/*
 *  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_init(&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 won't 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 won't 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_init(&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_flex(*ctbl, hash_list, clipt_size);
        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 = kvzalloc_objs(struct clip_entry, clipt_size);
        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) {
                kvfree(ctbl->cl_list);
                kvfree(ctbl);
        }
}
EXPORT_SYMBOL(t4_cleanup_clip_tbl);