diff options
Diffstat (limited to 'drivers/platform/surface/aggregator/controller.c')
| -rw-r--r-- | drivers/platform/surface/aggregator/controller.c | 332 |
1 files changed, 271 insertions, 61 deletions
diff --git a/drivers/platform/surface/aggregator/controller.c b/drivers/platform/surface/aggregator/controller.c index a06964aa96e7..b8c377b3f932 100644 --- a/drivers/platform/surface/aggregator/controller.c +++ b/drivers/platform/surface/aggregator/controller.c @@ -2,7 +2,7 @@ /* * Main SSAM/SSH controller structure and functionality. * - * Copyright (C) 2019-2020 Maximilian Luz <luzmaximilian@gmail.com> + * Copyright (C) 2019-2021 Maximilian Luz <luzmaximilian@gmail.com> */ #include <linux/acpi.h> @@ -408,6 +408,31 @@ ssam_nf_refcount_dec(struct ssam_nf *nf, struct ssam_event_registry reg, } /** + * ssam_nf_refcount_dec_free() - Decrement reference-/activation-count of the + * given event and free its entry if the reference count reaches zero. + * @nf: The notifier system reference. + * @reg: The registry used to enable/disable the event. + * @id: The event ID. + * + * Decrements the reference-/activation-count of the specified event, freeing + * its entry if it reaches zero. + * + * Note: ``nf->lock`` must be held when calling this function. + */ +static void ssam_nf_refcount_dec_free(struct ssam_nf *nf, + struct ssam_event_registry reg, + struct ssam_event_id id) +{ + struct ssam_nf_refcount_entry *entry; + + lockdep_assert_held(&nf->lock); + + entry = ssam_nf_refcount_dec(nf, reg, id); + if (entry && entry->refcount == 0) + kfree(entry); +} + +/** * ssam_nf_refcount_empty() - Test if the notification system has any * enabled/active events. * @nf: The notification system. @@ -2123,13 +2148,122 @@ int ssam_ctrl_notif_d0_entry(struct ssam_controller *ctrl) /* -- Top-level event registry interface. ----------------------------------- */ /** + * ssam_nf_refcount_enable() - Enable event for reference count entry if it has + * not already been enabled. + * @ctrl: The controller to enable the event on. + * @entry: The reference count entry for the event to be enabled. + * @flags: The flags used for enabling the event on the EC. + * + * Enable the event associated with the given reference count entry if the + * reference count equals one, i.e. the event has not previously been enabled. + * If the event has already been enabled (i.e. reference count not equal to + * one), check that the flags used for enabling match and warn about this if + * they do not. + * + * This does not modify the reference count itself, which is done with + * ssam_nf_refcount_inc() / ssam_nf_refcount_dec(). + * + * Note: ``nf->lock`` must be held when calling this function. + * + * Return: Returns zero on success. If the event is enabled by this call, + * returns the status of the event-enable EC command. + */ +static int ssam_nf_refcount_enable(struct ssam_controller *ctrl, + struct ssam_nf_refcount_entry *entry, u8 flags) +{ + const struct ssam_event_registry reg = entry->key.reg; + const struct ssam_event_id id = entry->key.id; + struct ssam_nf *nf = &ctrl->cplt.event.notif; + int status; + + lockdep_assert_held(&nf->lock); + + ssam_dbg(ctrl, "enabling event (reg: %#04x, tc: %#04x, iid: %#04x, rc: %d)\n", + reg.target_category, id.target_category, id.instance, entry->refcount); + + if (entry->refcount == 1) { + status = ssam_ssh_event_enable(ctrl, reg, id, flags); + if (status) + return status; + + entry->flags = flags; + + } else if (entry->flags != flags) { + ssam_warn(ctrl, + "inconsistent flags when enabling event: got %#04x, expected %#04x (reg: %#04x, tc: %#04x, iid: %#04x)\n", + flags, entry->flags, reg.target_category, id.target_category, + id.instance); + } + + return 0; +} + +/** + * ssam_nf_refcount_disable_free() - Disable event for reference count entry if it is + * no longer in use and free the corresponding entry. + * @ctrl: The controller to disable the event on. + * @entry: The reference count entry for the event to be disabled. + * @flags: The flags used for enabling the event on the EC. + * + * If the reference count equals zero, i.e. the event is no longer requested by + * any client, the event will be disabled and the corresponding reference count + * entry freed. The reference count entry must not be used any more after a + * call to this function. + * + * Also checks if the flags used for disabling the event match the flags used + * for enabling the event and warns if they do not (regardless of reference + * count). + * + * This does not modify the reference count itself, which is done with + * ssam_nf_refcount_inc() / ssam_nf_refcount_dec(). + * + * Note: ``nf->lock`` must be held when calling this function. + * + * Return: Returns zero on success. If the event is disabled by this call, + * returns the status of the event-enable EC command. + */ +static int ssam_nf_refcount_disable_free(struct ssam_controller *ctrl, + struct ssam_nf_refcount_entry *entry, u8 flags) +{ + const struct ssam_event_registry reg = entry->key.reg; + const struct ssam_event_id id = entry->key.id; + struct ssam_nf *nf = &ctrl->cplt.event.notif; + int status = 0; + + lockdep_assert_held(&nf->lock); + + ssam_dbg(ctrl, "disabling event (reg: %#04x, tc: %#04x, iid: %#04x, rc: %d)\n", + reg.target_category, id.target_category, id.instance, entry->refcount); + + if (entry->flags != flags) { + ssam_warn(ctrl, + "inconsistent flags when disabling event: got %#04x, expected %#04x (reg: %#04x, tc: %#04x, iid: %#04x)\n", + flags, entry->flags, reg.target_category, id.target_category, + id.instance); + } + + if (entry->refcount == 0) { + status = ssam_ssh_event_disable(ctrl, reg, id, flags); + kfree(entry); + } + + return status; +} + +/** * ssam_notifier_register() - Register an event notifier. * @ctrl: The controller to register the notifier on. * @n: The event notifier to register. * - * Register an event notifier and increment the usage counter of the - * associated SAM event. If the event was previously not enabled, it will be - * enabled during this call. + * Register an event notifier. Increment the usage counter of the associated + * SAM event if the notifier is not marked as an observer. If the event is not + * marked as an observer and is currently not enabled, it will be enabled + * during this call. If the notifier is marked as an observer, no attempt will + * be made at enabling any event and no reference count will be modified. + * + * Notifiers marked as observers do not need to be associated with one specific + * event, i.e. as long as no event matching is performed, only the event target + * category needs to be set. * * Return: Returns zero on success, %-ENOSPC if there have already been * %INT_MAX notifiers for the event ID/type associated with the notifier block @@ -2138,11 +2272,10 @@ int ssam_ctrl_notif_d0_entry(struct ssam_controller *ctrl) * for the specific associated event, returns the status of the event-enable * EC-command. */ -int ssam_notifier_register(struct ssam_controller *ctrl, - struct ssam_event_notifier *n) +int ssam_notifier_register(struct ssam_controller *ctrl, struct ssam_event_notifier *n) { u16 rqid = ssh_tc_to_rqid(n->event.id.target_category); - struct ssam_nf_refcount_entry *entry; + struct ssam_nf_refcount_entry *entry = NULL; struct ssam_nf_head *nf_head; struct ssam_nf *nf; int status; @@ -2155,44 +2288,32 @@ int ssam_notifier_register(struct ssam_controller *ctrl, mutex_lock(&nf->lock); - entry = ssam_nf_refcount_inc(nf, n->event.reg, n->event.id); - if (IS_ERR(entry)) { - mutex_unlock(&nf->lock); - return PTR_ERR(entry); + if (!(n->flags & SSAM_EVENT_NOTIFIER_OBSERVER)) { + entry = ssam_nf_refcount_inc(nf, n->event.reg, n->event.id); + if (IS_ERR(entry)) { + mutex_unlock(&nf->lock); + return PTR_ERR(entry); + } } - ssam_dbg(ctrl, "enabling event (reg: %#04x, tc: %#04x, iid: %#04x, rc: %d)\n", - n->event.reg.target_category, n->event.id.target_category, - n->event.id.instance, entry->refcount); - status = ssam_nfblk_insert(nf_head, &n->base); if (status) { - entry = ssam_nf_refcount_dec(nf, n->event.reg, n->event.id); - if (entry->refcount == 0) - kfree(entry); + if (entry) + ssam_nf_refcount_dec_free(nf, n->event.reg, n->event.id); mutex_unlock(&nf->lock); return status; } - if (entry->refcount == 1) { - status = ssam_ssh_event_enable(ctrl, n->event.reg, n->event.id, - n->event.flags); + if (entry) { + status = ssam_nf_refcount_enable(ctrl, entry, n->event.flags); if (status) { ssam_nfblk_remove(&n->base); - kfree(ssam_nf_refcount_dec(nf, n->event.reg, n->event.id)); + ssam_nf_refcount_dec_free(nf, n->event.reg, n->event.id); mutex_unlock(&nf->lock); synchronize_srcu(&nf_head->srcu); return status; } - - entry->flags = n->event.flags; - - } else if (entry->flags != n->event.flags) { - ssam_warn(ctrl, - "inconsistent flags when enabling event: got %#04x, expected %#04x (reg: %#04x, tc: %#04x, iid: %#04x)\n", - n->event.flags, entry->flags, n->event.reg.target_category, - n->event.id.target_category, n->event.id.instance); } mutex_unlock(&nf->lock); @@ -2205,17 +2326,16 @@ EXPORT_SYMBOL_GPL(ssam_notifier_register); * @ctrl: The controller the notifier has been registered on. * @n: The event notifier to unregister. * - * Unregister an event notifier and decrement the usage counter of the - * associated SAM event. If the usage counter reaches zero, the event will be - * disabled. + * Unregister an event notifier. Decrement the usage counter of the associated + * SAM event if the notifier is not marked as an observer. If the usage counter + * reaches zero, the event will be disabled. * * Return: Returns zero on success, %-ENOENT if the given notifier block has * not been registered on the controller. If the given notifier block was the * last one associated with its specific event, returns the status of the * event-disable EC-command. */ -int ssam_notifier_unregister(struct ssam_controller *ctrl, - struct ssam_event_notifier *n) +int ssam_notifier_unregister(struct ssam_controller *ctrl, struct ssam_event_notifier *n) { u16 rqid = ssh_tc_to_rqid(n->event.id.target_category); struct ssam_nf_refcount_entry *entry; @@ -2236,33 +2356,24 @@ int ssam_notifier_unregister(struct ssam_controller *ctrl, return -ENOENT; } - entry = ssam_nf_refcount_dec(nf, n->event.reg, n->event.id); - if (WARN_ON(!entry)) { - /* - * If this does not return an entry, there's a logic error - * somewhere: The notifier block is registered, but the event - * refcount entry is not there. Remove the notifier block - * anyways. - */ - status = -ENOENT; - goto remove; - } - - ssam_dbg(ctrl, "disabling event (reg: %#04x, tc: %#04x, iid: %#04x, rc: %d)\n", - n->event.reg.target_category, n->event.id.target_category, - n->event.id.instance, entry->refcount); - - if (entry->flags != n->event.flags) { - ssam_warn(ctrl, - "inconsistent flags when disabling event: got %#04x, expected %#04x (reg: %#04x, tc: %#04x, iid: %#04x)\n", - n->event.flags, entry->flags, n->event.reg.target_category, - n->event.id.target_category, n->event.id.instance); - } + /* + * If this is an observer notifier, do not attempt to disable the + * event, just remove it. + */ + if (!(n->flags & SSAM_EVENT_NOTIFIER_OBSERVER)) { + entry = ssam_nf_refcount_dec(nf, n->event.reg, n->event.id); + if (WARN_ON(!entry)) { + /* + * If this does not return an entry, there's a logic + * error somewhere: The notifier block is registered, + * but the event refcount entry is not there. Remove + * the notifier block anyways. + */ + status = -ENOENT; + goto remove; + } - if (entry->refcount == 0) { - status = ssam_ssh_event_disable(ctrl, n->event.reg, n->event.id, - n->event.flags); - kfree(entry); + status = ssam_nf_refcount_disable_free(ctrl, entry, n->event.flags); } remove: @@ -2275,6 +2386,105 @@ remove: EXPORT_SYMBOL_GPL(ssam_notifier_unregister); /** + * ssam_controller_event_enable() - Enable the specified event. + * @ctrl: The controller to enable the event for. + * @reg: The event registry to use for enabling the event. + * @id: The event ID specifying the event to be enabled. + * @flags: The SAM event flags used for enabling the event. + * + * Increment the event reference count of the specified event. If the event has + * not been enabled previously, it will be enabled by this call. + * + * Note: In general, ssam_notifier_register() with a non-observer notifier + * should be preferred for enabling/disabling events, as this will guarantee + * proper ordering and event forwarding in case of errors during event + * enabling/disabling. + * + * Return: Returns zero on success, %-ENOSPC if the reference count for the + * specified event has reached its maximum, %-ENOMEM if the corresponding event + * entry could not be allocated. If this is the first time that this event has + * been enabled (i.e. the reference count was incremented from zero to one by + * this call), returns the status of the event-enable EC-command. + */ +int ssam_controller_event_enable(struct ssam_controller *ctrl, + struct ssam_event_registry reg, + struct ssam_event_id id, u8 flags) +{ + u16 rqid = ssh_tc_to_rqid(id.target_category); + struct ssam_nf *nf = &ctrl->cplt.event.notif; + struct ssam_nf_refcount_entry *entry; + int status; + + if (!ssh_rqid_is_event(rqid)) + return -EINVAL; + + mutex_lock(&nf->lock); + + entry = ssam_nf_refcount_inc(nf, reg, id); + if (IS_ERR(entry)) { + mutex_unlock(&nf->lock); + return PTR_ERR(entry); + } + + status = ssam_nf_refcount_enable(ctrl, entry, flags); + if (status) { + ssam_nf_refcount_dec_free(nf, reg, id); + mutex_unlock(&nf->lock); + return status; + } + + mutex_unlock(&nf->lock); + return 0; +} +EXPORT_SYMBOL_GPL(ssam_controller_event_enable); + +/** + * ssam_controller_event_disable() - Disable the specified event. + * @ctrl: The controller to disable the event for. + * @reg: The event registry to use for disabling the event. + * @id: The event ID specifying the event to be disabled. + * @flags: The flags used when enabling the event. + * + * Decrement the reference count of the specified event. If the reference count + * reaches zero, the event will be disabled. + * + * Note: In general, ssam_notifier_register()/ssam_notifier_unregister() with a + * non-observer notifier should be preferred for enabling/disabling events, as + * this will guarantee proper ordering and event forwarding in case of errors + * during event enabling/disabling. + * + * Return: Returns zero on success, %-ENOENT if the given event has not been + * enabled on the controller. If the reference count of the event reaches zero + * during this call, returns the status of the event-disable EC-command. + */ +int ssam_controller_event_disable(struct ssam_controller *ctrl, + struct ssam_event_registry reg, + struct ssam_event_id id, u8 flags) +{ + u16 rqid = ssh_tc_to_rqid(id.target_category); + struct ssam_nf *nf = &ctrl->cplt.event.notif; + struct ssam_nf_refcount_entry *entry; + int status; + + if (!ssh_rqid_is_event(rqid)) + return -EINVAL; + + mutex_lock(&nf->lock); + + entry = ssam_nf_refcount_dec(nf, reg, id); + if (!entry) { + mutex_unlock(&nf->lock); + return -ENOENT; + } + + status = ssam_nf_refcount_disable_free(ctrl, entry, flags); + + mutex_unlock(&nf->lock); + return status; +} +EXPORT_SYMBOL_GPL(ssam_controller_event_disable); + +/** * ssam_notifier_disable_registered() - Disable events for all registered * notifiers. * @ctrl: The controller for which to disable the notifiers/events. |