/*
 * Copyright (c) 2004 Topspin Communications.  All rights reserved.
 * Copyright (c) 2005 Intel Corporation. All rights reserved.
 * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
 * Copyright (c) 2005 Voltaire, Inc. 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/module.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/netdevice.h>
#include <net/addrconf.h>

#include <rdma/ib_cache.h>

#include "core_priv.h"

struct ib_pkey_cache {
        int             table_len;
        u16             table[0];
};

struct ib_update_work {
        struct work_struct work;
        struct ib_device  *device;
        u8                 port_num;
};

union ib_gid zgid;
EXPORT_SYMBOL(zgid);

static const struct ib_gid_attr zattr;

enum gid_attr_find_mask {
        GID_ATTR_FIND_MASK_GID          = 1UL << 0,
        GID_ATTR_FIND_MASK_NETDEV       = 1UL << 1,
        GID_ATTR_FIND_MASK_DEFAULT      = 1UL << 2,
};

enum gid_table_entry_props {
        GID_TABLE_ENTRY_INVALID         = 1UL << 0,
        GID_TABLE_ENTRY_DEFAULT         = 1UL << 1,
};

enum gid_table_write_action {
        GID_TABLE_WRITE_ACTION_ADD,
        GID_TABLE_WRITE_ACTION_DEL,
        /* MODIFY only updates the GID table. Currently only used by
         * ib_cache_update.
         */
        GID_TABLE_WRITE_ACTION_MODIFY
};

struct ib_gid_table_entry {
        /* This lock protects an entry from being
         * read and written simultaneously.
         */
        rwlock_t            lock;
        unsigned long       props;
        union ib_gid        gid;
        struct ib_gid_attr  attr;
        void               *context;
};

struct ib_gid_table {
        int                  sz;
        /* In RoCE, adding a GID to the table requires:
         * (a) Find if this GID is already exists.
         * (b) Find a free space.
         * (c) Write the new GID
         *
         * Delete requires different set of operations:
         * (a) Find the GID
         * (b) Delete it.
         *
         * Add/delete should be carried out atomically.
         * This is done by locking this mutex from multiple
         * writers. We don't need this lock for IB, as the MAD
         * layer replaces all entries. All data_vec entries
         * are locked by this lock.
         **/
        struct mutex         lock;
        struct ib_gid_table_entry *data_vec;
};

static int write_gid(struct ib_device *ib_dev, u8 port,
                     struct ib_gid_table *table, int ix,
                     const union ib_gid *gid,
                     const struct ib_gid_attr *attr,
                     enum gid_table_write_action action,
                     bool  default_gid)
{
        int ret = 0;
        struct net_device *old_net_dev;
        unsigned long flags;

        /* in rdma_cap_roce_gid_table, this funciton should be protected by a
         * sleep-able lock.
         */
        write_lock_irqsave(&table->data_vec[ix].lock, flags);

        if (rdma_cap_roce_gid_table(ib_dev, port)) {
                table->data_vec[ix].props |= GID_TABLE_ENTRY_INVALID;
                write_unlock_irqrestore(&table->data_vec[ix].lock, flags);
                /* GID_TABLE_WRITE_ACTION_MODIFY currently isn't supported by
                 * RoCE providers and thus only updates the cache.
                 */
                if (action == GID_TABLE_WRITE_ACTION_ADD)
                        ret = ib_dev->add_gid(ib_dev, port, ix, gid, attr,
                                              &table->data_vec[ix].context);
                else if (action == GID_TABLE_WRITE_ACTION_DEL)
                        ret = ib_dev->del_gid(ib_dev, port, ix,
                                              &table->data_vec[ix].context);
                write_lock_irqsave(&table->data_vec[ix].lock, flags);
        }

        old_net_dev = table->data_vec[ix].attr.ndev;
        if (old_net_dev && old_net_dev != attr->ndev)
                dev_put(old_net_dev);
        /* if modify_gid failed, just delete the old gid */
        if (ret || action == GID_TABLE_WRITE_ACTION_DEL) {
                gid = &zgid;
                attr = &zattr;
                table->data_vec[ix].context = NULL;
        }
        if (default_gid)
                table->data_vec[ix].props |= GID_TABLE_ENTRY_DEFAULT;
        memcpy(&table->data_vec[ix].gid, gid, sizeof(*gid));
        memcpy(&table->data_vec[ix].attr, attr, sizeof(*attr));
        if (table->data_vec[ix].attr.ndev &&
            table->data_vec[ix].attr.ndev != old_net_dev)
                dev_hold(table->data_vec[ix].attr.ndev);

        table->data_vec[ix].props &= ~GID_TABLE_ENTRY_INVALID;

        write_unlock_irqrestore(&table->data_vec[ix].lock, flags);

        if (!ret && rdma_cap_roce_gid_table(ib_dev, port)) {
                struct ib_event event;

                event.device            = ib_dev;
                event.element.port_num  = port;
                event.event             = IB_EVENT_GID_CHANGE;

                ib_dispatch_event(&event);
        }
        return ret;
}

static int add_gid(struct ib_device *ib_dev, u8 port,
                   struct ib_gid_table *table, int ix,
                   const union ib_gid *gid,
                   const struct ib_gid_attr *attr,
                   bool  default_gid) {
        return write_gid(ib_dev, port, table, ix, gid, attr,
                         GID_TABLE_WRITE_ACTION_ADD, default_gid);
}

static int modify_gid(struct ib_device *ib_dev, u8 port,
                      struct ib_gid_table *table, int ix,
                      const union ib_gid *gid,
                      const struct ib_gid_attr *attr,
                      bool  default_gid) {
        return write_gid(ib_dev, port, table, ix, gid, attr,
                         GID_TABLE_WRITE_ACTION_MODIFY, default_gid);
}

static int del_gid(struct ib_device *ib_dev, u8 port,
                   struct ib_gid_table *table, int ix,
                   bool  default_gid) {
        return write_gid(ib_dev, port, table, ix, &zgid, &zattr,
                         GID_TABLE_WRITE_ACTION_DEL, default_gid);
}

static int find_gid(struct ib_gid_table *table, const union ib_gid *gid,
                    const struct ib_gid_attr *val, bool default_gid,
                    unsigned long mask)
{
        int i;

        for (i = 0; i < table->sz; i++) {
                unsigned long flags;
                struct ib_gid_attr *attr = &table->data_vec[i].attr;

                read_lock_irqsave(&table->data_vec[i].lock, flags);

                if (table->data_vec[i].props & GID_TABLE_ENTRY_INVALID)
                        goto next;

                if (mask & GID_ATTR_FIND_MASK_GID &&
                    memcmp(gid, &table->data_vec[i].gid, sizeof(*gid)))
                        goto next;

                if (mask & GID_ATTR_FIND_MASK_NETDEV &&
                    attr->ndev != val->ndev)
                        goto next;

                if (mask & GID_ATTR_FIND_MASK_DEFAULT &&
                    !!(table->data_vec[i].props & GID_TABLE_ENTRY_DEFAULT) !=
                    default_gid)
                        goto next;

                read_unlock_irqrestore(&table->data_vec[i].lock, flags);
                return i;
next:
                read_unlock_irqrestore(&table->data_vec[i].lock, flags);
        }

        return -1;
}

static void make_default_gid(struct  net_device *dev, union ib_gid *gid)
{
        gid->global.subnet_prefix = cpu_to_be64(0xfe80000000000000LL);
        addrconf_ifid_eui48(&gid->raw[8], dev);
}

int ib_cache_gid_add(struct ib_device *ib_dev, u8 port,
                     union ib_gid *gid, struct ib_gid_attr *attr)
{
        struct ib_gid_table **ports_table = ib_dev->cache.gid_cache;
        struct ib_gid_table *table;
        int ix;
        int ret = 0;
        struct net_device *idev;

        table = ports_table[port - rdma_start_port(ib_dev)];

        if (!memcmp(gid, &zgid, sizeof(*gid)))
                return -EINVAL;

        if (ib_dev->get_netdev) {
                idev = ib_dev->get_netdev(ib_dev, port);
                if (idev && attr->ndev != idev) {
                        union ib_gid default_gid;

                        /* Adding default GIDs in not permitted */
                        make_default_gid(idev, &default_gid);
                        if (!memcmp(gid, &default_gid, sizeof(*gid))) {
                                dev_put(idev);
                                return -EPERM;
                        }
                }
                if (idev)
                        dev_put(idev);
        }

        mutex_lock(&table->lock);

        ix = find_gid(table, gid, attr, false, GID_ATTR_FIND_MASK_GID |
                      GID_ATTR_FIND_MASK_NETDEV);
        if (ix >= 0)
                goto out_unlock;

        ix = find_gid(table, &zgid, NULL, false, GID_ATTR_FIND_MASK_GID |
                      GID_ATTR_FIND_MASK_DEFAULT);
        if (ix < 0) {
                ret = -ENOSPC;
                goto out_unlock;
        }

        add_gid(ib_dev, port, table, ix, gid, attr, false);

out_unlock:
        mutex_unlock(&table->lock);
        return ret;
}

int ib_cache_gid_del(struct ib_device *ib_dev, u8 port,
                     union ib_gid *gid, struct ib_gid_attr *attr)
{
        struct ib_gid_table **ports_table = ib_dev->cache.gid_cache;
        struct ib_gid_table *table;
        int ix;

        table = ports_table[port - rdma_start_port(ib_dev)];

        mutex_lock(&table->lock);

        ix = find_gid(table, gid, attr, false,
                      GID_ATTR_FIND_MASK_GID      |
                      GID_ATTR_FIND_MASK_NETDEV   |
                      GID_ATTR_FIND_MASK_DEFAULT);
        if (ix < 0)
                goto out_unlock;

        del_gid(ib_dev, port, table, ix, false);

out_unlock:
        mutex_unlock(&table->lock);
        return 0;
}

int ib_cache_gid_del_all_netdev_gids(struct ib_device *ib_dev, u8 port,
                                     struct net_device *ndev)
{
        struct ib_gid_table **ports_table = ib_dev->cache.gid_cache;
        struct ib_gid_table *table;
        int ix;

        table  = ports_table[port - rdma_start_port(ib_dev)];

        mutex_lock(&table->lock);

        for (ix = 0; ix < table->sz; ix++)
                if (table->data_vec[ix].attr.ndev == ndev)
                        del_gid(ib_dev, port, table, ix, false);

        mutex_unlock(&table->lock);
        return 0;
}

static int __ib_cache_gid_get(struct ib_device *ib_dev, u8 port, int index,
                              union ib_gid *gid, struct ib_gid_attr *attr)
{
        struct ib_gid_table **ports_table = ib_dev->cache.gid_cache;
        struct ib_gid_table *table;
        unsigned long flags;

        table = ports_table[port - rdma_start_port(ib_dev)];

        if (index < 0 || index >= table->sz)
                return -EINVAL;

        read_lock_irqsave(&table->data_vec[index].lock, flags);
        if (table->data_vec[index].props & GID_TABLE_ENTRY_INVALID) {
                read_unlock_irqrestore(&table->data_vec[index].lock, flags);
                return -EAGAIN;
        }

        memcpy(gid, &table->data_vec[index].gid, sizeof(*gid));
        if (attr) {
                memcpy(attr, &table->data_vec[index].attr, sizeof(*attr));
                if (attr->ndev)
                        dev_hold(attr->ndev);
        }

        read_unlock_irqrestore(&table->data_vec[index].lock, flags);
        return 0;
}

static int _ib_cache_gid_table_find(struct ib_device *ib_dev,
                                    const union ib_gid *gid,
                                    const struct ib_gid_attr *val,
                                    unsigned long mask,
                                    u8 *port, u16 *index)
{
        struct ib_gid_table **ports_table = ib_dev->cache.gid_cache;
        struct ib_gid_table *table;
        u8 p;
        int local_index;

        for (p = 0; p < ib_dev->phys_port_cnt; p++) {
                table = ports_table[p];
                local_index = find_gid(table, gid, val, false, mask);
                if (local_index >= 0) {
                        if (index)
                                *index = local_index;
                        if (port)
                                *port = p + rdma_start_port(ib_dev);
                        return 0;
                }
        }

        return -ENOENT;
}

static int ib_cache_gid_find(struct ib_device *ib_dev,
                             const union ib_gid *gid,
                             struct net_device *ndev, u8 *port,
                             u16 *index)
{
        unsigned long mask = GID_ATTR_FIND_MASK_GID;
        struct ib_gid_attr gid_attr_val = {.ndev = ndev};

        if (ndev)
                mask |= GID_ATTR_FIND_MASK_NETDEV;

        return _ib_cache_gid_table_find(ib_dev, gid, &gid_attr_val,
                                        mask, port, index);
}

int ib_find_cached_gid_by_port(struct ib_device *ib_dev,
                               const union ib_gid *gid,
                               u8 port, struct net_device *ndev,
                               u16 *index)
{
        int local_index;
        struct ib_gid_table **ports_table = ib_dev->cache.gid_cache;
        struct ib_gid_table *table;
        unsigned long mask = GID_ATTR_FIND_MASK_GID;
        struct ib_gid_attr val = {.ndev = ndev};

        if (port < rdma_start_port(ib_dev) ||
            port > rdma_end_port(ib_dev))
                return -ENOENT;

        table = ports_table[port - rdma_start_port(ib_dev)];

        if (ndev)
                mask |= GID_ATTR_FIND_MASK_NETDEV;

        local_index = find_gid(table, gid, &val, false, mask);
        if (local_index >= 0) {
                if (index)
                        *index = local_index;
                return 0;
        }

        return -ENOENT;
}
EXPORT_SYMBOL(ib_find_cached_gid_by_port);

/**
 * ib_find_gid_by_filter - Returns the GID table index where a specified
 * GID value occurs
 * @device: The device to query.
 * @gid: The GID value to search for.
 * @port_num: The port number of the device where the GID value could be
 *   searched.
 * @filter: The filter function is executed on any matching GID in the table.
 *   If the filter function returns true, the corresponding index is returned,
 *   otherwise, we continue searching the GID table. It's guaranteed that
 *   while filter is executed, ndev field is valid and the structure won't
 *   change. filter is executed in an atomic context. filter must not be NULL.
 * @index: The index into the cached GID table where the GID was found.  This
 *   parameter may be NULL.
 *
 * ib_cache_gid_find_by_filter() searches for the specified GID value
 * of which the filter function returns true in the port's GID table.
 * This function is only supported on RoCE ports.
 *
 */
static int ib_cache_gid_find_by_filter(struct ib_device *ib_dev,
                                       const union ib_gid *gid,
                                       u8 port,
                                       bool (*filter)(const union ib_gid *,
                                                      const struct ib_gid_attr *,
                                                      void *),
                                       void *context,
                                       u16 *index)
{
        struct ib_gid_table **ports_table = ib_dev->cache.gid_cache;
        struct ib_gid_table *table;
        unsigned int i;
        bool found = false;

        if (!ports_table)
                return -EOPNOTSUPP;

        if (port < rdma_start_port(ib_dev) ||
            port > rdma_end_port(ib_dev) ||
            !rdma_protocol_roce(ib_dev, port))
                return -EPROTONOSUPPORT;

        table = ports_table[port - rdma_start_port(ib_dev)];

        for (i = 0; i < table->sz; i++) {
                struct ib_gid_attr attr;
                unsigned long flags;

                read_lock_irqsave(&table->data_vec[i].lock, flags);
                if (table->data_vec[i].props & GID_TABLE_ENTRY_INVALID)
                        goto next;

                if (memcmp(gid, &table->data_vec[i].gid, sizeof(*gid)))
                        goto next;

                memcpy(&attr, &table->data_vec[i].attr, sizeof(attr));

                if (filter(gid, &attr, context))
                        found = true;

next:
                read_unlock_irqrestore(&table->data_vec[i].lock, flags);

                if (found)
                        break;
        }

        if (!found)
                return -ENOENT;

        if (index)
                *index = i;
        return 0;
}

static struct ib_gid_table *alloc_gid_table(int sz)
{
        unsigned int i;
        struct ib_gid_table *table =
                kzalloc(sizeof(struct ib_gid_table), GFP_KERNEL);
        if (!table)
                return NULL;

        table->data_vec = kcalloc(sz, sizeof(*table->data_vec), GFP_KERNEL);
        if (!table->data_vec)
                goto err_free_table;

        mutex_init(&table->lock);

        table->sz = sz;

        for (i = 0; i < sz; i++)
                rwlock_init(&table->data_vec[i].lock);

        return table;

err_free_table:
        kfree(table);
        return NULL;
}

static void release_gid_table(struct ib_gid_table *table)
{
        if (table) {
                kfree(table->data_vec);
                kfree(table);
        }
}

static void cleanup_gid_table_port(struct ib_device *ib_dev, u8 port,
                                   struct ib_gid_table *table)
{
        int i;

        if (!table)
                return;

        for (i = 0; i < table->sz; ++i) {
                if (memcmp(&table->data_vec[i].gid, &zgid,
                           sizeof(table->data_vec[i].gid)))
                        del_gid(ib_dev, port, table, i,
                                table->data_vec[i].props &
                                GID_ATTR_FIND_MASK_DEFAULT);
        }
}

void ib_cache_gid_set_default_gid(struct ib_device *ib_dev, u8 port,
                                  struct net_device *ndev,
                                  enum ib_cache_gid_default_mode mode)
{
        struct ib_gid_table **ports_table = ib_dev->cache.gid_cache;
        union ib_gid gid;
        struct ib_gid_attr gid_attr;
        struct ib_gid_table *table;
        int ix;
        union ib_gid current_gid;
        struct ib_gid_attr current_gid_attr = {};

        table  = ports_table[port - rdma_start_port(ib_dev)];

        make_default_gid(ndev, &gid);
        memset(&gid_attr, 0, sizeof(gid_attr));
        gid_attr.ndev = ndev;

        mutex_lock(&table->lock);
        ix = find_gid(table, NULL, NULL, true, GID_ATTR_FIND_MASK_DEFAULT);

        /* Coudn't find default GID location */
        WARN_ON(ix < 0);

        if (!__ib_cache_gid_get(ib_dev, port, ix,
                                &current_gid, &current_gid_attr) &&
            mode == IB_CACHE_GID_DEFAULT_MODE_SET &&
            !memcmp(&gid, &current_gid, sizeof(gid)) &&
            !memcmp(&gid_attr, &current_gid_attr, sizeof(gid_attr)))
                goto unlock;

        if ((memcmp(&current_gid, &zgid, sizeof(current_gid)) ||
             memcmp(&current_gid_attr, &zattr,
                    sizeof(current_gid_attr))) &&
            del_gid(ib_dev, port, table, ix, true)) {
                pr_warn("ib_cache_gid: can't delete index %d for default gid %pI6\n",
                        ix, gid.raw);
                goto unlock;
        }

        if (mode == IB_CACHE_GID_DEFAULT_MODE_SET)
                if (add_gid(ib_dev, port, table, ix, &gid, &gid_attr, true))
                        pr_warn("ib_cache_gid: unable to add default gid %pI6\n",
                                gid.raw);

unlock:
        if (current_gid_attr.ndev)
                dev_put(current_gid_attr.ndev);
        mutex_unlock(&table->lock);
}

static int gid_table_reserve_default(struct ib_device *ib_dev, u8 port,
                                     struct ib_gid_table *table)
{
        if (rdma_protocol_roce(ib_dev, port)) {
                struct ib_gid_table_entry *entry = &table->data_vec[0];

                entry->props |= GID_TABLE_ENTRY_DEFAULT;
        }

        return 0;
}

static int _gid_table_setup_one(struct ib_device *ib_dev)
{
        u8 port;
        struct ib_gid_table **table;
        int err = 0;

        table = kcalloc(ib_dev->phys_port_cnt, sizeof(*table), GFP_KERNEL);

        if (!table) {
                pr_warn("failed to allocate ib gid cache for %s\n",
                        ib_dev->name);
                return -ENOMEM;
        }

        for (port = 0; port < ib_dev->phys_port_cnt; port++) {
                u8 rdma_port = port + rdma_start_port(ib_dev);

                table[port] =
                        alloc_gid_table(
                                ib_dev->port_immutable[rdma_port].gid_tbl_len);
                if (!table[port]) {
                        err = -ENOMEM;
                        goto rollback_table_setup;
                }

                err = gid_table_reserve_default(ib_dev,
                                                port + rdma_start_port(ib_dev),
                                                table[port]);
                if (err)
                        goto rollback_table_setup;
        }

        ib_dev->cache.gid_cache = table;
        return 0;

rollback_table_setup:
        for (port = 0; port < ib_dev->phys_port_cnt; port++) {
                cleanup_gid_table_port(ib_dev, port + rdma_start_port(ib_dev),
                                       table[port]);
                release_gid_table(table[port]);
        }

        kfree(table);
        return err;
}

static void gid_table_release_one(struct ib_device *ib_dev)
{
        struct ib_gid_table **table = ib_dev->cache.gid_cache;
        u8 port;

        if (!table)
                return;

        for (port = 0; port < ib_dev->phys_port_cnt; port++)
                release_gid_table(table[port]);

        kfree(table);
        ib_dev->cache.gid_cache = NULL;
}

static void gid_table_cleanup_one(struct ib_device *ib_dev)
{
        struct ib_gid_table **table = ib_dev->cache.gid_cache;
        u8 port;

        if (!table)
                return;

        for (port = 0; port < ib_dev->phys_port_cnt; port++)
                cleanup_gid_table_port(ib_dev, port + rdma_start_port(ib_dev),
                                       table[port]);
}

static int gid_table_setup_one(struct ib_device *ib_dev)
{
        int err;

        err = _gid_table_setup_one(ib_dev);

        if (err)
                return err;

        err = roce_rescan_device(ib_dev);

        if (err) {
                gid_table_cleanup_one(ib_dev);
                gid_table_release_one(ib_dev);
        }

        return err;
}

int ib_get_cached_gid(struct ib_device *device,
                      u8                port_num,
                      int               index,
                      union ib_gid     *gid,
                      struct ib_gid_attr *gid_attr)
{
        if (port_num < rdma_start_port(device) || port_num > rdma_end_port(device))
                return -EINVAL;

        return __ib_cache_gid_get(device, port_num, index, gid, gid_attr);
}
EXPORT_SYMBOL(ib_get_cached_gid);

int ib_find_cached_gid(struct ib_device *device,
                       const union ib_gid *gid,
                       struct net_device *ndev,
                       u8               *port_num,
                       u16              *index)
{
        return ib_cache_gid_find(device, gid, ndev, port_num, index);
}
EXPORT_SYMBOL(ib_find_cached_gid);

int ib_find_gid_by_filter(struct ib_device *device,
                          const union ib_gid *gid,
                          u8 port_num,
                          bool (*filter)(const union ib_gid *gid,
                                         const struct ib_gid_attr *,
                                         void *),
                          void *context, u16 *index)
{
        /* Only RoCE GID table supports filter function */
        if (!rdma_cap_roce_gid_table(device, port_num) && filter)
                return -EPROTONOSUPPORT;

        return ib_cache_gid_find_by_filter(device, gid,
                                           port_num, filter,
                                           context, index);
}
EXPORT_SYMBOL(ib_find_gid_by_filter);

int ib_get_cached_pkey(struct ib_device *device,
                       u8                port_num,
                       int               index,
                       u16              *pkey)
{
        struct ib_pkey_cache *cache;
        unsigned long flags;
        int ret = 0;

        if (port_num < rdma_start_port(device) || port_num > rdma_end_port(device))
                return -EINVAL;

        read_lock_irqsave(&device->cache.lock, flags);

        cache = device->cache.pkey_cache[port_num - rdma_start_port(device)];

        if (index < 0 || index >= cache->table_len)
                ret = -EINVAL;
        else
                *pkey = cache->table[index];

        read_unlock_irqrestore(&device->cache.lock, flags);

        return ret;
}
EXPORT_SYMBOL(ib_get_cached_pkey);

int ib_find_cached_pkey(struct ib_device *device,
                        u8                port_num,
                        u16               pkey,
                        u16              *index)
{
        struct ib_pkey_cache *cache;
        unsigned long flags;
        int i;
        int ret = -ENOENT;
        int partial_ix = -1;

        if (port_num < rdma_start_port(device) || port_num > rdma_end_port(device))
                return -EINVAL;

        read_lock_irqsave(&device->cache.lock, flags);

        cache = device->cache.pkey_cache[port_num - rdma_start_port(device)];

        *index = -1;

        for (i = 0; i < cache->table_len; ++i)
                if ((cache->table[i] & 0x7fff) == (pkey & 0x7fff)) {
                        if (cache->table[i] & 0x8000) {
                                *index = i;
                                ret = 0;
                                break;
                        } else
                                partial_ix = i;
                }

        if (ret && partial_ix >= 0) {
                *index = partial_ix;
                ret = 0;
        }

        read_unlock_irqrestore(&device->cache.lock, flags);

        return ret;
}
EXPORT_SYMBOL(ib_find_cached_pkey);

int ib_find_exact_cached_pkey(struct ib_device *device,
                              u8                port_num,
                              u16               pkey,
                              u16              *index)
{
        struct ib_pkey_cache *cache;
        unsigned long flags;
        int i;
        int ret = -ENOENT;

        if (port_num < rdma_start_port(device) || port_num > rdma_end_port(device))
                return -EINVAL;

        read_lock_irqsave(&device->cache.lock, flags);

        cache = device->cache.pkey_cache[port_num - rdma_start_port(device)];

        *index = -1;

        for (i = 0; i < cache->table_len; ++i)
                if (cache->table[i] == pkey) {
                        *index = i;
                        ret = 0;
                        break;
                }

        read_unlock_irqrestore(&device->cache.lock, flags);

        return ret;
}
EXPORT_SYMBOL(ib_find_exact_cached_pkey);

int ib_get_cached_lmc(struct ib_device *device,
                      u8                port_num,
                      u8                *lmc)
{
        unsigned long flags;
        int ret = 0;

        if (port_num < rdma_start_port(device) || port_num > rdma_end_port(device))
                return -EINVAL;

        read_lock_irqsave(&device->cache.lock, flags);
        *lmc = device->cache.lmc_cache[port_num - rdma_start_port(device)];
        read_unlock_irqrestore(&device->cache.lock, flags);

        return ret;
}
EXPORT_SYMBOL(ib_get_cached_lmc);

static void ib_cache_update(struct ib_device *device,
                            u8                port)
{
        struct ib_port_attr       *tprops = NULL;
        struct ib_pkey_cache      *pkey_cache = NULL, *old_pkey_cache;
        struct ib_gid_cache {
                int             table_len;
                union ib_gid    table[0];
        }                         *gid_cache = NULL;
        int                        i;
        int                        ret;
        struct ib_gid_table       *table;
        struct ib_gid_table      **ports_table = device->cache.gid_cache;
        bool                       use_roce_gid_table =
                                        rdma_cap_roce_gid_table(device, port);

        if (port < rdma_start_port(device) || port > rdma_end_port(device))
                return;

        table = ports_table[port - rdma_start_port(device)];

        tprops = kmalloc(sizeof *tprops, GFP_KERNEL);
        if (!tprops)
                return;

        ret = ib_query_port(device, port, tprops);
        if (ret) {
                printk(KERN_WARNING "ib_query_port failed (%d) for %s\n",
                       ret, device->name);
                goto err;
        }

        pkey_cache = kmalloc(sizeof *pkey_cache + tprops->pkey_tbl_len *
                             sizeof *pkey_cache->table, GFP_KERNEL);
        if (!pkey_cache)
                goto err;

        pkey_cache->table_len = tprops->pkey_tbl_len;

        if (!use_roce_gid_table) {
                gid_cache = kmalloc(sizeof(*gid_cache) + tprops->gid_tbl_len *
                            sizeof(*gid_cache->table), GFP_KERNEL);
                if (!gid_cache)
                        goto err;

                gid_cache->table_len = tprops->gid_tbl_len;
        }

        for (i = 0; i < pkey_cache->table_len; ++i) {
                ret = ib_query_pkey(device, port, i, pkey_cache->table + i);
                if (ret) {
                        printk(KERN_WARNING "ib_query_pkey failed (%d) for %s (index %d)\n",
                               ret, device->name, i);
                        goto err;
                }
        }

        if (!use_roce_gid_table) {
                for (i = 0;  i < gid_cache->table_len; ++i) {
                        ret = ib_query_gid(device, port, i,
                                           gid_cache->table + i, NULL);
                        if (ret) {
                                printk(KERN_WARNING "ib_query_gid failed (%d) for %s (index %d)\n",
                                       ret, device->name, i);
                                goto err;
                        }
                }
        }

        write_lock_irq(&device->cache.lock);

        old_pkey_cache = device->cache.pkey_cache[port - rdma_start_port(device)];

        device->cache.pkey_cache[port - rdma_start_port(device)] = pkey_cache;
        if (!use_roce_gid_table) {
                for (i = 0; i < gid_cache->table_len; i++) {
                        modify_gid(device, port, table, i, gid_cache->table + i,
                                   &zattr, false);
                }
        }

        device->cache.lmc_cache[port - rdma_start_port(device)] = tprops->lmc;

        write_unlock_irq(&device->cache.lock);

        kfree(gid_cache);
        kfree(old_pkey_cache);
        kfree(tprops);
        return;

err:
        kfree(pkey_cache);
        kfree(gid_cache);
        kfree(tprops);
}

static void ib_cache_task(struct work_struct *_work)
{
        struct ib_update_work *work =
                container_of(_work, struct ib_update_work, work);

        ib_cache_update(work->device, work->port_num);
        kfree(work);
}

static void ib_cache_event(struct ib_event_handler *handler,
                           struct ib_event *event)
{
        struct ib_update_work *work;

        if (event->event == IB_EVENT_PORT_ERR    ||
            event->event == IB_EVENT_PORT_ACTIVE ||
            event->event == IB_EVENT_LID_CHANGE  ||
            event->event == IB_EVENT_PKEY_CHANGE ||
            event->event == IB_EVENT_SM_CHANGE   ||
            event->event == IB_EVENT_CLIENT_REREGISTER ||
            event->event == IB_EVENT_GID_CHANGE) {

                work = kmalloc(sizeof *work, GFP_ATOMIC);
                if (work) {
                        INIT_WORK(&work->work, ib_cache_task);
                        work->device   = event->device;
                        work->port_num = event->element.port_num;
                        queue_work(ib_wq, &work->work);
                }
        }
}

int ib_cache_setup_one(struct ib_device *device)
{
        int p;
        int err;

        rwlock_init(&device->cache.lock);

        device->cache.pkey_cache =
                kzalloc(sizeof *device->cache.pkey_cache *
                        (rdma_end_port(device) - rdma_start_port(device) + 1), GFP_KERNEL);
        device->cache.lmc_cache = kmalloc(sizeof *device->cache.lmc_cache *
                                          (rdma_end_port(device) -
                                           rdma_start_port(device) + 1),
                                          GFP_KERNEL);
        if (!device->cache.pkey_cache ||
            !device->cache.lmc_cache) {
                printk(KERN_WARNING "Couldn't allocate cache "
                       "for %s\n", device->name);
                return -ENOMEM;
        }

        err = gid_table_setup_one(device);
        if (err)
                /* Allocated memory will be cleaned in the release function */
                return err;

        for (p = 0; p <= rdma_end_port(device) - rdma_start_port(device); ++p)
                ib_cache_update(device, p + rdma_start_port(device));

        INIT_IB_EVENT_HANDLER(&device->cache.event_handler,
                              device, ib_cache_event);
        err = ib_register_event_handler(&device->cache.event_handler);
        if (err)
                goto err;

        return 0;

err:
        gid_table_cleanup_one(device);
        return err;
}

void ib_cache_release_one(struct ib_device *device)
{
        int p;

        /*
         * The release function frees all the cache elements.
         * This function should be called as part of freeing
         * all the device's resources when the cache could no
         * longer be accessed.
         */
        if (device->cache.pkey_cache)
                for (p = 0;
                     p <= rdma_end_port(device) - rdma_start_port(device); ++p)
                        kfree(device->cache.pkey_cache[p]);

        gid_table_release_one(device);
        kfree(device->cache.pkey_cache);
        kfree(device->cache.lmc_cache);
}

void ib_cache_cleanup_one(struct ib_device *device)
{
        /* The cleanup function unregisters the event handler,
         * waits for all in-progress workqueue elements and cleans
         * up the GID cache. This function should be called after
         * the device was removed from the devices list and all
         * clients were removed, so the cache exists but is
         * non-functional and shouldn't be updated anymore.
         */
        ib_unregister_event_handler(&device->cache.event_handler);
        flush_workqueue(ib_wq);
        gid_table_cleanup_one(device);
}

void __init ib_cache_setup(void)
{
        roce_gid_mgmt_init();
}

void __exit ib_cache_cleanup(void)
{
        roce_gid_mgmt_cleanup();
}