PCI: Export pci_iov_virtfn_bus() and pci_iov_virtfn_devfn()

On PowerNV, some resource reservation is needed for SR-IOV VFs that don't
exist at the bootup stage.  To do the match between resources and VFs, the
code need to get the VF's BDF in advance.

Rename virtfn_bus() and virtfn_devfn() to pci_iov_virtfn_bus() and
pci_iov_virtfn_devfn() and export them.

[bhelgaas: changelog, make "busnr" int]
Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

drivers/pci/iov.c

@@ -19,16 +19,20 @@
 
 #define VIRTFN_ID_LEN	16
 
-static inline u8 virtfn_bus(struct pci_dev *dev, int id)
+int pci_iov_virtfn_bus(struct pci_dev *dev, int vf_id)
 {
+	if (!dev->is_physfn)
+		return -EINVAL;
 	return dev->bus->number + ((dev->devfn + dev->sriov->offset +
-				    dev->sriov->stride * id) >> 8);
+				    dev->sriov->stride * vf_id) >> 8);
 }
 
-static inline u8 virtfn_devfn(struct pci_dev *dev, int id)
+int pci_iov_virtfn_devfn(struct pci_dev *dev, int vf_id)
 {
+	if (!dev->is_physfn)
+		return -EINVAL;
 	return (dev->devfn + dev->sriov->offset +
-		dev->sriov->stride * id) & 0xff;
+		dev->sriov->stride * vf_id) & 0xff;
 }
 
 /*
@@ -58,11 +62,11 @@ static inline u8 virtfn_max_buses(struct pci_dev *dev)
 	struct pci_sriov *iov = dev->sriov;
 	int nr_virtfn;
 	u8 max = 0;
-	u8 busnr;
+	int busnr;
 
 	for (nr_virtfn = 1; nr_virtfn <= iov->total_VFs; nr_virtfn++) {
 		pci_iov_set_numvfs(dev, nr_virtfn);
-		busnr = virtfn_bus(dev, nr_virtfn - 1);
+		busnr = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
 		if (busnr > max)
 			max = busnr;
 	}
@@ -116,7 +120,7 @@ static int virtfn_add(struct pci_dev *dev, int id, int reset)
 	struct pci_bus *bus;
 
 	mutex_lock(&iov->dev->sriov->lock);
-	bus = virtfn_add_bus(dev->bus, virtfn_bus(dev, id));
+	bus = virtfn_add_bus(dev->bus, pci_iov_virtfn_bus(dev, id));
 	if (!bus)
 		goto failed;
 
@@ -124,7 +128,7 @@ static int virtfn_add(struct pci_dev *dev, int id, int reset)
 	if (!virtfn)
 		goto failed0;
 
-	virtfn->devfn = virtfn_devfn(dev, id);
+	virtfn->devfn = pci_iov_virtfn_devfn(dev, id);
 	virtfn->vendor = dev->vendor;
 	pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_DID, &virtfn->device);
 	pci_setup_device(virtfn);
@@ -186,8 +190,8 @@ static void virtfn_remove(struct pci_dev *dev, int id, int reset)
 	struct pci_sriov *iov = dev->sriov;
 
 	virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
-					     virtfn_bus(dev, id),
-					     virtfn_devfn(dev, id));
+					     pci_iov_virtfn_bus(dev, id),
+					     pci_iov_virtfn_devfn(dev, id));
 	if (!virtfn)
 		return;
 
@@ -226,7 +230,7 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 	struct pci_dev *pdev;
 	struct pci_sriov *iov = dev->sriov;
 	int bars = 0;
-	u8 bus;
+	int bus;
 
 	if (!nr_virtfn)
 		return 0;
@@ -263,7 +267,7 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 	iov->offset = offset;
 	iov->stride = stride;
 
-	bus = virtfn_bus(dev, nr_virtfn - 1);
+	bus = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
 	if (bus > dev->bus->busn_res.end) {
 		dev_err(&dev->dev, "can't enable %d VFs (bus %02x out of range of %pR)\n",
 			nr_virtfn, bus, &dev->bus->busn_res);

include/linux/pci.h

@@ -1669,6 +1669,9 @@ int pci_ext_cfg_avail(void);
 void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar);
 
 #ifdef CONFIG_PCI_IOV
+int pci_iov_virtfn_bus(struct pci_dev *dev, int id);
+int pci_iov_virtfn_devfn(struct pci_dev *dev, int id);
+
 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn);
 void pci_disable_sriov(struct pci_dev *dev);
 int pci_num_vf(struct pci_dev *dev);
@@ -1677,6 +1680,14 @@ int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs);
 int pci_sriov_get_totalvfs(struct pci_dev *dev);
 resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno);
 #else
+static inline int pci_iov_virtfn_bus(struct pci_dev *dev, int id)
+{
+	return -ENOSYS;
+}
+static inline int pci_iov_virtfn_devfn(struct pci_dev *dev, int id)
+{
+	return -ENOSYS;
+}
 static inline int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 { return -ENODEV; }
 static inline void pci_disable_sriov(struct pci_dev *dev) { }