PCI: create function symlinks in /sys/bus/pci/slots/N/

Commit Message

Alexander Chiang March 8, 2010, 5:24 p.m. UTC

None

Patch

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index 25be325..428676c 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -133,6 +133,46 @@  Description:
 		The symbolic link points to the PCI device sysfs entry of the
 		Physical Function this device associates with.
 
+
+What:		/sys/bus/pci/slots/...
+Date:		April 2005 (possibly older)
+KernelVersion:	2.6.12 (possibly older)
+Contact:	[e-mail]
+Description:
+		When the appropriate driver is loaded, it will create a
+		directory per claimed physical PCI slot in
+		/sys/bus/pci/slots/.  The names of these directories are
+		specific to the driver, which in turn, are specific to the
+		platform, but in general, should match the label on the
+		machine's physical chassis.
+
+		The drivers that can create slot directories include the
+		PCI hotplug drivers, and as of 2.6.27, the pci_slot driver.
+
+		The slot directories contain, at a minimum, a file named
+		'address' which contains the PCI bus:device:function tuple.
+		Other files may appear as well, but are specific to the
+		driver.
+
+What:		/sys/bus/pci/slots/.../function[0-7]
+Date:		March 2010
+KernelVersion:	2.6.35
+Contact:	[e-mail]
+Description:
+		If PCI slot directories (as described above) are created,
+		and the physical slot is actually populated with a device,
+		symbolic links in the slot directory pointing to the
+		device's PCI functions are created as well.
+
+What:		/sys/bus/pci/devices/.../slot
+Date:		March 2010
+KernelVersion:	2.6.35
+Contact:	[e-mail]
+Description:
+		If PCI slot directories (as described above) are created,
+		a symbolic link pointing to the slot directory will be
+		created as well.
+
 What:		/sys/bus/pci/slots/.../module
 Date:		June 2009
 Contact:	[e-mail]
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 807224e..d234234 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1006,6 +1006,39 @@  error:
 	return retval;
 }
 
+static void pci_remove_slot_links(struct pci_dev *dev)
+{
+	char func[10];
+	struct pci_slot *slot;
+
+	sysfs_remove_link(&dev->dev.kobj, "slot");
+	list_for_each_entry(slot, &dev->bus->slots, list) {
+		if (slot->number != PCI_SLOT(dev->devfn))
+			continue;
+		snprintf(func, 10, "function%d", PCI_FUNC(dev->devfn));
+		sysfs_remove_link(&slot->kobj, func);
+	}
+}
+
+static int pci_create_slot_links(struct pci_dev *dev)
+{
+	int result = 0;
+	char func[10];
+	struct pci_slot *slot;
+
+	list_for_each_entry(slot, &dev->bus->slots, list) {
+		if (slot->number != PCI_SLOT(dev->devfn))
+			continue;
+		result = sysfs_create_link(&dev->dev.kobj, &slot->kobj, "slot");
+		if (result)
+			goto out;
+		snprintf(func, 10, "function%d", PCI_FUNC(dev->devfn));
+		result = sysfs_create_link(&slot->kobj, &dev->dev.kobj, func);
+	}
+out:
+	return result;
+}
+
 int __must_check pci_create_sysfs_dev_files (struct pci_dev *pdev)
 {
 	int retval;
@@ -1067,6 +1100,8 @@  int __must_check pci_create_sysfs_dev_files (struct pci_dev *pdev)
 	if (retval)
 		goto err_vga_file;
 
+	pci_create_slot_links(pdev);
+
 	return 0;
 
 err_vga_file:
@@ -1116,6 +1151,8 @@  void pci_remove_sysfs_dev_files(struct pci_dev *pdev)
 	if (!sysfs_initialized)
 		return;
 
+	pci_remove_slot_links(pdev);
+
 	pci_remove_capabilities_sysfs(pdev);
 
 	if (pdev->cfg_size < PCI_CFG_SPACE_EXP_SIZE)
diff --git a/drivers/pci/slot.c b/drivers/pci/slot.c
index 49c9e6c..a8e22c6 100644
--- a/drivers/pci/slot.c
+++ b/drivers/pci/slot.c
@@ -96,6 +96,50 @@  static ssize_t cur_speed_read_file(struct pci_slot *slot, char *buf)
 	return bus_speed_read(slot->bus->cur_bus_speed, buf);
 }
 
+static void remove_sysfs_files(struct pci_slot *slot)
+{
+	char func[10];
+	struct list_head *tmp;
+
+	list_for_each(tmp, &slot->bus->devices) {
+		struct pci_dev *dev = pci_dev_b(tmp);
+		if (PCI_SLOT(dev->devfn) != slot->number)
+			continue;
+		sysfs_remove_link(&dev->dev.kobj, "slot");
+
+		snprintf(func, 10, "function%d", PCI_FUNC(dev->devfn));
+		sysfs_remove_link(&slot->kobj, func);
+	}
+}
+
+static int create_sysfs_files(struct pci_slot *slot)
+{
+	int result;
+	char func[10];
+	struct list_head *tmp;
+
+	list_for_each(tmp, &slot->bus->devices) {
+		struct pci_dev *dev = pci_dev_b(tmp);
+		if (PCI_SLOT(dev->devfn) != slot->number)
+			continue;
+
+		result = sysfs_create_link(&dev->dev.kobj, &slot->kobj, "slot");
+		if (result)
+			goto fail;
+
+		snprintf(func, 10, "function%d", PCI_FUNC(dev->devfn));
+		result = sysfs_create_link(&slot->kobj, &dev->dev.kobj, func);
+		if (result)
+			goto fail;
+	}
+
+	return 0;
+
+fail:
+	remove_sysfs_files(slot);
+	return result;
+}
+
 static void pci_slot_release(struct kobject *kobj)
 {
 	struct pci_dev *dev;
@@ -108,6 +152,8 @@  static void pci_slot_release(struct kobject *kobj)
 		if (PCI_SLOT(dev->devfn) == slot->number)
 			dev->slot = NULL;
 
+	remove_sysfs_files(slot);
+
 	list_del(&slot->list);
 
 	kfree(slot);
@@ -299,6 +345,8 @@  placeholder:
 	INIT_LIST_HEAD(&slot->list);
 	list_add(&slot->list, &parent->slots);
 
+	create_sysfs_files(slot);
+
 	list_for_each_entry(dev, &parent->devices, bus_list)
 		if (PCI_SLOT(dev->devfn) == slot_nr)
 			dev->slot = slot;