diff options
Diffstat (limited to 'drivers/char/misc.c')
| -rw-r--r-- | drivers/char/misc.c | 33 |
1 files changed, 18 insertions, 15 deletions
diff --git a/drivers/char/misc.c b/drivers/char/misc.c index 541edc26ec89..d5accc10a110 100644 --- a/drivers/char/misc.c +++ b/drivers/char/misc.c @@ -58,31 +58,27 @@ static LIST_HEAD(misc_list); static DEFINE_MUTEX(misc_mtx); /* - * Assigned numbers, used for dynamic minors + * Assigned numbers. */ -#define DYNAMIC_MINORS 128 /* like dynamic majors */ static DEFINE_IDA(misc_minors_ida); -static int misc_minor_alloc(void) +static int misc_minor_alloc(int minor) { - int ret; + int ret = 0; - ret = ida_alloc_max(&misc_minors_ida, DYNAMIC_MINORS - 1, GFP_KERNEL); - if (ret >= 0) { - ret = DYNAMIC_MINORS - ret - 1; - } else { + if (minor == MISC_DYNAMIC_MINOR) { + /* allocate free id */ ret = ida_alloc_range(&misc_minors_ida, MISC_DYNAMIC_MINOR + 1, MINORMASK, GFP_KERNEL); + } else { + ret = ida_alloc_range(&misc_minors_ida, minor, minor, GFP_KERNEL); } return ret; } static void misc_minor_free(int minor) { - if (minor < DYNAMIC_MINORS) - ida_free(&misc_minors_ida, DYNAMIC_MINORS - minor - 1); - else if (minor > MISC_DYNAMIC_MINOR) - ida_free(&misc_minors_ida, minor); + ida_free(&misc_minors_ida, minor); } #ifdef CONFIG_PROC_FS @@ -219,7 +215,7 @@ int misc_register(struct miscdevice *misc) mutex_lock(&misc_mtx); if (is_dynamic) { - int i = misc_minor_alloc(); + int i = misc_minor_alloc(misc->minor); if (i < 0) { err = -EBUSY; @@ -228,6 +224,7 @@ int misc_register(struct miscdevice *misc) misc->minor = i; } else { struct miscdevice *c; + int i; list_for_each_entry(c, &misc_list, list) { if (c->minor == misc->minor) { @@ -235,6 +232,12 @@ int misc_register(struct miscdevice *misc) goto out; } } + + i = misc_minor_alloc(misc->minor); + if (i < 0) { + err = -EBUSY; + goto out; + } } dev = MKDEV(MISC_MAJOR, misc->minor); @@ -243,8 +246,8 @@ int misc_register(struct miscdevice *misc) device_create_with_groups(&misc_class, misc->parent, dev, misc, misc->groups, "%s", misc->name); if (IS_ERR(misc->this_device)) { + misc_minor_free(misc->minor); if (is_dynamic) { - misc_minor_free(misc->minor); misc->minor = MISC_DYNAMIC_MINOR; } err = PTR_ERR(misc->this_device); @@ -294,7 +297,7 @@ static int __init misc_init(void) goto fail_remove; err = -EIO; - if (register_chrdev(MISC_MAJOR, "misc", &misc_fops)) + if (__register_chrdev(MISC_MAJOR, 0, MINORMASK + 1, "misc", &misc_fops)) goto fail_printk; return 0; |