diff options
| -rw-r--r-- | drivers/infiniband/core/uverbs_main.c | 56 |
1 files changed, 50 insertions, 6 deletions
diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c index 8c594cde8a1d..7d42d550e87e 100644 --- a/drivers/infiniband/core/uverbs_main.c +++ b/drivers/infiniband/core/uverbs_main.c @@ -728,6 +728,34 @@ static ssize_t show_abi_version(struct class *class, char *buf) } static CLASS_ATTR(abi_version, S_IRUGO, show_abi_version, NULL); +static dev_t overflow_maj; +static DECLARE_BITMAP(overflow_map, IB_UVERBS_MAX_DEVICES); + +/* + * If we have more than IB_UVERBS_MAX_DEVICES, dynamically overflow by + * requesting a new major number and doubling the number of max devices we + * support. It's stupid, but simple. + */ +static int find_overflow_devnum(void) +{ + int ret; + + if (!overflow_maj) { + ret = alloc_chrdev_region(&overflow_maj, 0, IB_UVERBS_MAX_DEVICES, + "infiniband_verbs"); + if (ret) { + printk(KERN_ERR "user_verbs: couldn't register dynamic device number\n"); + return ret; + } + } + + ret = find_first_zero_bit(overflow_map, IB_UVERBS_MAX_DEVICES); + if (ret >= IB_UVERBS_MAX_DEVICES) + return -1; + + return ret; +} + static void ib_uverbs_add_one(struct ib_device *device) { int devnum; @@ -748,11 +776,19 @@ static void ib_uverbs_add_one(struct ib_device *device) devnum = find_first_zero_bit(dev_map, IB_UVERBS_MAX_DEVICES); if (devnum >= IB_UVERBS_MAX_DEVICES) { spin_unlock(&map_lock); - goto err; + devnum = find_overflow_devnum(); + if (devnum < 0) + goto err; + + spin_lock(&map_lock); + uverbs_dev->devnum = devnum + IB_UVERBS_MAX_DEVICES; + base = devnum + overflow_maj; + set_bit(devnum, overflow_map); + } else { + uverbs_dev->devnum = devnum; + base = devnum + IB_UVERBS_BASE_DEV; + set_bit(devnum, dev_map); } - uverbs_dev->devnum = devnum; - base = devnum + IB_UVERBS_BASE_DEV; - set_bit(devnum, dev_map); spin_unlock(&map_lock); uverbs_dev->ib_dev = device; @@ -785,7 +821,10 @@ err_class: err_cdev: cdev_del(&uverbs_dev->cdev); - clear_bit(devnum, dev_map); + if (uverbs_dev->devnum < IB_UVERBS_MAX_DEVICES) + clear_bit(devnum, dev_map); + else + clear_bit(devnum, overflow_map); err: kref_put(&uverbs_dev->ref, ib_uverbs_release_dev); @@ -805,7 +844,10 @@ static void ib_uverbs_remove_one(struct ib_device *device) device_destroy(uverbs_class, uverbs_dev->cdev.dev); cdev_del(&uverbs_dev->cdev); - clear_bit(uverbs_dev->devnum, dev_map); + if (uverbs_dev->devnum < IB_UVERBS_MAX_DEVICES) + clear_bit(uverbs_dev->devnum, dev_map); + else + clear_bit(uverbs_dev->devnum - IB_UVERBS_MAX_DEVICES, overflow_map); kref_put(&uverbs_dev->ref, ib_uverbs_release_dev); wait_for_completion(&uverbs_dev->comp); @@ -895,6 +937,8 @@ static void __exit ib_uverbs_cleanup(void) unregister_filesystem(&uverbs_event_fs); class_destroy(uverbs_class); unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES); + if (overflow_maj) + unregister_chrdev_region(overflow_maj, IB_UVERBS_MAX_DEVICES); idr_destroy(&ib_uverbs_pd_idr); idr_destroy(&ib_uverbs_mr_idr); idr_destroy(&ib_uverbs_mw_idr); |