[PATCH -v2 1/3] pci: add rescan to /sys/.../pci_bus/.../
After remove the device from /sys, we have to rescan all or
find out the bridge and access /sys../device/rescan there.
this patch add /sys/.../pci_bus/.../rescan. So user can rescan more easy.
that is more clean and easy to understand.
like after remove 0000:c4:00.0, you can rescan 0000:c4 directly.
-v2: According to Jesse, use function instead of exposing attr, so could hide
#ifdef in header file.
also add code to remove rescan file in remove path.
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
---
Documentation/ABI/testing/sysfs-bus-pci | 9 +++++++++
drivers/pci/bus.c | 4 ++++
drivers/pci/pci-sysfs.c | 31 +++++++++++++++++++++++++++++++
drivers/pci/pci.h | 10 ++++++++++
drivers/pci/probe.c | 5 +++++
drivers/pci/remove.c | 1 +
6 files changed, 60 insertions(+)
Index: linux-2.6/drivers/pci/pci-sysfs.c
===================================================================
--- linux-2.6.orig/drivers/pci/pci-sysfs.c
+++ linux-2.6/drivers/pci/pci-sysfs.c
@@ -318,6 +318,37 @@ remove_store(struct device *dev, struct
count = ret;
return count;
}
+
+static ssize_t
+dev_bus_rescan_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ unsigned long val;
+ struct pci_bus *bus = to_pci_bus(dev);
+
+ if (strict_strtoul(buf, 0, &val) < 0)
+ return -EINVAL;
+
+ if (val) {
+ mutex_lock(&pci_remove_rescan_mutex);
+ pci_rescan_bus(bus);
+ mutex_unlock(&pci_remove_rescan_mutex);
+ }
+ return count;
+}
+
+DEVICE_ATTR(rescan, (S_IWUSR|S_IWGRP), NULL, dev_bus_rescan_store);
+
+int pci_bus_create_rescan_file(struct pci_bus *bus)
+{
+ return device_create_file(&bus->dev, &dev_attr_rescan);
+}
+
+void pci_bus_remove_rescan_file(struct pci_bus *bus)
+{
+ device_remove_file(&bus->dev, &dev_attr_rescan);
+}
+
#endif
struct device_attribute pci_dev_attrs[] = {
Index: linux-2.6/drivers/pci/bus.c
===================================================================
--- linux-2.6.orig/drivers/pci/bus.c
+++ linux-2.6/drivers/pci/bus.c
@@ -163,6 +163,10 @@ int pci_bus_add_child(struct pci_bus *bu
bus->is_added = 1;
+ retval = pci_bus_create_rescan_file(bus);
+ if (retval)
+ return retval;
+
retval = device_create_file(&bus->dev, &dev_attr_cpuaffinity);
if (retval)
return retval;
Index: linux-2.6/drivers/pci/pci.h
===================================================================
--- linux-2.6.orig/drivers/pci/pci.h
+++ linux-2.6/drivers/pci/pci.h
@@ -159,9 +159,19 @@ extern struct device_attribute pci_dev_a
extern struct device_attribute dev_attr_cpuaffinity;
extern struct device_attribute dev_attr_cpulistaffinity;
#ifdef CONFIG_HOTPLUG
+int pci_bus_create_rescan_file(struct pci_bus *bus);
+void pci_bus_remove_rescan_file(struct pci_bus *bus);
+extern struct device_attribute dev_attr_rescan;
extern struct bus_attribute pci_bus_attrs[];
#else
#define pci_bus_attrs NULL
+static inline int pci_bus_create_rescan_file(struct device *dev)
+{
+ return 0;
+}
+static inline void pci_bus_remove_rescan_file(struct device *dev)
+{
+}
#endif
Index: linux-2.6/drivers/pci/probe.c
===================================================================
--- linux-2.6.orig/drivers/pci/probe.c
+++ linux-2.6/drivers/pci/probe.c
@@ -1471,6 +1471,9 @@ struct pci_bus * pci_create_bus(struct d
error = device_create_file(&b->dev, &dev_attr_cpuaffinity);
if (error)
goto dev_create_file_err;
+ error = pci_bus_create_rescan_file(b);
+ if (error)
+ goto dev_create_bus_rescan_err;
/* Create legacy_io and legacy_mem files for this bus */
pci_create_legacy_files(b);
@@ -1481,6 +1484,8 @@ struct pci_bus * pci_create_bus(struct d
return b;
+dev_create_bus_rescan_err:
+ device_remove_file(&b->dev, &dev_attr_cpuaffinity);
dev_create_file_err:
device_unregister(&b->dev);
class_dev_reg_err:
Index: linux-2.6/Documentation/ABI/testing/sysfs-bus-pci
===================================================================
--- linux-2.6.orig/Documentation/ABI/testing/sysfs-bus-pci
+++ linux-2.6/Documentation/ABI/testing/sysfs-bus-pci
@@ -74,6 +74,15 @@ Description:
hot-remove the PCI device 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@xxxxxxxxxxxxxxx>
+Description:
+ Writing a non-zero value to this attribute will
+ force a rescan of the bus and all child buses,
+ and re-discover devices removed earlier from this
+ part of the device tree. Depends on CONFIG_HOTPLUG.
+
What: /sys/bus/pci/devices/.../rescan
Date: January 2009
Contact: Linux PCI developers <linux-pci@xxxxxxxxxxxxxxx>
Index: linux-2.6/drivers/pci/remove.c
===================================================================
--- linux-2.6.orig/drivers/pci/remove.c
+++ linux-2.6/drivers/pci/remove.c
@@ -73,6 +73,7 @@ void pci_remove_bus(struct pci_bus *pci_
return;
pci_remove_legacy_files(pci_bus);
+ pci_bus_remove_rescan_file(pci_bus);
device_remove_file(&pci_bus->dev, &dev_attr_cpuaffinity);
device_remove_file(&pci_bus->dev, &dev_attr_cpulistaffinity);
device_unregister(&pci_bus->dev);
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