| /* |
| * Copyright 2012 Hauke Mehrtens <hauke@hauke-m.de> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| * Backport functionality introduced in Linux 3.1. |
| */ |
| |
| #include <linux/idr.h> |
| #include <linux/cpufreq.h> |
| |
| static DEFINE_SPINLOCK(compat_simple_ida_lock); |
| |
| /** |
| * ida_simple_get - get a new id. |
| * @ida: the (initialized) ida. |
| * @start: the minimum id (inclusive, < 0x8000000) |
| * @end: the maximum id (exclusive, < 0x8000000 or 0) |
| * @gfp_mask: memory allocation flags |
| * |
| * Allocates an id in the range start <= id < end, or returns -ENOSPC. |
| * On memory allocation failure, returns -ENOMEM. |
| * |
| * Use ida_simple_remove() to get rid of an id. |
| */ |
| int ida_simple_get(struct ida *ida, unsigned int start, unsigned int end, |
| gfp_t gfp_mask) |
| { |
| int ret, id; |
| unsigned int max; |
| unsigned long flags; |
| |
| BUG_ON((int)start < 0); |
| BUG_ON((int)end < 0); |
| |
| if (end == 0) |
| max = 0x80000000; |
| else { |
| BUG_ON(end < start); |
| max = end - 1; |
| } |
| |
| again: |
| if (!ida_pre_get(ida, gfp_mask)) |
| return -ENOMEM; |
| |
| spin_lock_irqsave(&compat_simple_ida_lock, flags); |
| ret = ida_get_new_above(ida, start, &id); |
| if (!ret) { |
| if (id > max) { |
| ida_remove(ida, id); |
| ret = -ENOSPC; |
| } else { |
| ret = id; |
| } |
| } |
| spin_unlock_irqrestore(&compat_simple_ida_lock, flags); |
| |
| if (unlikely(ret == -EAGAIN)) |
| goto again; |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(ida_simple_get); |
| |
| /** |
| * ida_simple_remove - remove an allocated id. |
| * @ida: the (initialized) ida. |
| * @id: the id returned by ida_simple_get. |
| */ |
| void ida_simple_remove(struct ida *ida, unsigned int id) |
| { |
| unsigned long flags; |
| |
| BUG_ON((int)id < 0); |
| spin_lock_irqsave(&compat_simple_ida_lock, flags); |
| ida_remove(ida, id); |
| spin_unlock_irqrestore(&compat_simple_ida_lock, flags); |
| } |
| EXPORT_SYMBOL_GPL(ida_simple_remove); |
| /* source lib/idr.c */ |
| |