /* Instead of trying to make the power_off code look like * halt when pm_power_off is not set do it the easy way. */ - if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off) + if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !kernel_can_power_off()) cmd = LINUX_REBOOT_CMD_HALT; mutex_lock(&system_transition_mutex); -- cgit v1.3-15-g9ac1 From fb61375ecfba49e153af561402f49f6fe3bebd39 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Tue, 10 May 2022 02:32:16 +0300 Subject: kernel/reboot: Add register_platform_power_off() Add platform-level registration helpers that will ease transition of the arch/platform power-off callbacks to the new sys-off based API, allowing us to remove the global pm_power_off variable in the future. Signed-off-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki --- include/linux/reboot.h | 3 +++ kernel/reboot.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 58 insertions(+) (limited to 'include/linux') diff --git a/include/linux/reboot.h b/include/linux/reboot.h index 5837c6c2fb40..a8fee1d09c65 100644 --- a/include/linux/reboot.h +++ b/include/linux/reboot.h @@ -141,6 +141,9 @@ int devm_register_sys_off_handler(struct device *dev, int (*callback)(struct sys_off_data *data), void *cb_data); +int register_platform_power_off(void (*power_off)(void)); +void unregister_platform_power_off(void (*power_off)(void)); + /* * Architecture independent implemenations of sys_reboot commands. */ diff --git a/kernel/reboot.c b/kernel/reboot.c index fb3f49350927..673d3f54dcad 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -469,6 +469,61 @@ int devm_register_sys_off_handler(struct device *dev, } EXPORT_SYMBOL_GPL(devm_register_sys_off_handler); +static struct sys_off_handler *platform_power_off_handler; + +static int platform_power_off_notify(struct sys_off_data *data) +{ + void (*platform_power_power_off_cb)(void) = data->cb_data; + + platform_power_power_off_cb(); + + return NOTIFY_DONE; +} + +/** + * register_platform_power_off - Register platform-level power-off callback + * @power_off: Power-off callback + * + * Registers power-off callback that will be called as last step + * of the power-off sequence. This callback is expected to be invoked + * for the last resort. Only one platform power-off callback is allowed + * to be registered at a time. + * + * Returns zero on success, or error code on failure. + */ +int register_platform_power_off(void (*power_off)(void)) +{ + struct sys_off_handler *handler; + + handler = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, + SYS_OFF_PRIO_PLATFORM, + platform_power_off_notify, + power_off); + if (IS_ERR(handler)) + return PTR_ERR(handler); + + platform_power_off_handler = handler; + + return 0; +} +EXPORT_SYMBOL_GPL(register_platform_power_off); + +/** + * unregister_platform_power_off - Unregister platform-level power-off callback + * @power_off: Power-off callback + * + * Unregisters previously registered platform power-off callback. + */ +void unregister_platform_power_off(void (*power_off)(void)) +{ + if (platform_power_off_handler && + platform_power_off_handler->cb_data == power_off) { + unregister_sys_off_handler(platform_power_off_handler); + platform_power_off_handler = NULL; + } +} +EXPORT_SYMBOL_GPL(unregister_platform_power_off); + static int legacy_pm_power_off_prepare(struct sys_off_data *data) { if (pm_power_off_prepare) -- cgit v1.3-15-g9ac1 From 5b71808eb7c97815fc3b9c386ca0ef6daf2dc053 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Tue, 10 May 2022 02:32:32 +0300 Subject: reboot: Remove pm_power_off_prepare() All pm_power_off_prepare() users were converted to sys-off handler API. Remove the obsolete global callback variable. Signed-off-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki --- include/linux/pm.h | 1 - kernel/reboot.c | 19 ------------------- 2 files changed, 20 deletions(-) (limited to 'include/linux') diff --git a/include/linux/pm.h b/include/linux/pm.h index e65b3ab28377..3786d306dad2 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -21,7 +21,6 @@ * Callbacks for platform drivers to implement. */ extern void (*pm_power_off)(void); -extern void (*pm_power_off_prepare)(void); struct device; /* we have a circular dep with device.h */ #ifdef CONFIG_VT_CONSOLE_SLEEP diff --git a/kernel/reboot.c b/kernel/reboot.c index 673d3f54dcad..88c835167d9e 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -63,13 +63,6 @@ struct sys_off_handler { */ void __weak (*pm_power_off)(void); -/* - * If set, this is used for preparing the system to power off. - */ - -void (*pm_power_off_prepare)(void); -EXPORT_SYMBOL_GPL(pm_power_off_prepare); - /** * emergency_restart - reboot the system * @@ -524,14 +517,6 @@ void unregister_platform_power_off(void (*power_off)(void)) } EXPORT_SYMBOL_GPL(unregister_platform_power_off); -static int legacy_pm_power_off_prepare(struct sys_off_data *data) -{ - if (pm_power_off_prepare) - pm_power_off_prepare(); - - return NOTIFY_DONE; -} - static int legacy_pm_power_off(struct sys_off_data *data) { if (pm_power_off) @@ -549,10 +534,6 @@ static int legacy_pm_power_off(struct sys_off_data *data) */ static int __init legacy_pm_init(void) { - register_sys_off_handler(SYS_OFF_MODE_POWER_OFF_PREPARE, - SYS_OFF_PRIO_DEFAULT, - legacy_pm_power_off_prepare, NULL); - register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, SYS_OFF_PRIO_DEFAULT, legacy_pm_power_off, NULL); -- cgit v1.3-15-g9ac1 From d2c5415327171e6c1bca2dc4d8a77f450ecf7150 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Tue, 10 May 2022 02:32:34 +0300 Subject: kernel/reboot: Add devm_register_power_off_handler() Add devm_register_power_off_handler() helper that registers sys-off handler using power-off mode and with a default priority. Most drivers will want to register power-off handler with a default priority, so this helper will reduce the boilerplate code and make code easier to read and follow. Signed-off-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki --- include/linux/reboot.h | 4 ++++ kernel/reboot.c | 22 ++++++++++++++++++++++ 2 files changed, 26 insertions(+) (limited to 'include/linux') diff --git a/include/linux/reboot.h b/include/linux/reboot.h index a8fee1d09c65..3b063c5b6118 100644 --- a/include/linux/reboot.h +++ b/include/linux/reboot.h @@ -141,6 +141,10 @@ int devm_register_sys_off_handler(struct device *dev, int (*callback)(struct sys_off_data *data), void *cb_data); +int devm_register_power_off_handler(struct device *dev, + int (*callback)(struct sys_off_data *data), + void *cb_data); + int register_platform_power_off(void (*power_off)(void)); void unregister_platform_power_off(void (*power_off)(void)); diff --git a/kernel/reboot.c b/kernel/reboot.c index 88c835167d9e..4dbb6e29247a 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -462,6 +462,28 @@ int devm_register_sys_off_handler(struct device *dev, } EXPORT_SYMBOL_GPL(devm_register_sys_off_handler); +/** + * devm_register_power_off_handler - Register power-off handler + * @dev: Device that registers callback + * @callback: Callback function + * @cb_data: Callback's argument + * + * Registers resource-managed sys-off handler with a default priority + * and using power-off mode. + * + * Returns zero on success, or error code on failure. + */ +int devm_register_power_off_handler(struct device *dev, + int (*callback)(struct sys_off_data *data), + void *cb_data) +{ + return devm_register_sys_off_handler(dev, + SYS_OFF_MODE_POWER_OFF, + SYS_OFF_PRIO_DEFAULT, + callback, cb_data); +} +EXPORT_SYMBOL_GPL(devm_register_power_off_handler); + static struct sys_off_handler *platform_power_off_handler; static int platform_power_off_notify(struct sys_off_data *data) -- cgit v1.3-15-g9ac1 From 6779db970bd287bb35b28bd5dc256fd7aef19d1c Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Tue, 10 May 2022 02:32:35 +0300 Subject: kernel/reboot: Add devm_register_restart_handler() Add devm_register_restart_handler() helper that registers sys-off handler using restart mode and with a default priority. Most drivers will want to register restart handler with a default priority, so this helper will reduce the boilerplate code and make code easier to read and follow. Signed-off-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki --- include/linux/reboot.h | 4 ++++ kernel/reboot.c | 22 ++++++++++++++++++++++ 2 files changed, 26 insertions(+) (limited to 'include/linux') diff --git a/include/linux/reboot.h b/include/linux/reboot.h index 3b063c5b6118..d29d37a2abb6 100644 --- a/include/linux/reboot.h +++ b/include/linux/reboot.h @@ -145,6 +145,10 @@ int devm_register_power_off_handler(struct device *dev, int (*callback)(struct sys_off_data *data), void *cb_data); +int devm_register_restart_handler(struct device *dev, + int (*callback)(struct sys_off_data *data), + void *cb_data); + int register_platform_power_off(void (*power_off)(void)); void unregister_platform_power_off(void (*power_off)(void)); diff --git a/kernel/reboot.c b/kernel/reboot.c index 4dbb6e29247a..bdb635842ec8 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -484,6 +484,28 @@ int devm_register_power_off_handler(struct device *dev, } EXPORT_SYMBOL_GPL(devm_register_power_off_handler); +/** + * devm_register_restart_handler - Register restart handler + * @dev: Device that registers callback + * @callback: Callback function + * @cb_data: Callback's argument + * + * Registers resource-managed sys-off handler with a default priority + * and using restart mode. + * + * Returns zero on success, or error code on failure. + */ +int devm_register_restart_handler(struct device *dev, + int (*callback)(struct sys_off_data *data), + void *cb_data) +{ + return devm_register_sys_off_handler(dev, + SYS_OFF_MODE_RESTART, + SYS_OFF_PRIO_DEFAULT, + callback, cb_data); +} +EXPORT_SYMBOL_GPL(devm_register_restart_handler); + static struct sys_off_handler *platform_power_off_handler; static int platform_power_off_notify(struct sys_off_data *data) -- cgit v1.3-15-g9ac1