| Message ID | 20240701060553.869989-4-dmitry.torokhov@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Simplify event handling logic in input core | expand |
On Jun 30 2024, Dmitry Torokhov wrote: > Streamline event handling code by providing batch implementations for > filtering and event processing and using them in place of the main > event handler, as needed, instead of having complex branching logic > in the middle of the event processing code. > > Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> > --- > drivers/input/input.c | 90 ++++++++++++++++++++++++------------------- > 1 file changed, 51 insertions(+), 39 deletions(-) > > diff --git a/drivers/input/input.c b/drivers/input/input.c > index 8434348faeac..eeb755cb12e7 100644 > --- a/drivers/input/input.c > +++ b/drivers/input/input.c > @@ -99,41 +99,6 @@ static void input_stop_autorepeat(struct input_dev *dev) > del_timer(&dev->timer); > } > > -/* > - * Pass event first through all filters and then, if event has not been > - * filtered out, through all open handles. This function is called with > - * dev->event_lock held and interrupts disabled. > - */ > -static unsigned int input_to_handler(struct input_handle *handle, > - struct input_value *vals, unsigned int count) > -{ > - struct input_handler *handler = handle->handler; > - struct input_value *end = vals; > - struct input_value *v; > - > - if (handler->filter) { > - for (v = vals; v != vals + count; v++) { > - if (handler->filter(handle, v->type, v->code, v->value)) > - continue; > - if (end != v) > - *end = *v; > - end++; > - } > - count = end - vals; > - } > - > - if (!count) > - return 0; > - > - if (handler->events) > - handler->events(handle, vals, count); > - else if (handler->event) > - for (v = vals; v != vals + count; v++) > - handler->event(handle, v->type, v->code, v->value); > - > - return count; > -} > - > /* > * Pass values first through all filters and then, if event has not been > * filtered out, through all open handles. This function is called with Nitpick: maybe that comment above input_pass_values() should also be amended now that the processing is more straightforward? > @@ -154,11 +119,12 @@ static void input_pass_values(struct input_dev *dev, > > handle = rcu_dereference(dev->grab); > if (handle) { > - count = input_to_handler(handle, vals, count); > + count = handle->handler->events(handle, vals, count); > } else { > list_for_each_entry_rcu(handle, &dev->h_list, d_node) > if (handle->open) { > - count = input_to_handler(handle, vals, count); > + count = handle->handler->events(handle, vals, > + count); > if (!count) > break; > } > @@ -2537,6 +2503,47 @@ static int input_handler_check_methods(const struct input_handler *handler) > return 0; > } > > +/* > + * An implementation of input_handler's events() method that simply > + * invokes handler->event() method for each event one by one. > + */ > +static unsigned int input_handler_events_default(struct input_handle *handle, > + struct input_value *vals, > + unsigned int count) > +{ > + struct input_handler *handler = handle->handler; > + struct input_value *v; > + > + for (v = vals; v != vals + count; v++) > + handler->event(handle, v->type, v->code, v->value); > + > + return count; > +} > + > +/* > + * An implementation of input_handler's events() method that invokes > + * handler->filter() method for each event one by one and removes events > + * that were filtered out from the "vals" array. > + */ > +static unsigned int input_handler_events_filter(struct input_handle *handle, > + struct input_value *vals, > + unsigned int count) > +{ > + struct input_handler *handler = handle->handler; > + struct input_value *end = vals; > + struct input_value *v; > + > + for (v = vals; v != vals + count; v++) { > + if (handler->filter(handle, v->type, v->code, v->value)) > + continue; > + if (end != v) > + *end = *v; > + end++; > + } > + > + return end - vals; > +} > + > /** > * input_register_handler - register a new input handler > * @handler: handler to be registered > @@ -2554,12 +2561,17 @@ int input_register_handler(struct input_handler *handler) > if (error) > return error; > > + INIT_LIST_HEAD(&handler->h_list); > + > + if (handler->filter) > + handler->events = input_handler_events_filter; > + else if (handler->event) > + handler->events = input_handler_events_default; > + > error = mutex_lock_interruptible(&input_mutex); > if (error) > return error; > > - INIT_LIST_HEAD(&handler->h_list); > - > list_add_tail(&handler->node, &input_handler_list); > > list_for_each_entry(dev, &input_dev_list, node) > -- > 2.45.2.803.g4e1b14247a-goog > Minor nitpick, but otherwise: Reviewed-by: Benjamin Tissoires <bentiss@kernel.org> Cheers, Benjamin
On Mon, Jul 01, 2024 at 09:41:22AM +0200, Benjamin Tissoires wrote: > On Jun 30 2024, Dmitry Torokhov wrote: > > /* > > * Pass values first through all filters and then, if event has not been > > * filtered out, through all open handles. This function is called with > > Nitpick: maybe that comment above input_pass_values() should also be > amended now that the processing is more straightforward? I think the comment is still accurate from the higher POV. We do want to send the event(s) first through all the filters and the remainder is through the handlers. This is achieved by placing filters at the head of the list of handles attacher to the device, and placing regular handles at the tail of the list. Do you want me to expand the comment? Thanks.
On Jul 01 2024, Dmitry Torokhov wrote: > On Mon, Jul 01, 2024 at 09:41:22AM +0200, Benjamin Tissoires wrote: > > On Jun 30 2024, Dmitry Torokhov wrote: > > > /* > > > * Pass values first through all filters and then, if event has not been > > > * filtered out, through all open handles. This function is called with > > > > Nitpick: maybe that comment above input_pass_values() should also be > > amended now that the processing is more straightforward? > > I think the comment is still accurate from the higher POV. We do want to > send the event(s) first through all the filters and the remainder is > through the handlers. This is achieved by placing filters at the head of > the list of handles attacher to the device, and placing regular handles > at the tail of the list. Oh right, I missed that in my review. > > Do you want me to expand the comment? Yeah, maybe add the blurb from above in the comment so we don't ask further questions next time we revisit that code. And given that you need to respin the series, it should be all right :) Cheers, Benjamin
diff --git a/drivers/input/input.c b/drivers/input/input.c index 8434348faeac..eeb755cb12e7 100644 --- a/drivers/input/input.c +++ b/drivers/input/input.c @@ -99,41 +99,6 @@ static void input_stop_autorepeat(struct input_dev *dev) del_timer(&dev->timer); } -/* - * Pass event first through all filters and then, if event has not been - * filtered out, through all open handles. This function is called with - * dev->event_lock held and interrupts disabled. - */ -static unsigned int input_to_handler(struct input_handle *handle, - struct input_value *vals, unsigned int count) -{ - struct input_handler *handler = handle->handler; - struct input_value *end = vals; - struct input_value *v; - - if (handler->filter) { - for (v = vals; v != vals + count; v++) { - if (handler->filter(handle, v->type, v->code, v->value)) - continue; - if (end != v) - *end = *v; - end++; - } - count = end - vals; - } - - if (!count) - return 0; - - if (handler->events) - handler->events(handle, vals, count); - else if (handler->event) - for (v = vals; v != vals + count; v++) - handler->event(handle, v->type, v->code, v->value); - - return count; -} - /* * Pass values first through all filters and then, if event has not been * filtered out, through all open handles. This function is called with @@ -154,11 +119,12 @@ static void input_pass_values(struct input_dev *dev, handle = rcu_dereference(dev->grab); if (handle) { - count = input_to_handler(handle, vals, count); + count = handle->handler->events(handle, vals, count); } else { list_for_each_entry_rcu(handle, &dev->h_list, d_node) if (handle->open) { - count = input_to_handler(handle, vals, count); + count = handle->handler->events(handle, vals, + count); if (!count) break; } @@ -2537,6 +2503,47 @@ static int input_handler_check_methods(const struct input_handler *handler) return 0; } +/* + * An implementation of input_handler's events() method that simply + * invokes handler->event() method for each event one by one. + */ +static unsigned int input_handler_events_default(struct input_handle *handle, + struct input_value *vals, + unsigned int count) +{ + struct input_handler *handler = handle->handler; + struct input_value *v; + + for (v = vals; v != vals + count; v++) + handler->event(handle, v->type, v->code, v->value); + + return count; +} + +/* + * An implementation of input_handler's events() method that invokes + * handler->filter() method for each event one by one and removes events + * that were filtered out from the "vals" array. + */ +static unsigned int input_handler_events_filter(struct input_handle *handle, + struct input_value *vals, + unsigned int count) +{ + struct input_handler *handler = handle->handler; + struct input_value *end = vals; + struct input_value *v; + + for (v = vals; v != vals + count; v++) { + if (handler->filter(handle, v->type, v->code, v->value)) + continue; + if (end != v) + *end = *v; + end++; + } + + return end - vals; +} + /** * input_register_handler - register a new input handler * @handler: handler to be registered @@ -2554,12 +2561,17 @@ int input_register_handler(struct input_handler *handler) if (error) return error; + INIT_LIST_HEAD(&handler->h_list); + + if (handler->filter) + handler->events = input_handler_events_filter; + else if (handler->event) + handler->events = input_handler_events_default; + error = mutex_lock_interruptible(&input_mutex); if (error) return error; - INIT_LIST_HEAD(&handler->h_list); - list_add_tail(&handler->node, &input_handler_list); list_for_each_entry(dev, &input_dev_list, node)
Streamline event handling code by providing batch implementations for filtering and event processing and using them in place of the main event handler, as needed, instead of having complex branching logic in the middle of the event processing code. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> --- drivers/input/input.c | 90 ++++++++++++++++++++++++------------------- 1 file changed, 51 insertions(+), 39 deletions(-)