// 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 KMSG_COMPONENT "ctcm"
#define pr_fmt(fmt) KMSG_COMPONENT ": " 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,
};