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iommu/amd: Reorder attach device code

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Ideally in attach device path, it should take dev_data lock before
making changes to device data including IOPF enablement. So far dev_data
was using spinlock and it was hitting lock order issue when it tries to
enable IOPF. Hence Commit 526606b0a1 ("iommu/amd: Fix Invalid wait
context issue") moved IOPF enablement outside dev_data->lock.

Previous patch converted dev_data lock to mutex. Now its safe to call
amd_iommu_iopf_add_device() with dev_data->mutex. Hence move back PCI
device capability enablement (ATS, PRI, PASID) and IOPF enablement code
inside the lock. Also in attach_device(), update 'dev_data->domain' at
the end so that error handling becomes simple.

Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20241030063556.6104-11-vasant.hegde@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Vasant Hegde
2024-10-30 06:35:54 +00:00
committed by Joerg Roedel
parent e843aedbeb
commit 0b136493d3
1 changed files with 29 additions and 36 deletions
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drivers/iommu/amd/iommu.c
+29 -36
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@@ -2090,6 +2090,7 @@ static int attach_device(struct device *dev,
{
struct iommu_dev_data *dev_data = dev_iommu_priv_get(dev);
struct amd_iommu *iommu = get_amd_iommu_from_dev_data(dev_data);
struct pci_dev *pdev;
int ret = 0;
mutex_lock(&dev_data->mutex);
@@ -2099,10 +2100,6 @@ static int attach_device(struct device *dev,
goto out;
}
/* Update data structures */
dev_data->domain = domain;
list_add(&dev_data->list, &domain->dev_list);
/* Do reference counting */
ret = pdom_attach_iommu(iommu, domain);
if (ret)
@@ -2117,6 +2114,28 @@ static int attach_device(struct device *dev,
}
}
pdev = dev_is_pci(dev_data->dev) ? to_pci_dev(dev_data->dev) : NULL;
if (pdev && pdom_is_sva_capable(domain)) {
pdev_enable_caps(pdev);
/*
* Device can continue to function even if IOPF
* enablement failed. Hence in error path just
* disable device PRI support.
*/
if (amd_iommu_iopf_add_device(iommu, dev_data))
pdev_disable_cap_pri(pdev);
} else if (pdev) {
pdev_enable_cap_ats(pdev);
}
/* Update data structures */
dev_data->domain = domain;
list_add(&dev_data->list, &domain->dev_list);
/* Update device table */
dev_update_dte(dev_data, true);
out:
mutex_unlock(&dev_data->mutex);
@@ -2131,7 +2150,6 @@ static void detach_device(struct device *dev)
struct iommu_dev_data *dev_data = dev_iommu_priv_get(dev);
struct amd_iommu *iommu = get_amd_iommu_from_dev_data(dev_data);
struct protection_domain *domain = dev_data->domain;
bool ppr = dev_data->ppr;
unsigned long flags;
mutex_lock(&dev_data->mutex);
@@ -2145,13 +2163,15 @@ static void detach_device(struct device *dev)
if (WARN_ON(!dev_data->domain))
goto out;
if (ppr) {
/* Remove IOPF handler */
if (dev_data->ppr) {
iopf_queue_flush_dev(dev);
/* Updated here so that it gets reflected in DTE */
dev_data->ppr = false;
amd_iommu_iopf_remove_device(iommu, dev_data);
}
if (dev_is_pci(dev))
pdev_disable_caps(to_pci_dev(dev));
/* Clear DTE and flush the entry */
dev_update_dte(dev_data, false);
@@ -2173,14 +2193,6 @@ static void detach_device(struct device *dev)
out:
mutex_unlock(&dev_data->mutex);
/* Remove IOPF handler */
if (ppr)
amd_iommu_iopf_remove_device(iommu, dev_data);
if (dev_is_pci(dev))
pdev_disable_caps(to_pci_dev(dev));
}
static struct iommu_device *amd_iommu_probe_device(struct device *dev)
@@ -2509,7 +2521,6 @@ static int amd_iommu_attach_device(struct iommu_domain *dom,
struct iommu_dev_data *dev_data = dev_iommu_priv_get(dev);
struct protection_domain *domain = to_pdomain(dom);
struct amd_iommu *iommu = get_amd_iommu_from_dev(dev);
struct pci_dev *pdev;
int ret;
/*
@@ -2542,24 +2553,6 @@ static int amd_iommu_attach_device(struct iommu_domain *dom,
}
#endif
pdev = dev_is_pci(dev_data->dev) ? to_pci_dev(dev_data->dev) : NULL;
if (pdev && pdom_is_sva_capable(domain)) {
pdev_enable_caps(pdev);
/*
* Device can continue to function even if IOPF
* enablement failed. Hence in error path just
* disable device PRI support.
*/
if (amd_iommu_iopf_add_device(iommu, dev_data))
pdev_disable_cap_pri(pdev);
} else if (pdev) {
pdev_enable_cap_ats(pdev);
}
/* Update device table */
dev_update_dte(dev_data, true);
return ret;
}