3 files changed, 54 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index e6ad047cb3c2..daa791a9e85e 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -66,6 +66,14 @@ Description:
                 re-discover previously removed devices.
                 Depends on CONFIG_HOTPLUG.
 
+What:           /sys/bus/pci/devices/.../remove
+Date:           January 2009
+Contact:        Linux PCI developers <linux-pci@vger.kernel.org>
+Description:
+                Writing a non-zero value to this attribute will
+                hot-remove the PCI device and any of its children.
+                Depends on CONFIG_HOTPLUG.
+
 What:           /sys/bus/pci/devices/.../vpd
 Date:           February 2008
 Contact:        Ben Hutchings <bhutchings@solarflare.com>
diff --git a/Documentation/filesystems/sysfs-pci.txt b/Documentation/filesystems/sysfs-pci.txt
index 9f8740ca3f3b..26e4b8bc53ee 100644
--- a/Documentation/filesystems/sysfs-pci.txt
+++ b/Documentation/filesystems/sysfs-pci.txt
@@ -12,6 +12,7 @@ that support it.  For example, a given bus might look like this:
      |   |-- enable
      |   |-- irq
      |   |-- local_cpus
+     |   |-- remove
      |   |-- resource
      |   |-- resource0
      |   |-- resource1
@@ -36,6 +37,7 @@ files, each with their own function.
        enable              Whether the device is enabled (ascii, rw)
        irq                 IRQ number (ascii, ro)
        local_cpus          nearby CPU mask (cpumask, ro)
+       remove              remove device from kernel's list (ascii, wo)
        resource            PCI resource host addresses (ascii, ro)
        resource0..N        PCI resource N, if present (binary, mmap)
        resource0_wc..N_wc  PCI WC map resource N, if prefetchable (binary, mmap)
@@ -46,6 +48,7 @@ files, each with their own function.
 
   ro - read only file
   rw - file is readable and writable
+  wo - write only file
   mmap - file is mmapable
   ascii - file contains ascii text
   binary - file contains binary data
@@ -73,6 +76,13 @@ that the device must be enabled for a rom read to return data succesfully.
 In the event a driver is not bound to the device, it can be enabled using the
 'enable' file, documented above.
 
+The 'remove' file is used to remove the PCI device, by writing a non-zero
+integer to the file.  This does not involve any kind of hot-plug functionality,
+e.g. powering off the device.  The device is removed from the kernel's list of
+PCI devices, the sysfs directory for it is removed, and the device will be
+removed from any drivers attached to it. Removal of PCI root buses is
+disallowed.
+
 Accessing legacy resources through sysfs
 ----------------------------------------
 
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index be7468a5eb72..e16990ecc024 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -243,6 +243,39 @@ struct bus_attribute pci_bus_attrs[] = {
         __ATTR(rescan, (S_IWUSR|S_IWGRP), NULL, bus_rescan_store),
         __ATTR_NULL
 };
+
+static void remove_callback(struct device *dev)
+{
+        struct pci_dev *pdev = to_pci_dev(dev);
+
+        mutex_lock(&pci_remove_rescan_mutex);
+        pci_remove_bus_device(pdev);
+        mutex_unlock(&pci_remove_rescan_mutex);
+}
+
+static ssize_t
+remove_store(struct device *dev, struct device_attribute *dummy,
+             const char *buf, size_t count)
+{
+        int ret = 0;
+        unsigned long val;
+        struct pci_dev *pdev = to_pci_dev(dev);
+
+        if (strict_strtoul(buf, 0, &val) < 0)
+                return -EINVAL;
+
+        if (pci_is_root_bus(pdev->bus))
+                return -EBUSY;
+
+        /* An attribute cannot be unregistered by one of its own methods,
+         * so we have to use this roundabout approach.
+         */
+        if (val)
+                ret = device_schedule_callback(dev, remove_callback);
+        if (ret)
+                count = ret;
+        return count;
+}
 #endif
 
 struct device_attribute pci_dev_attrs[] = {
@@ -263,6 +296,9 @@ struct device_attribute pci_dev_attrs[] = {
         __ATTR(broken_parity_status,(S_IRUGO|S_IWUSR),
                 broken_parity_status_show,broken_parity_status_store),
         __ATTR(msi_bus, 0644, msi_bus_show, msi_bus_store),
+#ifdef CONFIG_HOTPLUG
+        __ATTR(remove, (S_IWUSR|S_IWGRP), NULL, remove_store),
+#endif
         __ATTR_NULL,
 };