From b9d320fcb6259baffaeaf93a5fce252cd09333d6 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Thu, 12 May 2011 17:11:39 -0700 Subject: 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: Greg Kroah-Hartman Signed-off-by: Yinghai Lu Signed-off-by: Jesse Barnes --- Documentation/ABI/testing/sysfs-bus-pci | 9 +++++++++ drivers/pci/pci-sysfs.c | 26 ++++++++++++++++++++++++++ drivers/pci/pci.h | 1 + drivers/pci/probe.c | 1 + 4 files changed, 37 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci index 36bf454..349ecf2 100644 --- a/Documentation/ABI/testing/sysfs-bus-pci +++ b/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 +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 diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index f8deb3e..c690abc 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -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) { diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index a6ec200..dcf640a 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -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 diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 44cbbba..c471295 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -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) -- cgit v1.1