[PATCH 19/23] PCI: add /sys/bus/pci/rescan_root

Yinghai Lu
2012-03-06T07:17:04Z

It will be used to rediscover removed pci root buses.

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 | 9 +++++++++
drivers/pci/pci-sysfs.c | 21 +++++++++++++++++++++
2 files changed, 30 insertions(+), 0 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index 22392de..eb826bd 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -66,6 +66,15 @@ Description:
re-discover previously removed devices.
Depends on CONFIG_HOTPLUG.

+What: /sys/bus/pci/rescan_root
+Date: March 2012
+Contact: Linux PCI developers <linux-pci@vger.kernel.org>
+Description:
+ Writing a non-zero value to this attribute will
+ cause a rescan of all PCI root buses in the system, and
+ re-discover previously removed PCI root buses.
+ Depends on CONFIG_HOTPLUG.
+
What: /sys/bus/pci/devices/.../msi_irqs/
Date: September, 2011
Contact: Neil Horman <nhorman@tuxdriver.com>
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index f855b4b..d6221e5 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -302,8 +302,29 @@ static ssize_t bus_rescan_store(struct bus_type *bus, const char *buf,
return count;
}

+void __weak acpi_pci_root_rescan(void) { }
+void __weak pcibios_root_rescan(void) { }
+
+static ssize_t bus_rescan_root_store(struct bus_type *bus, const char *buf,
+ size_t count)
+{
+ unsigned long val;
+
+ if (strict_strtoul(buf, 0, &val) < 0)
+ return -EINVAL;
+
+ if (val) {
+ mutex_lock(&pci_remove_rescan_mutex);
+ acpi_pci_root_rescan();
+ pcibios_root_rescan();
+ mutex_unlock(&pci_remove_rescan_mutex);
+ }
+ return count;
+}
+
struct bus_attribute pci_bus_attrs[] = {
__ATTR(rescan, (S_IWUSR|S_IWGRP), NULL, bus_rescan_store),
+ __ATTR(rescan_root, (S_IWUSR|S_IWGRP), NULL, bus_rescan_root_store),
__ATTR_NULL
};

--
1.7.7