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
  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);