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author | Alex Chiang <achiang@hp.com> | 2009-03-20 14:56:31 -0600 |
---|---|---|
committer | Jesse Barnes <jbarnes@virtuousgeek.org> | 2009-03-20 14:57:58 -0700 |
commit | 705b1aaa823e800490f157cd9366ad8cff385f5f (patch) | |
tree | 634ea8ba227a305074938f49c110fea8e68e8bb3 | |
parent | 3ed4fd96b3188406ac5357d9290bcffa08c65cf6 (diff) | |
download | kernel_samsung_crespo-705b1aaa823e800490f157cd9366ad8cff385f5f.zip kernel_samsung_crespo-705b1aaa823e800490f157cd9366ad8cff385f5f.tar.gz kernel_samsung_crespo-705b1aaa823e800490f157cd9366ad8cff385f5f.tar.bz2 |
PCI: Introduce /sys/bus/pci/rescan
This interface allows the user to force a rescan of all PCI buses
in system, and rediscover devices that have been removed earlier.
pci_bus_attrs implementation from Trent Piepho.
Thanks to Vegard Nossum for discovering locking issues with the
sysfs interface.
Cc: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
-rw-r--r-- | Documentation/ABI/testing/sysfs-bus-pci | 9 | ||||
-rw-r--r-- | drivers/pci/pci-driver.c | 1 | ||||
-rw-r--r-- | drivers/pci/pci-sysfs.c | 26 | ||||
-rw-r--r-- | drivers/pci/pci.h | 6 | ||||
-rw-r--r-- | drivers/pci/probe.c | 4 |
5 files changed, 44 insertions, 2 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci index d175a2a..e6ad047 100644 --- a/Documentation/ABI/testing/sysfs-bus-pci +++ b/Documentation/ABI/testing/sysfs-bus-pci @@ -57,6 +57,15 @@ Description: match the driver to the device. For example: # echo "8086 10f5" > /sys/bus/pci/drivers/foo/remove_id +What: /sys/bus/pci/rescan +Date: January 2009 +Contact: Linux PCI developers <linux-pci@vger.kernel.org> +Description: + Writing a non-zero value to this attribute will + force a rescan of all PCI buses in the system, and + re-discover previously removed devices. + 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-driver.c b/drivers/pci/pci-driver.c index 87a5ddb..95d1985 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -1049,6 +1049,7 @@ struct bus_type pci_bus_type = { .remove = pci_device_remove, .shutdown = pci_device_shutdown, .dev_attrs = pci_dev_attrs, + .bus_attrs = pci_bus_attrs, .pm = PCI_PM_OPS_PTR, }; diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index ec7a175..be7468a 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -219,6 +219,32 @@ msi_bus_store(struct device *dev, struct device_attribute *attr, return count; } +#ifdef CONFIG_HOTPLUG +static DEFINE_MUTEX(pci_remove_rescan_mutex); +static ssize_t bus_rescan_store(struct bus_type *bus, const char *buf, + size_t count) +{ + unsigned long val; + struct pci_bus *b = NULL; + + if (strict_strtoul(buf, 0, &val) < 0) + return -EINVAL; + + if (val) { + mutex_lock(&pci_remove_rescan_mutex); + while ((b = pci_find_next_bus(b)) != NULL) + pci_rescan_bus(b); + 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_NULL +}; +#endif + struct device_attribute pci_dev_attrs[] = { __ATTR_RO(resource), __ATTR_RO(vendor), diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 22dcfdb..45833a5 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -138,6 +138,12 @@ extern int pcie_mch_quirk; extern struct device_attribute pci_dev_attrs[]; extern struct device_attribute dev_attr_cpuaffinity; extern struct device_attribute dev_attr_cpulistaffinity; +#ifdef CONFIG_HOTPLUG +extern struct bus_attribute pci_bus_attrs[]; +#else +#define pci_bus_attrs NULL +#endif + /** * pci_match_one_device - Tell if a PCI device structure has a matching diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 60a8e5f..56c71e5 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1228,13 +1228,13 @@ unsigned int __devinit pci_rescan_bus(struct pci_bus *bus) max = pci_scan_child_bus(bus); - up_read(&pci_bus_sem); + down_read(&pci_bus_sem); list_for_each_entry(dev, &bus->devices, bus_list) if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE || dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) if (dev->subordinate) pci_bus_size_bridges(dev->subordinate); - down_read(&pci_bus_sem); + up_read(&pci_bus_sem); pci_bus_assign_resources(bus); pci_enable_bridges(bus); |