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Commit 59120e06 authored by Mika Westerberg's avatar Mika Westerberg Committed by David S. Miller
Browse files

thunderbolt: Use spinlock in NHI serialization 



This is needed because ring polling functionality can be called from
atomic contexts when networking and other high-speed traffic is
transferred over a Thunderbolt cable.

Signed-off-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: default avatarMichael Jamet <michael.jamet@intel.com>
Reviewed-by: default avatarYehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 22b7de10

drivers/thunderbolt/nhi.c

+41 −34
Original line number Diff line number Diff line
@@ -327,21 +327,9 @@ static struct tb_ring *tb_ring_alloc(struct tb_nhi *nhi, u32 hop, int size, 
	if (transmit && hop == RING_E2E_UNUSED_HOPID)

		return NULL;



	mutex_lock(&nhi->lock);

	if (hop >= nhi->hop_count) {

		dev_WARN(&nhi->pdev->dev, "invalid hop: %d\n", hop);

		goto err;

	}

	if (transmit && nhi->tx_rings[hop]) {

		dev_WARN(&nhi->pdev->dev, "TX hop %d already allocated\n", hop);

		goto err;

	} else if (!transmit && nhi->rx_rings[hop]) {

		dev_WARN(&nhi->pdev->dev, "RX hop %d already allocated\n", hop);

		goto err;

	}

	ring = kzalloc(sizeof(*ring), GFP_KERNEL);

	if (!ring)

		goto err;

		return NULL;



	spin_lock_init(&ring->lock);

	INIT_LIST_HEAD(&ring->queue);
@@ -359,25 +347,45 @@ static struct tb_ring *tb_ring_alloc(struct tb_nhi *nhi, u32 hop, int size, 
	ring->tail = 0;

	ring->running = false;



	if (ring_request_msix(ring, flags & RING_FLAG_NO_SUSPEND))

		goto err;



	ring->descriptors = dma_alloc_coherent(&ring->nhi->pdev->dev,

			size * sizeof(*ring->descriptors),

			&ring->descriptors_dma, GFP_KERNEL | __GFP_ZERO);

	if (!ring->descriptors)

		goto err;

		goto err_free_ring;



	if (ring_request_msix(ring, flags & RING_FLAG_NO_SUSPEND))

		goto err_free_descs;



	spin_lock_irq(&nhi->lock);

	if (hop >= nhi->hop_count) {

		dev_WARN(&nhi->pdev->dev, "invalid hop: %d\n", hop);

		goto err_release_msix;

	}

	if (transmit && nhi->tx_rings[hop]) {

		dev_WARN(&nhi->pdev->dev, "TX hop %d already allocated\n", hop);

		goto err_release_msix;

	} else if (!transmit && nhi->rx_rings[hop]) {

		dev_WARN(&nhi->pdev->dev, "RX hop %d already allocated\n", hop);

		goto err_release_msix;

	}

	if (transmit)

		nhi->tx_rings[hop] = ring;

	else

		nhi->rx_rings[hop] = ring;

	mutex_unlock(&nhi->lock);

	spin_unlock_irq(&nhi->lock);



	return ring;



err:

err_release_msix:

	spin_unlock_irq(&nhi->lock);

	ring_release_msix(ring);

err_free_descs:

	dma_free_coherent(&ring->nhi->pdev->dev,

			  ring->size * sizeof(*ring->descriptors),

			  ring->descriptors, ring->descriptors_dma);

err_free_ring:

	kfree(ring);

	mutex_unlock(&nhi->lock);



	return NULL;

}
@@ -421,8 +429,8 @@ void tb_ring_start(struct tb_ring *ring) 
	u16 frame_size;

	u32 flags;



	mutex_lock(&ring->nhi->lock);

	spin_lock_irq(&ring->lock);

	spin_lock_irq(&ring->nhi->lock);

	spin_lock(&ring->lock);

	if (ring->nhi->going_away)

		goto err;

	if (ring->running) {
@@ -469,8 +477,8 @@ void tb_ring_start(struct tb_ring *ring) 
	ring_interrupt_active(ring, true);

	ring->running = true;

err:

	spin_unlock_irq(&ring->lock);

	mutex_unlock(&ring->nhi->lock);

	spin_unlock(&ring->lock);

	spin_unlock_irq(&ring->nhi->lock);

}

EXPORT_SYMBOL_GPL(tb_ring_start);
@@ -489,8 +497,8 @@ EXPORT_SYMBOL_GPL(tb_ring_start); 
 */

void tb_ring_stop(struct tb_ring *ring)

{

	mutex_lock(&ring->nhi->lock);

	spin_lock_irq(&ring->lock);

	spin_lock_irq(&ring->nhi->lock);

	spin_lock(&ring->lock);

	dev_info(&ring->nhi->pdev->dev, "stopping %s %d\n",

		 RING_TYPE(ring), ring->hop);

	if (ring->nhi->going_away)
@@ -511,8 +519,8 @@ void tb_ring_stop(struct tb_ring *ring) 
	ring->running = false;



err:

	spin_unlock_irq(&ring->lock);

	mutex_unlock(&ring->nhi->lock);

	spin_unlock(&ring->lock);

	spin_unlock_irq(&ring->nhi->lock);



	/*

	 * schedule ring->work to invoke callbacks on all remaining frames.
@@ -534,7 +542,7 @@ EXPORT_SYMBOL_GPL(tb_ring_stop); 
 */

void tb_ring_free(struct tb_ring *ring)

{

	mutex_lock(&ring->nhi->lock);

	spin_lock_irq(&ring->nhi->lock);

	/*

	 * Dissociate the ring from the NHI. This also ensures that

	 * nhi_interrupt_work cannot reschedule ring->work.
@@ -564,7 +572,7 @@ void tb_ring_free(struct tb_ring *ring) 
		 RING_TYPE(ring),

		 ring->hop);



	mutex_unlock(&ring->nhi->lock);

	spin_unlock_irq(&ring->nhi->lock);

	/**

	 * ring->work can no longer be scheduled (it is scheduled only

	 * by nhi_interrupt_work, ring_stop and ring_msix). Wait for it
@@ -639,7 +647,7 @@ static void nhi_interrupt_work(struct work_struct *work) 
	int type = 0; /* current interrupt type 0: TX, 1: RX, 2: RX overflow */

	struct tb_ring *ring;



	mutex_lock(&nhi->lock);

	spin_lock_irq(&nhi->lock);



	/*

	 * Starting at REG_RING_NOTIFY_BASE there are three status bitfields
@@ -677,7 +685,7 @@ static void nhi_interrupt_work(struct work_struct *work) 
		/* we do not check ring->running, this is done in ring->work */

		schedule_work(&ring->work);

	}

	mutex_unlock(&nhi->lock);

	spin_unlock_irq(&nhi->lock);

}



static irqreturn_t nhi_msi(int irq, void *data)
@@ -767,7 +775,6 @@ static void nhi_shutdown(struct tb_nhi *nhi) 
		devm_free_irq(&nhi->pdev->dev, nhi->pdev->irq, nhi);

		flush_work(&nhi->interrupt_work);

	}

	mutex_destroy(&nhi->lock);

	ida_destroy(&nhi->msix_ida);

}
@@ -856,7 +863,7 @@ static int nhi_probe(struct pci_dev *pdev, const struct pci_device_id *id) 
		return res;

	}



	mutex_init(&nhi->lock);

	spin_lock_init(&nhi->lock);



	pci_set_master(pdev);

include/linux/thunderbolt.h

+1 −1
Original line number Diff line number Diff line
@@ -415,7 +415,7 @@ static inline struct tb_xdomain *tb_service_parent(struct tb_service *svc) 
 * @hop_count: Number of rings (end point hops) supported by NHI.

 */

struct tb_nhi {

	struct mutex lock;

	spinlock_t lock;

	struct pci_dev *pdev;

	void __iomem *iobase;

	struct tb_ring **tx_rings;