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