LXR linux/net/core/hwbm.c

   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
  17void 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}
  24EXPORT_SYMBOL_GPL(hwbm_buf_free);
  25
  26/* Refill processing for HW buffer management */
  27int 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}
  48EXPORT_SYMBOL_GPL(hwbm_pool_refill);
  49
  50int 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}
  90EXPORT_SYMBOL_GPL(hwbm_pool_add);
  91