x86/amd-iommu: Use get_device_id and check_device where appropriate

The logic of these two functions is reimplemented (at least
in parts) in places in the code. This patch removes these
code duplications and uses the functions instead. As a side
effect it moves check_device() to the helper function code
section.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

arch/x86/kernel/amd_iommu.c

@@ -111,6 +111,33 @@ static struct dma_ops_domain *find_protection_domain(u16 devid)
 	return ret;
 }
 
+/*
+ * This function checks if the driver got a valid device from the caller to
+ * avoid dereferencing invalid pointers.
+ */
+static bool check_device(struct device *dev)
+{
+	u16 devid;
+
+	if (!dev || !dev->dma_mask)
+		return false;
+
+	/* No device or no PCI device */
+	if (!dev || dev->bus != &pci_bus_type)
+		return false;
+
+	devid = get_device_id(dev);
+
+	/* Out of our scope? */
+	if (devid > amd_iommu_last_bdf)
+		return false;
+
+	if (amd_iommu_rlookup_table[devid] == NULL)
+		return false;
+
+	return true;
+}
+
 #ifdef CONFIG_AMD_IOMMU_STATS
 
 /*
@@ -1386,22 +1413,17 @@ static int device_change_notifier(struct notifier_block *nb,
 				  unsigned long action, void *data)
 {
 	struct device *dev = data;
-	struct pci_dev *pdev = to_pci_dev(dev);
-	u16 devid = calc_devid(pdev->bus->number, pdev->devfn);
+	u16 devid;
 	struct protection_domain *domain;
 	struct dma_ops_domain *dma_domain;
 	struct amd_iommu *iommu;
 	unsigned long flags;
 
-	if (devid > amd_iommu_last_bdf)
-		goto out;
-
-	devid = amd_iommu_alias_table[devid];
-
-	iommu = amd_iommu_rlookup_table[devid];
-	if (iommu == NULL)
-		goto out;
+	if (!check_device(dev))
+		return 0;
 
+	devid  = get_device_id(dev);
+	iommu  = amd_iommu_rlookup_table[devid];
 	domain = domain_for_device(dev);
 
 	if (domain && !dma_ops_domain(domain))
@@ -1452,36 +1474,6 @@ static struct notifier_block device_nb = {
  *
  *****************************************************************************/
 
-/*
- * This function checks if the driver got a valid device from the caller to
- * avoid dereferencing invalid pointers.
- */
-static bool check_device(struct device *dev)
-{
-	u16 bdf;
-	struct pci_dev *pcidev;
-
-	if (!dev || !dev->dma_mask)
-		return false;
-
-	/* No device or no PCI device */
-	if (!dev || dev->bus != &pci_bus_type)
-		return false;
-
-	pcidev = to_pci_dev(dev);
-
-	bdf = calc_devid(pcidev->bus->number, pcidev->devfn);
-
-	/* Out of our scope? */
-	if (bdf > amd_iommu_last_bdf)
-		return false;
-
-	if (amd_iommu_rlookup_table[bdf] == NULL)
-		return false;
-
-	return true;
-}
-
 /*
  * In the dma_ops path we only have the struct device. This function
  * finds the corresponding IOMMU, the protection domain and the
@@ -2094,15 +2086,20 @@ static void prealloc_protection_domains(void)
 	struct pci_dev *dev = NULL;
 	struct dma_ops_domain *dma_dom;
 	struct amd_iommu *iommu;
-	u16 devid, __devid;
+	u16 devid;
 
 	while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
-		__devid = devid = calc_devid(dev->bus->number, dev->devfn);
-		if (devid > amd_iommu_last_bdf)
+
+		/* Do we handle this device? */
+		if (!check_device(&dev->dev))
 			continue;
-		devid = amd_iommu_alias_table[devid];
+
+		/* Is there already any domain for it? */
 		if (domain_for_device(&dev->dev))
 			continue;
+
+		devid = get_device_id(&dev->dev);
+
 		iommu = amd_iommu_rlookup_table[devid];
 		if (!iommu)
 			continue;
@@ -2294,17 +2291,14 @@ static void amd_iommu_detach_device(struct iommu_domain *dom,
 				    struct device *dev)
 {
 	struct amd_iommu *iommu;
-	struct pci_dev *pdev;
 	u16 devid;
 
-	if (dev->bus != &pci_bus_type)
+	if (!check_device(dev))
 		return;
 
-	pdev = to_pci_dev(dev);
-
-	devid = calc_devid(pdev->bus->number, pdev->devfn);
+	devid = get_device_id(dev);
 
-	if (devid > 0)
+	if (amd_iommu_pd_table[devid] != NULL)
 		detach_device(dev);
 
 	iommu = amd_iommu_rlookup_table[devid];
@@ -2321,20 +2315,13 @@ static int amd_iommu_attach_device(struct iommu_domain *dom,
 	struct protection_domain *domain = dom->priv;
 	struct protection_domain *old_domain;
 	struct amd_iommu *iommu;
-	struct pci_dev *pdev;
 	int ret;
 	u16 devid;
 
-	if (dev->bus != &pci_bus_type)
+	if (!check_device(dev))
 		return -EINVAL;
 
-	pdev = to_pci_dev(dev);
-
-	devid = calc_devid(pdev->bus->number, pdev->devfn);
-
-	if (devid >= amd_iommu_last_bdf ||
-			devid != amd_iommu_alias_table[devid])
-		return -EINVAL;
+	devid = get_device_id(dev);
 
 	iommu = amd_iommu_rlookup_table[devid];
 	if (!iommu)
@@ -2458,10 +2445,11 @@ int __init amd_iommu_init_passthrough(void)
 
 	while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
 
-		devid = calc_devid(dev->bus->number, dev->devfn);
-		if (devid > amd_iommu_last_bdf)
+		if (!check_device(&dev->dev))
 			continue;
 
+		devid = get_device_id(&dev->dev);
+
 		iommu = amd_iommu_rlookup_table[devid];
 		if (!iommu)
 			continue;