iommu/amd: Add support for enable/disable IOPF

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 <suravee.suthikulpanit@amd.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20240418103400.6229-13-vasant.hegde@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 41 insertions, 0 deletions

diff --git a/drivers/iommu/amd/ppr.c b/drivers/iommu/amd/ppr.c
index 9bdd1db5f60a..0463daa2d46b 100644
--- a/drivers/iommu/amd/ppr.c
+++ b/drivers/iommu/amd/ppr.c
@@ -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);
+}