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iommu/amd: Add support for enable/disable IOPF
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Return success from enable_feature(IOPF) path as this interface is going
away. Instead we will enable/disable IOPF support in attach/detach device
path.

In attach device path, if device is capable of PRI, then we will add it to
per IOMMU IOPF queue and enable PPR support in IOMMU. Also it will
attach device to domain even if it fails to enable PRI or add device to
IOPF queue as device can continue to work without PRI support.

In detach device patch it follows following sequence:
  - Flush the queue for the given device
  - Disable PPR support in DTE[devid]
  - Remove device from IOPF queue
  - Disable device PRI

Also add IOMMU_IOPF as dependency to AMD_IOMMU driver.

Co-developed-by: Suravee Suthikulpanit <[email protected]>
Signed-off-by: Suravee Suthikulpanit <[email protected]>
Signed-off-by: Vasant Hegde <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Joerg Roedel <[email protected]>
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hegdevasant authored and joergroedel committed Apr 26, 2024
1 parent 978d626 commit c4cb231
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Showing 4 changed files with 77 additions and 8 deletions.
1 change: 1 addition & 0 deletions drivers/iommu/amd/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -10,6 +10,7 @@ config AMD_IOMMU
select IOMMU_API
select IOMMU_IOVA
select IOMMU_IO_PGTABLE
select IOMMU_IOPF
select IOMMUFD_DRIVER if IOMMUFD
depends on X86_64 && PCI && ACPI && HAVE_CMPXCHG_DOUBLE
help
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4 changes: 4 additions & 0 deletions drivers/iommu/amd/amd_iommu.h
Original file line number Diff line number Diff line change
Expand Up @@ -51,6 +51,10 @@ int amd_iommu_iopf_init(struct amd_iommu *iommu);
void amd_iommu_iopf_uninit(struct amd_iommu *iommu);
void amd_iommu_page_response(struct device *dev, struct iopf_fault *evt,
struct iommu_page_response *resp);
int amd_iommu_iopf_add_device(struct amd_iommu *iommu,
struct iommu_dev_data *dev_data);
void amd_iommu_iopf_remove_device(struct amd_iommu *iommu,
struct iommu_dev_data *dev_data);

/* GCR3 setup */
int amd_iommu_set_gcr3(struct iommu_dev_data *dev_data,
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39 changes: 31 additions & 8 deletions drivers/iommu/amd/iommu.c
Original file line number Diff line number Diff line change
Expand Up @@ -2057,8 +2057,17 @@ static int do_attach(struct iommu_dev_data *dev_data,
if (ret)
return ret;

if (pdev)
if (pdev) {
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);
}
Expand Down Expand Up @@ -2130,12 +2139,11 @@ static int attach_device(struct device *dev,
*/
static void detach_device(struct device *dev)
{
struct protection_domain *domain;
struct iommu_dev_data *dev_data;
struct iommu_dev_data *dev_data = dev_iommu_priv_get(dev);
struct protection_domain *domain = dev_data->domain;
struct amd_iommu *iommu = get_amd_iommu_from_dev_data(dev_data);
unsigned long flags;

dev_data = dev_iommu_priv_get(dev);
domain = dev_data->domain;
bool ppr = dev_data->ppr;

spin_lock_irqsave(&domain->lock, flags);

Expand All @@ -2150,8 +2158,19 @@ static void detach_device(struct device *dev)
if (WARN_ON(!dev_data->domain))
goto out;

if (ppr) {
iopf_queue_flush_dev(dev);

/* Updated here so that it gets reflected in DTE */
dev_data->ppr = false;
}

do_detach(dev_data);

/* 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));

Expand Down Expand Up @@ -2814,9 +2833,11 @@ static const struct iommu_dirty_ops amd_dirty_ops = {
static int amd_iommu_dev_enable_feature(struct device *dev,
enum iommu_dev_features feat)
{
int ret;
int ret = 0;

switch (feat) {
case IOMMU_DEV_FEAT_IOPF:
break;
default:
ret = -EINVAL;
break;
Expand All @@ -2827,9 +2848,11 @@ static int amd_iommu_dev_enable_feature(struct device *dev,
static int amd_iommu_dev_disable_feature(struct device *dev,
enum iommu_dev_features feat)
{
int ret;
int ret = 0;

switch (feat) {
case IOMMU_DEV_FEAT_IOPF:
break;
default:
ret = -EINVAL;
break;
Expand Down
41 changes: 41 additions & 0 deletions drivers/iommu/amd/ppr.c
Original file line number Diff line number Diff line change
Expand Up @@ -243,3 +243,44 @@ void amd_iommu_page_response(struct device *dev, struct iopf_fault *evt,
{
amd_iommu_complete_ppr(dev, resp->pasid, resp->code, resp->grpid);
}

int amd_iommu_iopf_add_device(struct amd_iommu *iommu,
struct iommu_dev_data *dev_data)
{
unsigned long flags;
int ret = 0;

if (!dev_data->pri_enabled)
return ret;

raw_spin_lock_irqsave(&iommu->lock, flags);

if (!iommu->iopf_queue) {
ret = -EINVAL;
goto out_unlock;
}

ret = iopf_queue_add_device(iommu->iopf_queue, dev_data->dev);
if (ret)
goto out_unlock;

dev_data->ppr = true;

out_unlock:
raw_spin_unlock_irqrestore(&iommu->lock, flags);
return ret;
}

/* Its assumed that caller has verified that device was added to iopf queue */
void amd_iommu_iopf_remove_device(struct amd_iommu *iommu,
struct iommu_dev_data *dev_data)
{
unsigned long flags;

raw_spin_lock_irqsave(&iommu->lock, flags);

iopf_queue_remove_device(iommu->iopf_queue, dev_data->dev);
dev_data->ppr = false;

raw_spin_unlock_irqrestore(&iommu->lock, flags);
}

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