107 lines
3.1 KiB
C
107 lines
3.1 KiB
C
|
/*
|
||
|
|
* Copyright (c) 2011 Chelsio Communications. All rights reserved.
|
||
|
|
*
|
||
|
|
* This software is available to you under a choice of one of two
|
||
|
|
* licenses. You may choose to be licensed under the terms of the GNU
|
||
|
|
* General Public License (GPL) Version 2, available from the file
|
||
|
|
* COPYING in the main directory of this source tree, or the
|
||
|
|
* OpenIB.org BSD license below:
|
||
|
|
*
|
||
|
|
* Redistribution and use in source and binary forms, with or
|
||
|
|
* without modification, are permitted provided that the following
|
||
|
|
* conditions are met:
|
||
|
|
*
|
||
|
|
* - Redistributions of source code must retain the above
|
||
|
|
* copyright notice, this list of conditions and the following
|
||
|
|
* disclaimer.
|
||
|
|
*
|
||
|
|
* - Redistributions in binary form must reproduce the above
|
||
|
|
* copyright notice, this list of conditions and the following
|
||
|
|
* disclaimer in the documentation and/or other materials
|
||
|
|
* provided with the distribution.
|
||
|
|
*
|
||
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
||
|
|
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
||
|
|
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
||
|
|
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
|
||
|
|
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
|
||
|
|
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
|
||
|
|
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
||
|
|
* SOFTWARE.
|
||
|
|
*/
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
#include <linux/random.h>
|
||
|
|
#include "iw_cxgb4.h"
|
||
|
|
|
||
|
|
#define RANDOM_SKIP 16
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Trivial bitmap-based allocator. If the random flag is set, the
|
||
|
|
* allocator is designed to:
|
||
|
|
* - pseudo-randomize the id returned such that it is not trivially predictable.
|
||
|
|
* - avoid reuse of recently used id (at the expense of predictability)
|
||
|
|
*/
|
||
|
|
u32 c4iw_id_alloc(struct c4iw_id_table *alloc)
|
||
|
|
{
|
||
|
|
unsigned long flags;
|
||
|
|
u32 obj;
|
||
|
|
|
||
|
|
spin_lock_irqsave(&alloc->lock, flags);
|
||
|
|
|
||
|
|
obj = find_next_zero_bit(alloc->table, alloc->max, alloc->last);
|
||
|
|
if (obj >= alloc->max)
|
||
|
|
obj = find_first_zero_bit(alloc->table, alloc->max);
|
||
|
|
|
||
|
|
if (obj < alloc->max) {
|
||
|
|
if (alloc->flags & C4IW_ID_TABLE_F_RANDOM)
|
||
|
|
alloc->last += get_random_u32_below(RANDOM_SKIP);
|
||
|
|
else
|
||
|
|
alloc->last = obj + 1;
|
||
|
|
if (alloc->last >= alloc->max)
|
||
|
|
alloc->last = 0;
|
||
|
|
__set_bit(obj, alloc->table);
|
||
|
|
obj += alloc->start;
|
||
|
|
} else
|
||
|
|
obj = -1;
|
||
|
|
|
||
|
|
spin_unlock_irqrestore(&alloc->lock, flags);
|
||
|
|
return obj;
|
||
|
|
}
|
||
|
|
|
||
|
|
void c4iw_id_free(struct c4iw_id_table *alloc, u32 obj)
|
||
|
|
{
|
||
|
|
unsigned long flags;
|
||
|
|
|
||
|
|
obj -= alloc->start;
|
||
|
|
|
||
|
|
spin_lock_irqsave(&alloc->lock, flags);
|
||
|
|
__clear_bit(obj, alloc->table);
|
||
|
|
spin_unlock_irqrestore(&alloc->lock, flags);
|
||
|
|
}
|
||
|
|
|
||
|
|
int c4iw_id_table_alloc(struct c4iw_id_table *alloc, u32 start, u32 num,
|
||
|
|
u32 reserved, u32 flags)
|
||
|
|
{
|
||
|
|
alloc->start = start;
|
||
|
|
alloc->flags = flags;
|
||
|
|
if (flags & C4IW_ID_TABLE_F_RANDOM)
|
||
|
|
alloc->last = get_random_u32_below(RANDOM_SKIP);
|
||
|
|
else
|
||
|
|
alloc->last = 0;
|
||
|
|
alloc->max = num;
|
||
|
|
spin_lock_init(&alloc->lock);
|
||
|
|
alloc->table = bitmap_zalloc(num, GFP_KERNEL);
|
||
|
|
if (!alloc->table)
|
||
|
|
return -ENOMEM;
|
||
|
|
|
||
|
|
if (!(alloc->flags & C4IW_ID_TABLE_F_EMPTY))
|
||
|
|
bitmap_set(alloc->table, 0, reserved);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
void c4iw_id_table_free(struct c4iw_id_table *alloc)
|
||
|
|
{
|
||
|
|
bitmap_free(alloc->table);
|
||
|
|
}
|