iommu/amd: Enable device ATS/PASID/PRI capabilities independently

Introduce helper functions to enable/disable device ATS/PASID/PRI
capabilities independently along with the new pasid_enabled and
pri_enabled variables in struct iommu_dev_data to keep track,
which allows attach_device() and detach_device() to be simplified.

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>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Link: https://lore.kernel.org/r/20230921092147.5930-14-vasant.hegde@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Author: hegdevasant

drivers/iommu/amd/amd_iommu.h

@@ -51,6 +51,10 @@ int amd_iommu_pc_get_reg(struct amd_iommu *iommu, u8 bank, u8 cntr,
 int amd_iommu_pc_set_reg(struct amd_iommu *iommu, u8 bank, u8 cntr,
 			 u8 fxn, u64 *value);
 
+/* Device capabilities */
+int amd_iommu_pdev_enable_cap_pri(struct pci_dev *pdev);
+void amd_iommu_pdev_disable_cap_pri(struct pci_dev *pdev);
+
 int amd_iommu_register_ppr_notifier(struct notifier_block *nb);
 int amd_iommu_unregister_ppr_notifier(struct notifier_block *nb);
 void amd_iommu_domain_direct_map(struct iommu_domain *dom);

drivers/iommu/amd/amd_iommu_types.h

@@ -815,6 +815,8 @@ struct iommu_dev_data {
 	u32 flags;			  /* Holds AMD_IOMMU_DEVICE_FLAG_<*> */
 	int ats_qdep;
 	u8 ats_enabled  :1;		  /* ATS state */
+	u8 pri_enabled  :1;		  /* PRI state */
+	u8 pasid_enabled:1;		  /* PASID state */
 	u8 pri_tlp      :1;		  /* PASID TLB required for
 					     PPR completions */
 	u8 ppr          :1;		  /* Enable device PPR support */

drivers/iommu/amd/iommu.c

@@ -349,6 +349,113 @@ static u32 pdev_get_caps(struct pci_dev *pdev)
 	return flags;
 }
 
+static inline int pdev_enable_cap_ats(struct pci_dev *pdev)
+{
+	struct iommu_dev_data *dev_data = dev_iommu_priv_get(&pdev->dev);
+	int ret = -EINVAL;
+
+	if (dev_data->ats_enabled)
+		return 0;
+
+	if (amd_iommu_iotlb_sup &&
+	    (dev_data->flags & AMD_IOMMU_DEVICE_FLAG_ATS_SUP)) {
+		ret = pci_enable_ats(pdev, PAGE_SHIFT);
+		if (!ret) {
+			dev_data->ats_enabled = 1;
+			dev_data->ats_qdep    = pci_ats_queue_depth(pdev);
+		}
+	}
+
+	return ret;
+}
+
+static inline void pdev_disable_cap_ats(struct pci_dev *pdev)
+{
+	struct iommu_dev_data *dev_data = dev_iommu_priv_get(&pdev->dev);
+
+	if (dev_data->ats_enabled) {
+		pci_disable_ats(pdev);
+		dev_data->ats_enabled = 0;
+	}
+}
+
+int amd_iommu_pdev_enable_cap_pri(struct pci_dev *pdev)
+{
+	struct iommu_dev_data *dev_data = dev_iommu_priv_get(&pdev->dev);
+	int ret = -EINVAL;
+
+	if (dev_data->pri_enabled)
+		return 0;
+
+	if (dev_data->flags & AMD_IOMMU_DEVICE_FLAG_PRI_SUP) {
+		/*
+		 * First reset the PRI state of the device.
+		 * FIXME: Hardcode number of outstanding requests for now
+		 */
+		if (!pci_reset_pri(pdev) && !pci_enable_pri(pdev, 32)) {
+			dev_data->pri_enabled = 1;
+			dev_data->pri_tlp     = pci_prg_resp_pasid_required(pdev);
+
+			ret = 0;
+		}
+	}
+
+	return ret;
+}
+
+void amd_iommu_pdev_disable_cap_pri(struct pci_dev *pdev)
+{
+	struct iommu_dev_data *dev_data = dev_iommu_priv_get(&pdev->dev);
+
+	if (dev_data->pri_enabled) {
+		pci_disable_pri(pdev);
+		dev_data->pri_enabled = 0;
+	}
+}
+
+static inline int pdev_enable_cap_pasid(struct pci_dev *pdev)
+{
+	struct iommu_dev_data *dev_data = dev_iommu_priv_get(&pdev->dev);
+	int ret = -EINVAL;
+
+	if (dev_data->pasid_enabled)
+		return 0;
+
+	if (dev_data->flags & AMD_IOMMU_DEVICE_FLAG_PASID_SUP) {
+		/* Only allow access to user-accessible pages */
+		ret = pci_enable_pasid(pdev, 0);
+		if (!ret)
+			dev_data->pasid_enabled = 1;
+	}
+
+	return ret;
+}
+
+static inline void pdev_disable_cap_pasid(struct pci_dev *pdev)
+{
+	struct iommu_dev_data *dev_data = dev_iommu_priv_get(&pdev->dev);
+
+	if (dev_data->pasid_enabled) {
+		pci_disable_pasid(pdev);
+		dev_data->pasid_enabled = 0;
+	}
+}
+
+static void pdev_enable_caps(struct pci_dev *pdev)
+{
+	pdev_enable_cap_ats(pdev);
+	pdev_enable_cap_pasid(pdev);
+	amd_iommu_pdev_enable_cap_pri(pdev);
+
+}
+
+static void pdev_disable_caps(struct pci_dev *pdev)
+{
+	pdev_disable_cap_ats(pdev);
+	pdev_disable_cap_pasid(pdev);
+	amd_iommu_pdev_disable_cap_pri(pdev);
+}
+
 /*
  * This function checks if the driver got a valid device from the caller to
  * avoid dereferencing invalid pointers.
@@ -1777,48 +1884,6 @@ static void do_detach(struct iommu_dev_data *dev_data)
 	domain->dev_cnt                 -= 1;
 }
 
-static void pdev_iommuv2_disable(struct pci_dev *pdev)
-{
-	pci_disable_ats(pdev);
-	pci_disable_pri(pdev);
-	pci_disable_pasid(pdev);
-}
-
-static int pdev_pri_ats_enable(struct pci_dev *pdev)
-{
-	int ret;
-
-	/* Only allow access to user-accessible pages */
-	ret = pci_enable_pasid(pdev, 0);
-	if (ret)
-		return ret;
-
-	/* First reset the PRI state of the device */
-	ret = pci_reset_pri(pdev);
-	if (ret)
-		goto out_err_pasid;
-
-	/* Enable PRI */
-	/* FIXME: Hardcode number of outstanding requests for now */
-	ret = pci_enable_pri(pdev, 32);
-	if (ret)
-		goto out_err_pasid;
-
-	ret = pci_enable_ats(pdev, PAGE_SHIFT);
-	if (ret)
-		goto out_err_pri;
-
-	return 0;
-
-out_err_pri:
-	pci_disable_pri(pdev);
-
-out_err_pasid:
-	pci_disable_pasid(pdev);
-
-	return ret;
-}
-
 /*
  * If a device is not yet associated with a domain, this function makes the
  * device visible in the domain
@@ -1827,55 +1892,22 @@ static int attach_device(struct device *dev,
 			 struct protection_domain *domain)
 {
 	struct iommu_dev_data *dev_data;
-	struct pci_dev *pdev;
 	unsigned long flags;
-	int ret;
+	int ret = 0;
 
 	spin_lock_irqsave(&domain->lock, flags);
 
 	dev_data = dev_iommu_priv_get(dev);
 
 	spin_lock(&dev_data->lock);
 
-	ret = -EBUSY;
-	if (dev_data->domain != NULL)
+	if (dev_data->domain != NULL) {
+		ret = -EBUSY;
 		goto out;
-
-	if (!dev_is_pci(dev))
-		goto skip_ats_check;
-
-	pdev = to_pci_dev(dev);
-	if (domain->flags & PD_IOMMUV2_MASK) {
-		struct iommu_domain *def_domain = iommu_get_dma_domain(dev);
-
-		ret = -EINVAL;
-
-		/*
-		 * In case of using AMD_IOMMU_V1 page table mode and the device
-		 * is enabling for PPR/ATS support (using v2 table),
-		 * we need to make sure that the domain type is identity map.
-		 */
-		if ((amd_iommu_pgtable == AMD_IOMMU_V1) &&
-		    def_domain->type != IOMMU_DOMAIN_IDENTITY) {
-			goto out;
-		}
-
-		if (pdev_pasid_supported(dev_data)) {
-			if (pdev_pri_ats_enable(pdev) != 0)
-				goto out;
-
-			dev_data->ats_enabled = 1;
-			dev_data->ats_qdep    = pci_ats_queue_depth(pdev);
-			dev_data->pri_tlp     = pci_prg_resp_pasid_required(pdev);
-		}
-	} else if (amd_iommu_iotlb_sup &&
-		   pci_enable_ats(pdev, PAGE_SHIFT) == 0) {
-		dev_data->ats_enabled = 1;
-		dev_data->ats_qdep    = pci_ats_queue_depth(pdev);
 	}
 
-skip_ats_check:
-	ret = 0;
+	if (dev_is_pci(dev))
+		pdev_enable_caps(to_pci_dev(dev));
 
 	do_attach(dev_data, domain);
 
@@ -1923,15 +1955,8 @@ static void detach_device(struct device *dev)
 
 	do_detach(dev_data);
 
-	if (!dev_is_pci(dev))
-		goto out;
-
-	if (domain->flags & PD_IOMMUV2_MASK && pdev_pasid_supported(dev_data))
-		pdev_iommuv2_disable(to_pci_dev(dev));
-	else if (dev_data->ats_enabled)
-		pci_disable_ats(to_pci_dev(dev));
-
-	dev_data->ats_enabled = 0;
+	if (dev_is_pci(dev))
+		pdev_disable_caps(to_pci_dev(dev));
 
 out:
 	spin_unlock(&dev_data->lock);