From 22b7de1000e66d739c431d6be4e7e97c69fa7c98 Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Mon, 2 Oct 2017 13:38:39 +0300 Subject: thunderbolt: Use spinlock in ring serialization This makes it possible to enqueue frames also from atomic context which is needed for example, when networking packets are sent over a Thunderbolt cable. Signed-off-by: Mika Westerberg Reviewed-by: Michael Jamet Reviewed-by: Yehezkel Bernat Reviewed-by: Andy Shevchenko Signed-off-by: David S. Miller --- drivers/thunderbolt/nhi.c | 26 ++++++++++++++------------ 1 file changed, 14 insertions(+), 12 deletions(-) (limited to 'drivers/thunderbolt/nhi.c') diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c index e0a47f7581cb..7d1891ec3c47 100644 --- a/drivers/thunderbolt/nhi.c +++ b/drivers/thunderbolt/nhi.c @@ -212,8 +212,10 @@ static void ring_work(struct work_struct *work) struct tb_ring *ring = container_of(work, typeof(*ring), work); struct ring_frame *frame; bool canceled = false; + unsigned long flags; LIST_HEAD(done); - mutex_lock(&ring->lock); + + spin_lock_irqsave(&ring->lock, flags); if (!ring->running) { /* Move all frames to done and mark them as canceled. */ @@ -241,7 +243,8 @@ static void ring_work(struct work_struct *work) ring_write_descriptors(ring); invoke_callback: - mutex_unlock(&ring->lock); /* allow callbacks to schedule new work */ + /* allow callbacks to schedule new work */ + spin_unlock_irqrestore(&ring->lock, flags); while (!list_empty(&done)) { frame = list_first_entry(&done, typeof(*frame), list); /* @@ -255,15 +258,17 @@ invoke_callback: int __tb_ring_enqueue(struct tb_ring *ring, struct ring_frame *frame) { + unsigned long flags; int ret = 0; - mutex_lock(&ring->lock); + + spin_lock_irqsave(&ring->lock, flags); if (ring->running) { list_add_tail(&frame->list, &ring->queue); ring_write_descriptors(ring); } else { ret = -ESHUTDOWN; } - mutex_unlock(&ring->lock); + spin_unlock_irqrestore(&ring->lock, flags); return ret; } EXPORT_SYMBOL_GPL(__tb_ring_enqueue); @@ -338,7 +343,7 @@ static struct tb_ring *tb_ring_alloc(struct tb_nhi *nhi, u32 hop, int size, if (!ring) goto err; - mutex_init(&ring->lock); + spin_lock_init(&ring->lock); INIT_LIST_HEAD(&ring->queue); INIT_LIST_HEAD(&ring->in_flight); INIT_WORK(&ring->work, ring_work); @@ -371,8 +376,6 @@ static struct tb_ring *tb_ring_alloc(struct tb_nhi *nhi, u32 hop, int size, return ring; err: - if (ring) - mutex_destroy(&ring->lock); kfree(ring); mutex_unlock(&nhi->lock); return NULL; @@ -419,7 +422,7 @@ void tb_ring_start(struct tb_ring *ring) u32 flags; mutex_lock(&ring->nhi->lock); - mutex_lock(&ring->lock); + spin_lock_irq(&ring->lock); if (ring->nhi->going_away) goto err; if (ring->running) { @@ -466,7 +469,7 @@ void tb_ring_start(struct tb_ring *ring) ring_interrupt_active(ring, true); ring->running = true; err: - mutex_unlock(&ring->lock); + spin_unlock_irq(&ring->lock); mutex_unlock(&ring->nhi->lock); } EXPORT_SYMBOL_GPL(tb_ring_start); @@ -487,7 +490,7 @@ EXPORT_SYMBOL_GPL(tb_ring_start); void tb_ring_stop(struct tb_ring *ring) { mutex_lock(&ring->nhi->lock); - mutex_lock(&ring->lock); + spin_lock_irq(&ring->lock); dev_info(&ring->nhi->pdev->dev, "stopping %s %d\n", RING_TYPE(ring), ring->hop); if (ring->nhi->going_away) @@ -508,7 +511,7 @@ void tb_ring_stop(struct tb_ring *ring) ring->running = false; err: - mutex_unlock(&ring->lock); + spin_unlock_irq(&ring->lock); mutex_unlock(&ring->nhi->lock); /* @@ -568,7 +571,6 @@ void tb_ring_free(struct tb_ring *ring) * to finish before freeing the ring. */ flush_work(&ring->work); - mutex_destroy(&ring->lock); kfree(ring); } EXPORT_SYMBOL_GPL(tb_ring_free); -- cgit v1.2.3