From a3aca3dabbcf00f2088d472f27755c29acaa992e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Kristian=20H=C3=B8gsberg?= Date: Wed, 7 Mar 2007 12:12:44 -0500 Subject: firewire: Switch cdev code over to use register_chrdev and keep a list of devices. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The old mechanism kept a struct cdev for each fw device, but fops->release would reference this struct after the device got freed in some cases. Signed-off-by: Kristian Høgsberg Signed-off-by: Stefan Richter --- drivers/firewire/fw-device.c | 56 ++++++++++++++++++++++++++++---------------- 1 file changed, 36 insertions(+), 20 deletions(-) (limited to 'drivers/firewire/fw-device.c') diff --git a/drivers/firewire/fw-device.c b/drivers/firewire/fw-device.c index ccc05e511a4..b24090ae9c7 100644 --- a/drivers/firewire/fw-device.c +++ b/drivers/firewire/fw-device.c @@ -25,6 +25,7 @@ #include #include #include +#include #include "fw-transaction.h" #include "fw-topology.h" #include "fw-device.h" @@ -407,14 +408,31 @@ static int shutdown_unit(struct device *device, void *data) return 0; } +static DEFINE_IDR(fw_device_idr); +int fw_cdev_major; + +struct fw_device *fw_device_from_devt(dev_t devt) +{ + struct fw_device *device; + + down_read(&fw_bus_type.subsys.rwsem); + device = idr_find(&fw_device_idr, MINOR(devt)); + up_read(&fw_bus_type.subsys.rwsem); + + return device; +} + static void fw_device_shutdown(struct work_struct *work) { struct fw_device *device = container_of(work, struct fw_device, work.work); + int minor = MINOR(device->device.devt); + + down_write(&fw_bus_type.subsys.rwsem); + idr_remove(&fw_device_idr, minor); + up_write(&fw_bus_type.subsys.rwsem); device_remove_file(&device->device, &config_rom_attribute); - cdev_del(&device->cdev); - unregister_chrdev_region(device->device.devt, 1); device_for_each_child(&device->device, NULL, shutdown_unit); device_unregister(&device->device); } @@ -434,9 +452,9 @@ static void fw_device_shutdown(struct work_struct *work) static void fw_device_init(struct work_struct *work) { - static atomic_t serial = ATOMIC_INIT(-1); struct fw_device *device = container_of(work, struct fw_device, work.work); + int minor, err; /* All failure paths here set node->data to NULL, so that we * don't try to do device_for_each_child() on a kfree()'d @@ -456,28 +474,24 @@ static void fw_device_init(struct work_struct *work) return; } + err = -ENOMEM; + down_write(&fw_bus_type.subsys.rwsem); + if (idr_pre_get(&fw_device_idr, GFP_KERNEL)) + err = idr_get_new(&fw_device_idr, device, &minor); + up_write(&fw_bus_type.subsys.rwsem); + if (err < 0) + goto error; + device->device.bus = &fw_bus_type; device->device.release = fw_device_release; device->device.parent = device->card->device; + device->device.devt = MKDEV(fw_cdev_major, minor); snprintf(device->device.bus_id, sizeof device->device.bus_id, - "fw%d", atomic_inc_return(&serial)); - - if (alloc_chrdev_region(&device->device.devt, 0, 1, "fw")) { - fw_error("Failed to register char device region.\n"); - goto error; - } - - cdev_init(&device->cdev, &fw_device_ops); - device->cdev.owner = THIS_MODULE; - kobject_set_name(&device->cdev.kobj, device->device.bus_id); - if (cdev_add(&device->cdev, device->device.devt, 1)) { - fw_error("Failed to register char device.\n"); - goto error; - } + "fw%d", minor); if (device_add(&device->device)) { fw_error("Failed to add device.\n"); - goto error; + goto error_with_cdev; } if (device_create_file(&device->device, &config_rom_attribute) < 0) { @@ -513,9 +527,11 @@ static void fw_device_init(struct work_struct *work) error_with_device: device_del(&device->device); + error_with_cdev: + down_write(&fw_bus_type.subsys.rwsem); + idr_remove(&fw_device_idr, minor); + up_write(&fw_bus_type.subsys.rwsem); error: - cdev_del(&device->cdev); - unregister_chrdev_region(device->device.devt, 1); put_device(&device->device); } -- cgit v1.2.3