LXR linux/net/core/hwbm.c

   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
  13void 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}
  20EXPORT_SYMBOL_GPL(hwbm_buf_free);
  21
  22/* Refill processing for HW buffer management */
  23int 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}
  44EXPORT_SYMBOL_GPL(hwbm_pool_refill);
  45
  46int 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}
  85EXPORT_SYMBOL_GPL(hwbm_pool_add);
  86