3 files changed, 125 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index 25be3250f7d6..428676cfa61e 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:        linux-pci@vger.kernel.org
+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:        linux-pci@vger.kernel.org
+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:        linux-pci@vger.kernel.org
+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:        linux-pci@vger.kernel.org
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index fad93983bfed..941e939d1da9 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1011,6 +1011,39 @@ 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;
@@ -1073,6 +1106,8 @@ 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:
@@ -1122,6 +1157,8 @@ 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 659eaa0fc48f..e0189cf7c558 100644
--- a/drivers/pci/slot.c
+++ b/drivers/pci/slot.c
@@ -97,6 +97,50 @@ 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;
@@ -109,6 +153,8 @@ 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);
@@ -300,6 +346,8 @@ 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;