Commit f6c0bfce authored by Joerg Roedel's avatar Joerg Roedel
Browse files

iommu/amd: Take domain->lock for complete attach/detach path 



The code-paths before __attach_device() and __detach_device() are called
also access and modify domain state, so take the domain lock there too.
This allows to get rid of the __detach_device() function.

Fixes: 92d420ec ("iommu/amd: Relax locking in dma_ops path")
Reviewed-by: default avatarFilippo Sironi <sironi@amazon.de>
Reviewed-by: default avatarJerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 3a11905b

drivers/iommu/amd_iommu.c

+26 −39
Original line number Diff line number Diff line
@@ -2079,27 +2079,13 @@ static void do_detach(struct iommu_dev_data *dev_data) 
static int __attach_device(struct iommu_dev_data *dev_data,

			   struct protection_domain *domain)

{

	unsigned long flags;

	int ret;



	/* lock domain */

	spin_lock_irqsave(&domain->lock, flags);



	ret = -EBUSY;

	if (dev_data->domain != NULL)

		goto out_unlock;

		return -EBUSY;



	/* Attach alias group root */

	do_attach(dev_data, domain);



	ret = 0;



out_unlock:



	/* ready */

	spin_unlock_irqrestore(&domain->lock, flags);



	return ret;

	return 0;

}
@@ -2181,8 +2167,11 @@ static int attach_device(struct device *dev, 
{

	struct pci_dev *pdev;

	struct iommu_dev_data *dev_data;

	unsigned long flags;

	int ret;



	spin_lock_irqsave(&domain->lock, flags);



	dev_data = get_dev_data(dev);



	if (!dev_is_pci(dev))
@@ -2190,12 +2179,13 @@ static int attach_device(struct device *dev, 


	pdev = to_pci_dev(dev);

	if (domain->flags & PD_IOMMUV2_MASK) {

		ret = -EINVAL;

		if (!dev_data->passthrough)

			return -EINVAL;

			goto out;



		if (dev_data->iommu_v2) {

			if (pdev_iommuv2_enable(pdev) != 0)

				return -EINVAL;

				goto out;



			dev_data->ats.enabled = true;

			dev_data->ats.qdep    = pci_ats_queue_depth(pdev);
@@ -2219,24 +2209,10 @@ skip_ats_check: 


	domain_flush_complete(domain);



	return ret;

}



/*

 * Removes a device from a protection domain (unlocked)

 */

static void __detach_device(struct iommu_dev_data *dev_data)

{

	struct protection_domain *domain;

	unsigned long flags;



	domain = dev_data->domain;



	spin_lock_irqsave(&domain->lock, flags);



	do_detach(dev_data);



out:

	spin_unlock_irqrestore(&domain->lock, flags);



	return ret;

}



/*
@@ -2246,10 +2222,13 @@ static void detach_device(struct device *dev) 
{

	struct protection_domain *domain;

	struct iommu_dev_data *dev_data;

	unsigned long flags;



	dev_data = get_dev_data(dev);

	domain   = dev_data->domain;



	spin_lock_irqsave(&domain->lock, flags);



	/*

	 * First check if the device is still attached. It might already

	 * be detached from its domain because the generic
@@ -2257,12 +2236,12 @@ static void detach_device(struct device *dev) 
	 * our alias handling.

	 */

	if (WARN_ON(!dev_data->domain))

		return;

		goto out;



	__detach_device(dev_data);

	do_detach(dev_data);



	if (!dev_is_pci(dev))

		return;

		goto out;



	if (domain->flags & PD_IOMMUV2_MASK && dev_data->iommu_v2)

		pdev_iommuv2_disable(to_pci_dev(dev));
@@ -2270,6 +2249,9 @@ static void detach_device(struct device *dev) 
		pci_disable_ats(to_pci_dev(dev));



	dev_data->ats.enabled = false;



out:

	spin_unlock_irqrestore(&domain->lock, flags);

}



static int amd_iommu_add_device(struct device *dev)
@@ -2904,13 +2886,18 @@ int __init amd_iommu_init_dma_ops(void) 
static void cleanup_domain(struct protection_domain *domain)

{

	struct iommu_dev_data *entry;

	unsigned long flags;



	spin_lock_irqsave(&domain->lock, flags);



	while (!list_empty(&domain->dev_list)) {

		entry = list_first_entry(&domain->dev_list,

					 struct iommu_dev_data, list);

		BUG_ON(!entry->domain);

		__detach_device(entry);

		do_detach(entry);

	}



	spin_unlock_irqrestore(&domain->lock, flags);

}



static void protection_domain_free(struct protection_domain *domain)

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