iommu/amd: Introduce helper function get_dte256()

[ Upstream commit a2ce608 ]

And use it in clone_alias() along with update_dte256().
Also use get_dte256() in dump_dte_entry().

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Link: https://lore.kernel.org/r/20241118054937.5203-7-suravee.suthikulpanit@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Stable-dep-of: faad224 ("iommu/amd: Fix clone_alias() to use the original device's devid")
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: ssuthiku-amd

drivers/iommu/amd/iommu.c

@@ -79,6 +79,8 @@ static void set_dte_entry(struct amd_iommu *iommu,
 
 static void iommu_flush_dte_sync(struct amd_iommu *iommu, u16 devid);
 
+static struct iommu_dev_data *find_dev_data(struct amd_iommu *iommu, u16 devid);
+
 /****************************************************************************
  *
  * Helper functions
@@ -196,6 +198,21 @@ static void update_dte256(struct amd_iommu *iommu, struct iommu_dev_data *dev_da
 	spin_unlock_irqrestore(&dev_data->dte_lock, flags);
 }
 
+static void get_dte256(struct amd_iommu *iommu, struct iommu_dev_data *dev_data,
+		      struct dev_table_entry *dte)
+{
+	unsigned long flags;
+	struct dev_table_entry *ptr;
+	struct dev_table_entry *dev_table = get_dev_table(iommu);
+
+	ptr = &dev_table[dev_data->devid];
+
+	spin_lock_irqsave(&dev_data->dte_lock, flags);
+	dte->data128[0] = ptr->data128[0];
+	dte->data128[1] = ptr->data128[1];
+	spin_unlock_irqrestore(&dev_data->dte_lock, flags);
+}
+
 static inline bool pdom_is_v2_pgtbl_mode(struct protection_domain *pdom)
 {
 	return (pdom && (pdom->pd_mode == PD_MODE_V2));
@@ -367,9 +384,11 @@ static struct iommu_dev_data *search_dev_data(struct amd_iommu *iommu, u16 devid
 
 static int clone_alias(struct pci_dev *pdev, u16 alias, void *data)
 {
+	struct dev_table_entry new;
 	struct amd_iommu *iommu;
-	struct dev_table_entry *dev_table;
+	struct iommu_dev_data *dev_data, *alias_data;
 	u16 devid = pci_dev_id(pdev);
+	int ret = 0;
 
 	if (devid == alias)
 		return 0;
@@ -378,13 +397,27 @@ static int clone_alias(struct pci_dev *pdev, u16 alias, void *data)
 	if (!iommu)
 		return 0;
 
-	amd_iommu_set_rlookup_table(iommu, alias);
-	dev_table = get_dev_table(iommu);
-	memcpy(dev_table[alias].data,
-	       dev_table[devid].data,
-	       sizeof(dev_table[alias].data));
+	/* Copy the data from pdev */
+	dev_data = dev_iommu_priv_get(&pdev->dev);
+	if (!dev_data) {
+		pr_err("%s : Failed to get dev_data for 0x%x\n", __func__, devid);
+		ret = -EINVAL;
+		goto out;
+	}
+	get_dte256(iommu, dev_data, &new);
 
-	return 0;
+	/* Setup alias */
+	alias_data = find_dev_data(iommu, alias);
+	if (!alias_data) {
+		pr_err("%s : Failed to get alias dev_data for 0x%x\n", __func__, alias);
+		ret = -EINVAL;
+		goto out;
+	}
+	update_dte256(iommu, alias_data, &new);
+
+	amd_iommu_set_rlookup_table(iommu, alias);
+out:
+	return ret;
 }
 
 static void clone_aliases(struct amd_iommu *iommu, struct device *dev)
@@ -657,6 +690,12 @@ static int iommu_init_device(struct amd_iommu *iommu, struct device *dev)
 		return -ENOMEM;
 
 	dev_data->dev = dev;
+
+	/*
+	 * The dev_iommu_priv_set() needes to be called before setup_aliases.
+	 * Otherwise, subsequent call to dev_iommu_priv_get() will fail.
+	 */
+	dev_iommu_priv_set(dev, dev_data);
 	setup_aliases(iommu, dev);
 
 	/*
@@ -670,8 +709,6 @@ static int iommu_init_device(struct amd_iommu *iommu, struct device *dev)
 		dev_data->flags = pdev_get_caps(to_pci_dev(dev));
 	}
 
-	dev_iommu_priv_set(dev, dev_data);
-
 	return 0;
 }
 
@@ -718,10 +755,13 @@ static void amd_iommu_uninit_device(struct device *dev)
 static void dump_dte_entry(struct amd_iommu *iommu, u16 devid)
 {
 	int i;
-	struct dev_table_entry *dev_table = get_dev_table(iommu);
+	struct dev_table_entry dte;
+	struct iommu_dev_data *dev_data = find_dev_data(iommu, devid);
+
+	get_dte256(iommu, dev_data, &dte);
 
 	for (i = 0; i < 4; ++i)
-		pr_err("DTE[%d]: %016llx\n", i, dev_table[devid].data[i]);
+		pr_err("DTE[%d]: %016llx\n", i, dte.data[i]);
 }
 
 static void dump_command(unsigned long phys_addr)