diff options
author | Alexander Chiang <achiang@hp.com> | 2010-02-02 19:09:06 +0000 |
---|---|---|
committer | Roland Dreier <rolandd@cisco.com> | 2010-02-24 10:23:48 -0800 |
commit | daa913580e1a927aaf54f02ecfdf59c7b6bc2f6e (patch) | |
tree | 1765fa757c539a79430b8710277d5d1b5c77ab75 /drivers | |
parent | 31d14b6e10657113f72d496121d52ca779156b2e (diff) | |
download | linux-daa913580e1a927aaf54f02ecfdf59c7b6bc2f6e.tar.bz2 |
IB/ucm: Increase maximum devices supported
Some large systems may support more than IB_UCM_MAX_DEVICES
(currently 32).
This change allows us to support more devices in a backwards-compatible
manner. the first IB_UCM_MAX_DEVICES keep the same major/minor device
numbers they've always had.
If there are more than IB_UCM_MAX_DEVICES, then we dynamically request
a new major device number (new minors start at 0).
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/infiniband/core/ucm.c | 53 |
1 files changed, 45 insertions, 8 deletions
diff --git a/drivers/infiniband/core/ucm.c b/drivers/infiniband/core/ucm.c index 06c50d80f0d8..2e0d53eeec09 100644 --- a/drivers/infiniband/core/ucm.c +++ b/drivers/infiniband/core/ucm.c @@ -1215,7 +1215,10 @@ static void ib_ucm_release_dev(struct device *dev) ucm_dev = container_of(dev, struct ib_ucm_device, dev); cdev_del(&ucm_dev->cdev); - clear_bit(ucm_dev->devnum, dev_map); + if (ucm_dev->devnum < IB_UCM_MAX_DEVICES) + clear_bit(ucm_dev->devnum, dev_map); + else + clear_bit(ucm_dev->devnum - IB_UCM_MAX_DEVICES, dev_map); kfree(ucm_dev); } @@ -1237,6 +1240,28 @@ static ssize_t show_ibdev(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL); +static dev_t overflow_maj; +static DECLARE_BITMAP(overflow_map, IB_UCM_MAX_DEVICES); +static int find_overflow_devnum(void) +{ + int ret; + + if (!overflow_maj) { + ret = alloc_chrdev_region(&overflow_maj, 0, IB_UCM_MAX_DEVICES, + "infiniband_cm"); + if (ret) { + printk(KERN_ERR "ucm: couldn't register dynamic device number\n"); + return ret; + } + } + + ret = find_first_zero_bit(overflow_map, IB_UCM_MAX_DEVICES); + if (ret >= IB_UCM_MAX_DEVICES) + return -1; + + return ret; +} + static void ib_ucm_add_one(struct ib_device *device) { int devnum; @@ -1254,12 +1279,19 @@ static void ib_ucm_add_one(struct ib_device *device) ucm_dev->ib_dev = device; devnum = find_first_zero_bit(dev_map, IB_UCM_MAX_DEVICES); - if (devnum >= IB_UCM_MAX_DEVICES) - goto err; - - ucm_dev->devnum = devnum; - base = devnum + IB_UCM_BASE_DEV; - set_bit(devnum, dev_map); + if (devnum >= IB_UCM_MAX_DEVICES) { + devnum = find_overflow_devnum(); + if (devnum < 0) + goto err; + + ucm_dev->devnum = devnum + IB_UCM_MAX_DEVICES; + base = devnum + overflow_maj; + set_bit(devnum, overflow_map); + } else { + ucm_dev->devnum = devnum; + base = devnum + IB_UCM_BASE_DEV; + set_bit(devnum, dev_map); + } cdev_init(&ucm_dev->cdev, &ucm_fops); ucm_dev->cdev.owner = THIS_MODULE; @@ -1285,7 +1317,10 @@ err_dev: device_unregister(&ucm_dev->dev); err_cdev: cdev_del(&ucm_dev->cdev); - clear_bit(devnum, dev_map); + if (ucm_dev->devnum < IB_UCM_MAX_DEVICES) + clear_bit(devnum, dev_map); + else + clear_bit(devnum, overflow_map); err: kfree(ucm_dev); return; @@ -1344,6 +1379,8 @@ static void __exit ib_ucm_cleanup(void) ib_unregister_client(&ucm_client); class_remove_file(&cm_class, &class_attr_abi_version); unregister_chrdev_region(IB_UCM_BASE_DEV, IB_UCM_MAX_DEVICES); + if (overflow_maj) + unregister_chrdev_region(overflow_maj, IB_UCM_MAX_DEVICES); idr_destroy(&ctx_id_table); } |