/*
 *  This file is part of the Chelsio T4 Ethernet driver for Linux.
 *  Copyright (C) 2003-2014 Chelsio Communications.  All rights reserved.
 *
 *  Written by Deepak (deepak.s@chelsio.com)
 *
 *  This program is distributed in the hope that it will be useful, but WITHOUT
 *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 *  FITNESS FOR A PARTICULAR PURPOSE.  See the LICENSE file included in this
 *  release for licensing terms and conditions.
 */

#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/jhash.h>
#include <linux/if_vlan.h>
#include <net/addrconf.h>
#include "cxgb4.h"
#include "clip_tbl.h"

static inline unsigned int ipv4_clip_hash(struct clip_tbl *c, const u32 *key)
{
	unsigned int clipt_size_half = c->clipt_size / 2;

	return jhash_1word(*key, 0) % clipt_size_half;
}

static inline unsigned int ipv6_clip_hash(struct clip_tbl *d, const u32 *key)
{
	unsigned int clipt_size_half = d->clipt_size / 2;
	u32 xor = key[0] ^ key[1] ^ key[2] ^ key[3];

	return clipt_size_half +
		(jhash_1word(xor, 0) % clipt_size_half);
}

static unsigned int clip_addr_hash(struct clip_tbl *ctbl, const u32 *addr,
				   u8 v6)
{
	return v6 ? ipv6_clip_hash(ctbl, addr) :
			ipv4_clip_hash(ctbl, addr);
}

static int clip6_get_mbox(const struct net_device *dev,
			  const struct in6_addr *lip)
{
	struct adapter *adap = netdev2adap(dev);
	struct fw_clip_cmd c;

	memset(&c, 0, sizeof(c));
	c.op_to_write = htonl(FW_CMD_OP_V(FW_CLIP_CMD) |
			      FW_CMD_REQUEST_F | FW_CMD_WRITE_F);
	c.alloc_to_len16 = htonl(FW_CLIP_CMD_ALLOC_F | FW_LEN16(c));
	*(__be64 *)&c.ip_hi = *(__be64 *)(lip->s6_addr);
	*(__be64 *)&c.ip_lo = *(__be64 *)(lip->s6_addr + 8);
	return t4_wr_mbox_meat(adap, adap->mbox, &c, sizeof(c), &c, false);
}

static int clip6_release_mbox(const struct net_device *dev,
			      const struct in6_addr *lip)
{
	struct adapter *adap = netdev2adap(dev);
	struct fw_clip_cmd c;

	memset(&c, 0, sizeof(c));
	c.op_to_write = htonl(FW_CMD_OP_V(FW_CLIP_CMD) |
			      FW_CMD_REQUEST_F | FW_CMD_READ_F);
	c.alloc_to_len16 = htonl(FW_CLIP_CMD_FREE_F | FW_LEN16(c));
	*(__be64 *)&c.ip_hi = *(__be64 *)(lip->s6_addr);
	*(__be64 *)&c.ip_lo = *(__be64 *)(lip->s6_addr + 8);
	return t4_wr_mbox_meat(adap, adap->mbox, &c, sizeof(c), &c, false);
}

int cxgb4_clip_get(const struct net_device *dev, const u32 *lip, u8 v6)
{
	struct adapter *adap = netdev2adap(dev);
	struct clip_tbl *ctbl = adap->clipt;
	struct clip_entry *ce, *cte;
	u32 *addr = (u32 *)lip;
	int hash;
	int ret = -1;

	if (!ctbl)
		return 0;

	hash = clip_addr_hash(ctbl, addr, v6);

	read_lock_bh(&ctbl->lock);
	list_for_each_entry(cte, &ctbl->hash_list[hash], list) {
		if (cte->addr6.sin6_family == AF_INET6 && v6)
			ret = memcmp(lip, cte->addr6.sin6_addr.s6_addr,
				     sizeof(struct in6_addr));
		else if (cte->addr.sin_family == AF_INET && !v6)
			ret = memcmp(lip, (char *)(&cte->addr.sin_addr),
				     sizeof(struct in_addr));
		if (!ret) {
			ce = cte;
			read_unlock_bh(&ctbl->lock);
			refcount_inc(&ce->refcnt);
			return 0;
		}
	}
	read_unlock_bh(&ctbl->lock);

	write_lock_bh(&ctbl->lock);
	if (!list_empty(&ctbl->ce_free_head)) {
		ce = list_first_entry(&ctbl->ce_free_head,
				      struct clip_entry, list);
		list_del(&ce->list);
		INIT_LIST_HEAD(&ce->list);
		spin_lock_init(&ce->lock);
		refcount_set(&ce->refcnt, 0);
		atomic_dec(&ctbl->nfree);
		list_add_tail(&ce->list, &ctbl->hash_list[hash]);
		if (v6) {
			ce->addr6.sin6_family = AF_INET6;
			memcpy(ce->addr6.sin6_addr.s6_addr,
			       lip, sizeof(struct in6_addr));
			ret = clip6_get_mbox(dev, (const struct in6_addr *)lip);
			if (ret) {
				write_unlock_bh(&ctbl->lock);
				dev_err(adap->pdev_dev,
					"CLIP FW cmd failed with error %d, "
					"Connections using %pI6c wont be "
					"offloaded",
					ret, ce->addr6.sin6_addr.s6_addr);
				return ret;
			}
		} else {
			ce->addr.sin_family = AF_INET;
			memcpy((char *)(&ce->addr.sin_addr), lip,
			       sizeof(struct in_addr));
		}
	} else {
		write_unlock_bh(&ctbl->lock);
		dev_info(adap->pdev_dev, "CLIP table overflow, "
			 "Connections using %pI6c wont be offloaded",
			 (void *)lip);
		return -ENOMEM;
	}
	write_unlock_bh(&ctbl->lock);
	refcount_set(&ce->refcnt, 1);
	return 0;
}
EXPORT_SYMBOL(cxgb4_clip_get);

void cxgb4_clip_release(const struct net_device *dev, const u32 *lip, u8 v6)
{
	struct adapter *adap = netdev2adap(dev);
	struct clip_tbl *ctbl = adap->clipt;
	struct clip_entry *ce, *cte;
	u32 *addr = (u32 *)lip;
	int hash;
	int ret = -1;

	if (!ctbl)
		return;

	hash = clip_addr_hash(ctbl, addr, v6);

	read_lock_bh(&ctbl->lock);
	list_for_each_entry(cte, &ctbl->hash_list[hash], list) {
		if (cte->addr6.sin6_family == AF_INET6 && v6)
			ret = memcmp(lip, cte->addr6.sin6_addr.s6_addr,
				     sizeof(struct in6_addr));
		else if (cte->addr.sin_family == AF_INET && !v6)
			ret = memcmp(lip, (char *)(&cte->addr.sin_addr),
				     sizeof(struct in_addr));
		if (!ret) {
			ce = cte;
			read_unlock_bh(&ctbl->lock);
			goto found;
		}
	}
	read_unlock_bh(&ctbl->lock);

	return;
found:
	write_lock_bh(&ctbl->lock);
	spin_lock_bh(&ce->lock);
	if (refcount_dec_and_test(&ce->refcnt)) {
		list_del(&ce->list);
		INIT_LIST_HEAD(&ce->list);
		list_add_tail(&ce->list, &ctbl->ce_free_head);
		atomic_inc(&ctbl->nfree);
		if (v6)
			clip6_release_mbox(dev, (const struct in6_addr *)lip);
	}
	spin_unlock_bh(&ce->lock);
	write_unlock_bh(&ctbl->lock);
}
EXPORT_SYMBOL(cxgb4_clip_release);

/* Retrieves IPv6 addresses from a root device (bond, vlan) associated with
 * a physical device.
 * The physical device reference is needed to send the actul CLIP command.
 */
static int cxgb4_update_dev_clip(struct net_device *root_dev,
				 struct net_device *dev)
{
	struct inet6_dev *idev = NULL;
	struct inet6_ifaddr *ifa;
	int ret = 0;

	idev = __in6_dev_get(root_dev);
	if (!idev)
		return ret;

	read_lock_bh(&idev->lock);
	list_for_each_entry(ifa, &idev->addr_list, if_list) {
		ret = cxgb4_clip_get(dev, (const u32 *)ifa->addr.s6_addr, 1);
		if (ret < 0)
			break;
	}
	read_unlock_bh(&idev->lock);

	return ret;
}

int cxgb4_update_root_dev_clip(struct net_device *dev)
{
	struct net_device *root_dev = NULL;
	int i, ret = 0;

	/* First populate the real net device's IPv6 addresses */
	ret = cxgb4_update_dev_clip(dev, dev);
	if (ret)
		return ret;

	/* Parse all bond and vlan devices layered on top of the physical dev */
	root_dev = netdev_master_upper_dev_get_rcu(dev);
	if (root_dev) {
		ret = cxgb4_update_dev_clip(root_dev, dev);
		if (ret)
			return ret;
	}

	for (i = 0; i < VLAN_N_VID; i++) {
		root_dev = __vlan_find_dev_deep_rcu(dev, htons(ETH_P_8021Q), i);
		if (!root_dev)
			continue;

		ret = cxgb4_update_dev_clip(root_dev, dev);
		if (ret)
			break;
	}

	return ret;
}
EXPORT_SYMBOL(cxgb4_update_root_dev_clip);

int clip_tbl_show(struct seq_file *seq, void *v)
{
	struct adapter *adapter = seq->private;
	struct clip_tbl *ctbl = adapter->clipt;
	struct clip_entry *ce;
	char ip[60];
	int i;

	read_lock_bh(&ctbl->lock);

	seq_puts(seq, "IP Address                  Users\n");
	for (i = 0 ; i < ctbl->clipt_size;  ++i) {
		list_for_each_entry(ce, &ctbl->hash_list[i], list) {
			ip[0] = '\0';
			sprintf(ip, "%pISc", &ce->addr);
			seq_printf(seq, "%-25s   %u\n", ip,
				   refcount_read(&ce->refcnt));
		}
	}
	seq_printf(seq, "Free clip entries : %d\n", atomic_read(&ctbl->nfree));

	read_unlock_bh(&ctbl->lock);

	return 0;
}

struct clip_tbl *t4_init_clip_tbl(unsigned int clipt_start,
				  unsigned int clipt_end)
{
	struct clip_entry *cl_list;
	struct clip_tbl *ctbl;
	unsigned int clipt_size;
	int i;

	if (clipt_start >= clipt_end)
		return NULL;
	clipt_size = clipt_end - clipt_start + 1;
	if (clipt_size < CLIPT_MIN_HASH_BUCKETS)
		return NULL;

	ctbl = kvzalloc(struct_size(ctbl, hash_list, clipt_size), GFP_KERNEL);
	if (!ctbl)
		return NULL;

	ctbl->clipt_start = clipt_start;
	ctbl->clipt_size = clipt_size;
	INIT_LIST_HEAD(&ctbl->ce_free_head);

	atomic_set(&ctbl->nfree, clipt_size);
	rwlock_init(&ctbl->lock);

	for (i = 0; i < ctbl->clipt_size; ++i)
		INIT_LIST_HEAD(&ctbl->hash_list[i]);

	cl_list = kvcalloc(clipt_size, sizeof(struct clip_entry), GFP_KERNEL);
	if (!cl_list) {
		kvfree(ctbl);
		return NULL;
	}
	ctbl->cl_list = (void *)cl_list;

	for (i = 0; i < clipt_size; i++) {
		INIT_LIST_HEAD(&cl_list[i].list);
		list_add_tail(&cl_list[i].list, &ctbl->ce_free_head);
	}

	return ctbl;
}

void t4_cleanup_clip_tbl(struct adapter *adap)
{
	struct clip_tbl *ctbl = adap->clipt;

	if (ctbl) {
		if (ctbl->cl_list)
			kvfree(ctbl->cl_list);
		kvfree(ctbl);
	}
}
EXPORT_SYMBOL(t4_cleanup_clip_tbl);