[RFC PATCH 04/10] PCI: Introduce /sys/bus/pci/devices/.../remove

Alex Chiang
2009-01-28T22:01:15Z

This patch adds an attribute named "remove" to a PCI device's sysfs
directory. Writing a non-zero value to this attribute will remove the PCI
device and any of its children.

Code was originally written by Trent Piepho, with a small cleanup and
additional documentation from me.

Cc: Trent Piepho <xyzzy@speakeasy.org>
Cc: djwong@us.ibm.com
Reviewed-by: James Cameron <qz@hp.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
---

Documentation/ABI/testing/sysfs-bus-pci | 8 ++++++++
drivers/pci/pci-sysfs.c | 30 ++++++++++++++++++++++++++++++
2 files changed, 38 insertions(+), 0 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index ceddcff..faa21de 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -1,3 +1,11 @@
+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/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index db7ec14..603a32d 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -219,6 +219,33 @@ msi_bus_store(struct device *dev, struct device_attribute *attr,
return count;
}

+#ifdef CONFIG_HOTPLUG
+static void remove_callback(void *data)
+{
+ pci_remove_bus_device((struct pci_dev *)data);
+}
+
+static ssize_t
+remove_store(struct device *dev, struct device_attribute *dummy,
+ const char *buf, size_t count)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ unsigned long val;
+
+ if (strict_strtoul(buf, 0, &val) < 0)
+ return -EINVAL;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if (val)
+ sysfs_schedule_callback(&dev->kobj, remove_callback, pdev,
+ THIS_MODULE);
+
+ return count;
+}
+#endif
+
struct device_attribute pci_dev_attrs[] = {
__ATTR_RO(resource),
__ATTR_RO(vendor),
@@ -237,6 +264,9 @@ 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, NULL, remove_store),
+#endif
__ATTR_NULL,
};