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Commit 1ddc6dd8 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'for-linus-4.2-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip 

Pull xen bug fixes from David Vrabel:

 - don't lose interrupts when offlining CPUs

 - fix gntdev oops during unmap

 - drop the balloon lock occasionally to allow domain create/destroy

* tag 'for-linus-4.2-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/events/fifo: Handle linked events when closing a port
  xen: release lock occasionally during ballooning
  xen/gntdevt: Fix race condition in gntdev_release()
parents ed8bbba0 fcdf31a7

drivers/xen/balloon.c

+7 −8
Original line number Diff line number Diff line
@@ -472,7 +472,7 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp) 
}



/*

 * We avoid multiple worker processes conflicting via the balloon mutex.

 * As this is a work item it is guaranteed to run as a single instance only.

 * We may of course race updates of the target counts (which are protected

 * by the balloon lock), or with changes to the Xen hard limit, but we will

 * recover from these in time.
@@ -482,9 +482,10 @@ static void balloon_process(struct work_struct *work) 
	enum bp_state state = BP_DONE;

	long credit;



	mutex_lock(&balloon_mutex);



	do {

		mutex_lock(&balloon_mutex);



		credit = current_credit();



		if (credit > 0) {
@@ -499,17 +500,15 @@ static void balloon_process(struct work_struct *work) 


		state = update_schedule(state);



#ifndef CONFIG_PREEMPT

		if (need_resched())

			schedule();

#endif

		mutex_unlock(&balloon_mutex);



		cond_resched();



	} while (credit && state == BP_DONE);



	/* Schedule more work if there is some still to be done. */

	if (state == BP_EAGAIN)

		schedule_delayed_work(&balloon_worker, balloon_stats.schedule_delay * HZ);



	mutex_unlock(&balloon_mutex);

}



/* Resets the Xen limit, sets new target, and kicks off processing. */

drivers/xen/events/events_base.c

+6 −4
Original line number Diff line number Diff line
@@ -452,10 +452,12 @@ static void xen_free_irq(unsigned irq) 
	irq_free_desc(irq);

}



static void xen_evtchn_close(unsigned int port)

static void xen_evtchn_close(unsigned int port, unsigned int cpu)

{

	struct evtchn_close close;



	xen_evtchn_op_close(port, cpu);



	close.port = port;

	if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)

		BUG();
@@ -544,7 +546,7 @@ static unsigned int __startup_pirq(unsigned int irq) 


err:

	pr_err("irq%d: Failed to set port to irq mapping (%d)\n", irq, rc);

	xen_evtchn_close(evtchn);

	xen_evtchn_close(evtchn, NR_CPUS);

	return 0;

}
@@ -565,7 +567,7 @@ static void shutdown_pirq(struct irq_data *data) 
		return;



	mask_evtchn(evtchn);

	xen_evtchn_close(evtchn);

	xen_evtchn_close(evtchn, cpu_from_evtchn(evtchn));

	xen_irq_info_cleanup(info);

}
@@ -609,7 +611,7 @@ static void __unbind_from_irq(unsigned int irq) 
	if (VALID_EVTCHN(evtchn)) {

		unsigned int cpu = cpu_from_irq(irq);



		xen_evtchn_close(evtchn);

		xen_evtchn_close(evtchn, cpu);



		switch (type_from_irq(irq)) {

		case IRQT_VIRQ:

drivers/xen/events/events_fifo.c

+40 −5
Original line number Diff line number Diff line
@@ -255,6 +255,12 @@ static void evtchn_fifo_unmask(unsigned port) 
	}

}



static bool evtchn_fifo_is_linked(unsigned port)

{

	event_word_t *word = event_word_from_port(port);

	return sync_test_bit(EVTCHN_FIFO_BIT(LINKED, word), BM(word));

}



static uint32_t clear_linked(volatile event_word_t *word)

{

	event_word_t new, old, w;
@@ -281,7 +287,8 @@ static void handle_irq_for_port(unsigned port) 


static void consume_one_event(unsigned cpu,

			      struct evtchn_fifo_control_block *control_block,

			      unsigned priority, unsigned long *ready)

			      unsigned priority, unsigned long *ready,

			      bool drop)

{

	struct evtchn_fifo_queue *q = &per_cpu(cpu_queue, cpu);

	uint32_t head;
@@ -313,13 +320,15 @@ static void consume_one_event(unsigned cpu, 
	if (head == 0)

		clear_bit(priority, ready);



	if (evtchn_fifo_is_pending(port) && !evtchn_fifo_is_masked(port))

	if (evtchn_fifo_is_pending(port) && !evtchn_fifo_is_masked(port)) {

		if (likely(!drop))

			handle_irq_for_port(port);

	}



	q->head[priority] = head;

}



static void evtchn_fifo_handle_events(unsigned cpu)

static void __evtchn_fifo_handle_events(unsigned cpu, bool drop)

{

	struct evtchn_fifo_control_block *control_block;

	unsigned long ready;
@@ -331,11 +340,16 @@ static void evtchn_fifo_handle_events(unsigned cpu) 


	while (ready) {

		q = find_first_bit(&ready, EVTCHN_FIFO_MAX_QUEUES);

		consume_one_event(cpu, control_block, q, &ready);

		consume_one_event(cpu, control_block, q, &ready, drop);

		ready |= xchg(&control_block->ready, 0);

	}

}



static void evtchn_fifo_handle_events(unsigned cpu)

{

	__evtchn_fifo_handle_events(cpu, false);

}



static void evtchn_fifo_resume(void)

{

	unsigned cpu;
@@ -371,6 +385,26 @@ static void evtchn_fifo_resume(void) 
	event_array_pages = 0;

}



static void evtchn_fifo_close(unsigned port, unsigned int cpu)

{

	if (cpu == NR_CPUS)

		return;



	get_online_cpus();

	if (cpu_online(cpu)) {

		if (WARN_ON(irqs_disabled()))

			goto out;



		while (evtchn_fifo_is_linked(port))

			cpu_relax();

	} else {

		__evtchn_fifo_handle_events(cpu, true);

	}



out:

	put_online_cpus();

}



static const struct evtchn_ops evtchn_ops_fifo = {

	.max_channels      = evtchn_fifo_max_channels,

	.nr_channels       = evtchn_fifo_nr_channels,
@@ -384,6 +418,7 @@ static const struct evtchn_ops evtchn_ops_fifo = { 
	.unmask            = evtchn_fifo_unmask,

	.handle_events     = evtchn_fifo_handle_events,

	.resume            = evtchn_fifo_resume,

	.close             = evtchn_fifo_close,

};



static int evtchn_fifo_alloc_control_block(unsigned cpu)

drivers/xen/events/events_internal.h

+7 −0
Original line number Diff line number Diff line
@@ -68,6 +68,7 @@ struct evtchn_ops { 
	bool (*test_and_set_mask)(unsigned port);

	void (*mask)(unsigned port);

	void (*unmask)(unsigned port);

	void (*close)(unsigned port, unsigned cpu);



	void (*handle_events)(unsigned cpu);

	void (*resume)(void);
@@ -145,6 +146,12 @@ static inline void xen_evtchn_resume(void) 
		evtchn_ops->resume();

}



static inline void xen_evtchn_op_close(unsigned port, unsigned cpu)

{

	if (evtchn_ops->close)

		return evtchn_ops->close(port, cpu);

}



void xen_evtchn_2l_init(void);

int xen_evtchn_fifo_init(void);

drivers/xen/gntdev.c

+2 −0
Original line number Diff line number Diff line
@@ -568,12 +568,14 @@ static int gntdev_release(struct inode *inode, struct file *flip) 


	pr_debug("priv %p\n", priv);



	mutex_lock(&priv->lock);

	while (!list_empty(&priv->maps)) {

		map = list_entry(priv->maps.next, struct grant_map, next);

		list_del(&map->next);

		gntdev_put_map(NULL /* already removed */, map);

	}

	WARN_ON(!list_empty(&priv->freeable_maps));

	mutex_unlock(&priv->lock);



	if (use_ptemod)

		mmu_notifier_unregister(&priv->mn, priv->mm);