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Message-Id: <20101005141334.6a0f15fd.sfr@canb.auug.org.au>
Date: Tue, 5 Oct 2010 14:13:34 +1100
From: Stephen Rothwell <sfr@...b.auug.org.au>
To: Tejun Heo <tj@...nel.org>
Cc: linux-next@...r.kernel.org, linux-kernel@...r.kernel.org,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...e.hu>, "H. Peter Anvin" <hpa@...or.com>,
Peter Zijlstra <peterz@...radead.org>
Subject: linux-next: manual merge of the lost-spurious-irq tree with the tip
tree
Hi Tejun,
Today's linux-next merge of the lost-spurious-irq tree got a conflict in
kernel/irq/spurious.c between commits
6b8ff3120c758340505dddf08ad685ebb841d5d5 ("genirq: Convert core code to
irq_data") and bd151412263a67b5321e9dd1d5b4bf6d96fdebf3 ("genirq: Provide
config option to disable deprecated code") from the tip tree and commits
32b5d378f49485f3ae172eb0ac2bfc4ebbbdb060 ("irq: cleanup irqfixup") and
80f97e2b33c3e66c11b10abd2890506a3abeb320 ("irq: make spurious poll timer
per desc") from the lost-spurious-irq tree.
I think I fixed it all up (see below). I can carry this fix (or a better
one) as necessary.
--
Cheers,
Stephen Rothwell sfr@...b.auug.org.au
diff --cc kernel/irq/spurious.c
index 3089d3b,b34b023..0000000
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@@ -16,14 -75,558 +75,558 @@@
#include "internals.h"
- static int irqfixup __read_mostly;
+ /*
+ * I spent quite some time thinking about each parameter but they
+ * still are just numbers pulled out of my ass. If you think your ass
+ * is prettier than mine, please go ahead and suggest better ones.
+ *
+ * Most parameters are intentionally fixed constants and not
+ * adjustable through API. The nature of IRQ delivery failures isn't
+ * usually dependent on specific drivers and the timing parameters are
+ * more about human perceivable latencies rather than any specific
+ * controller timing details, so figuring out constant values which
+ * can work for most cases shouldn't be too hard. This allows tighter
+ * control over polling behaviors, eases future changes and makes the
+ * interface easy for drivers.
+ */
+ enum {
+ /* irqfixup levels */
+ IRQFIXUP_SPURIOUS = 0, /* spurious storm detection */
+ IRQFIXUP_MISROUTED = 1, /* misrouted IRQ fixup */
+ IRQFIXUP_POLL = 2, /* enable polling by default */
+
+ /* IRQ polling common parameters */
+ IRQ_POLL_SLOW_INTV = 3 * HZ, /* not too slow for ppl, slow enough for machine */
+ IRQ_POLL_INTV = HZ / 100, /* from the good ol' 100HZ tick */
+ IRQ_POLL_QUICK_INTV = HZ / 1000, /* on every tick, basically */
+
+ IRQ_POLL_SLOW_SLACK = HZ,
+ IRQ_POLL_SLACK = HZ / 250, /* 1 tick slack w/ the popular 250HZ config */
+ IRQ_POLL_QUICK_SLACK = HZ / 10000, /* no slack, basically */
+
+ /*
+ * IRQ expect parameters.
+ *
+ * Because IRQ expecting is tightly coupled with the actual
+ * activity of the controller, we can be slightly aggressive
+ * and try to minimize the effect of lost interrupts.
+ *
+ * An irqaction must accumulate VERIFY_GOAL good deliveries,
+ * where one bad delivery (delivered by polling) costs
+ * BAD_FACTOR good ones, before reaching the verified state.
+ *
+ * QUICK_SAMPLES IRQ deliveries are examined and if
+ * >=QUICK_THRESHOLD of them are polled on the first poll, the
+ * IRQ is considered to be quick and QUICK_INTV is used
+ * instead.
+ *
+ * Keep QUICK_SAMPLES much higher than VERIFY_GOAL so that
+ * quick polling doesn't interfact with the initial
+ * verification attempt (quicker polling increases the chance
+ * of polled deliveries).
+ */
+ IRQ_EXP_BAD_FACTOR = 10,
+ IRQ_EXP_VERIFY_GOAL = 256,
+ IRQ_EXP_QUICK_SAMPLES = IRQ_EXP_VERIFY_GOAL * 4,
+ IRQ_EXP_QUICK_THRESHOLD = IRQ_EXP_QUICK_SAMPLES * 8 / 10,
+
+ /* IRQ expect flags */
+ IRQ_EXPECTING = (1 << 0), /* expecting in progress */
+ IRQ_EXP_VERIFIED = (1 << 1), /* delivery verified, use slow interval */
+ IRQ_EXP_QUICK = (1 << 2), /* quick polling enabled */
+ IRQ_EXP_WARNED = (1 << 3), /* already whined */
+
+ /*
+ * IRQ watch parameters.
+ *
+ * As IRQ watching has much less information about what's
+ * going on, the parameters are more conservative. It will
+ * terminate unless it can reliably determine that IRQ
+ * delivery isn't working.
+ *
+ * IRQs are watched in timed intervals which is BASE_PERIOD
+ * long by default. Polling interval starts at BASE_INTV and
+ * grows upto SLOW_INTV if no bad delivery is detected.
+ *
+ * If a period contains zero sample and no bad delivery was
+ * seen since watch started, watch terminates.
+ *
+ * If a period contains >=1 but <MIN_SAMPLES deliveries,
+ * collected samples are inherited to the next period.
+ *
+ * If it contains enough samples, the ratio between good and
+ * bad deliveries are examined, if >=BAD_PCT% are bad, the
+ * irqaction is tagged bad and watched indefinitely. if
+ * BAD_PCT% > nr_bad >= WARY_PCT%, WARY_PERIOD is used instead
+ * of BASE_PERIOD and the whole process is restarted. If
+ * <WARY_PCT% are bad, watch terminates.
+ */
+ IRQ_WAT_MIN_SAMPLES = 10,
+ IRQ_WAT_BASE_INTV = HZ / 2,
+ IRQ_WAT_BASE_PERIOD = 60 * HZ,
+ IRQ_WAT_WARY_PERIOD = 600 * HZ,
+ IRQ_WAT_WARY_PCT = 1,
+ IRQ_WAT_BAD_PCT = 10,
+
+ /* IRQ watch flags */
+ IRQ_WATCHING = (1 << 0),
+ IRQ_WAT_POLLED = (1 << 1),
+ IRQ_WAT_WARY = (1 << 2),
+ IRQ_WAT_BAD = (1 << 3),
+
+ /*
+ * Spurious IRQ handling parameters.
+ *
+ * As this per-IRQ spurious handling is cheaper than the
+ * previous system wide spurious handling, it can afford to
+ * use more responsive settings but these parameters are still
+ * pretty conservative. If ever necessary, making it more
+ * responsive shouldn't cause any problem.
+ *
+ * Spurious IRQs are monitored in segments of PERIOD_SAMPLES
+ * IRQs which can stretch PERIOD_DURATION at maximum. If
+ * there are less than PERIOD_SAMPLES IRQs per
+ * PERIOD_DURATION, the period is considered good.
+ *
+ * If >=BAD_THRESHOLD IRQs are bad ones, the period is
+ * considered bad and spurious IRQ handling kicks in - the IRQ
+ * is disabled and polled. The IRQ is given another shot
+ * after certain number IRQs are handled, which is at minimum
+ * POLL_CNT_MIN, increased by 1 << POLL_CNT_INC_SHIFT times
+ * after each bad period and decreased by factor of
+ * POLL_CNT_INC_DEC_SHIFT after each good one.
+ */
+ IRQ_SPR_PERIOD_DURATION = 10 * HZ,
+ IRQ_SPR_PERIOD_SAMPLES = 10000,
+ IRQ_SPR_BAD_THRESHOLD = 9900,
+ IRQ_SPR_POLL_CNT_MIN = 10000,
+ IRQ_SPR_POLL_CNT_INF = UINT_MAX,
+ IRQ_SPR_POLL_CNT_INC_SHIFT = 3,
+ IRQ_SPR_POLL_CNT_DEC_SHIFT = 1,
+ IRQ_SPR_POLL_CNT_MAX_DEC_SHIFT = BITS_PER_BYTE * sizeof(int) / 4,
+ };
+
+ struct irq_expect {
+ struct irq_expect *next;
+ struct irq_desc *desc; /* the associated IRQ desc */
+ struct irqaction *act; /* the associated IRQ action */
+
+ unsigned int flags; /* IRQ_EXP_* flags */
+ unsigned int nr_samples; /* nr of collected samples in this period */
+ unsigned int nr_quick; /* nr of polls completed after single attempt */
+ unsigned int nr_good; /* nr of good IRQ deliveries */
+ unsigned long started; /* when this period started */
+ };
+
+ int noirqdebug __read_mostly;
+ static int irqfixup __read_mostly = IRQFIXUP_SPURIOUS;
+
+ static struct irqaction *find_irq_action(struct irq_desc *desc, void *dev_id)
+ {
+ struct irqaction *act;
+
+ for (act = desc->action; act; act = act->next)
+ if (act->dev_id == dev_id)
+ return act;
+ return NULL;
+ }
+
+ static void print_irq_handlers(struct irq_desc *desc)
+ {
+ struct irqaction *action;
+
+ printk(KERN_ERR "handlers:\n");
+
+ action = desc->action;
+ while (action) {
+ printk(KERN_ERR "[<%p>]", action->handler);
+ print_symbol(" (%s)", (unsigned long)action->handler);
+ printk("\n");
+ action = action->next;
+ }
+ }
+
+ static void warn_irq_poll(struct irq_desc *desc, struct irqaction *act)
+ {
+ if (desc->poll_warned)
+ return;
+
+ desc->poll_warned = true;
+
+ printk(KERN_WARNING "IRQ %u: %s: can't verify IRQ, will keep polling\n",
- desc->irq, act->name);
++ desc->irq_data.irq, act->name);
+ printk(KERN_WARNING "IRQ %u: %s: system performance may be affected\n",
- desc->irq, act->name);
++ desc->irq_data.irq, act->name);
+ }
+
+ static unsigned long irq_poll_slack(unsigned long intv)
+ {
+ if (intv >= IRQ_POLL_SLOW_INTV)
+ return IRQ_POLL_SLOW_SLACK;
+ else if (intv >= IRQ_POLL_INTV)
+ return IRQ_POLL_SLACK;
+ else
+ return IRQ_POLL_QUICK_SLACK;
+ }
+
+ /**
+ * irq_schedule_poll - schedule IRQ poll
+ * @desc: IRQ desc to schedule poll for
+ * @intv: poll interval
+ *
+ * Schedules @desc->poll_timer. If the timer is already scheduled,
+ * it's modified iff jiffies + @intv + slack is before the timer's
+ * expires. poll_timers aren't taken offline behind this function's
+ * back and the users of this function are guaranteed that poll_irq()
+ * will be called at or before jiffies + @intv + slack.
+ *
+ * CONTEXT:
+ * desc->lock
+ */
+ static void irq_schedule_poll(struct irq_desc *desc, unsigned long intv)
+ {
+ unsigned long expires = jiffies + intv;
+ int slack = irq_poll_slack(intv);
+
+ if (timer_pending(&desc->poll_timer) &&
+ time_before_eq(desc->poll_timer.expires, expires + slack))
+ return;
+
+ set_timer_slack(&desc->poll_timer, slack);
+ mod_timer(&desc->poll_timer, expires);
+ }
+
+ static unsigned long irq_exp_intv(struct irq_expect *exp)
+ {
+ if (!(exp->flags & IRQ_EXPECTING))
+ return MAX_JIFFY_OFFSET;
+ if (exp->flags & IRQ_EXP_VERIFIED)
+ return IRQ_POLL_SLOW_INTV;
+ if (exp->flags & IRQ_EXP_QUICK)
+ return IRQ_POLL_QUICK_INTV;
+ return IRQ_POLL_INTV;
+ }
+
+ /**
+ * init_irq_expect - initialize IRQ expecting
+ * @irq: IRQ to expect
+ * @dev_id: dev_id of the irqaction to expect
+ *
+ * Initializes IRQ expecting and returns expect token to use. This
+ * function can be called multiple times for the same irqaction and
+ * each token can be used independently.
+ *
+ * CONTEXT:
+ * Does GFP_KERNEL allocation.
+ *
+ * RETURNS:
+ * irq_expect token to use on success, %NULL on failure.
+ */
+ struct irq_expect *init_irq_expect(unsigned int irq, void *dev_id)
+ {
+ struct irq_desc *desc = irq_to_desc(irq);
+ struct irqaction *act;
+ struct irq_expect *exp;
+ unsigned long flags;
+
+ if (noirqdebug || WARN_ON_ONCE(!desc))
+ return NULL;
+
+ exp = kzalloc(sizeof(*exp), GFP_KERNEL);
+ if (!exp) {
+ printk(KERN_WARNING "IRQ %u: failed to initialize IRQ expect, "
+ "allocation failed\n", irq);
+ return NULL;
+ }
+
+ exp->desc = desc;
+
+ raw_spin_lock_irqsave(&desc->lock, flags);
+
+ act = find_irq_action(desc, dev_id);
+ if (!WARN_ON_ONCE(!act)) {
+ exp->act = act;
+ exp->next = act->expects;
+ act->expects = exp;
+ } else {
+ kfree(exp);
+ exp = NULL;
+ }
+
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+
+ return exp;
+ }
+ EXPORT_SYMBOL_GPL(init_irq_expect);
+
+ /**
+ * expect_irq - expect IRQ
+ * @exp: expect token acquired from init_irq_expect(), %NULL is allowed
+ *
+ * Tell IRQ subsystem to expect an IRQ. The IRQ might be polled until
+ * unexpect_irq() is called on @exp. If @exp is %NULL, this function
+ * becomes noop.
+ *
+ * This function is fairly cheap and drivers can call it for each
+ * interrupt driven operation without adding noticeable overhead in
+ * most cases.
+ *
+ * CONTEXT:
+ * Don't care. The caller is responsible for ensuring
+ * [un]expect_irq() calls don't overlap. Overlapping may lead to
+ * unexpected polling behaviors but won't directly cause a failure.
+ */
+ void expect_irq(struct irq_expect *exp)
+ {
+ struct irq_desc *desc;
+ unsigned long intv, deadline;
+ unsigned long flags;
+
+ /* @exp is NULL if noirqdebug */
+ if (unlikely(!exp))
+ return;
+
+ desc = exp->desc;
+ exp->flags |= IRQ_EXPECTING;
+
+ /*
+ * Paired with mb in poll_irq(). Either we see timer pending
+ * cleared or poll_irq() sees IRQ_EXPECTING.
+ */
+ smp_mb();
+
+ exp->started = jiffies;
+ intv = irq_exp_intv(exp);
+ deadline = exp->started + intv + irq_poll_slack(intv);
+
+ /*
+ * poll_timer is never explicitly killed unless there's no
+ * action left on the irq; also, while it's online, timer
+ * duration is only shortened, which means that if we see
+ * ->expires in the future and not later than our deadline,
+ * the timer is guaranteed to fire before it.
+ */
+ if (!timer_pending(&desc->poll_timer) ||
+ time_after_eq(jiffies, desc->poll_timer.expires) ||
+ time_before(deadline, desc->poll_timer.expires)) {
+ raw_spin_lock_irqsave(&desc->lock, flags);
+ irq_schedule_poll(desc, intv);
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+ }
+ }
+ EXPORT_SYMBOL_GPL(expect_irq);
+
+ /**
+ * unexpect_irq - unexpect IRQ
+ * @exp: expect token acquired from init_irq_expect(), %NULL is allowed
+ * @timedout: did the IRQ timeout?
+ *
+ * Tell IRQ subsystem to stop expecting an IRQ. Set @timedout to
+ * %true if the expected IRQ never arrived. If @exp is %NULL, this
+ * function becomes noop.
+ *
+ * This function is fairly cheap and drivers can call it for each
+ * interrupt driven operation without adding noticeable overhead in
+ * most cases.
+ *
+ * CONTEXT:
+ * Don't care. The caller is responsible for ensuring
+ * [un]expect_irq() calls don't overlap. Overlapping may lead to
+ * unexpected polling behaviors but won't directly cause a failure.
+ */
+ void unexpect_irq(struct irq_expect *exp, bool timedout)
+ {
+ struct irq_desc *desc;
+
+ /* @exp is NULL if noirqdebug */
+ if (unlikely(!exp) || (!(exp->flags & IRQ_EXPECTING) && !timedout))
+ return;
+
+ desc = exp->desc;
+ exp->flags &= ~IRQ_EXPECTING;
+
+ /* succesful completion from IRQ? */
+ if (likely(!(desc->status & IRQ_IN_POLLING) && !timedout)) {
+ /*
+ * IRQ seems a bit more trustworthy. Allow nr_good to
+ * increase till VERIFY_GOAL + BAD_FACTOR - 1 so that
+ * single succesful delivery can recover verified
+ * state after an accidental polling hit.
+ */
+ if (unlikely(exp->nr_good <
+ IRQ_EXP_VERIFY_GOAL + IRQ_EXP_BAD_FACTOR - 1) &&
+ ++exp->nr_good >= IRQ_EXP_VERIFY_GOAL) {
+ exp->flags |= IRQ_EXP_VERIFIED;
+ exp->nr_samples = 0;
+ exp->nr_quick = 0;
+ }
+ return;
+ }
+
+ /* timedout or polled */
+ if (timedout) {
+ exp->nr_good = 0;
+ } else {
+ exp->nr_good -= min_t(unsigned int,
+ exp->nr_good, IRQ_EXP_BAD_FACTOR);
+
+ if (time_before_eq(jiffies, exp->started + IRQ_POLL_INTV))
+ exp->nr_quick++;
+
+ if (++exp->nr_samples >= IRQ_EXP_QUICK_SAMPLES) {
+ /*
+ * Use quick sampling checkpoints as warning
+ * checkpoints too.
+ */
+ if (!(exp->flags & IRQ_EXP_WARNED) &&
+ !desc->spr.poll_rem) {
+ warn_irq_poll(desc, exp->act);
+ exp->flags |= IRQ_EXP_WARNED;
+ }
+
+ exp->flags &= ~IRQ_EXP_QUICK;
+ if (exp->nr_quick >= IRQ_EXP_QUICK_THRESHOLD)
+ exp->flags |= IRQ_EXP_QUICK;
+ exp->nr_samples = 0;
+ exp->nr_quick = 0;
+ }
+ }
+
+ exp->flags &= ~IRQ_EXP_VERIFIED;
+ }
+ EXPORT_SYMBOL_GPL(unexpect_irq);
+
+ /**
+ * irq_update_watch - IRQ handled, update watch state
+ * @desc: IRQ desc of interest
+ * @act: IRQ action of interest
+ * @via_poll: IRQ was handled via poll
+ *
+ * Called after IRQ is successfully delievered or polled. Updates
+ * watch state accordingly and determines which watch interval to use.
+ *
+ * CONTEXT:
+ * desc->lock
+ *
+ * RETURNS:
+ * Watch poll interval to use, MAX_JIFFY_OFFSET if watch polling isn't
+ * necessary.
+ */
+ static unsigned long irq_update_watch(struct irq_desc *desc,
+ struct irqaction *act, bool via_poll)
+ {
+ struct irq_watch *wat = &act->watch;
+ unsigned long period = wat->flags & IRQ_WAT_WARY ?
+ IRQ_WAT_WARY_PERIOD : IRQ_WAT_BASE_PERIOD;
+
+ /* if not watching or already determined to be bad, it's easy */
+ if (!(wat->flags & IRQ_WATCHING))
+ return MAX_JIFFY_OFFSET;
+ if (wat->flags & IRQ_WAT_BAD)
+ return IRQ_POLL_INTV;
+
+ /* don't expire watch period while spurious polling is in effect */
+ if (desc->spr.poll_rem) {
+ wat->started = jiffies;
+ return IRQ_POLL_INTV;
+ }
+
+ /* IRQ was handled, record whether it was a good or bad delivery */
+ if (wat->last_ret == IRQ_HANDLED) {
+ wat->nr_samples++;
+ if (via_poll) {
+ wat->nr_polled++;
+ wat->flags |= IRQ_WAT_POLLED;
+ }
+ }
+
+ /* is this watch period over? */
+ if (time_after(jiffies, wat->started + period)) {
+ unsigned int wry_thr = wat->nr_samples * IRQ_WAT_WARY_PCT / 100;
+ unsigned int bad_thr = wat->nr_samples * IRQ_WAT_BAD_PCT / 100;
+
+ if (wat->nr_samples >= IRQ_WAT_MIN_SAMPLES) {
+ /* have enough samples, determine what to do */
+ if (wat->nr_polled <= wry_thr)
+ wat->flags &= ~IRQ_WATCHING;
+ else if (wat->nr_polled <= bad_thr)
+ wat->flags |= IRQ_WAT_WARY;
+ else {
+ warn_irq_poll(desc, act);
+ wat->flags |= IRQ_WAT_BAD;
+ }
+ wat->nr_samples = 0;
+ wat->nr_polled = 0;
+ } else if (!wat->nr_samples || !(wat->flags & IRQ_WAT_POLLED)) {
+ /* not sure but let's not hold onto it */
+ wat->flags &= ~IRQ_WATCHING;
+ }
+
+ wat->started = jiffies;
+ }
+
+ if (!(wat->flags & IRQ_WATCHING))
+ return MAX_JIFFY_OFFSET;
+ if (wat->flags & IRQ_WAT_POLLED)
+ return IRQ_POLL_INTV;
+ /* every delivery upto this point has been successful, grow interval */
+ return clamp_t(unsigned long, jiffies - wat->started,
+ IRQ_WAT_BASE_INTV, IRQ_POLL_SLOW_INTV);
+ }
+
+ /**
+ * watch_irq - watch an irqaction
+ * @irq: IRQ the irqaction to watch belongs to
+ * @dev_id: dev_id for the irqaction to watch
+ *
+ * LOCKING:
+ * Grabs and releases desc->lock.
+ */
+ void watch_irq(unsigned int irq, void *dev_id)
+ {
+ struct irq_desc *desc = irq_to_desc(irq);
+ struct irqaction *act;
+ unsigned long flags;
+
+ if (WARN_ON_ONCE(!desc))
+ return;
+
+ raw_spin_lock_irqsave(&desc->lock, flags);
+
+ act = find_irq_action(desc, dev_id);
+ if (!WARN_ON_ONCE(!act)) {
+ struct irq_watch *wat = &act->watch;
+
+ wat->flags |= IRQ_WATCHING;
+ wat->started = jiffies;
+ wat->nr_samples = 0;
+ wat->nr_polled = 0;
+ desc->status |= IRQ_CHECK_WATCHES;
+ irq_schedule_poll(desc, IRQ_WAT_BASE_INTV);
+ }
+
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+ }
+ EXPORT_SYMBOL_GPL(watch_irq);
+
+ /* start a new spurious handling period */
+ static void irq_spr_new_period(struct irq_spr *spr)
+ {
+ spr->period_start = jiffies;
+ spr->nr_samples = 0;
+ spr->nr_bad = 0;
+ }
- #define POLL_SPURIOUS_IRQ_INTERVAL (HZ/10)
- static void poll_spurious_irqs(unsigned long dummy);
- static DEFINE_TIMER(poll_spurious_irq_timer, poll_spurious_irqs, 0, 0);
+ /* Reset spurious handling. After this, poll_timer will offline itself soon. */
+ static void irq_spr_reset(struct irq_spr *spr)
+ {
+ irq_spr_new_period(spr);
+ spr->poll_cnt = IRQ_SPR_POLL_CNT_MIN;
+ spr->poll_rem = 0;
+ }
/*
- * Recovery handler for misrouted interrupts.
+ * Perform an actual poll.
*/
static int try_one_irq(int irq, struct irq_desc *desc)
{
@@@ -80,9 -682,8 +682,8 @@@
* If we did actual work for the real IRQ line we must let the
* IRQ controller clean up too
*/
- if (work && desc->chip && desc->chip->end)
- desc->chip->end(irq);
+ if (work)
+ irq_end(irq, desc);
- raw_spin_unlock(&desc->lock);
return ok;
}
@@@ -106,165 -709,266 +709,266 @@@ static int misrouted_irq(int irq
return ok;
}
- static void poll_spurious_irqs(unsigned long dummy)
+ /*
+ * IRQ delivery notification function. Called after each IRQ delivery.
+ */
+ void __note_interrupt(unsigned int irq, struct irq_desc *desc,
+ irqreturn_t action_ret)
{
- struct irq_desc *desc;
- int i;
+ struct irq_spr *spr = &desc->spr;
+ unsigned long dur;
+ unsigned int cnt, abbr;
+ char unit = 'k';
- for_each_irq_desc(i, desc) {
- unsigned int status;
+ /* first, take care of IRQ watches */
+ if (unlikely(desc->status & IRQ_CHECK_WATCHES)) {
+ unsigned long intv = MAX_JIFFY_OFFSET;
+ struct irqaction *act;
- if (!i)
- continue;
+ raw_spin_lock(&desc->lock);
- /* Racy but it doesn't matter */
- status = desc->status;
- barrier();
- if (!(status & IRQ_SPURIOUS_DISABLED))
- continue;
+ for (act = desc->action; act; act = act->next)
+ intv = min(intv, irq_update_watch(desc, act, false));
- local_irq_disable();
- try_one_irq(i, desc);
- local_irq_enable();
+ if (intv < MAX_JIFFY_OFFSET)
+ irq_schedule_poll(desc, intv);
+ else
+ desc->status &= ~IRQ_CHECK_WATCHES;
+
+ raw_spin_unlock(&desc->lock);
+ }
+
+ /*
+ * Account for unhandled interrupt. We don't care whether
+ * spurious accounting update races with irq open/close and
+ * gets some values wrong. Do it w/o locking.
+ */
+ if (unlikely(action_ret != IRQ_HANDLED)) {
+ static int bogus_count = 100;
+
+ spr->last_bad = jiffies - INITIAL_JIFFIES;
+ spr->nr_bad++;
+ if (likely(action_ret == IRQ_NONE)) {
+ if (unlikely(irqfixup >= IRQFIXUP_MISROUTED &&
+ misrouted_irq(irq)))
+ spr->nr_bad--;
+ } else if (bogus_count > 0) {
+ bogus_count--;
+ printk(KERN_ERR "IRQ %u: bogus return value %x\n",
+ irq, action_ret);
+ dump_stack();
+ print_irq_handlers(desc);
+ }
}
- mod_timer(&poll_spurious_irq_timer,
- jiffies + POLL_SPURIOUS_IRQ_INTERVAL);
+ /* did we finish this spurious period? */
+ spr->nr_samples++;
+ if (likely(spr->nr_samples < IRQ_SPR_PERIOD_SAMPLES))
+ return;
+
+ /* if so, was it a good one? */
+ dur = jiffies - spr->period_start;
+ if (likely(spr->nr_bad < IRQ_SPR_BAD_THRESHOLD ||
+ dur > IRQ_SPR_PERIOD_DURATION)) {
+ /*
+ * If longer than PERIOD_DURATION has passed, consider
+ * multiple good periods have happened.
+ */
+ int sft = IRQ_SPR_POLL_CNT_DEC_SHIFT *
+ (dur >> order_base_2(IRQ_SPR_PERIOD_DURATION));
+
+ /* but don't kill poll_cnt at once */
+ sft = clamp(sft, 1, IRQ_SPR_POLL_CNT_MAX_DEC_SHIFT);
+
+ spr->poll_cnt >>= sft;
+ irq_spr_new_period(spr);
+ return;
+ }
+
+ /*
+ * It was a bad one, start polling. This is a slow path and
+ * we're gonna be changing states which require proper
+ * synchronization, grab desc->lock.
+ */
+ raw_spin_lock(&desc->lock);
+
+ irq_spr_new_period(spr);
+
+ /* update spr_poll_cnt considering the lower and upper bounds */
+ cnt = max_t(unsigned int, spr->poll_cnt, IRQ_SPR_POLL_CNT_MIN);
+ spr->poll_cnt = cnt << IRQ_SPR_POLL_CNT_INC_SHIFT;
+ if (spr->poll_cnt < cnt) /* did it overflow? */
+ spr->poll_cnt = IRQ_SPR_POLL_CNT_INF;
+
+ /* whine, plug IRQ and kick poll timer */
+ abbr = cnt / 1000;
+ if (abbr > 1000) {
+ abbr /= 1000;
+ unit = 'm';
+ }
+ printk(KERN_ERR "IRQ %u: too many spurious IRQs, disabling and "
+ "polling for %u%c %umsec intervals.\n",
- desc->irq, abbr, unit, jiffies_to_msecs(IRQ_POLL_INTV));
++ desc->irq_data.irq, abbr, unit, jiffies_to_msecs(IRQ_POLL_INTV));
+ printk(KERN_ERR "IRQ %u: system performance may be affected\n",
- desc->irq);
++ desc->irq_data.irq);
+ print_irq_handlers(desc);
+
+ desc->status |= IRQ_DISABLED | IRQ_SPURIOUS_DISABLED;
+ desc->depth++;
- desc->chip->disable(desc->irq);
++ desc->irq_data.chip->irq_disable(&desc->irq_data);
+
+ spr->poll_rem = cnt;
+ irq_schedule_poll(desc, IRQ_POLL_INTV);
+
+ raw_spin_unlock(&desc->lock);
}
/*
- * If 99,900 of the previous 100,000 interrupts have not been handled
- * then assume that the IRQ is stuck in some manner. Drop a diagnostic
- * and try to turn the IRQ off.
- *
- * (The other 100-of-100,000 interrupts may have been a correctly
- * functioning device sharing an IRQ with the failing one)
- *
- * Called under desc->lock
+ * IRQ poller. Called from desc->poll_timer.
*/
-
- static void
- __report_bad_irq(unsigned int irq, struct irq_desc *desc,
- irqreturn_t action_ret)
+ void poll_irq(unsigned long arg)
{
- struct irqaction *action;
+ struct irq_desc *desc = (void *)arg;
+ struct irq_spr *spr = &desc->spr;
+ unsigned long intv = MAX_JIFFY_OFFSET;
+ bool reenable_irq = false;
+ struct irqaction *act;
+ struct irq_expect *exp;
+
+ raw_spin_lock_irq(&desc->lock);
+
+ /* poll the IRQ */
+ desc->status |= IRQ_IN_POLLING;
- try_one_irq(desc->irq, desc);
++ try_one_irq(desc->irq_data.irq, desc);
+ desc->status &= ~IRQ_IN_POLLING;
+
+ /* take care of spurious handling */
+ if (spr->poll_rem) {
+ if (spr->poll_rem != IRQ_SPR_POLL_CNT_INF)
+ spr->poll_rem--;
+ if (spr->poll_rem)
+ intv = IRQ_POLL_INTV;
+ else
+ irq_spr_new_period(spr);
+ }
+ if (!spr->poll_rem)
+ reenable_irq = desc->status & IRQ_SPURIOUS_DISABLED;
- if (action_ret != IRQ_HANDLED && action_ret != IRQ_NONE) {
- printk(KERN_ERR "irq event %d: bogus return value %x\n",
- irq, action_ret);
- } else {
- printk(KERN_ERR "irq %d: nobody cared (try booting with "
- "the \"irqpoll\" option)\n", irq);
+ /*
+ * Paired with mb in expect_irq() so that either they see
+ * timer pending cleared or irq_exp_intv() below sees
+ * IRQ_EXPECTING.
+ */
+ smp_mb();
+
+ /* take care of expects and watches */
+ for (act = desc->action; act; act = act->next) {
+ intv = min(irq_update_watch(desc, act, true), intv);
+ for (exp = act->expects; exp; exp = exp->next)
+ intv = min(irq_exp_intv(exp), intv);
}
- dump_stack();
- printk(KERN_ERR "handlers:\n");
- action = desc->action;
- while (action) {
- printk(KERN_ERR "[<%p>]", action->handler);
- print_symbol(" (%s)",
- (unsigned long)action->handler);
- printk("\n");
- action = action->next;
+ /* need to poll again? */
+ if (intv < MAX_JIFFY_OFFSET)
+ irq_schedule_poll(desc, intv);
+
+ raw_spin_unlock_irq(&desc->lock);
+
+ if (!reenable_irq)
+ return;
+
+ /* need to do locking dance for chip_bus_lock() to reenable IRQ */
- chip_bus_lock(desc->irq, desc);
++ chip_bus_lock(desc->irq_data.irq, desc);
+ raw_spin_lock_irq(&desc->lock);
+
+ /* make sure we haven't raced with anyone inbetween */
+ if (!spr->poll_rem && (desc->status & IRQ_SPURIOUS_DISABLED)) {
+ printk(KERN_INFO "IRQ %u: spurious polling finished, "
- "reenabling IRQ\n", desc->irq);
- __enable_irq(desc, desc->irq, false);
++ "reenabling IRQ\n", desc->irq_data.irq);
++ __enable_irq(desc, desc->irq_data.irq, false);
+ desc->status &= ~IRQ_SPURIOUS_DISABLED;
}
+
+ raw_spin_unlock_irq(&desc->lock);
- chip_bus_sync_unlock(desc->irq, desc);
++ chip_bus_sync_unlock(desc->irq_data.irq, desc);
}
- static void
- report_bad_irq(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret)
+ void irq_poll_action_added(struct irq_desc *desc, struct irqaction *action)
{
- static int count = 100;
+ struct irq_spr *spr = &desc->spr;
+ unsigned long flags;
- if (count > 0) {
- count--;
- __report_bad_irq(irq, desc, action_ret);
+ raw_spin_lock_irqsave(&desc->lock, flags);
+
+ if ((action->flags & IRQF_SHARED) && irqfixup >= IRQFIXUP_POLL) {
+ if (!spr->poll_rem)
+ printk(KERN_INFO "IRQ %u: starting IRQFIXUP_POLL\n",
- desc->irq);
++ desc->irq_data.irq);
+ spr->poll_rem = IRQ_SPR_POLL_CNT_INF;
+ irq_schedule_poll(desc, IRQ_POLL_INTV);
+ } else {
+ /* new irqaction registered, give the IRQ another chance */
+ irq_spr_reset(spr);
}
+
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
}
- static inline int
- try_misrouted_irq(unsigned int irq, struct irq_desc *desc,
- irqreturn_t action_ret)
+ void irq_poll_action_removed(struct irq_desc *desc, struct irqaction *action)
{
- struct irqaction *action;
+ bool irq_enabled = false, timer_killed = false;
+ struct irq_expect *exp, *next;
+ unsigned long flags;
+ int rc;
- if (!irqfixup)
- return 0;
+ raw_spin_lock_irqsave(&desc->lock, flags);
- /* We didn't actually handle the IRQ - see if it was misrouted? */
- if (action_ret == IRQ_NONE)
- return 1;
+ /* give the IRQ another chance */
+ if (irqfixup < IRQFIXUP_POLL)
+ irq_spr_reset(&desc->spr);
/*
- * But for 'irqfixup == 2' we also do it for handled interrupts if
- * they are marked as IRQF_IRQPOLL (or for irq zero, which is the
- * traditional PC timer interrupt.. Legacy)
+ * Make sure the timer is offline if no irqaction is left as
+ * the irq_desc will be reinitialized when the next irqaction
+ * is added; otherwise, the timer can be left alone. It will
+ * offline itself if no longer necessary.
*/
- if (irqfixup < 2)
- return 0;
-
- if (!irq)
- return 1;
+ while (!desc->action) {
+ rc = try_to_del_timer_sync(&desc->poll_timer);
+ if (rc >= 0) {
+ timer_killed = rc > 0;
+ break;
+ }
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+ cpu_relax();
+ raw_spin_lock_irqsave(&desc->lock, flags);
+ }
/*
- * Since we don't get the descriptor lock, "action" can
- * change under us. We don't really care, but we don't
- * want to follow a NULL pointer. So tell the compiler to
- * just load it once by using a barrier.
+ * If the timer was forcefully shut down, it might not have
+ * had the chance to reenable IRQ. Make sure it's enabled.
*/
- action = desc->action;
- barrier();
- return action && (action->flags & IRQF_IRQPOLL);
- }
-
- void note_interrupt(unsigned int irq, struct irq_desc *desc,
- irqreturn_t action_ret)
- {
- if (unlikely(action_ret != IRQ_HANDLED)) {
- /*
- * If we are seeing only the odd spurious IRQ caused by
- * bus asynchronicity then don't eventually trigger an error,
- * otherwise the counter becomes a doomsday timer for otherwise
- * working systems
- */
- if (time_after(jiffies, desc->last_unhandled + HZ/10))
- desc->irqs_unhandled = 1;
- else
- desc->irqs_unhandled++;
- desc->last_unhandled = jiffies;
- if (unlikely(action_ret != IRQ_NONE))
- report_bad_irq(irq, desc, action_ret);
+ if (timer_killed && (desc->status & IRQ_SPURIOUS_DISABLED)) {
- __enable_irq(desc, desc->irq, false);
++ __enable_irq(desc, desc->irq_data.irq, false);
+ desc->status &= ~IRQ_SPURIOUS_DISABLED;
+ irq_enabled = true;
}
- if (unlikely(try_misrouted_irq(irq, desc, action_ret))) {
- int ok = misrouted_irq(irq);
- if (action_ret == IRQ_NONE)
- desc->irqs_unhandled -= ok;
- }
-
- desc->irq_count++;
- if (likely(desc->irq_count < 100000))
- return;
+ if (timer_killed || irq_enabled)
- printk(KERN_INFO "IRQ %u:%s%s%s\n", desc->irq,
++ printk(KERN_INFO "IRQ %u:%s%s%s\n", desc->irq_data.irq,
+ timer_killed ? " polling stopped" : "",
+ timer_killed && irq_enabled ? " and" : "",
+ irq_enabled ? " IRQ reenabled" : "");
- desc->irq_count = 0;
- if (unlikely(desc->irqs_unhandled > 99900)) {
- /*
- * The interrupt is stuck
- */
- __report_bad_irq(irq, desc, action_ret);
- /*
- * Now kill the IRQ
- */
- printk(KERN_EMERG "Disabling IRQ #%d\n", irq);
- desc->status |= IRQ_DISABLED | IRQ_SPURIOUS_DISABLED;
- desc->depth++;
- desc->irq_data.chip->irq_disable(&desc->irq_data);
-
- mod_timer(&poll_spurious_irq_timer,
- jiffies + POLL_SPURIOUS_IRQ_INTERVAL);
+ /* free expect tokens */
+ for (exp = action->expects; exp; exp = next) {
+ next = exp->next;
+ kfree(exp);
}
- desc->irqs_unhandled = 0;
- }
+ action->expects = NULL;
- int noirqdebug __read_mostly;
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+ }
int noirqdebug_setup(char *str)
{
--
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