/*
 * Copyright (c) 2013 - 2017 Intel Corporation.  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/debugfs.h>
#include <linux/seq_file.h>
#include <linux/kernel.h>
#include <linux/export.h>

#include "qib.h"
#include "qib_verbs.h"
#include "qib_debugfs.h"

static struct dentry *qib_dbg_root;

#define DEBUGFS_FILE(name) \
static const struct seq_operations _##name##_seq_ops = { \
        .start = _##name##_seq_start, \
        .next  = _##name##_seq_next, \
        .stop  = _##name##_seq_stop, \
        .show  = _##name##_seq_show \
}; \
static int _##name##_open(struct inode *inode, struct file *s) \
{ \
        struct seq_file *seq; \
        int ret; \
        ret =  seq_open(s, &_##name##_seq_ops); \
        if (ret) \
                return ret; \
        seq = s->private_data; \
        seq->private = inode->i_private; \
        return 0; \
} \
static const struct file_operations _##name##_file_ops = { \
        .owner   = THIS_MODULE, \
        .open    = _##name##_open, \
        .read    = seq_read, \
        .llseek  = seq_lseek, \
        .release = seq_release \
};

static void *_opcode_stats_seq_start(struct seq_file *s, loff_t *pos)
{
        struct qib_opcode_stats_perctx *opstats;

        if (*pos >= ARRAY_SIZE(opstats->stats))
                return NULL;
        return pos;
}

static void *_opcode_stats_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
        struct qib_opcode_stats_perctx *opstats;

        ++*pos;
        if (*pos >= ARRAY_SIZE(opstats->stats))
                return NULL;
        return pos;
}


static void _opcode_stats_seq_stop(struct seq_file *s, void *v)
{
        /* nothing allocated */
}

static int _opcode_stats_seq_show(struct seq_file *s, void *v)
{
        loff_t *spos = v;
        loff_t i = *spos, j;
        u64 n_packets = 0, n_bytes = 0;
        struct qib_ibdev *ibd = (struct qib_ibdev *)s->private;
        struct qib_devdata *dd = dd_from_dev(ibd);

        for (j = 0; j < dd->first_user_ctxt; j++) {
                if (!dd->rcd[j])
                        continue;
                n_packets += dd->rcd[j]->opstats->stats[i].n_packets;
                n_bytes += dd->rcd[j]->opstats->stats[i].n_bytes;
        }
        if (!n_packets && !n_bytes)
                return SEQ_SKIP;
        seq_printf(s, "%02llx %llu/%llu\n", i,
                (unsigned long long) n_packets,
                (unsigned long long) n_bytes);

        return 0;
}

DEBUGFS_FILE(opcode_stats)

static void *_ctx_stats_seq_start(struct seq_file *s, loff_t *pos)
{
        struct qib_ibdev *ibd = (struct qib_ibdev *)s->private;
        struct qib_devdata *dd = dd_from_dev(ibd);

        if (!*pos)
                return SEQ_START_TOKEN;
        if (*pos >= dd->first_user_ctxt)
                return NULL;
        return pos;
}

static void *_ctx_stats_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
        struct qib_ibdev *ibd = (struct qib_ibdev *)s->private;
        struct qib_devdata *dd = dd_from_dev(ibd);

        if (v == SEQ_START_TOKEN)
                return pos;

        ++*pos;
        if (*pos >= dd->first_user_ctxt)
                return NULL;
        return pos;
}

static void _ctx_stats_seq_stop(struct seq_file *s, void *v)
{
        /* nothing allocated */
}

static int _ctx_stats_seq_show(struct seq_file *s, void *v)
{
        loff_t *spos;
        loff_t i, j;
        u64 n_packets = 0;
        struct qib_ibdev *ibd = (struct qib_ibdev *)s->private;
        struct qib_devdata *dd = dd_from_dev(ibd);

        if (v == SEQ_START_TOKEN) {
                seq_puts(s, "Ctx:npkts\n");
                return 0;
        }

        spos = v;
        i = *spos;

        if (!dd->rcd[i])
                return SEQ_SKIP;

        for (j = 0; j < ARRAY_SIZE(dd->rcd[i]->opstats->stats); j++)
                n_packets += dd->rcd[i]->opstats->stats[j].n_packets;

        if (!n_packets)
                return SEQ_SKIP;

        seq_printf(s, "  %llu:%llu\n", i, n_packets);
        return 0;
}

DEBUGFS_FILE(ctx_stats)

static void *_qp_stats_seq_start(struct seq_file *s, loff_t *pos)
        __acquires(RCU)
{
        struct rvt_qp_iter *iter;
        loff_t n = *pos;

        iter = rvt_qp_iter_init(s->private, 0, NULL);

        /* stop calls rcu_read_unlock */
        rcu_read_lock();

        if (!iter)
                return NULL;

        do {
                if (rvt_qp_iter_next(iter)) {
                        kfree(iter);
                        return NULL;
                }
        } while (n--);

        return iter;
}

static void *_qp_stats_seq_next(struct seq_file *s, void *iter_ptr,
                                   loff_t *pos)
        __must_hold(RCU)
{
        struct rvt_qp_iter *iter = iter_ptr;

        (*pos)++;

        if (rvt_qp_iter_next(iter)) {
                kfree(iter);
                return NULL;
        }

        return iter;
}

static void _qp_stats_seq_stop(struct seq_file *s, void *iter_ptr)
        __releases(RCU)
{
        rcu_read_unlock();
}

static int _qp_stats_seq_show(struct seq_file *s, void *iter_ptr)
{
        struct rvt_qp_iter *iter = iter_ptr;

        if (!iter)
                return 0;

        qib_qp_iter_print(s, iter);

        return 0;
}

DEBUGFS_FILE(qp_stats)

void qib_dbg_ibdev_init(struct qib_ibdev *ibd)
{
        struct dentry *root;
        char name[10];

        snprintf(name, sizeof(name), "qib%d", dd_from_dev(ibd)->unit);
        root = debugfs_create_dir(name, qib_dbg_root);
        ibd->qib_ibdev_dbg = root;

        debugfs_create_file("opcode_stats", 0400, root, ibd,
                            &_opcode_stats_file_ops);
        debugfs_create_file("ctx_stats", 0400, root, ibd, &_ctx_stats_file_ops);
        debugfs_create_file("qp_stats", 0400, root, ibd, &_qp_stats_file_ops);
}

void qib_dbg_ibdev_exit(struct qib_ibdev *ibd)
{
        if (!qib_dbg_root)
                goto out;
        debugfs_remove_recursive(ibd->qib_ibdev_dbg);
out:
        ibd->qib_ibdev_dbg = NULL;
}

void qib_dbg_init(void)
{
        qib_dbg_root = debugfs_create_dir(QIB_DRV_NAME, NULL);
}

void qib_dbg_exit(void)
{
        debugfs_remove_recursive(qib_dbg_root);
        qib_dbg_root = NULL;
}