xref: /linux/net/core/hwbm.c (revision af873fcecef567abf8a3468b06dd4e4aab46da6d)
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, gfp_t gfp)
47 {
48 	int err, i;
49 	unsigned long flags;
50 
51 	spin_lock_irqsave(&bm_pool->lock, flags);
52 	if (bm_pool->buf_num == bm_pool->size) {
53 		pr_warn("pool already filled\n");
54 		spin_unlock_irqrestore(&bm_pool->lock, flags);
55 		return bm_pool->buf_num;
56 	}
57 
58 	if (buf_num + bm_pool->buf_num > bm_pool->size) {
59 		pr_warn("cannot allocate %d buffers for pool\n",
60 			buf_num);
61 		spin_unlock_irqrestore(&bm_pool->lock, flags);
62 		return 0;
63 	}
64 
65 	if ((buf_num + bm_pool->buf_num) < bm_pool->buf_num) {
66 		pr_warn("Adding %d buffers to the %d current buffers will overflow\n",
67 			buf_num,  bm_pool->buf_num);
68 		spin_unlock_irqrestore(&bm_pool->lock, flags);
69 		return 0;
70 	}
71 
72 	for (i = 0; i < buf_num; i++) {
73 		err = hwbm_pool_refill(bm_pool, gfp);
74 		if (err < 0)
75 			break;
76 	}
77 
78 	/* Update BM driver with number of buffers added to pool */
79 	bm_pool->buf_num += i;
80 
81 	pr_debug("hwpm pool: %d of %d buffers added\n", i, buf_num);
82 	spin_unlock_irqrestore(&bm_pool->lock, flags);
83 
84 	return i;
85 }
86 EXPORT_SYMBOL_GPL(hwbm_pool_add);
87