/*
 * Copyright (c) 2006 Oracle.  All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */
#include <linux/percpu.h>
#include <linux/seq_file.h>
#include <linux/proc_fs.h>
#include <linux/export.h>

#include "rds.h"

DEFINE_PER_CPU_SHARED_ALIGNED(struct rds_statistics, rds_stats);
EXPORT_PER_CPU_SYMBOL_GPL(rds_stats);

/* :.,$s/unsigned long\>.*\<s_\(.*\);/"\1",/g */

static const char *const rds_stat_names[] = {
        "conn_reset",
        "recv_drop_bad_checksum",
        "recv_drop_old_seq",
        "recv_drop_no_sock",
        "recv_drop_dead_sock",
        "recv_deliver_raced",
        "recv_delivered",
        "recv_queued",
        "recv_immediate_retry",
        "recv_delayed_retry",
        "recv_ack_required",
        "recv_rdma_bytes",
        "recv_ping",
        "send_queue_empty",
        "send_queue_full",
        "send_lock_contention",
        "send_lock_queue_raced",
        "send_immediate_retry",
        "send_delayed_retry",
        "send_drop_acked",
        "send_ack_required",
        "send_queued",
        "send_rdma",
        "send_rdma_bytes",
        "send_pong",
        "page_remainder_hit",
        "page_remainder_miss",
        "copy_to_user",
        "copy_from_user",
        "cong_update_queued",
        "cong_update_received",
        "cong_send_error",
        "cong_send_blocked",
        "recv_bytes_added_to_sock",
        "recv_bytes_freed_fromsock",
        "send_stuck_rm",
        "mprds_catchup_tx0_retries",
};

void rds_stats_info_copy(struct rds_info_iterator *iter,
                         uint64_t *values, const char *const *names, size_t nr)
{
        struct rds_info_counter ctr;
        size_t i;

        for (i = 0; i < nr; i++) {
                BUG_ON(strlen(names[i]) >= sizeof(ctr.name));
                strscpy_pad(ctr.name, names[i]);
                ctr.value = values[i];

                rds_info_copy(iter, &ctr, sizeof(ctr));
        }
}
EXPORT_SYMBOL_GPL(rds_stats_info_copy);

/*
 * This gives global counters across all the transports.  The strings
 * are copied in so that the tool doesn't need knowledge of the specific
 * stats that we're exporting.  Some are pretty implementation dependent
 * and may change over time.  That doesn't stop them from being useful.
 *
 * This is the only function in the chain that knows about the byte granular
 * length in userspace.  It converts it to number of stat entries that the
 * rest of the functions operate in.
 */
static void rds_stats_info(struct socket *sock, unsigned int len,
                           struct rds_info_iterator *iter,
                           struct rds_info_lengths *lens)
{
        struct rds_statistics stats = {0, };
        uint64_t *src;
        uint64_t *sum;
        size_t i;
        int cpu;
        unsigned int avail;

        avail = len / sizeof(struct rds_info_counter);

        if (avail < ARRAY_SIZE(rds_stat_names)) {
                avail = 0;
                goto trans;
        }

        for_each_online_cpu(cpu) {
                src = (uint64_t *)&(per_cpu(rds_stats, cpu));
                sum = (uint64_t *)&stats;
                for (i = 0; i < sizeof(stats) / sizeof(uint64_t); i++)
                        *(sum++) += *(src++);
        }

        rds_stats_info_copy(iter, (uint64_t *)&stats, rds_stat_names,
                            ARRAY_SIZE(rds_stat_names));
        avail -= ARRAY_SIZE(rds_stat_names);

trans:
        lens->each = sizeof(struct rds_info_counter);
        lens->nr = rds_trans_stats_info_copy(iter, avail) +
                   ARRAY_SIZE(rds_stat_names);
}

void rds_stats_exit(void)
{
        rds_info_deregister_func(RDS_INFO_COUNTERS, rds_stats_info);
}

int rds_stats_init(void)
{
        rds_info_register_func(RDS_INFO_COUNTERS, rds_stats_info);
        return 0;
}