1/*
2 * Copyright (c) 2011-2013 Chelsio Communications. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
9 *
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
12 * conditions are met:
13 *
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer.
17 *
18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 */
32#include <sys/cdefs.h>
| 1/*
2 * Copyright (c) 2011-2013 Chelsio Communications. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
9 *
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
12 * conditions are met:
13 *
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer.
17 *
18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 */
32#include <sys/cdefs.h>
|
34
35#include "opt_inet.h"
36
37#ifdef TCP_OFFLOAD
38#include <sys/libkern.h>
39#include "iw_cxgbe.h"
40
41#define RANDOM_SKIP 16
42
43/*
44 * Trivial bitmap-based allocator. If the random flag is set, the
45 * allocator is designed to:
46 * - pseudo-randomize the id returned such that it is not trivially predictable.
47 * - avoid reuse of recently used id (at the expense of predictability)
48 */
49u32 c4iw_id_alloc(struct c4iw_id_table *alloc)
50{
51 unsigned long flags;
52 u32 obj;
53
54 spin_lock_irqsave(&alloc->lock, flags);
55
56 obj = find_next_zero_bit(alloc->table, alloc->max, alloc->last);
57 if (obj >= alloc->max)
58 obj = find_first_zero_bit(alloc->table, alloc->max);
59
60 if (obj < alloc->max) {
61 if (alloc->flags & C4IW_ID_TABLE_F_RANDOM)
62 alloc->last += arc4random() % RANDOM_SKIP;
63 else
64 alloc->last = obj + 1;
65 if (alloc->last >= alloc->max)
66 alloc->last = 0;
67 set_bit(obj, alloc->table);
68 obj += alloc->start;
69 } else
70 obj = -1;
71
72 spin_unlock_irqrestore(&alloc->lock, flags);
73 return obj;
74}
75
76void c4iw_id_free(struct c4iw_id_table *alloc, u32 obj)
77{
78 unsigned long flags;
79
80 obj -= alloc->start;
81 BUG_ON((int)obj < 0);
82
83 spin_lock_irqsave(&alloc->lock, flags);
84 clear_bit(obj, alloc->table);
85 spin_unlock_irqrestore(&alloc->lock, flags);
86}
87
88int c4iw_id_table_alloc(struct c4iw_id_table *alloc, u32 start, u32 num,
89 u32 reserved, u32 flags)
90{
91 int i;
92
93 alloc->start = start;
94 alloc->flags = flags;
95 if (flags & C4IW_ID_TABLE_F_RANDOM)
96 alloc->last = arc4random() % RANDOM_SKIP;
97 else
98 alloc->last = 0;
99 alloc->max = num;
100 spin_lock_init(&alloc->lock);
101 alloc->table = kmalloc(BITS_TO_LONGS(num) * sizeof(long),
102 GFP_KERNEL);
103 if (!alloc->table)
104 return -ENOMEM;
105
106 bitmap_zero(alloc->table, num);
107 if (!(alloc->flags & C4IW_ID_TABLE_F_EMPTY))
108 for (i = 0; i < reserved; ++i)
109 set_bit(i, alloc->table);
110
111 return 0;
112}
113
114void c4iw_id_table_free(struct c4iw_id_table *alloc)
115{
116 kfree(alloc->table);
117}
118#endif
| 34
35#include "opt_inet.h"
36
37#ifdef TCP_OFFLOAD
38#include <sys/libkern.h>
39#include "iw_cxgbe.h"
40
41#define RANDOM_SKIP 16
42
43/*
44 * Trivial bitmap-based allocator. If the random flag is set, the
45 * allocator is designed to:
46 * - pseudo-randomize the id returned such that it is not trivially predictable.
47 * - avoid reuse of recently used id (at the expense of predictability)
48 */
49u32 c4iw_id_alloc(struct c4iw_id_table *alloc)
50{
51 unsigned long flags;
52 u32 obj;
53
54 spin_lock_irqsave(&alloc->lock, flags);
55
56 obj = find_next_zero_bit(alloc->table, alloc->max, alloc->last);
57 if (obj >= alloc->max)
58 obj = find_first_zero_bit(alloc->table, alloc->max);
59
60 if (obj < alloc->max) {
61 if (alloc->flags & C4IW_ID_TABLE_F_RANDOM)
62 alloc->last += arc4random() % RANDOM_SKIP;
63 else
64 alloc->last = obj + 1;
65 if (alloc->last >= alloc->max)
66 alloc->last = 0;
67 set_bit(obj, alloc->table);
68 obj += alloc->start;
69 } else
70 obj = -1;
71
72 spin_unlock_irqrestore(&alloc->lock, flags);
73 return obj;
74}
75
76void c4iw_id_free(struct c4iw_id_table *alloc, u32 obj)
77{
78 unsigned long flags;
79
80 obj -= alloc->start;
81 BUG_ON((int)obj < 0);
82
83 spin_lock_irqsave(&alloc->lock, flags);
84 clear_bit(obj, alloc->table);
85 spin_unlock_irqrestore(&alloc->lock, flags);
86}
87
88int c4iw_id_table_alloc(struct c4iw_id_table *alloc, u32 start, u32 num,
89 u32 reserved, u32 flags)
90{
91 int i;
92
93 alloc->start = start;
94 alloc->flags = flags;
95 if (flags & C4IW_ID_TABLE_F_RANDOM)
96 alloc->last = arc4random() % RANDOM_SKIP;
97 else
98 alloc->last = 0;
99 alloc->max = num;
100 spin_lock_init(&alloc->lock);
101 alloc->table = kmalloc(BITS_TO_LONGS(num) * sizeof(long),
102 GFP_KERNEL);
103 if (!alloc->table)
104 return -ENOMEM;
105
106 bitmap_zero(alloc->table, num);
107 if (!(alloc->flags & C4IW_ID_TABLE_F_EMPTY))
108 for (i = 0; i < reserved; ++i)
109 set_bit(i, alloc->table);
110
111 return 0;
112}
113
114void c4iw_id_table_free(struct c4iw_id_table *alloc)
115{
116 kfree(alloc->table);
117}
118#endif
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