diff options
Diffstat (limited to 'drivers/char/misc.c')
| -rw-r--r-- | drivers/char/misc.c | 26 |
1 files changed, 11 insertions, 15 deletions
diff --git a/drivers/char/misc.c b/drivers/char/misc.c index 96f1cd086dd2..94a136e96c06 100644 --- a/drivers/char/misc.c +++ b/drivers/char/misc.c @@ -60,9 +60,7 @@ static DEFINE_MUTEX(misc_mtx); * Assigned numbers, used for dynamic minors */ #define DYNAMIC_MINORS 64 /* like dynamic majors */ -static unsigned char misc_minors[DYNAMIC_MINORS / 8]; - -extern int pmu_device_init(void); +static DECLARE_BITMAP(misc_minors, DYNAMIC_MINORS); #ifdef CONFIG_PROC_FS static void *misc_seq_start(struct seq_file *seq, loff_t *pos) @@ -198,24 +196,23 @@ int misc_register(struct miscdevice * misc) } if (misc->minor == MISC_DYNAMIC_MINOR) { - int i = DYNAMIC_MINORS; - while (--i >= 0) - if ( (misc_minors[i>>3] & (1 << (i&7))) == 0) - break; - if (i<0) { + int i = find_first_zero_bit(misc_minors, DYNAMIC_MINORS); + if (i >= DYNAMIC_MINORS) { mutex_unlock(&misc_mtx); return -EBUSY; } - misc->minor = i; + misc->minor = DYNAMIC_MINORS - i - 1; + set_bit(i, misc_minors); } - if (misc->minor < DYNAMIC_MINORS) - misc_minors[misc->minor >> 3] |= 1 << (misc->minor & 7); dev = MKDEV(MISC_MAJOR, misc->minor); misc->this_device = device_create(misc_class, misc->parent, dev, misc, "%s", misc->name); if (IS_ERR(misc->this_device)) { + int i = DYNAMIC_MINORS - misc->minor - 1; + if (i < DYNAMIC_MINORS && i >= 0) + clear_bit(i, misc_minors); err = PTR_ERR(misc->this_device); goto out; } @@ -242,7 +239,7 @@ int misc_register(struct miscdevice * misc) int misc_deregister(struct miscdevice *misc) { - int i = misc->minor; + int i = DYNAMIC_MINORS - misc->minor - 1; if (list_empty(&misc->list)) return -EINVAL; @@ -250,9 +247,8 @@ int misc_deregister(struct miscdevice *misc) mutex_lock(&misc_mtx); list_del(&misc->list); device_destroy(misc_class, MKDEV(MISC_MAJOR, misc->minor)); - if (i < DYNAMIC_MINORS && i>0) { - misc_minors[i>>3] &= ~(1 << (misc->minor & 7)); - } + if (i < DYNAMIC_MINORS && i >= 0) + clear_bit(i, misc_minors); mutex_unlock(&misc_mtx); return 0; } |