From: Erik Arfvidson Date: Tue, 5 May 2015 22:37:07 +0000 (-0400) Subject: staging: unisys: move periodic_work.c into the visorbus directory X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=53490b545cb07c9d2e1b36aa680afaf0d435aec8;p=openwrt%2Fstaging%2Fblogic.git staging: unisys: move periodic_work.c into the visorbus directory This patch removes visorutil directory, move periodic_work.c into the visorbus directory. Signed-off-by: Erik Arfvidson Signed-off-by: Benjamin Romer Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/unisys/Kconfig b/drivers/staging/unisys/Kconfig index e0562f133613..0c3e9a1368a8 100644 --- a/drivers/staging/unisys/Kconfig +++ b/drivers/staging/unisys/Kconfig @@ -11,7 +11,6 @@ menuconfig UNISYSSPAR if UNISYSSPAR -source "drivers/staging/unisys/visorutil/Kconfig" source "drivers/staging/unisys/visorbus/Kconfig" endif # UNISYSSPAR diff --git a/drivers/staging/unisys/visorbus/Makefile b/drivers/staging/unisys/visorbus/Makefile index 16d3ff507a0a..72d4d4429684 100644 --- a/drivers/staging/unisys/visorbus/Makefile +++ b/drivers/staging/unisys/visorbus/Makefile @@ -7,6 +7,7 @@ obj-$(CONFIG_UNISYS_VISORBUS) += visorbus.o visorbus-y := visorbus_main.o visorbus-y += visorchannel.o visorbus-y += visorchipset.o +visorbus-y += periodic_work.o ccflags-y += -Idrivers/staging/unisys/include ccflags-y += -Idrivers/staging/unisys/common-spar/include diff --git a/drivers/staging/unisys/visorbus/periodic_work.c b/drivers/staging/unisys/visorbus/periodic_work.c new file mode 100644 index 000000000000..3562e8b2824b --- /dev/null +++ b/drivers/staging/unisys/visorbus/periodic_work.c @@ -0,0 +1,205 @@ +/* periodic_work.c + * + * Copyright (C) 2010 - 2013 UNISYS CORPORATION + * All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for more + * details. + */ + +/* + * Helper functions to schedule periodic work in Linux kernel mode. + */ +#include + +#include "periodic_work.h" + +#define MYDRVNAME "periodic_work" + +struct periodic_work { + rwlock_t lock; + struct delayed_work work; + void (*workfunc)(void *); + void *workfuncarg; + bool is_scheduled; + bool want_to_stop; + ulong jiffy_interval; + struct workqueue_struct *workqueue; + const char *devnam; +}; + +static void periodic_work_func(struct work_struct *work) +{ + struct periodic_work *pw; + + pw = container_of(work, struct periodic_work, work.work); + (*pw->workfunc)(pw->workfuncarg); +} + +struct periodic_work *visor_periodic_work_create(ulong jiffy_interval, + struct workqueue_struct *workqueue, + void (*workfunc)(void *), + void *workfuncarg, + const char *devnam) +{ + struct periodic_work *pw; + + pw = kzalloc(sizeof(*pw), GFP_KERNEL | __GFP_NORETRY); + if (!pw) + return NULL; + + rwlock_init(&pw->lock); + pw->jiffy_interval = jiffy_interval; + pw->workqueue = workqueue; + pw->workfunc = workfunc; + pw->workfuncarg = workfuncarg; + pw->devnam = devnam; + return pw; +} +EXPORT_SYMBOL_GPL(visor_periodic_work_create); + +void visor_periodic_work_destroy(struct periodic_work *pw) +{ + kfree(pw); +} +EXPORT_SYMBOL_GPL(visor_periodic_work_destroy); + +/** Call this from your periodic work worker function to schedule the next + * call. + * If this function returns false, there was a failure and the + * periodic work is no longer scheduled + */ +bool visor_periodic_work_nextperiod(struct periodic_work *pw) +{ + bool rc = false; + + write_lock(&pw->lock); + if (pw->want_to_stop) { + pw->is_scheduled = false; + pw->want_to_stop = false; + rc = true; /* yes, true; see visor_periodic_work_stop() */ + goto unlock; + } else if (queue_delayed_work(pw->workqueue, &pw->work, + pw->jiffy_interval) < 0) { + pw->is_scheduled = false; + rc = false; + goto unlock; + } + rc = true; +unlock: + write_unlock(&pw->lock); + return rc; +} +EXPORT_SYMBOL_GPL(visor_periodic_work_nextperiod); + +/** This function returns true iff new periodic work was actually started. + * If this function returns false, then no work was started + * (either because it was already started, or because of a failure). + */ +bool visor_periodic_work_start(struct periodic_work *pw) +{ + bool rc = false; + + write_lock(&pw->lock); + if (pw->is_scheduled) { + rc = false; + goto unlock; + } + if (pw->want_to_stop) { + rc = false; + goto unlock; + } + INIT_DELAYED_WORK(&pw->work, &periodic_work_func); + if (queue_delayed_work(pw->workqueue, &pw->work, + pw->jiffy_interval) < 0) { + rc = false; + goto unlock; + } + pw->is_scheduled = true; + rc = true; +unlock: + write_unlock(&pw->lock); + return rc; +} +EXPORT_SYMBOL_GPL(visor_periodic_work_start); + +/** This function returns true iff your call actually stopped the periodic + * work. + * + * -- PAY ATTENTION... this is important -- + * + * NO NO #1 + * + * Do NOT call this function from some function that is running on the + * same workqueue as the work you are trying to stop might be running + * on! If you violate this rule, visor_periodic_work_stop() MIGHT work, + * but it also MIGHT get hung up in an infinite loop saying + * "waiting for delayed work...". This will happen if the delayed work + * you are trying to cancel has been put in the workqueue list, but can't + * run yet because we are running that same workqueue thread right now. + * + * Bottom line: If you need to call visor_periodic_work_stop() from a + * workitem, be sure the workitem is on a DIFFERENT workqueue than the + * workitem that you are trying to cancel. + * + * If I could figure out some way to check for this "no no" condition in + * the code, I would. It would have saved me the trouble of writing this + * long comment. And also, don't think this is some "theoretical" race + * condition. It is REAL, as I have spent the day chasing it. + * + * NO NO #2 + * + * Take close note of the locks that you own when you call this function. + * You must NOT own any locks that are needed by the periodic work + * function that is currently installed. If you DO, a deadlock may result, + * because stopping the periodic work often involves waiting for the last + * iteration of the periodic work function to complete. Again, if you hit + * this deadlock, you will get hung up in an infinite loop saying + * "waiting for delayed work...". + */ +bool visor_periodic_work_stop(struct periodic_work *pw) +{ + bool stopped_something = false; + + write_lock(&pw->lock); + stopped_something = pw->is_scheduled && (!pw->want_to_stop); + while (pw->is_scheduled) { + pw->want_to_stop = true; + if (cancel_delayed_work(&pw->work)) { + /* We get here if the delayed work was pending as + * delayed work, but was NOT run. + */ + WARN_ON(!pw->is_scheduled); + pw->is_scheduled = false; + } else { + /* If we get here, either the delayed work: + * - was run, OR, + * - is running RIGHT NOW on another processor, OR, + * - wasn't even scheduled (there is a miniscule + * timing window where this could be the case) + * flush_workqueue() would make sure it is finished + * executing, but that still isn't very useful, which + * explains the loop... + */ + } + if (pw->is_scheduled) { + write_unlock(&pw->lock); + __set_current_state(TASK_INTERRUPTIBLE); + schedule_timeout(10); + write_lock(&pw->lock); + } else { + pw->want_to_stop = false; + } + } + write_unlock(&pw->lock); + return stopped_something; +} +EXPORT_SYMBOL_GPL(visor_periodic_work_stop); diff --git a/drivers/staging/unisys/visorutil/Kconfig b/drivers/staging/unisys/visorutil/Kconfig deleted file mode 100644 index be9c2cf890cc..000000000000 --- a/drivers/staging/unisys/visorutil/Kconfig +++ /dev/null @@ -1,9 +0,0 @@ -# -# Unisys timskmod configuration -# - -config UNISYS_VISORUTIL - tristate "Unisys visorutil driver" - ---help--- - If you say Y here, you will enable the Unisys visorutil driver. - diff --git a/drivers/staging/unisys/visorutil/Makefile b/drivers/staging/unisys/visorutil/Makefile deleted file mode 100644 index 8f6a3e3afffb..000000000000 --- a/drivers/staging/unisys/visorutil/Makefile +++ /dev/null @@ -1,9 +0,0 @@ -# -# Makefile for Unisys timskmod -# - -obj-$(CONFIG_UNISYS_VISORUTIL) += visorutil.o - -visorutil-y := periodic_work.o - -ccflags-y += -Idrivers/staging/unisys/include diff --git a/drivers/staging/unisys/visorutil/periodic_work.c b/drivers/staging/unisys/visorutil/periodic_work.c deleted file mode 100644 index 3562e8b2824b..000000000000 --- a/drivers/staging/unisys/visorutil/periodic_work.c +++ /dev/null @@ -1,205 +0,0 @@ -/* periodic_work.c - * - * Copyright (C) 2010 - 2013 UNISYS CORPORATION - * All rights reserved. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or (at - * your option) any later version. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or - * NON INFRINGEMENT. See the GNU General Public License for more - * details. - */ - -/* - * Helper functions to schedule periodic work in Linux kernel mode. - */ -#include - -#include "periodic_work.h" - -#define MYDRVNAME "periodic_work" - -struct periodic_work { - rwlock_t lock; - struct delayed_work work; - void (*workfunc)(void *); - void *workfuncarg; - bool is_scheduled; - bool want_to_stop; - ulong jiffy_interval; - struct workqueue_struct *workqueue; - const char *devnam; -}; - -static void periodic_work_func(struct work_struct *work) -{ - struct periodic_work *pw; - - pw = container_of(work, struct periodic_work, work.work); - (*pw->workfunc)(pw->workfuncarg); -} - -struct periodic_work *visor_periodic_work_create(ulong jiffy_interval, - struct workqueue_struct *workqueue, - void (*workfunc)(void *), - void *workfuncarg, - const char *devnam) -{ - struct periodic_work *pw; - - pw = kzalloc(sizeof(*pw), GFP_KERNEL | __GFP_NORETRY); - if (!pw) - return NULL; - - rwlock_init(&pw->lock); - pw->jiffy_interval = jiffy_interval; - pw->workqueue = workqueue; - pw->workfunc = workfunc; - pw->workfuncarg = workfuncarg; - pw->devnam = devnam; - return pw; -} -EXPORT_SYMBOL_GPL(visor_periodic_work_create); - -void visor_periodic_work_destroy(struct periodic_work *pw) -{ - kfree(pw); -} -EXPORT_SYMBOL_GPL(visor_periodic_work_destroy); - -/** Call this from your periodic work worker function to schedule the next - * call. - * If this function returns false, there was a failure and the - * periodic work is no longer scheduled - */ -bool visor_periodic_work_nextperiod(struct periodic_work *pw) -{ - bool rc = false; - - write_lock(&pw->lock); - if (pw->want_to_stop) { - pw->is_scheduled = false; - pw->want_to_stop = false; - rc = true; /* yes, true; see visor_periodic_work_stop() */ - goto unlock; - } else if (queue_delayed_work(pw->workqueue, &pw->work, - pw->jiffy_interval) < 0) { - pw->is_scheduled = false; - rc = false; - goto unlock; - } - rc = true; -unlock: - write_unlock(&pw->lock); - return rc; -} -EXPORT_SYMBOL_GPL(visor_periodic_work_nextperiod); - -/** This function returns true iff new periodic work was actually started. - * If this function returns false, then no work was started - * (either because it was already started, or because of a failure). - */ -bool visor_periodic_work_start(struct periodic_work *pw) -{ - bool rc = false; - - write_lock(&pw->lock); - if (pw->is_scheduled) { - rc = false; - goto unlock; - } - if (pw->want_to_stop) { - rc = false; - goto unlock; - } - INIT_DELAYED_WORK(&pw->work, &periodic_work_func); - if (queue_delayed_work(pw->workqueue, &pw->work, - pw->jiffy_interval) < 0) { - rc = false; - goto unlock; - } - pw->is_scheduled = true; - rc = true; -unlock: - write_unlock(&pw->lock); - return rc; -} -EXPORT_SYMBOL_GPL(visor_periodic_work_start); - -/** This function returns true iff your call actually stopped the periodic - * work. - * - * -- PAY ATTENTION... this is important -- - * - * NO NO #1 - * - * Do NOT call this function from some function that is running on the - * same workqueue as the work you are trying to stop might be running - * on! If you violate this rule, visor_periodic_work_stop() MIGHT work, - * but it also MIGHT get hung up in an infinite loop saying - * "waiting for delayed work...". This will happen if the delayed work - * you are trying to cancel has been put in the workqueue list, but can't - * run yet because we are running that same workqueue thread right now. - * - * Bottom line: If you need to call visor_periodic_work_stop() from a - * workitem, be sure the workitem is on a DIFFERENT workqueue than the - * workitem that you are trying to cancel. - * - * If I could figure out some way to check for this "no no" condition in - * the code, I would. It would have saved me the trouble of writing this - * long comment. And also, don't think this is some "theoretical" race - * condition. It is REAL, as I have spent the day chasing it. - * - * NO NO #2 - * - * Take close note of the locks that you own when you call this function. - * You must NOT own any locks that are needed by the periodic work - * function that is currently installed. If you DO, a deadlock may result, - * because stopping the periodic work often involves waiting for the last - * iteration of the periodic work function to complete. Again, if you hit - * this deadlock, you will get hung up in an infinite loop saying - * "waiting for delayed work...". - */ -bool visor_periodic_work_stop(struct periodic_work *pw) -{ - bool stopped_something = false; - - write_lock(&pw->lock); - stopped_something = pw->is_scheduled && (!pw->want_to_stop); - while (pw->is_scheduled) { - pw->want_to_stop = true; - if (cancel_delayed_work(&pw->work)) { - /* We get here if the delayed work was pending as - * delayed work, but was NOT run. - */ - WARN_ON(!pw->is_scheduled); - pw->is_scheduled = false; - } else { - /* If we get here, either the delayed work: - * - was run, OR, - * - is running RIGHT NOW on another processor, OR, - * - wasn't even scheduled (there is a miniscule - * timing window where this could be the case) - * flush_workqueue() would make sure it is finished - * executing, but that still isn't very useful, which - * explains the loop... - */ - } - if (pw->is_scheduled) { - write_unlock(&pw->lock); - __set_current_state(TASK_INTERRUPTIBLE); - schedule_timeout(10); - write_lock(&pw->lock); - } else { - pw->want_to_stop = false; - } - } - write_unlock(&pw->lock); - return stopped_something; -} -EXPORT_SYMBOL_GPL(visor_periodic_work_stop);