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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: 92d420ec02 ("iommu/amd: Relax locking in dma_ops path")
Reviewed-by: Filippo Sironi <sironi@amazon.de>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Joerg Roedel 2019-09-25 15:22:57 +02:00
parent 3a11905b69
commit f6c0bfce27
1 changed files with 26 additions and 39 deletions
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65
drivers/iommu/amd_iommu.c
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@ -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 @@ static int attach_device(struct device *dev,
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)