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Commit e277d2fc authored by Yu Zhao's avatar Yu Zhao Committed by David Woodhouse
Browse files

PCI: handle Virtual Function ATS enabling 



The SR-IOV spec requires that the Smallest Translation Unit and
the Invalidate Queue Depth fields in the Virtual Function ATS
capability are hardwired to 0. If a function is a Virtual Function,
then and set its Physical Function's STU before enabling the ATS.

Signed-off-by: default avatarYu Zhao <yu.zhao@intel.com>
Acked-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent 302b4215

drivers/pci/iov.c

+52 −14
Original line number Diff line number Diff line
@@ -491,10 +491,10 @@ static int sriov_init(struct pci_dev *dev, int pos) 


	if (pdev)

		iov->dev = pci_dev_get(pdev);

	else {

	else

		iov->dev = dev;



	mutex_init(&iov->lock);

	}



	dev->sriov = iov;

	dev->is_physfn = 1;
@@ -514,11 +514,11 @@ static void sriov_release(struct pci_dev *dev) 
{

	BUG_ON(dev->sriov->nr_virtfn);



	if (dev == dev->sriov->dev)

		mutex_destroy(&dev->sriov->lock);

	else

	if (dev != dev->sriov->dev)

		pci_dev_put(dev->sriov->dev);



	mutex_destroy(&dev->sriov->lock);



	kfree(dev->sriov);

	dev->sriov = NULL;

}
@@ -723,19 +723,40 @@ int pci_enable_ats(struct pci_dev *dev, int ps) 
	int rc;

	u16 ctrl;



	BUG_ON(dev->ats);

	BUG_ON(dev->ats && dev->ats->is_enabled);



	if (ps < PCI_ATS_MIN_STU)

		return -EINVAL;



	if (dev->is_physfn || dev->is_virtfn) {

		struct pci_dev *pdev = dev->is_physfn ? dev : dev->physfn;



		mutex_lock(&pdev->sriov->lock);

		if (pdev->ats)

			rc = pdev->ats->stu == ps ? 0 : -EINVAL;

		else

			rc = ats_alloc_one(pdev, ps);



		if (!rc)

			pdev->ats->ref_cnt++;

		mutex_unlock(&pdev->sriov->lock);

		if (rc)

			return rc;

	}



	if (!dev->is_physfn) {

		rc = ats_alloc_one(dev, ps);

		if (rc)

			return rc;

	}



	ctrl = PCI_ATS_CTRL_ENABLE;

	if (!dev->is_virtfn)

		ctrl |= PCI_ATS_CTRL_STU(ps - PCI_ATS_MIN_STU);

	pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl);



	dev->ats->is_enabled = 1;



	return 0;

}
@@ -747,12 +768,25 @@ void pci_disable_ats(struct pci_dev *dev) 
{

	u16 ctrl;



	BUG_ON(!dev->ats);

	BUG_ON(!dev->ats || !dev->ats->is_enabled);



	pci_read_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, &ctrl);

	ctrl &= ~PCI_ATS_CTRL_ENABLE;

	pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl);



	dev->ats->is_enabled = 0;



	if (dev->is_physfn || dev->is_virtfn) {

		struct pci_dev *pdev = dev->is_physfn ? dev : dev->physfn;



		mutex_lock(&pdev->sriov->lock);

		pdev->ats->ref_cnt--;

		if (!pdev->ats->ref_cnt)

			ats_free_one(pdev);

		mutex_unlock(&pdev->sriov->lock);

	}



	if (!dev->is_physfn)

		ats_free_one(dev);

}
@@ -765,13 +799,17 @@ void pci_disable_ats(struct pci_dev *dev) 
 * The ATS spec uses 0 in the Invalidate Queue Depth field to

 * indicate that the function can accept 32 Invalidate Request.

 * But here we use the `real' values (i.e. 1~32) for the Queue

 * Depth.

 * Depth; and 0 indicates the function shares the Queue with

 * other functions (doesn't exclusively own a Queue).

 */

int pci_ats_queue_depth(struct pci_dev *dev)

{

	int pos;

	u16 cap;



	if (dev->is_virtfn)

		return 0;



	if (dev->ats)

		return dev->ats->qdep;

drivers/pci/pci.h

+3 −1
Original line number Diff line number Diff line
@@ -234,6 +234,8 @@ struct pci_ats { 
	int pos;	/* capability position */

	int stu;	/* Smallest Translation Unit */

	int qdep;	/* Invalidate Queue Depth */

	int ref_cnt;	/* Physical Function reference count */

	int is_enabled:1;	/* Enable bit is set */

};



#ifdef CONFIG_PCI_IOV
@@ -255,7 +257,7 @@ extern int pci_ats_queue_depth(struct pci_dev *dev); 
 */

static inline int pci_ats_enabled(struct pci_dev *dev)

{

	return !!dev->ats;

	return dev->ats && dev->ats->is_enabled;

}

#else

static inline int pci_iov_init(struct pci_dev *dev)