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: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Joerg Roedel 2017-08-10 16:58:18 +02:00
parent 8109c2a2f8
commit 9a005a800a
2 changed files with 40 additions and 0 deletions

View File

@ -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);

View File

@ -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)