xref: /openbmc/linux/net/core/hwbm.c (revision a2818ee4)
1  /* Support for hardware buffer manager.
2   *
3   * Copyright (C) 2016 Marvell
4   *
5   * Gregory CLEMENT <gregory.clement@free-electrons.com>
6   *
7   *  This program is free software; you can redistribute it and/or modify
8   *  it under the terms of the GNU General Public License as published by
9   *  the Free Software Foundation; either version 2 of the License, or
10   *  (at your option) any later version.
11   */
12  #include <linux/kernel.h>
13  #include <linux/printk.h>
14  #include <linux/skbuff.h>
15  #include <net/hwbm.h>
16  
17  void hwbm_buf_free(struct hwbm_pool *bm_pool, void *buf)
18  {
19  	if (likely(bm_pool->frag_size <= PAGE_SIZE))
20  		skb_free_frag(buf);
21  	else
22  		kfree(buf);
23  }
24  EXPORT_SYMBOL_GPL(hwbm_buf_free);
25  
26  /* Refill processing for HW buffer management */
27  int hwbm_pool_refill(struct hwbm_pool *bm_pool, gfp_t gfp)
28  {
29  	int frag_size = bm_pool->frag_size;
30  	void *buf;
31  
32  	if (likely(frag_size <= PAGE_SIZE))
33  		buf = netdev_alloc_frag(frag_size);
34  	else
35  		buf = kmalloc(frag_size, gfp);
36  
37  	if (!buf)
38  		return -ENOMEM;
39  
40  	if (bm_pool->construct)
41  		if (bm_pool->construct(bm_pool, buf)) {
42  			hwbm_buf_free(bm_pool, buf);
43  			return -ENOMEM;
44  		}
45  
46  	return 0;
47  }
48  EXPORT_SYMBOL_GPL(hwbm_pool_refill);
49  
50  int hwbm_pool_add(struct hwbm_pool *bm_pool, unsigned int buf_num, gfp_t gfp)
51  {
52  	int err, i;
53  	unsigned long flags;
54  
55  	spin_lock_irqsave(&bm_pool->lock, flags);
56  	if (bm_pool->buf_num == bm_pool->size) {
57  		pr_warn("pool already filled\n");
58  		spin_unlock_irqrestore(&bm_pool->lock, flags);
59  		return bm_pool->buf_num;
60  	}
61  
62  	if (buf_num + bm_pool->buf_num > bm_pool->size) {
63  		pr_warn("cannot allocate %d buffers for pool\n",
64  			buf_num);
65  		spin_unlock_irqrestore(&bm_pool->lock, flags);
66  		return 0;
67  	}
68  
69  	if ((buf_num + bm_pool->buf_num) < bm_pool->buf_num) {
70  		pr_warn("Adding %d buffers to the %d current buffers will overflow\n",
71  			buf_num,  bm_pool->buf_num);
72  		spin_unlock_irqrestore(&bm_pool->lock, flags);
73  		return 0;
74  	}
75  
76  	for (i = 0; i < buf_num; i++) {
77  		err = hwbm_pool_refill(bm_pool, gfp);
78  		if (err < 0)
79  			break;
80  	}
81  
82  	/* Update BM driver with number of buffers added to pool */
83  	bm_pool->buf_num += i;
84  
85  	pr_debug("hwpm pool: %d of %d buffers added\n", i, buf_num);
86  	spin_unlock_irqrestore(&bm_pool->lock, flags);
87  
88  	return i;
89  }
90  EXPORT_SYMBOL_GPL(hwbm_pool_add);
91