diff options
Diffstat (limited to 'drivers/iommu/iova.c')
| -rw-r--r-- | drivers/iommu/iova.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c index 246f14c83944..33edfa794ae9 100644 --- a/drivers/iommu/iova.c +++ b/drivers/iommu/iova.c @@ -32,6 +32,8 @@ static unsigned long iova_rcache_get(struct iova_domain *iovad, unsigned long limit_pfn); 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, @@ -50,10 +52,61 @@ init_iova_domain(struct iova_domain *iovad, unsigned long granule, iovad->granule = granule; iovad->start_pfn = start_pfn; iovad->dma_32bit_pfn = pfn_32bit + 1; + iovad->flush_cb = NULL; + iovad->fq = NULL; init_iova_rcaches(iovad); } EXPORT_SYMBOL_GPL(init_iova_domain); +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; + iovad->flush_cb = NULL; + iovad->entry_dtor = NULL; +} + +int init_iova_flush_queue(struct iova_domain *iovad, + iova_flush_cb flush_cb, iova_entry_dtor entry_dtor) +{ + 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) + return -ENOMEM; + + iovad->flush_cb = flush_cb; + iovad->entry_dtor = entry_dtor; + + for_each_possible_cpu(cpu) { + struct iova_fq *fq; + + fq = per_cpu_ptr(iovad->fq, cpu); + fq->head = 0; + fq->tail = 0; + + 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); + static struct rb_node * __get_cached_rbnode(struct iova_domain *iovad, unsigned long *limit_pfn) { @@ -423,6 +476,135 @@ free_iova_fast(struct iova_domain *iovad, unsigned long pfn, unsigned long size) } EXPORT_SYMBOL_GPL(free_iova_fast); +#define fq_ring_for_each(i, fq) \ + for ((i) = (fq)->head; (i) != (fq)->tail; (i) = ((i) + 1) % IOVA_FQ_SIZE) + +static inline bool fq_full(struct iova_fq *fq) +{ + assert_spin_locked(&fq->lock); + return (((fq->tail + 1) % IOVA_FQ_SIZE) == fq->head); +} + +static inline unsigned fq_ring_add(struct iova_fq *fq) +{ + unsigned idx = fq->tail; + + assert_spin_locked(&fq->lock); + + fq->tail = (idx + 1) % IOVA_FQ_SIZE; + + return idx; +} + +static void fq_ring_free(struct iova_domain *iovad, struct iova_fq *fq) +{ + u64 counter = atomic64_read(&iovad->fq_flush_finish_cnt); + unsigned idx; + + assert_spin_locked(&fq->lock); + + fq_ring_for_each(idx, fq) { + + if (fq->entries[idx].counter >= counter) + break; + + if (iovad->entry_dtor) + iovad->entry_dtor(fq->entries[idx].data); + + free_iova_fast(iovad, + fq->entries[idx].iova_pfn, + fq->entries[idx].pages); + + fq->head = (fq->head + 1) % IOVA_FQ_SIZE; + } +} + +static void iova_domain_flush(struct iova_domain *iovad) +{ + atomic64_inc(&iovad->fq_flush_start_cnt); + iovad->flush_cb(iovad); + atomic64_inc(&iovad->fq_flush_finish_cnt); +} + +static void fq_destroy_all_entries(struct iova_domain *iovad) +{ + int cpu; + + /* + * This code runs when the iova_domain is being detroyed, so don't + * bother to free iovas, just call the entry_dtor on all remaining + * entries. + */ + if (!iovad->entry_dtor) + return; + + for_each_possible_cpu(cpu) { + struct iova_fq *fq = per_cpu_ptr(iovad->fq, cpu); + int idx; + + fq_ring_for_each(idx, fq) + iovad->entry_dtor(fq->entries[idx].data); + } +} + +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) +{ + struct iova_fq *fq = get_cpu_ptr(iovad->fq); + unsigned long flags; + unsigned idx; + + spin_lock_irqsave(&fq->lock, flags); + + /* + * First remove all entries from the flush queue that have already been + * flushed out on another CPU. This makes the fq_full() check below less + * likely to be true. + */ + fq_ring_free(iovad, fq); + + if (fq_full(fq)) { + iova_domain_flush(iovad); + fq_ring_free(iovad, fq); + } + + idx = fq_ring_add(fq); + + fq->entries[idx].iova_pfn = pfn; + fq->entries[idx].pages = pages; + fq->entries[idx].data = data; + 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); + /** * put_iova_domain - destroys the iova doamin * @iovad: - iova domain in question. @@ -433,6 +615,7 @@ void put_iova_domain(struct iova_domain *iovad) struct rb_node *node; unsigned long flags; + free_iova_flush_queue(iovad); free_iova_rcaches(iovad); spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); node = rb_first(&iovad->rbroot); |