[V2] Use firmware provided index to register a network interface

Commit Message

Narendra K Oct. 7, 2010, 2:23 p.m. UTC

None

Patch

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 3cdb4d8..73edbc0 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1529,6 +1529,12 @@  and is between 256 and 4096 characters. It is defined in the file
 			This usage is only documented in each driver source
 			file if at all.
 
+	no_netfwindex	[NET] Do not use firmware index to derive ethN names
+			Names for onboard network interfaces are derived from
+			the firmware provided index for these devices. Using
+			this parameter would result in firmware index not being
+			used to derive ethN names.
+
 	nf_conntrack.acct=
 			[NETFILTER] Enable connection tracking flow accounting
 			0 to disable accounting
diff --git a/drivers/pci/pci-label.c b/drivers/pci/pci-label.c
index 90c0a72..8086268 100644
--- a/drivers/pci/pci-label.c
+++ b/drivers/pci/pci-label.c
@@ -55,6 +55,7 @@  find_smbios_instance_string(struct pci_dev *pdev, char *buf,
 							 "%s\n",
 							 dmi->name);
 			}
+			pdev->firmware_index = donboard->instance;
 			return strlen(dmi->name);
 		}
 	}
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index b5a7d9b..448ed9d 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -28,6 +28,7 @@ 
 #include "pci.h"
 
 static int sysfs_initialized;	/* = 0 */
+int pci_netdevs_with_fwindex;
 
 /* show configuration fields */
 #define pci_config_attr(field, format_string)				\
@@ -1167,6 +1168,10 @@  int __must_check pci_create_sysfs_dev_files (struct pci_dev *pdev)
 
 	pci_create_firmware_label_files(pdev);
 
+	if (pdev->firmware_index && (pdev->class >> 16) ==
+						PCI_BASE_CLASS_NETWORK)
+		pci_netdevs_with_fwindex++;
+
 	return 0;
 
 err_vga_file:
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 46c36ff..4398dcf 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1080,6 +1080,8 @@  struct net_device {
 
 #define	NETDEV_ALIGN		32
 
+extern int pci_netdevs_with_fwindex;
+
 static inline
 struct netdev_queue *netdev_get_tx_queue(const struct net_device *dev,
 					 unsigned int index)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index b1d1795..90113bb 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -243,6 +243,7 @@  struct pci_dev {
 	unsigned short	subsystem_vendor;
 	unsigned short	subsystem_device;
 	unsigned int	class;		/* 3 bytes: (base,sub,prog-if) */
+	unsigned int	firmware_index; /* Firmware provided index */
 	u8		revision;	/* PCI revision, low byte of class word */
 	u8		hdr_type;	/* PCI header type (`multi' flag masked out) */
 	u8		pcie_cap;	/* PCI-E capability offset */
diff --git a/net/core/dev.c b/net/core/dev.c
index 1ae6543..f7982c4 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -853,9 +853,18 @@  int dev_valid_name(const char *name)
 }
 EXPORT_SYMBOL(dev_valid_name);
 
+int netdev_use_fwindex = 1;
+
+static int __init netdev_use_fwindex_to_register(char *str)
+{
+	netdev_use_fwindex = 0;
+	return 0;
+}
+early_param("no_netfwindex", netdev_use_fwindex_to_register);
+
 /**
  *	__dev_alloc_name - allocate a name for a device
- *	@net: network namespace to allocate the device name in
+ *	@dev:  device
  *	@name: name format string
  *	@buf:  scratch buffer and result name string
  *
@@ -868,13 +877,15 @@  EXPORT_SYMBOL(dev_valid_name);
  *	Returns the number of the unit assigned or a negative errno code.
  */
 
-static int __dev_alloc_name(struct net *net, const char *name, char *buf)
+static int __dev_alloc_name(struct net_device *dev, const char *name, char *buf)
 {
 	int i = 0;
 	const char *p;
 	const int max_netdevices = 8*PAGE_SIZE;
 	unsigned long *inuse;
 	struct net_device *d;
+	struct net *net;
+	struct pci_dev *pdev;
 
 	p = strnchr(name, IFNAMSIZ-1, '%');
 	if (p) {
@@ -886,15 +897,36 @@  static int __dev_alloc_name(struct net *net, const char *name, char *buf)
 		if (p[1] != 'd' || strchr(p + 2, '%'))
 			return -EINVAL;
 
+		if (likely(netdev_use_fwindex)) {
+			pdev = to_pci_dev(dev->dev.parent);
+			if (pdev && pdev->firmware_index) {
+				snprintf(buf, IFNAMSIZ, name,
+					 pdev->firmware_index - 1);
+				return pdev->firmware_index - 1;
+			}
+		}
+
 		/* Use one page as a bit array of possible slots */
 		inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
 		if (!inuse)
 			return -ENOMEM;
 
+		/* Reserve 0 to < pci_netdevs_with_fwindex for integrated
+		 * ports with fwindex and allocate from pci_netdevs_with_fwindex
+		 * onwards for add-in devices
+		 */
+		if (likely(netdev_use_fwindex)) {
+			for (i = 0; i < pci_netdevs_with_fwindex; i++)
+				set_bit(i, inuse);
+		} else
+			pci_netdevs_with_fwindex = 0;
+
+		net = dev_net(dev);
+
 		for_each_netdev(net, d) {
 			if (!sscanf(d->name, name, &i))
 				continue;
-			if (i < 0 || i >= max_netdevices)
+			if (i < pci_netdevs_with_fwindex || i >= max_netdevices)
 				continue;
 
 			/*  avoid cases where sscanf is not exact inverse of printf */
@@ -936,12 +968,10 @@  static int __dev_alloc_name(struct net *net, const char *name, char *buf)
 int dev_alloc_name(struct net_device *dev, const char *name)
 {
 	char buf[IFNAMSIZ];
-	struct net *net;
 	int ret;
 
 	BUG_ON(!dev_net(dev));
-	net = dev_net(dev);
-	ret = __dev_alloc_name(net, name, buf);
+	ret = __dev_alloc_name(dev, name, buf);
 	if (ret >= 0)
 		strlcpy(dev->name, buf, IFNAMSIZ);
 	return ret;