net/core/hwbm.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /* Support for hardware buffer manager.
0003  *
0004  * Copyright (C) 2016 Marvell
0005  *
0006  * Gregory CLEMENT <gregory.clement@free-electrons.com>
0007  */
0008 #include <linux/kernel.h>
0009 #include <linux/printk.h>
0010 #include <linux/skbuff.h>
0011 #include <net/hwbm.h>
0012
0013 void hwbm_buf_free(struct hwbm_pool *bm_pool, void *buf)
0014 {
0015     if (likely(bm_pool->frag_size <= PAGE_SIZE))
0016         skb_free_frag(buf);
0017     else
0018         kfree(buf);
0019 }
0020 EXPORT_SYMBOL_GPL(hwbm_buf_free);
0021
0022 /* Refill processing for HW buffer management */
0023 int hwbm_pool_refill(struct hwbm_pool *bm_pool, gfp_t gfp)
0024 {
0025     int frag_size = bm_pool->frag_size;
0026     void *buf;
0027
0028     if (likely(frag_size <= PAGE_SIZE))
0029         buf = netdev_alloc_frag(frag_size);
0030     else
0031         buf = kmalloc(frag_size, gfp);
0032
0033     if (!buf)
0034         return -ENOMEM;
0035
0036     if (bm_pool->construct)
0037         if (bm_pool->construct(bm_pool, buf)) {
0038             hwbm_buf_free(bm_pool, buf);
0039             return -ENOMEM;
0040         }
0041
0042     return 0;
0043 }
0044 EXPORT_SYMBOL_GPL(hwbm_pool_refill);
0045
0046 int hwbm_pool_add(struct hwbm_pool *bm_pool, unsigned int buf_num)
0047 {
0048     int err, i;
0049
0050     mutex_lock(&bm_pool->buf_lock);
0051     if (bm_pool->buf_num == bm_pool->size) {
0052         pr_warn("pool already filled\n");
0053         mutex_unlock(&bm_pool->buf_lock);
0054         return bm_pool->buf_num;
0055     }
0056
0057     if (buf_num + bm_pool->buf_num > bm_pool->size) {
0058         pr_warn("cannot allocate %d buffers for pool\n",
0059             buf_num);
0060         mutex_unlock(&bm_pool->buf_lock);
0061         return 0;
0062     }
0063
0064     if ((buf_num + bm_pool->buf_num) < bm_pool->buf_num) {
0065         pr_warn("Adding %d buffers to the %d current buffers will overflow\n",
0066             buf_num,  bm_pool->buf_num);
0067         mutex_unlock(&bm_pool->buf_lock);
0068         return 0;
0069     }
0070
0071     for (i = 0; i < buf_num; i++) {
0072         err = hwbm_pool_refill(bm_pool, GFP_KERNEL);
0073         if (err < 0)
0074             break;
0075     }
0076
0077     /* Update BM driver with number of buffers added to pool */
0078     bm_pool->buf_num += i;
0079
0080     pr_debug("hwpm pool: %d of %d buffers added\n", i, buf_num);
0081     mutex_unlock(&bm_pool->buf_lock);
0082
0083     return i;
0084 }
0085 EXPORT_SYMBOL_GPL(hwbm_pool_add);