/*
 * 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;
        bool               enforce_security;
};

union ib_gid zgid;
EXPORT_SYMBOL(zgid);

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,
        GID_ATTR_FIND_MASK_GID_TYPE     = 1UL << 3,
};

enum gid_table_entry_state {
        GID_TABLE_ENTRY_INVALID         = 1,
        GID_TABLE_ENTRY_VALID           = 2,
        /*
         * Indicates that entry is pending to be removed, there may
         * be active users of this GID entry.
         * When last user of the GID entry releases reference to it,
         * GID entry is detached from the table.
         */
        GID_TABLE_ENTRY_PENDING_DEL     = 3,
};

struct ib_gid_table_entry {
        struct kref                     kref;
        struct work_struct              del_work;
        struct ib_gid_attr              attr;
        void                            *context;
        enum gid_table_entry_state      state;
};

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.
         *
         **/
        /* Any writer to data_vec must hold this lock and the write side of
         * rwlock. Readers must hold only rwlock. All writers must be in a
         * sleepable context.
         */
        struct mutex                    lock;
        /* rwlock protects data_vec[ix]->state and entry pointer.
         */
        rwlock_t                        rwlock;
        struct ib_gid_table_entry       **data_vec;
        /* bit field, each bit indicates the index of default GID */
        u32                             default_gid_indices;
};

static void dispatch_gid_change_event(struct ib_device *ib_dev, u8 port)
{
        struct ib_event event;

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

        ib_dispatch_event(&event);
}

static const char * const gid_type_str[] = {
        [IB_GID_TYPE_IB]        = "IB/RoCE v1",
        [IB_GID_TYPE_ROCE_UDP_ENCAP]    = "RoCE v2",
};

const char *ib_cache_gid_type_str(enum ib_gid_type gid_type)
{
        if (gid_type < ARRAY_SIZE(gid_type_str) && gid_type_str[gid_type])
                return gid_type_str[gid_type];

        return "Invalid GID type";
}
EXPORT_SYMBOL(ib_cache_gid_type_str);

/** rdma_is_zero_gid - Check if given GID is zero or not.
 * @gid:        GID to check
 * Returns true if given GID is zero, returns false otherwise.
 */
bool rdma_is_zero_gid(const union ib_gid *gid)
{
        return !memcmp(gid, &zgid, sizeof(*gid));
}
EXPORT_SYMBOL(rdma_is_zero_gid);

/** is_gid_index_default - Check if a given index belongs to
 * reserved default GIDs or not.
 * @table:      GID table pointer
 * @index:      Index to check in GID table
 * Returns true if index is one of the reserved default GID index otherwise
 * returns false.
 */
static bool is_gid_index_default(const struct ib_gid_table *table,
                                 unsigned int index)
{
        return index < 32 && (BIT(index) & table->default_gid_indices);
}

int ib_cache_gid_parse_type_str(const char *buf)
{
        unsigned int i;
        size_t len;
        int err = -EINVAL;

        len = strlen(buf);
        if (len == 0)
                return -EINVAL;

        if (buf[len - 1] == '\n')
                len--;

        for (i = 0; i < ARRAY_SIZE(gid_type_str); ++i)
                if (gid_type_str[i] && !strncmp(buf, gid_type_str[i], len) &&
                    len == strlen(gid_type_str[i])) {
                        err = i;
                        break;
                }

        return err;
}
EXPORT_SYMBOL(ib_cache_gid_parse_type_str);

static struct ib_gid_table *rdma_gid_table(struct ib_device *device, u8 port)
{
        return device->port_data[port].cache.gid;
}

static bool is_gid_entry_free(const struct ib_gid_table_entry *entry)
{
        return !entry;
}

static bool is_gid_entry_valid(const struct ib_gid_table_entry *entry)
{
        return entry && entry->state == GID_TABLE_ENTRY_VALID;
}

static void schedule_free_gid(struct kref *kref)
{
        struct ib_gid_table_entry *entry =
                        container_of(kref, struct ib_gid_table_entry, kref);

        queue_work(ib_wq, &entry->del_work);
}

static void free_gid_entry_locked(struct ib_gid_table_entry *entry)
{
        struct ib_device *device = entry->attr.device;
        u8 port_num = entry->attr.port_num;
        struct ib_gid_table *table = rdma_gid_table(device, port_num);

        dev_dbg(&device->dev, "%s port=%d index=%d gid %pI6\n", __func__,
                port_num, entry->attr.index, entry->attr.gid.raw);

        write_lock_irq(&table->rwlock);

        /*
         * The only way to avoid overwriting NULL in table is
         * by comparing if it is same entry in table or not!
         * If new entry in table is added by the time we free here,
         * don't overwrite the table entry.
         */
        if (entry == table->data_vec[entry->attr.index])
                table->data_vec[entry->attr.index] = NULL;
        /* Now this index is ready to be allocated */
        write_unlock_irq(&table->rwlock);

        if (entry->attr.ndev)
                dev_put(entry->attr.ndev);
        kfree(entry);
}

static void free_gid_entry(struct kref *kref)
{
        struct ib_gid_table_entry *entry =
                        container_of(kref, struct ib_gid_table_entry, kref);

        free_gid_entry_locked(entry);
}

/**
 * free_gid_work - Release reference to the GID entry
 * @work: Work structure to refer to GID entry which needs to be
 * deleted.
 *
 * free_gid_work() frees the entry from the HCA's hardware table
 * if provider supports it. It releases reference to netdevice.
 */
static void free_gid_work(struct work_struct *work)
{
        struct ib_gid_table_entry *entry =
                container_of(work, struct ib_gid_table_entry, del_work);
        struct ib_device *device = entry->attr.device;
        u8 port_num = entry->attr.port_num;
        struct ib_gid_table *table = rdma_gid_table(device, port_num);

        mutex_lock(&table->lock);
        free_gid_entry_locked(entry);
        mutex_unlock(&table->lock);
}

static struct ib_gid_table_entry *
alloc_gid_entry(const struct ib_gid_attr *attr)
{
        struct ib_gid_table_entry *entry;

        entry = kzalloc(sizeof(*entry), GFP_KERNEL);
        if (!entry)
                return NULL;
        kref_init(&entry->kref);
        memcpy(&entry->attr, attr, sizeof(*attr));
        if (entry->attr.ndev)
                dev_hold(entry->attr.ndev);
        INIT_WORK(&entry->del_work, free_gid_work);
        entry->state = GID_TABLE_ENTRY_INVALID;
        return entry;
}

static void store_gid_entry(struct ib_gid_table *table,
                            struct ib_gid_table_entry *entry)
{
        entry->state = GID_TABLE_ENTRY_VALID;

        dev_dbg(&entry->attr.device->dev, "%s port=%d index=%d gid %pI6\n",
                __func__, entry->attr.port_num, entry->attr.index,
                entry->attr.gid.raw);

        lockdep_assert_held(&table->lock);
        write_lock_irq(&table->rwlock);
        table->data_vec[entry->attr.index] = entry;
        write_unlock_irq(&table->rwlock);
}

static void get_gid_entry(struct ib_gid_table_entry *entry)
{
        kref_get(&entry->kref);
}

static void put_gid_entry(struct ib_gid_table_entry *entry)
{
        kref_put(&entry->kref, schedule_free_gid);
}

static void put_gid_entry_locked(struct ib_gid_table_entry *entry)
{
        kref_put(&entry->kref, free_gid_entry);
}

static int add_roce_gid(struct ib_gid_table_entry *entry)
{
        const struct ib_gid_attr *attr = &entry->attr;
        int ret;

        if (!attr->ndev) {
                dev_err(&attr->device->dev, "%s NULL netdev port=%d index=%d\n",
                        __func__, attr->port_num, attr->index);
                return -EINVAL;
        }
        if (rdma_cap_roce_gid_table(attr->device, attr->port_num)) {
                ret = attr->device->ops.add_gid(attr, &entry->context);
                if (ret) {
                        dev_err(&attr->device->dev,
                                "%s GID add failed port=%d index=%d\n",
                                __func__, attr->port_num, attr->index);
                        return ret;
                }
        }
        return 0;
}

/**
 * del_gid - Delete GID table entry
 *
 * @ib_dev:     IB device whose GID entry to be deleted
 * @port:       Port number of the IB device
 * @table:      GID table of the IB device for a port
 * @ix:         GID entry index to delete
 *
 */
static void del_gid(struct ib_device *ib_dev, u8 port,
                    struct ib_gid_table *table, int ix)
{
        struct ib_gid_table_entry *entry;

        lockdep_assert_held(&table->lock);

        dev_dbg(&ib_dev->dev, "%s port=%d index=%d gid %pI6\n", __func__, port,
                ix, table->data_vec[ix]->attr.gid.raw);

        write_lock_irq(&table->rwlock);
        entry = table->data_vec[ix];
        entry->state = GID_TABLE_ENTRY_PENDING_DEL;
        /*
         * For non RoCE protocol, GID entry slot is ready to use.
         */
        if (!rdma_protocol_roce(ib_dev, port))
                table->data_vec[ix] = NULL;
        write_unlock_irq(&table->rwlock);

        if (rdma_cap_roce_gid_table(ib_dev, port))
                ib_dev->ops.del_gid(&entry->attr, &entry->context);

        put_gid_entry_locked(entry);
}

/**
 * add_modify_gid - Add or modify GID table entry
 *
 * @table:      GID table in which GID to be added or modified
 * @attr:       Attributes of the GID
 *
 * Returns 0 on success or appropriate error code. It accepts zero
 * GID addition for non RoCE ports for HCA's who report them as valid
 * GID. However such zero GIDs are not added to the cache.
 */
static int add_modify_gid(struct ib_gid_table *table,
                          const struct ib_gid_attr *attr)
{
        struct ib_gid_table_entry *entry;
        int ret = 0;

        /*
         * Invalidate any old entry in the table to make it safe to write to
         * this index.
         */
        if (is_gid_entry_valid(table->data_vec[attr->index]))
                del_gid(attr->device, attr->port_num, table, attr->index);

        /*
         * Some HCA's report multiple GID entries with only one valid GID, and
         * leave other unused entries as the zero GID. Convert zero GIDs to
         * empty table entries instead of storing them.
         */
        if (rdma_is_zero_gid(&attr->gid))
                return 0;

        entry = alloc_gid_entry(attr);
        if (!entry)
                return -ENOMEM;

        if (rdma_protocol_roce(attr->device, attr->port_num)) {
                ret = add_roce_gid(entry);
                if (ret)
                        goto done;
        }

        store_gid_entry(table, entry);
        return 0;

done:
        put_gid_entry(entry);
        return ret;
}

/* rwlock should be read locked, or lock should be held */
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 *pempty)
{
        int i = 0;
        int found = -1;
        int empty = pempty ? -1 : 0;

        while (i < table->sz && (found < 0 || empty < 0)) {
                struct ib_gid_table_entry *data = table->data_vec[i];
                struct ib_gid_attr *attr;
                int curr_index = i;

                i++;

                /* find_gid() is used during GID addition where it is expected
                 * to return a free entry slot which is not duplicate.
                 * Free entry slot is requested and returned if pempty is set,
                 * so lookup free slot only if requested.
                 */
                if (pempty && empty < 0) {
                        if (is_gid_entry_free(data) &&
                            default_gid ==
                                is_gid_index_default(table, curr_index)) {
                                /*
                                 * Found an invalid (free) entry; allocate it.
                                 * If default GID is requested, then our
                                 * found slot must be one of the DEFAULT
                                 * reserved slots or we fail.
                                 * This ensures that only DEFAULT reserved
                                 * slots are used for default property GIDs.
                                 */
                                empty = curr_index;
                        }
                }

                /*
                 * Additionally find_gid() is used to find valid entry during
                 * lookup operation; so ignore the entries which are marked as
                 * pending for removal and the entries which are marked as
                 * invalid.
                 */
                if (!is_gid_entry_valid(data))
                        continue;

                if (found >= 0)
                        continue;

                attr = &data->attr;
                if (mask & GID_ATTR_FIND_MASK_GID_TYPE &&
                    attr->gid_type != val->gid_type)
                        continue;

                if (mask & GID_ATTR_FIND_MASK_GID &&
                    memcmp(gid, &data->attr.gid, sizeof(*gid)))
                        continue;

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

                if (mask & GID_ATTR_FIND_MASK_DEFAULT &&
                    is_gid_index_default(table, curr_index) != default_gid)
                        continue;

                found = curr_index;
        }

        if (pempty)
                *pempty = empty;

        return found;
}

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);
}

static int __ib_cache_gid_add(struct ib_device *ib_dev, u8 port,
                              union ib_gid *gid, struct ib_gid_attr *attr,
                              unsigned long mask, bool default_gid)
{
        struct ib_gid_table *table;
        int ret = 0;
        int empty;
        int ix;

        /* Do not allow adding zero GID in support of
         * IB spec version 1.3 section 4.1.1 point (6) and
         * section 12.7.10 and section 12.7.20
         */
        if (rdma_is_zero_gid(gid))
                return -EINVAL;

        table = rdma_gid_table(ib_dev, port);

        mutex_lock(&table->lock);

        ix = find_gid(table, gid, attr, default_gid, mask, &empty);
        if (ix >= 0)
                goto out_unlock;

        if (empty < 0) {
                ret = -ENOSPC;
                goto out_unlock;
        }
        attr->device = ib_dev;
        attr->index = empty;
        attr->port_num = port;
        attr->gid = *gid;
        ret = add_modify_gid(table, attr);
        if (!ret)
                dispatch_gid_change_event(ib_dev, port);

out_unlock:
        mutex_unlock(&table->lock);
        if (ret)
                pr_warn("%s: unable to add gid %pI6 error=%d\n",
                        __func__, gid->raw, ret);
        return ret;
}

int ib_cache_gid_add(struct ib_device *ib_dev, u8 port,
                     union ib_gid *gid, struct ib_gid_attr *attr)
{
        struct net_device *idev;
        unsigned long mask;
        int ret;

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

                /* Adding default GIDs is 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);

        mask = GID_ATTR_FIND_MASK_GID |
               GID_ATTR_FIND_MASK_GID_TYPE |
               GID_ATTR_FIND_MASK_NETDEV;

        ret = __ib_cache_gid_add(ib_dev, port, gid, attr, mask, false);
        return ret;
}

static int
_ib_cache_gid_del(struct ib_device *ib_dev, u8 port,
                  union ib_gid *gid, struct ib_gid_attr *attr,
                  unsigned long mask, bool default_gid)
{
        struct ib_gid_table *table;
        int ret = 0;
        int ix;

        table = rdma_gid_table(ib_dev, port);

        mutex_lock(&table->lock);

        ix = find_gid(table, gid, attr, default_gid, mask, NULL);
        if (ix < 0) {
                ret = -EINVAL;
                goto out_unlock;
        }

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

out_unlock:
        mutex_unlock(&table->lock);
        if (ret)
                pr_debug("%s: can't delete gid %pI6 error=%d\n",
                         __func__, gid->raw, ret);
        return ret;
}

int ib_cache_gid_del(struct ib_device *ib_dev, u8 port,
                     union ib_gid *gid, struct ib_gid_attr *attr)
{
        unsigned long mask = GID_ATTR_FIND_MASK_GID       |
                             GID_ATTR_FIND_MASK_GID_TYPE |
                             GID_ATTR_FIND_MASK_DEFAULT  |
                             GID_ATTR_FIND_MASK_NETDEV;

        return _ib_cache_gid_del(ib_dev, port, gid, attr, mask, false);
}

int ib_cache_gid_del_all_netdev_gids(struct ib_device *ib_dev, u8 port,
                                     struct net_device *ndev)
{
        struct ib_gid_table *table;
        int ix;
        bool deleted = false;

        table = rdma_gid_table(ib_dev, port);

        mutex_lock(&table->lock);

        for (ix = 0; ix < table->sz; ix++) {
                if (is_gid_entry_valid(table->data_vec[ix]) &&
                    table->data_vec[ix]->attr.ndev == ndev) {
                        del_gid(ib_dev, port, table, ix);
                        deleted = true;
                }
        }

        mutex_unlock(&table->lock);

        if (deleted)
                dispatch_gid_change_event(ib_dev, port);

        return 0;
}

/**
 * rdma_find_gid_by_port - Returns the GID entry attributes when it finds
 * a valid GID entry for given search parameters. It searches for the specified
 * GID value in the local software cache.
 * @device: The device to query.
 * @gid: The GID value to search for.
 * @gid_type: The GID type to search for.
 * @port_num: The port number of the device where the GID value should be
 *   searched.
 * @ndev: In RoCE, the net device of the device. NULL means ignore.
 *
 * Returns sgid attributes if the GID is found with valid reference or
 * returns ERR_PTR for the error.
 * The caller must invoke rdma_put_gid_attr() to release the reference.
 */
const struct ib_gid_attr *
rdma_find_gid_by_port(struct ib_device *ib_dev,
                      const union ib_gid *gid,
                      enum ib_gid_type gid_type,
                      u8 port, struct net_device *ndev)
{
        int local_index;
        struct ib_gid_table *table;
        unsigned long mask = GID_ATTR_FIND_MASK_GID |
                             GID_ATTR_FIND_MASK_GID_TYPE;
        struct ib_gid_attr val = {.ndev = ndev, .gid_type = gid_type};
        const struct ib_gid_attr *attr;
        unsigned long flags;

        if (!rdma_is_port_valid(ib_dev, port))
                return ERR_PTR(-ENOENT);

        table = rdma_gid_table(ib_dev, port);

        if (ndev)
                mask |= GID_ATTR_FIND_MASK_NETDEV;

        read_lock_irqsave(&table->rwlock, flags);
        local_index = find_gid(table, gid, &val, false, mask, NULL);
        if (local_index >= 0) {
                get_gid_entry(table->data_vec[local_index]);
                attr = &table->data_vec[local_index]->attr;
                read_unlock_irqrestore(&table->rwlock, flags);
                return attr;
        }

        read_unlock_irqrestore(&table->rwlock, flags);
        return ERR_PTR(-ENOENT);
}
EXPORT_SYMBOL(rdma_find_gid_by_port);

/**
 * rdma_find_gid_by_filter - Returns the GID table attribute where a
 * specified GID value occurs
 * @device: The device to query.
 * @gid: The GID value to search for.
 * @port: 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.
 *
 * rdma_find_gid_by_filter() searches for the specified GID value
 * of which the filter function returns true in the port's GID table.
 *
 */
const struct ib_gid_attr *rdma_find_gid_by_filter(
        struct ib_device *ib_dev, const union ib_gid *gid, u8 port,
        bool (*filter)(const union ib_gid *gid, const struct ib_gid_attr *,
                       void *),
        void *context)
{
        const struct ib_gid_attr *res = ERR_PTR(-ENOENT);
        struct ib_gid_table *table;
        unsigned long flags;
        unsigned int i;

        if (!rdma_is_port_valid(ib_dev, port))
                return ERR_PTR(-EINVAL);

        table = rdma_gid_table(ib_dev, port);

        read_lock_irqsave(&table->rwlock, flags);
        for (i = 0; i < table->sz; i++) {
                struct ib_gid_table_entry *entry = table->data_vec[i];

                if (!is_gid_entry_valid(entry))
                        continue;

                if (memcmp(gid, &entry->attr.gid, sizeof(*gid)))
                        continue;

                if (filter(gid, &entry->attr, context)) {
                        get_gid_entry(entry);
                        res = &entry->attr;
                        break;
                }
        }
        read_unlock_irqrestore(&table->rwlock, flags);
        return res;
}

static struct ib_gid_table *alloc_gid_table(int sz)
{
        struct ib_gid_table *table = kzalloc(sizeof(*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;
        rwlock_init(&table->rwlock);
        return table;

err_free_table:
        kfree(table);
        return NULL;
}

static void release_gid_table(struct ib_device *device,
                              struct ib_gid_table *table)
{
        bool leak = false;
        int i;

        if (!table)
                return;

        for (i = 0; i < table->sz; i++) {
                if (is_gid_entry_free(table->data_vec[i]))
                        continue;
                if (kref_read(&table->data_vec[i]->kref) > 1) {
                        dev_err(&device->dev,
                                "GID entry ref leak for index %d ref=%d\n", i,
                                kref_read(&table->data_vec[i]->kref));
                        leak = true;
                }
        }
        if (leak)
                return;

        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;
        bool deleted = false;

        if (!table)
                return;

        mutex_lock(&table->lock);
        for (i = 0; i < table->sz; ++i) {
                if (is_gid_entry_valid(table->data_vec[i])) {
                        del_gid(ib_dev, port, table, i);
                        deleted = true;
                }
        }
        mutex_unlock(&table->lock);

        if (deleted)
                dispatch_gid_change_event(ib_dev, port);
}

void ib_cache_gid_set_default_gid(struct ib_device *ib_dev, u8 port,
                                  struct net_device *ndev,
                                  unsigned long gid_type_mask,
                                  enum ib_cache_gid_default_mode mode)
{
        union ib_gid gid = { };
        struct ib_gid_attr gid_attr;
        unsigned int gid_type;
        unsigned long mask;

        mask = GID_ATTR_FIND_MASK_GID_TYPE |
               GID_ATTR_FIND_MASK_DEFAULT |
               GID_ATTR_FIND_MASK_NETDEV;
        memset(&gid_attr, 0, sizeof(gid_attr));
        gid_attr.ndev = ndev;

        for (gid_type = 0; gid_type < IB_GID_TYPE_SIZE; ++gid_type) {
                if (1UL << gid_type & ~gid_type_mask)
                        continue;

                gid_attr.gid_type = gid_type;

                if (mode == IB_CACHE_GID_DEFAULT_MODE_SET) {
                        make_default_gid(ndev, &gid);
                        __ib_cache_gid_add(ib_dev, port, &gid,
                                           &gid_attr, mask, true);
                } else if (mode == IB_CACHE_GID_DEFAULT_MODE_DELETE) {
                        _ib_cache_gid_del(ib_dev, port, &gid,
                                          &gid_attr, mask, true);
                }
        }
}

static void gid_table_reserve_default(struct ib_device *ib_dev, u8 port,
                                      struct ib_gid_table *table)
{
        unsigned int i;
        unsigned long roce_gid_type_mask;
        unsigned int num_default_gids;

        roce_gid_type_mask = roce_gid_type_mask_support(ib_dev, port);
        num_default_gids = hweight_long(roce_gid_type_mask);
        /* Reserve starting indices for default GIDs */
        for (i = 0; i < num_default_gids && i < table->sz; i++)
                table->default_gid_indices |= BIT(i);
}


static void gid_table_release_one(struct ib_device *ib_dev)
{
        unsigned int p;

        rdma_for_each_port (ib_dev, p) {
                release_gid_table(ib_dev, ib_dev->port_data[p].cache.gid);
                ib_dev->port_data[p].cache.gid = NULL;
        }
}

static int _gid_table_setup_one(struct ib_device *ib_dev)
{
        struct ib_gid_table *table;
        unsigned int rdma_port;

        rdma_for_each_port (ib_dev, rdma_port) {
                table = alloc_gid_table(
                        ib_dev->port_data[rdma_port].immutable.gid_tbl_len);
                if (!table)
                        goto rollback_table_setup;

                gid_table_reserve_default(ib_dev, rdma_port, table);
                ib_dev->port_data[rdma_port].cache.gid = table;
        }
        return 0;

rollback_table_setup:
        gid_table_release_one(ib_dev);
        return -ENOMEM;
}

static void gid_table_cleanup_one(struct ib_device *ib_dev)
{
        unsigned int p;

        rdma_for_each_port (ib_dev, p)
                cleanup_gid_table_port(ib_dev, p,
                                       ib_dev->port_data[p].cache.gid);
}

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

        err = _gid_table_setup_one(ib_dev);

        if (err)
                return err;

        rdma_roce_rescan_device(ib_dev);

        return err;
}

/**
 * rdma_query_gid - Read the GID content from the GID software cache
 * @device:             Device to query the GID
 * @port_num:           Port number of the device
 * @index:              Index of the GID table entry to read
 * @gid:                Pointer to GID where to store the entry's GID
 *
 * rdma_query_gid() only reads the GID entry content for requested device,
 * port and index. It reads for IB, RoCE and iWarp link layers.  It doesn't
 * hold any reference to the GID table entry in the HCA or software cache.
 *
 * Returns 0 on success or appropriate error code.
 *
 */
int rdma_query_gid(struct ib_device *device, u8 port_num,
                   int index, union ib_gid *gid)
{
        struct ib_gid_table *table;
        unsigned long flags;
        int res = -EINVAL;

        if (!rdma_is_port_valid(device, port_num))
                return -EINVAL;

        table = rdma_gid_table(device, port_num);
        read_lock_irqsave(&table->rwlock, flags);

        if (index < 0 || index >= table->sz ||
            !is_gid_entry_valid(table->data_vec[index]))
                goto done;

        memcpy(gid, &table->data_vec[index]->attr.gid, sizeof(*gid));
        res = 0;

done:
        read_unlock_irqrestore(&table->rwlock, flags);
        return res;
}
EXPORT_SYMBOL(rdma_query_gid);

/**
 * rdma_find_gid - Returns SGID attributes if the matching GID is found.
 * @device: The device to query.
 * @gid: The GID value to search for.
 * @gid_type: The GID type to search for.
 * @ndev: In RoCE, the net device of the device. NULL means ignore.
 *
 * rdma_find_gid() searches for the specified GID value in the software cache.
 *
 * Returns GID attributes if a valid GID is found or returns ERR_PTR for the
 * error. The caller must invoke rdma_put_gid_attr() to release the reference.
 *
 */
const struct ib_gid_attr *rdma_find_gid(struct ib_device *device,
                                        const union ib_gid *gid,
                                        enum ib_gid_type gid_type,
                                        struct net_device *ndev)
{
        unsigned long mask = GID_ATTR_FIND_MASK_GID |
                             GID_ATTR_FIND_MASK_GID_TYPE;
        struct ib_gid_attr gid_attr_val = {.ndev = ndev, .gid_type = gid_type};
        unsigned int p;

        if (ndev)
                mask |= GID_ATTR_FIND_MASK_NETDEV;

        rdma_for_each_port(device, p) {
                struct ib_gid_table *table;
                unsigned long flags;
                int index;

                table = device->port_data[p].cache.gid;
                read_lock_irqsave(&table->rwlock, flags);
                index = find_gid(table, gid, &gid_attr_val, false, mask, NULL);
                if (index >= 0) {
                        const struct ib_gid_attr *attr;

                        get_gid_entry(table->data_vec[index]);
                        attr = &table->data_vec[index]->attr;
                        read_unlock_irqrestore(&table->rwlock, flags);
                        return attr;
                }
                read_unlock_irqrestore(&table->rwlock, flags);
        }

        return ERR_PTR(-ENOENT);
}
EXPORT_SYMBOL(rdma_find_gid);

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 (!rdma_is_port_valid(device, port_num))
                return -EINVAL;

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

        cache = device->port_data[port_num].cache.pkey;

        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_get_cached_subnet_prefix(struct ib_device *device,
                                u8                port_num,
                                u64              *sn_pfx)
{
        unsigned long flags;

        if (!rdma_is_port_valid(device, port_num))
                return -EINVAL;

        read_lock_irqsave(&device->cache.lock, flags);
        *sn_pfx = device->port_data[port_num].cache.subnet_prefix;
        read_unlock_irqrestore(&device->cache.lock, flags);

        return 0;
}
EXPORT_SYMBOL(ib_get_cached_subnet_prefix);

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 (!rdma_is_port_valid(device, port_num))
                return -EINVAL;

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

        cache = device->port_data[port_num].cache.pkey;

        *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 (!rdma_is_port_valid(device, port_num))
                return -EINVAL;

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

        cache = device->port_data[port_num].cache.pkey;

        *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 (!rdma_is_port_valid(device, port_num))
                return -EINVAL;

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

        return ret;
}
EXPORT_SYMBOL(ib_get_cached_lmc);

int ib_get_cached_port_state(struct ib_device   *device,
                             u8                  port_num,
                             enum ib_port_state *port_state)
{
        unsigned long flags;
        int ret = 0;

        if (!rdma_is_port_valid(device, port_num))
                return -EINVAL;

        read_lock_irqsave(&device->cache.lock, flags);
        *port_state = device->port_data[port_num].cache.port_state;
        read_unlock_irqrestore(&device->cache.lock, flags);

        return ret;
}
EXPORT_SYMBOL(ib_get_cached_port_state);

/**
 * rdma_get_gid_attr - Returns GID attributes for a port of a device
 * at a requested gid_index, if a valid GID entry exists.
 * @device:             The device to query.
 * @port_num:           The port number on the device where the GID value
 *                      is to be queried.
 * @index:              Index of the GID table entry whose attributes are to
 *                      be queried.
 *
 * rdma_get_gid_attr() acquires reference count of gid attributes from the
 * cached GID table. Caller must invoke rdma_put_gid_attr() to release
 * reference to gid attribute regardless of link layer.
 *
 * Returns pointer to valid gid attribute or ERR_PTR for the appropriate error
 * code.
 */
const struct ib_gid_attr *
rdma_get_gid_attr(struct ib_device *device, u8 port_num, int index)
{
        const struct ib_gid_attr *attr = ERR_PTR(-EINVAL);
        struct ib_gid_table *table;
        unsigned long flags;

        if (!rdma_is_port_valid(device, port_num))
                return ERR_PTR(-EINVAL);

        table = rdma_gid_table(device, port_num);
        if (index < 0 || index >= table->sz)
                return ERR_PTR(-EINVAL);

        read_lock_irqsave(&table->rwlock, flags);
        if (!is_gid_entry_valid(table->data_vec[index]))
                goto done;

        get_gid_entry(table->data_vec[index]);
        attr = &table->data_vec[index]->attr;
done:
        read_unlock_irqrestore(&table->rwlock, flags);
        return attr;
}
EXPORT_SYMBOL(rdma_get_gid_attr);

/**
 * rdma_put_gid_attr - Release reference to the GID attribute
 * @attr:               Pointer to the GID attribute whose reference
 *                      needs to be released.
 *
 * rdma_put_gid_attr() must be used to release reference whose
 * reference is acquired using rdma_get_gid_attr() or any APIs
 * which returns a pointer to the ib_gid_attr regardless of link layer
 * of IB or RoCE.
 *
 */
void rdma_put_gid_attr(const struct ib_gid_attr *attr)
{
        struct ib_gid_table_entry *entry =
                container_of(attr, struct ib_gid_table_entry, attr);

        put_gid_entry(entry);
}
EXPORT_SYMBOL(rdma_put_gid_attr);

/**
 * rdma_hold_gid_attr - Get reference to existing GID attribute
 *
 * @attr:               Pointer to the GID attribute whose reference
 *                      needs to be taken.
 *
 * Increase the reference count to a GID attribute to keep it from being
 * freed. Callers are required to already be holding a reference to attribute.
 *
 */
void rdma_hold_gid_attr(const struct ib_gid_attr *attr)
{
        struct ib_gid_table_entry *entry =
                container_of(attr, struct ib_gid_table_entry, attr);

        get_gid_entry(entry);
}
EXPORT_SYMBOL(rdma_hold_gid_attr);

/**
 * rdma_read_gid_attr_ndev_rcu - Read GID attribute netdevice
 * which must be in UP state.
 *
 * @attr:Pointer to the GID attribute
 *
 * Returns pointer to netdevice if the netdevice was attached to GID and
 * netdevice is in UP state. Caller must hold RCU lock as this API
 * reads the netdev flags which can change while netdevice migrates to
 * different net namespace. Returns ERR_PTR with error code otherwise.
 *
 */
struct net_device *rdma_read_gid_attr_ndev_rcu(const struct ib_gid_attr *attr)
{
        struct ib_gid_table_entry *entry =
                        container_of(attr, struct ib_gid_table_entry, attr);
        struct ib_device *device = entry->attr.device;
        struct net_device *ndev = ERR_PTR(-ENODEV);
        u8 port_num = entry->attr.port_num;
        struct ib_gid_table *table;
        unsigned long flags;
        bool valid;

        table = rdma_gid_table(device, port_num);

        read_lock_irqsave(&table->rwlock, flags);
        valid = is_gid_entry_valid(table->data_vec[attr->index]);
        if (valid && attr->ndev && (READ_ONCE(attr->ndev->flags) & IFF_UP))
                ndev = attr->ndev;
        read_unlock_irqrestore(&table->rwlock, flags);
        return ndev;
}

static int config_non_roce_gid_cache(struct ib_device *device,
                                     u8 port, int gid_tbl_len)
{
        struct ib_gid_attr gid_attr = {};
        struct ib_gid_table *table;
        int ret = 0;
        int i;

        gid_attr.device = device;
        gid_attr.port_num = port;
        table = rdma_gid_table(device, port);

        mutex_lock(&table->lock);
        for (i = 0; i < gid_tbl_len; ++i) {
                if (!device->ops.query_gid)
                        continue;
                ret = device->ops.query_gid(device, port, i, &gid_attr.gid);
                if (ret) {
                        dev_warn(&device->dev,
                                 "query_gid failed (%d) for index %d\n", ret,
                                 i);
                        goto err;
                }
                gid_attr.index = i;
                add_modify_gid(table, &gid_attr);
        }
err:
        mutex_unlock(&table->lock);
        return ret;
}

static void ib_cache_update(struct ib_device *device,
                            u8                port,
                            bool              enforce_security)
{
        struct ib_port_attr       *tprops = NULL;
        struct ib_pkey_cache      *pkey_cache = NULL, *old_pkey_cache;
        int                        i;
        int                        ret;

        if (!rdma_is_port_valid(device, port))
                return;

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

        ret = ib_query_port(device, port, tprops);
        if (ret) {
                dev_warn(&device->dev, "ib_query_port failed (%d)\n", ret);
                goto err;
        }

        if (!rdma_protocol_roce(device, port)) {
                ret = config_non_roce_gid_cache(device, port,
                                                tprops->gid_tbl_len);
                if (ret)
                        goto err;
        }

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

        pkey_cache->table_len = tprops->pkey_tbl_len;

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

        write_lock_irq(&device->cache.lock);

        old_pkey_cache = device->port_data[port].cache.pkey;

        device->port_data[port].cache.pkey = pkey_cache;
        device->port_data[port].cache.lmc = tprops->lmc;
        device->port_data[port].cache.port_state = tprops->state;

        device->port_data[port].cache.subnet_prefix = tprops->subnet_prefix;
        write_unlock_irq(&device->cache.lock);

        if (enforce_security)
                ib_security_cache_change(device,
                                         port,
                                         tprops->subnet_prefix);

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

err:
        kfree(pkey_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,
                        work->enforce_security);
        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;
                        if (event->event == IB_EVENT_PKEY_CHANGE ||
                            event->event == IB_EVENT_GID_CHANGE)
                                work->enforce_security = true;
                        else
                                work->enforce_security = false;

                        queue_work(ib_wq, &work->work);
                }
        }
}

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

        rwlock_init(&device->cache.lock);

        err = gid_table_setup_one(device);
        if (err)
                return err;

        rdma_for_each_port (device, p)
                ib_cache_update(device, p, true);

        INIT_IB_EVENT_HANDLER(&device->cache.event_handler,
                              device, ib_cache_event);
        ib_register_event_handler(&device->cache.event_handler);
        return 0;
}

void ib_cache_release_one(struct ib_device *device)
{
        unsigned 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.
         */
        rdma_for_each_port (device, p)
                kfree(device->port_data[p].cache.pkey);

        gid_table_release_one(device);
}

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);

        /*
         * Flush the wq second time for any pending GID delete work.
         */
        flush_workqueue(ib_wq);
}