cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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hwbm.c (1926B)

      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);