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Commit b9d320fc authored by Yinghai Lu's avatar Yinghai Lu Committed by Jesse Barnes
Browse files

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.
-v3: GregKH pointed out that we should use dev_attrs to avoid racing.
     So add pcibus_attrs and make it to be member of pcibus_attrs.
-v4: Change name to pcibus_dev_attrs according to GregKH

Acked-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent da7822e5

Documentation/ABI/testing/sysfs-bus-pci

+9 −0
Original line number Diff line number Diff line
@@ -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@vger.kernel.org>

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@vger.kernel.org>

drivers/pci/pci-sysfs.c

+26 −0
Original line number Diff line number Diff line
@@ -318,6 +318,25 @@ remove_store(struct device *dev, struct device_attribute *dummy, 
		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;

}



#endif



struct device_attribute pci_dev_attrs[] = {
@@ -347,6 +366,13 @@ struct device_attribute pci_dev_attrs[] = { 
	__ATTR_NULL,

};



struct device_attribute pcibus_dev_attrs[] = {

#ifdef CONFIG_HOTPLUG

	__ATTR(rescan, (S_IWUSR|S_IWGRP), NULL, dev_bus_rescan_store),

#endif

	__ATTR_NULL,

};



static ssize_t

boot_vga_show(struct device *dev, struct device_attribute *attr, char *buf)

{

drivers/pci/pci.h

+1 −0
Original line number Diff line number Diff line
@@ -156,6 +156,7 @@ static inline int pci_no_d1d2(struct pci_dev *dev) 


}

extern struct device_attribute pci_dev_attrs[];

extern struct device_attribute pcibus_dev_attrs[];

extern struct device_attribute dev_attr_cpuaffinity;

extern struct device_attribute dev_attr_cpulistaffinity;

#ifdef CONFIG_HOTPLUG

drivers/pci/probe.c

+1 −0
Original line number Diff line number Diff line
@@ -95,6 +95,7 @@ static void release_pcibus_dev(struct device *dev) 
static struct class pcibus_class = {

	.name		= "pci_bus",

	.dev_release	= &release_pcibus_dev,

	.dev_attrs	= pcibus_dev_attrs,

};



static int __init pcibus_class_init(void)