Commit 9a005a80 authored by Joerg Roedel's avatar Joerg Roedel
Browse files

iommu/iova: Add flush timer 



Add a timer to flush entries from the Flush-Queues every
10ms. This makes sure that no stale TLB entries remain for
too long after an IOVA has been unmapped.

Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 8109c2a2

drivers/iommu/iova.c

+32 −0
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ static unsigned long iova_rcache_get(struct iova_domain *iovad, 
static void init_iova_rcaches(struct iova_domain *iovad);

static void free_iova_rcaches(struct iova_domain *iovad);

static void fq_destroy_all_entries(struct iova_domain *iovad);

static void fq_flush_timeout(unsigned long data);



void

init_iova_domain(struct iova_domain *iovad, unsigned long granule,
@@ -62,7 +63,11 @@ static void free_iova_flush_queue(struct iova_domain *iovad) 
	if (!iovad->fq)

		return;



	if (timer_pending(&iovad->fq_timer))

		del_timer(&iovad->fq_timer);



	fq_destroy_all_entries(iovad);



	free_percpu(iovad->fq);



	iovad->fq         = NULL;
@@ -95,6 +100,9 @@ int init_iova_flush_queue(struct iova_domain *iovad, 
		spin_lock_init(&fq->lock);

	}



	setup_timer(&iovad->fq_timer, fq_flush_timeout, (unsigned long)iovad);

	atomic_set(&iovad->fq_timer_on, 0);



	return 0;

}

EXPORT_SYMBOL_GPL(init_iova_flush_queue);
@@ -539,6 +547,25 @@ static void fq_destroy_all_entries(struct iova_domain *iovad) 
	}

}



static void fq_flush_timeout(unsigned long data)

{

	struct iova_domain *iovad = (struct iova_domain *)data;

	int cpu;



	atomic_set(&iovad->fq_timer_on, 0);

	iova_domain_flush(iovad);



	for_each_possible_cpu(cpu) {

		unsigned long flags;

		struct iova_fq *fq;



		fq = per_cpu_ptr(iovad->fq, cpu);

		spin_lock_irqsave(&fq->lock, flags);

		fq_ring_free(iovad, fq);

		spin_unlock_irqrestore(&fq->lock, flags);

	}

}



void queue_iova(struct iova_domain *iovad,

		unsigned long pfn, unsigned long pages,

		unsigned long data)
@@ -569,6 +596,11 @@ void queue_iova(struct iova_domain *iovad, 
	fq->entries[idx].counter  = atomic64_read(&iovad->fq_flush_start_cnt);



	spin_unlock_irqrestore(&fq->lock, flags);



	if (atomic_cmpxchg(&iovad->fq_timer_on, 0, 1) == 0)

		mod_timer(&iovad->fq_timer,

			  jiffies + msecs_to_jiffies(IOVA_FQ_TIMEOUT));



	put_cpu_ptr(iovad->fq);

}

EXPORT_SYMBOL_GPL(queue_iova);

include/linux/iova.h

+8 −0
Original line number Diff line number Diff line
@@ -48,6 +48,9 @@ typedef void (* iova_entry_dtor)(unsigned long data); 
/* Number of entries per Flush Queue */

#define IOVA_FQ_SIZE	256



/* Timeout (in ms) after which entries are flushed from the Flush-Queue */

#define IOVA_FQ_TIMEOUT	10



/* Flush Queue entry for defered flushing */

struct iova_fq_entry {

	unsigned long iova_pfn;
@@ -86,6 +89,11 @@ struct iova_domain { 


	atomic64_t	fq_flush_finish_cnt;	/* Number of TLB flushes that

						   have been finished */



	struct timer_list fq_timer;		/* Timer to regularily empty the

						   flush-queues */

	atomic_t fq_timer_on;			/* 1 when timer is active, 0

						   when not */

};



static inline unsigned long iova_size(struct iova *iova)