[PATCH 16/23] PCI: add pci bus removal through /sys/.../pci_bus/.../remove

Yinghai Lu
2012-03-06T07:16:39Z

it supports both pci root bus and pci bus under pci bridge.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-doc@vger.kernel.org
---
Documentation/ABI/testing/sysfs-bus-pci | 8 ++++++++
drivers/pci/pci-sysfs.c | 28 ++++++++++++++++++++++++++++
2 files changed, 36 insertions(+), 0 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index 95f0f37..22392de 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -92,6 +92,14 @@ Description:
hot-remove the PCI device and any of its children.
Depends on CONFIG_HOTPLUG.

+What: /sys/bus/pci/devices/.../pci_bus/.../remove
+Date: March 2012
+Contact: Linux PCI developers <linux-pci@vger.kernel.org>
+Description:
+ Writing a non-zero value to this attribute will
+ hot-remove the PCI bus and any of its children.
+ Depends on CONFIG_HOTPLUG.
+
What: /sys/bus/pci/devices/.../pci_bus/.../rescan
Date: May 2011
Contact: Linux PCI developers <linux-pci@vger.kernel.org>
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 1794508..f855b4b 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -385,6 +385,33 @@ remove_store(struct device *dev, struct device_attribute *dummy,
return count;
}

+static void bus_remove_callback(struct device *dev)
+{
+ struct pci_bus *bus = to_pci_bus(dev);
+
+ mutex_lock(&pci_remove_rescan_mutex);
+ pci_stop_and_remove_bus(bus);
+ mutex_unlock(&pci_remove_rescan_mutex);
+}
+static ssize_t
+dev_bus_remove_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int ret = 0;
+ unsigned long val;
+
+ if (kstrtoul(buf, 0, &val) < 0)
+ return -EINVAL;
+
+ if (val)
+ ret = device_schedule_callback(dev, bus_remove_callback);
+
+ if (ret)
+ count = ret;
+
+ return count;
+}
+
static void bus_rescan_callback(struct device *dev)
{
struct pci_bus *bus = to_pci_bus(dev);
@@ -444,6 +471,7 @@ struct device_attribute pci_dev_attrs[] = {
struct device_attribute pcibus_dev_attrs[] = {
#ifdef CONFIG_HOTPLUG
__ATTR(rescan, (S_IWUSR|S_IWGRP), NULL, dev_bus_rescan_store),
+ __ATTR(remove, (S_IWUSR|S_IWGRP), NULL, dev_bus_remove_store),
#endif
__ATTR(cpuaffinity, S_IRUGO, pci_bus_show_cpumaskaffinity, NULL),
__ATTR(cpulistaffinity, S_IRUGO, pci_bus_show_cpulistaffinity, NULL),
--
1.7.7