diff options
author | Otavio Salvador <otavio@ossystems.com.br> | 2019-12-19 00:14:33 -0300 |
---|---|---|
committer | GitHub <noreply@github.com> | 2019-12-19 00:14:33 -0300 |
commit | fa8a03bec68d9ef89da72277bd3501ed3daa6217 (patch) | |
tree | 3d3218332bcb34cb0afa01d6ad996058a3dbcb77 /drivers/iommu/iova.c | |
parent | 6b774eec1f9d3064e9b33634dfa99d5666d0a73a (diff) | |
parent | 1ddf624b0b268fdc0b80b1de618b98f8d117afea (diff) |
Merge pull request #55 from toradex/4.14-2.0.x-imx
4.14 2.0.x imx
Diffstat (limited to 'drivers/iommu/iova.c')
-rw-r--r-- | drivers/iommu/iova.c | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c index 33edfa794ae9..4edf65dbbcab 100644 --- a/drivers/iommu/iova.c +++ b/drivers/iommu/iova.c @@ -58,9 +58,14 @@ init_iova_domain(struct iova_domain *iovad, unsigned long granule, } EXPORT_SYMBOL_GPL(init_iova_domain); +bool has_iova_flush_queue(struct iova_domain *iovad) +{ + return !!iovad->fq; +} + static void free_iova_flush_queue(struct iova_domain *iovad) { - if (!iovad->fq) + if (!has_iova_flush_queue(iovad)) return; if (timer_pending(&iovad->fq_timer)) @@ -78,13 +83,14 @@ static void free_iova_flush_queue(struct iova_domain *iovad) int init_iova_flush_queue(struct iova_domain *iovad, iova_flush_cb flush_cb, iova_entry_dtor entry_dtor) { + struct iova_fq __percpu *queue; int cpu; atomic64_set(&iovad->fq_flush_start_cnt, 0); atomic64_set(&iovad->fq_flush_finish_cnt, 0); - iovad->fq = alloc_percpu(struct iova_fq); - if (!iovad->fq) + queue = alloc_percpu(struct iova_fq); + if (!queue) return -ENOMEM; iovad->flush_cb = flush_cb; @@ -93,13 +99,17 @@ int init_iova_flush_queue(struct iova_domain *iovad, for_each_possible_cpu(cpu) { struct iova_fq *fq; - fq = per_cpu_ptr(iovad->fq, cpu); + fq = per_cpu_ptr(queue, cpu); fq->head = 0; fq->tail = 0; spin_lock_init(&fq->lock); } + smp_wmb(); + + iovad->fq = queue; + setup_timer(&iovad->fq_timer, fq_flush_timeout, (unsigned long)iovad); atomic_set(&iovad->fq_timer_on, 0); @@ -597,7 +607,9 @@ void queue_iova(struct iova_domain *iovad, spin_unlock_irqrestore(&fq->lock, flags); - if (atomic_cmpxchg(&iovad->fq_timer_on, 0, 1) == 0) + /* Avoid false sharing as much as possible. */ + if (!atomic_read(&iovad->fq_timer_on) && + !atomic_cmpxchg(&iovad->fq_timer_on, 0, 1)) mod_timer(&iovad->fq_timer, jiffies + msecs_to_jiffies(IOVA_FQ_TIMEOUT)); |