// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright IBM Corp. 2007, 2007
 * Authors:     Peter Tiedemann (ptiedem@de.ibm.com)
 *
 */

#undef DEBUG
#undef DEBUGDATA
#undef DEBUGCCW

#define pr_fmt(fmt) "ctcm: " fmt

#include <linux/device.h>
#include <linux/sysfs.h>
#include <linux/slab.h>
#include "ctcm_main.h"

/*
 * sysfs attributes
 */

static ssize_t ctcm_buffer_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct ctcm_priv *priv = dev_get_drvdata(dev);

        if (!priv)
                return -ENODEV;
        return sysfs_emit(buf, "%d\n", priv->buffer_size);
}

static ssize_t ctcm_buffer_write(struct device *dev,
                struct device_attribute *attr, const char *buf, size_t count)
{
        struct net_device *ndev;
        unsigned int bs1;
        struct ctcm_priv *priv = dev_get_drvdata(dev);
        int rc;

        if (!(priv && priv->channel[CTCM_READ] &&
              priv->channel[CTCM_READ]->netdev)) {
                CTCM_DBF_TEXT(SETUP, CTC_DBF_ERROR, "bfnondev");
                return -ENODEV;
        }
        ndev = priv->channel[CTCM_READ]->netdev;

        rc = kstrtouint(buf, 0, &bs1);
        if (rc)
                goto einval;
        if (bs1 > CTCM_BUFSIZE_LIMIT)
                                        goto einval;
        if (bs1 < (576 + LL_HEADER_LENGTH + 2))
                                        goto einval;
        priv->buffer_size = bs1;        /* just to overwrite the default */

        if ((ndev->flags & IFF_RUNNING) &&
            (bs1 < (ndev->mtu + LL_HEADER_LENGTH + 2)))
                                        goto einval;

        priv->channel[CTCM_READ]->max_bufsize = bs1;
        priv->channel[CTCM_WRITE]->max_bufsize = bs1;
        if (!(ndev->flags & IFF_RUNNING))
                ndev->mtu = bs1 - LL_HEADER_LENGTH - 2;
        priv->channel[CTCM_READ]->flags |= CHANNEL_FLAGS_BUFSIZE_CHANGED;
        priv->channel[CTCM_WRITE]->flags |= CHANNEL_FLAGS_BUFSIZE_CHANGED;

        CTCM_DBF_DEV(SETUP, ndev, buf);
        return count;

einval:
        CTCM_DBF_DEV(SETUP, ndev, "buff_err");
        return -EINVAL;
}

static void ctcm_print_statistics(struct ctcm_priv *priv)
{
        char *sbuf;
        char *p;

        if (!priv)
                return;
        sbuf = kmalloc(2048, GFP_KERNEL);
        if (sbuf == NULL)
                return;
        p = sbuf;

        p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  Device FSM state: %s\n",
                       fsm_getstate_str(priv->fsm));
        p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  RX channel FSM state: %s\n",
                       fsm_getstate_str(priv->channel[CTCM_READ]->fsm));
        p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  TX channel FSM state: %s\n",
                       fsm_getstate_str(priv->channel[CTCM_WRITE]->fsm));
        p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  Max. TX buffer used: %ld\n",
                       priv->channel[WRITE]->prof.maxmulti);
        p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  Max. chained SKBs: %ld\n",
                       priv->channel[WRITE]->prof.maxcqueue);
        p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  TX single write ops: %ld\n",
                       priv->channel[WRITE]->prof.doios_single);
        p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  TX multi write ops: %ld\n",
                       priv->channel[WRITE]->prof.doios_multi);
        p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  Netto bytes written: %ld\n",
                       priv->channel[WRITE]->prof.txlen);
        p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  Max. TX IO-time: %u\n",
                       jiffies_to_usecs(priv->channel[WRITE]->prof.tx_time));

        printk(KERN_INFO "Statistics for %s:\n%s",
                                priv->channel[CTCM_WRITE]->netdev->name, sbuf);
        kfree(sbuf);
        return;
}

static ssize_t stats_show(struct device *dev,
                          struct device_attribute *attr, char *buf)
{
        struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
        struct ctcm_priv *priv = dev_get_drvdata(dev);

        if (!priv || gdev->state != CCWGROUP_ONLINE)
                return -ENODEV;
        ctcm_print_statistics(priv);
        return sysfs_emit(buf, "0\n");
}

static ssize_t stats_write(struct device *dev, struct device_attribute *attr,
                                const char *buf, size_t count)
{
        struct ctcm_priv *priv = dev_get_drvdata(dev);
        if (!priv)
                return -ENODEV;
        /* Reset statistics */
        memset(&priv->channel[WRITE]->prof, 0,
                                sizeof(priv->channel[CTCM_WRITE]->prof));
        return count;
}

static ssize_t ctcm_proto_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct ctcm_priv *priv = dev_get_drvdata(dev);
        if (!priv)
                return -ENODEV;

        return sysfs_emit(buf, "%d\n", priv->protocol);
}

static ssize_t ctcm_proto_store(struct device *dev,
                struct device_attribute *attr, const char *buf, size_t count)
{
        int value, rc;
        struct ctcm_priv *priv = dev_get_drvdata(dev);

        if (!priv)
                return -ENODEV;
        rc = kstrtoint(buf, 0, &value);
        if (rc ||
            !((value == CTCM_PROTO_S390)  ||
              (value == CTCM_PROTO_LINUX) ||
              (value == CTCM_PROTO_MPC) ||
              (value == CTCM_PROTO_OS390)))
                return -EINVAL;
        priv->protocol = value;
        CTCM_DBF_DEV(SETUP, dev, buf);

        return count;
}

static const char *ctcm_type[] = {
        "not a channel",
        "CTC/A",
        "FICON channel",
        "ESCON channel",
        "unknown channel type",
        "unsupported channel type",
};

static ssize_t ctcm_type_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct ccwgroup_device *cgdev;

        cgdev = to_ccwgroupdev(dev);
        if (!cgdev)
                return -ENODEV;

        return sysfs_emit(buf, "%s\n",
                          ctcm_type[cgdev->cdev[0]->id.driver_info]);
}

static DEVICE_ATTR(buffer, 0644, ctcm_buffer_show, ctcm_buffer_write);
static DEVICE_ATTR(protocol, 0644, ctcm_proto_show, ctcm_proto_store);
static DEVICE_ATTR(type, 0444, ctcm_type_show, NULL);
static DEVICE_ATTR(stats, 0644, stats_show, stats_write);

static struct attribute *ctcm_attr[] = {
        &dev_attr_protocol.attr,
        &dev_attr_type.attr,
        &dev_attr_buffer.attr,
        &dev_attr_stats.attr,
        NULL,
};

static struct attribute_group ctcm_attr_group = {
        .attrs = ctcm_attr,
};
const struct attribute_group *ctcm_attr_groups[] = {
        &ctcm_attr_group,
        NULL,
};