From 0994375e9614f78657031e04e30019b9cdb62795 Mon Sep 17 00:00:00 2001 From: Chris Wright Date: Mon, 23 Feb 2009 21:52:23 -0800 Subject: [PATCH] PCI: add remove_id sysfs entry This adds a remove_id sysfs entry to allow users of new_id to later remove the added dynid. One use case is management tools that want to dynamically bind/unbind devices to pci-stub driver while devices are assigned to KVM guests. Rather than having to track which driver was originally bound to the driver, a mangement tool can simply: Guest uses device Signed-off-by: Chris Wright Signed-off-by: Jesse Barnes --- Documentation/ABI/testing/sysfs-bus-pci | 16 +++++ drivers/pci/pci-driver.c | 80 ++++++++++++++++++++++++- 2 files changed, 94 insertions(+), 2 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci index e638e15a8895..3d29793a0ea2 100644 --- a/Documentation/ABI/testing/sysfs-bus-pci +++ b/Documentation/ABI/testing/sysfs-bus-pci @@ -41,6 +41,22 @@ Description: for the device and attempt to bind to it. For example: # echo "8086 10f5" > /sys/bus/pci/drivers/foo/new_id +What: /sys/bus/pci/drivers/.../remove_id +Date: February 2009 +Contact: Chris Wright +Description: + Writing a device ID to this file will remove an ID + that was dynamically added via the new_id sysfs entry. + The format for the device ID is: + VVVV DDDD SVVV SDDD CCCC MMMM. That is Vendor ID, Device + ID, Subsystem Vendor ID, Subsystem Device ID, Class, + and Class Mask. The Vendor ID and Device ID fields are + required, the rest are optional. After successfully + removing an ID, the driver will no longer support the + device. This is useful to ensure auto probing won't + match the driver to the device. For example: + # echo "8086 10f5" > /sys/bus/pci/drivers/foo/remove_id + What: /sys/bus/pci/devices/.../vpd Date: February 2008 Contact: Ben Hutchings diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 93eac1423585..87a5ddbb324f 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -99,6 +99,52 @@ store_new_id(struct device_driver *driver, const char *buf, size_t count) } static DRIVER_ATTR(new_id, S_IWUSR, NULL, store_new_id); +/** + * store_remove_id - remove a PCI device ID from this driver + * @driver: target device driver + * @buf: buffer for scanning device ID data + * @count: input size + * + * Removes a dynamic pci device ID to this driver. + */ +static ssize_t +store_remove_id(struct device_driver *driver, const char *buf, size_t count) +{ + struct pci_dynid *dynid, *n; + struct pci_driver *pdrv = to_pci_driver(driver); + __u32 vendor, device, subvendor = PCI_ANY_ID, + subdevice = PCI_ANY_ID, class = 0, class_mask = 0; + int fields = 0; + int retval = -ENODEV; + + fields = sscanf(buf, "%x %x %x %x %x %x", + &vendor, &device, &subvendor, &subdevice, + &class, &class_mask); + if (fields < 2) + return -EINVAL; + + spin_lock(&pdrv->dynids.lock); + list_for_each_entry_safe(dynid, n, &pdrv->dynids.list, node) { + struct pci_device_id *id = &dynid->id; + if ((id->vendor == vendor) && + (id->device == device) && + (subvendor == PCI_ANY_ID || id->subvendor == subvendor) && + (subdevice == PCI_ANY_ID || id->subdevice == subdevice) && + !((id->class ^ class) & class_mask)) { + list_del(&dynid->node); + kfree(dynid); + retval = 0; + break; + } + } + spin_unlock(&pdrv->dynids.lock); + + if (retval) + return retval; + return count; +} +static DRIVER_ATTR(remove_id, S_IWUSR, NULL, store_remove_id); + static void pci_free_dynids(struct pci_driver *drv) { @@ -125,6 +171,20 @@ static void pci_remove_newid_file(struct pci_driver *drv) { driver_remove_file(&drv->driver, &driver_attr_new_id); } + +static int +pci_create_removeid_file(struct pci_driver *drv) +{ + int error = 0; + if (drv->probe != NULL) + error = driver_create_file(&drv->driver,&driver_attr_remove_id); + return error; +} + +static void pci_remove_removeid_file(struct pci_driver *drv) +{ + driver_remove_file(&drv->driver, &driver_attr_remove_id); +} #else /* !CONFIG_HOTPLUG */ static inline void pci_free_dynids(struct pci_driver *drv) {} static inline int pci_create_newid_file(struct pci_driver *drv) @@ -132,6 +192,11 @@ static inline int pci_create_newid_file(struct pci_driver *drv) return 0; } static inline void pci_remove_newid_file(struct pci_driver *drv) {} +static inline int pci_create_removeid_file(struct pci_driver *drv) +{ + return 0; +} +static inline void pci_remove_removeid_file(struct pci_driver *drv) {} #endif /** @@ -852,13 +917,23 @@ int __pci_register_driver(struct pci_driver *drv, struct module *owner, /* register with core */ error = driver_register(&drv->driver); if (error) - return error; + goto out; error = pci_create_newid_file(drv); if (error) - driver_unregister(&drv->driver); + goto out_newid; + error = pci_create_removeid_file(drv); + if (error) + goto out_removeid; +out: return error; + +out_removeid: + pci_remove_newid_file(drv); +out_newid: + driver_unregister(&drv->driver); + goto out; } /** @@ -874,6 +949,7 @@ int __pci_register_driver(struct pci_driver *drv, struct module *owner, void pci_unregister_driver(struct pci_driver *drv) { + pci_remove_removeid_file(drv); pci_remove_newid_file(drv); driver_unregister(&drv->driver); pci_free_dynids(drv); -- 2.20.1