1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Support for hardware buffer manager.
3 *
4 * Copyright (C) 2016 Marvell
5 *
6 * Gregory CLEMENT <gregory.clement@free-electrons.com>
7 */
8 #include <linux/kernel.h>
9 #include <linux/printk.h>
10 #include <linux/skbuff.h>
11 #include <net/hwbm.h>
12
13 void hwbm_buf_free(struct hwbm_pool *bm_pool, void *buf)
14 {
15 if (likely(bm_pool->frag_size <= PAGE_SIZE))
16 skb_free_frag(buf);
17 else
18 kfree(buf);
19 }
20 EXPORT_SYMBOL_GPL(hwbm_buf_free);
21
22 /* Refill processing for HW buffer management */
23 int hwbm_pool_refill(struct hwbm_pool *bm_pool, gfp_t gfp)
24 {
25 int frag_size = bm_pool->frag_size;
26 void *buf;
27
28 if (likely(frag_size <= PAGE_SIZE))
29 buf = netdev_alloc_frag(frag_size);
30 else
31 buf = kmalloc(frag_size, gfp);
32
33 if (!buf)
34 return -ENOMEM;
35
36 if (bm_pool->construct)
37 if (bm_pool->construct(bm_pool, buf)) {
38 hwbm_buf_free(bm_pool, buf);
39 return -ENOMEM;
40 }
41
42 return 0;
43 }
44 EXPORT_SYMBOL_GPL(hwbm_pool_refill);
45
46 int hwbm_pool_add(struct hwbm_pool *bm_pool, unsigned int buf_num)
47 {
48 int err, i;
49
50 mutex_lock(&bm_pool->buf_lock);
51 if (bm_pool->buf_num == bm_pool->size) {
52 pr_warn("pool already filled\n");
53 mutex_unlock(&bm_pool->buf_lock);
54 return bm_pool->buf_num;
55 }
56
57 if (buf_num + bm_pool->buf_num > bm_pool->size) {
58 pr_warn("cannot allocate %d buffers for pool\n",
59 buf_num);
60 mutex_unlock(&bm_pool->buf_lock);
61 return 0;
62 }
63
64 if ((buf_num + bm_pool->buf_num) < bm_pool->buf_num) {
65 pr_warn("Adding %d buffers to the %d current buffers will overflow\n",
66 buf_num, bm_pool->buf_num);
67 mutex_unlock(&bm_pool->buf_lock);
68 return 0;
69 }
70
71 for (i = 0; i < buf_num; i++) {
72 err = hwbm_pool_refill(bm_pool, GFP_KERNEL);
73 if (err < 0)
74 break;
75 }
76
77 /* Update BM driver with number of buffers added to pool */
78 bm_pool->buf_num += i;
79
80 pr_debug("hwpm pool: %d of %d buffers added\n", i, buf_num);
81 mutex_unlock(&bm_pool->buf_lock);
82
83 return i;
84 }
85 EXPORT_SYMBOL_GPL(hwbm_pool_add);
86
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