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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mpfs.c (5484B)


      1/*
      2 * Copyright (c) 2017, Mellanox Technologies. All rights reserved.
      3 *
      4 * This software is available to you under a choice of one of two
      5 * licenses.  You may choose to be licensed under the terms of the GNU
      6 * General Public License (GPL) Version 2, available from the file
      7 * COPYING in the main directory of this source tree, or the
      8 * OpenIB.org BSD license below:
      9 *
     10 *     Redistribution and use in source and binary forms, with or
     11 *     without modification, are permitted provided that the following
     12 *     conditions are met:
     13 *
     14 *      - Redistributions of source code must retain the above
     15 *        copyright notice, this list of conditions and the following
     16 *        disclaimer.
     17 *
     18 *      - Redistributions in binary form must reproduce the above
     19 *        copyright notice, this list of conditions and the following
     20 *        disclaimer in the documentation and/or other materials
     21 *        provided with the distribution.
     22 *
     23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
     24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
     25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
     26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
     27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
     28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
     29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
     30 * SOFTWARE.
     31 */
     32
     33#include <linux/etherdevice.h>
     34#include <linux/mlx5/driver.h>
     35#include <linux/mlx5/mlx5_ifc.h>
     36#include <linux/mlx5/mpfs.h>
     37#include <linux/mlx5/eswitch.h>
     38#include "mlx5_core.h"
     39#include "lib/mpfs.h"
     40
     41/* HW L2 Table (MPFS) management */
     42static int set_l2table_entry_cmd(struct mlx5_core_dev *dev, u32 index, u8 *mac)
     43{
     44	u32 in[MLX5_ST_SZ_DW(set_l2_table_entry_in)] = {};
     45	u8 *in_mac_addr;
     46
     47	MLX5_SET(set_l2_table_entry_in, in, opcode, MLX5_CMD_OP_SET_L2_TABLE_ENTRY);
     48	MLX5_SET(set_l2_table_entry_in, in, table_index, index);
     49
     50	in_mac_addr = MLX5_ADDR_OF(set_l2_table_entry_in, in, mac_address);
     51	ether_addr_copy(&in_mac_addr[2], mac);
     52
     53	return mlx5_cmd_exec_in(dev, set_l2_table_entry, in);
     54}
     55
     56static int del_l2table_entry_cmd(struct mlx5_core_dev *dev, u32 index)
     57{
     58	u32 in[MLX5_ST_SZ_DW(delete_l2_table_entry_in)] = {};
     59
     60	MLX5_SET(delete_l2_table_entry_in, in, opcode, MLX5_CMD_OP_DELETE_L2_TABLE_ENTRY);
     61	MLX5_SET(delete_l2_table_entry_in, in, table_index, index);
     62	return mlx5_cmd_exec_in(dev, delete_l2_table_entry, in);
     63}
     64
     65/* UC L2 table hash node */
     66struct l2table_node {
     67	struct l2addr_node node;
     68	u32                index; /* index in HW l2 table */
     69	int                ref_count;
     70};
     71
     72struct mlx5_mpfs {
     73	struct hlist_head    hash[MLX5_L2_ADDR_HASH_SIZE];
     74	struct mutex         lock; /* Synchronize l2 table access */
     75	u32                  size;
     76	unsigned long        *bitmap;
     77};
     78
     79static int alloc_l2table_index(struct mlx5_mpfs *l2table, u32 *ix)
     80{
     81	int err = 0;
     82
     83	*ix = find_first_zero_bit(l2table->bitmap, l2table->size);
     84	if (*ix >= l2table->size)
     85		err = -ENOSPC;
     86	else
     87		__set_bit(*ix, l2table->bitmap);
     88
     89	return err;
     90}
     91
     92static void free_l2table_index(struct mlx5_mpfs *l2table, u32 ix)
     93{
     94	__clear_bit(ix, l2table->bitmap);
     95}
     96
     97int mlx5_mpfs_init(struct mlx5_core_dev *dev)
     98{
     99	int l2table_size = 1 << MLX5_CAP_GEN(dev, log_max_l2_table);
    100	struct mlx5_mpfs *mpfs;
    101
    102	if (!MLX5_ESWITCH_MANAGER(dev))
    103		return 0;
    104
    105	mpfs = kzalloc(sizeof(*mpfs), GFP_KERNEL);
    106	if (!mpfs)
    107		return -ENOMEM;
    108
    109	mutex_init(&mpfs->lock);
    110	mpfs->size   = l2table_size;
    111	mpfs->bitmap = bitmap_zalloc(l2table_size, GFP_KERNEL);
    112	if (!mpfs->bitmap) {
    113		kfree(mpfs);
    114		return -ENOMEM;
    115	}
    116
    117	dev->priv.mpfs = mpfs;
    118	return 0;
    119}
    120
    121void mlx5_mpfs_cleanup(struct mlx5_core_dev *dev)
    122{
    123	struct mlx5_mpfs *mpfs = dev->priv.mpfs;
    124
    125	if (!MLX5_ESWITCH_MANAGER(dev))
    126		return;
    127
    128	WARN_ON(!hlist_empty(mpfs->hash));
    129	bitmap_free(mpfs->bitmap);
    130	kfree(mpfs);
    131}
    132
    133int mlx5_mpfs_add_mac(struct mlx5_core_dev *dev, u8 *mac)
    134{
    135	struct mlx5_mpfs *mpfs = dev->priv.mpfs;
    136	struct l2table_node *l2addr;
    137	int err = 0;
    138	u32 index;
    139
    140	if (!MLX5_ESWITCH_MANAGER(dev))
    141		return 0;
    142
    143	mutex_lock(&mpfs->lock);
    144
    145	l2addr = l2addr_hash_find(mpfs->hash, mac, struct l2table_node);
    146	if (l2addr) {
    147		l2addr->ref_count++;
    148		goto out;
    149	}
    150
    151	err = alloc_l2table_index(mpfs, &index);
    152	if (err)
    153		goto out;
    154
    155	l2addr = l2addr_hash_add(mpfs->hash, mac, struct l2table_node, GFP_KERNEL);
    156	if (!l2addr) {
    157		err = -ENOMEM;
    158		goto hash_add_err;
    159	}
    160
    161	err = set_l2table_entry_cmd(dev, index, mac);
    162	if (err)
    163		goto set_table_entry_err;
    164
    165	l2addr->index = index;
    166	l2addr->ref_count = 1;
    167
    168	mlx5_core_dbg(dev, "MPFS mac added %pM, index (%d)\n", mac, index);
    169	goto out;
    170
    171set_table_entry_err:
    172	l2addr_hash_del(l2addr);
    173hash_add_err:
    174	free_l2table_index(mpfs, index);
    175out:
    176	mutex_unlock(&mpfs->lock);
    177	return err;
    178}
    179EXPORT_SYMBOL(mlx5_mpfs_add_mac);
    180
    181int mlx5_mpfs_del_mac(struct mlx5_core_dev *dev, u8 *mac)
    182{
    183	struct mlx5_mpfs *mpfs = dev->priv.mpfs;
    184	struct l2table_node *l2addr;
    185	int err = 0;
    186	u32 index;
    187
    188	if (!MLX5_ESWITCH_MANAGER(dev))
    189		return 0;
    190
    191	mutex_lock(&mpfs->lock);
    192
    193	l2addr = l2addr_hash_find(mpfs->hash, mac, struct l2table_node);
    194	if (!l2addr) {
    195		err = -ENOENT;
    196		goto unlock;
    197	}
    198
    199	if (--l2addr->ref_count > 0)
    200		goto unlock;
    201
    202	index = l2addr->index;
    203	del_l2table_entry_cmd(dev, index);
    204	l2addr_hash_del(l2addr);
    205	free_l2table_index(mpfs, index);
    206	mlx5_core_dbg(dev, "MPFS mac deleted %pM, index (%d)\n", mac, index);
    207unlock:
    208	mutex_unlock(&mpfs->lock);
    209	return err;
    210}
    211EXPORT_SYMBOL(mlx5_mpfs_del_mac);