sa_query.c

Go to the documentation of this file.

/*
 * Copyright (c) 2004 Topspin Communications.  All rights reserved.
 * Copyright (c) 2005 Voltaire, Inc.  All rights reserved.
 * Copyright (c) 2006 Intel Corporation.  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/init.h>
#include <linux/err.h>
#include <linux/random.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/dma-mapping.h>
#include <linux/kref.h>
#include <linux/idr.h>
#include <linux/workqueue.h>

#include <rdma/ib_pack.h>
#include <rdma/ib_cache.h>
#include "sa.h"

MODULE_AUTHOR("Roland Dreier");
MODULE_DESCRIPTION("InfiniBand subnet administration query support");
MODULE_LICENSE("Dual BSD/GPL");

struct ib_sa_sm_ah {
    struct ib_ah        *ah;
    struct kref          ref;
    u16          pkey_index;
    u8           src_path_mask;
};

struct ib_sa_port {
    struct ib_mad_agent *agent;
    struct ib_sa_sm_ah  *sm_ah;
    struct work_struct   update_task;
    spinlock_t           ah_lock;
    u8                   port_num;
};

struct ib_sa_device {
    int                     start_port, end_port;
    struct ib_event_handler event_handler;
    struct ib_sa_port port[0];
};

struct ib_sa_query {
    void (*callback)(struct ib_sa_query *, int, struct ib_sa_mad *);
    void (*release)(struct ib_sa_query *);
    struct ib_sa_client    *client;
    struct ib_sa_port      *port;
    struct ib_mad_send_buf *mad_buf;
    struct ib_sa_sm_ah     *sm_ah;
    int         id;
};

struct ib_sa_service_query {
    void (*callback)(int, struct ib_sa_service_rec *, void *);
    void *context;
    struct ib_sa_query sa_query;
};

struct ib_sa_path_query {
    void (*callback)(int, struct ib_sa_path_rec *, void *);
    void *context;
    struct ib_sa_query sa_query;
};

struct ib_sa_guidinfo_query {
    void (*callback)(int, struct ib_sa_guidinfo_rec *, void *);
    void *context;
    struct ib_sa_query sa_query;
};

struct ib_sa_mcmember_query {
    void (*callback)(int, struct ib_sa_mcmember_rec *, void *);
    void *context;
    struct ib_sa_query sa_query;
};

static void ib_sa_add_one(struct ib_device *device);
static void ib_sa_remove_one(struct ib_device *device);

static struct ib_client sa_client = {
    .name   = "sa",
    .add    = ib_sa_add_one,
    .remove = ib_sa_remove_one
};

static DEFINE_SPINLOCK(idr_lock);
static DEFINE_IDR(query_idr);

static DEFINE_SPINLOCK(tid_lock);
static u32 tid;

#define PATH_REC_FIELD(field) \
    .struct_offset_bytes = offsetof(struct ib_sa_path_rec, field),      \
    .struct_size_bytes   = sizeof ((struct ib_sa_path_rec *) 0)->field, \
    .field_name          = "sa_path_rec:" #field

static const struct ib_field path_rec_table[] = {
    { PATH_REC_FIELD(service_id),
      .offset_words = 0,
      .offset_bits  = 0,
      .size_bits    = 64 },
    { PATH_REC_FIELD(dgid),
      .offset_words = 2,
      .offset_bits  = 0,
      .size_bits    = 128 },
    { PATH_REC_FIELD(sgid),
      .offset_words = 6,
      .offset_bits  = 0,
      .size_bits    = 128 },
    { PATH_REC_FIELD(dlid),
      .offset_words = 10,
      .offset_bits  = 0,
      .size_bits    = 16 },
    { PATH_REC_FIELD(slid),
      .offset_words = 10,
      .offset_bits  = 16,
      .size_bits    = 16 },
    { PATH_REC_FIELD(raw_traffic),
      .offset_words = 11,
      .offset_bits  = 0,
      .size_bits    = 1 },
    { RESERVED,
      .offset_words = 11,
      .offset_bits  = 1,
      .size_bits    = 3 },
    { PATH_REC_FIELD(flow_label),
      .offset_words = 11,
      .offset_bits  = 4,
      .size_bits    = 20 },
    { PATH_REC_FIELD(hop_limit),
      .offset_words = 11,
      .offset_bits  = 24,
      .size_bits    = 8 },
    { PATH_REC_FIELD(traffic_class),
      .offset_words = 12,
      .offset_bits  = 0,
      .size_bits    = 8 },
    { PATH_REC_FIELD(reversible),
      .offset_words = 12,
      .offset_bits  = 8,
      .size_bits    = 1 },
    { PATH_REC_FIELD(numb_path),
      .offset_words = 12,
      .offset_bits  = 9,
      .size_bits    = 7 },
    { PATH_REC_FIELD(pkey),
      .offset_words = 12,
      .offset_bits  = 16,
      .size_bits    = 16 },
    { PATH_REC_FIELD(qos_class),
      .offset_words = 13,
      .offset_bits  = 0,
      .size_bits    = 12 },
    { PATH_REC_FIELD(sl),
      .offset_words = 13,
      .offset_bits  = 12,
      .size_bits    = 4 },
    { PATH_REC_FIELD(mtu_selector),
      .offset_words = 13,
      .offset_bits  = 16,
      .size_bits    = 2 },
    { PATH_REC_FIELD(mtu),
      .offset_words = 13,
      .offset_bits  = 18,
      .size_bits    = 6 },
    { PATH_REC_FIELD(rate_selector),
      .offset_words = 13,
      .offset_bits  = 24,
      .size_bits    = 2 },
    { PATH_REC_FIELD(rate),
      .offset_words = 13,
      .offset_bits  = 26,
      .size_bits    = 6 },
    { PATH_REC_FIELD(packet_life_time_selector),
      .offset_words = 14,
      .offset_bits  = 0,
      .size_bits    = 2 },
    { PATH_REC_FIELD(packet_life_time),
      .offset_words = 14,
      .offset_bits  = 2,
      .size_bits    = 6 },
    { PATH_REC_FIELD(preference),
      .offset_words = 14,
      .offset_bits  = 8,
      .size_bits    = 8 },
    { RESERVED,
      .offset_words = 14,
      .offset_bits  = 16,
      .size_bits    = 48 },
};

#define MCMEMBER_REC_FIELD(field) \
    .struct_offset_bytes = offsetof(struct ib_sa_mcmember_rec, field),  \
    .struct_size_bytes   = sizeof ((struct ib_sa_mcmember_rec *) 0)->field, \
    .field_name          = "sa_mcmember_rec:" #field

static const struct ib_field mcmember_rec_table[] = {
    { MCMEMBER_REC_FIELD(mgid),
      .offset_words = 0,
      .offset_bits  = 0,
      .size_bits    = 128 },
    { MCMEMBER_REC_FIELD(port_gid),
      .offset_words = 4,
      .offset_bits  = 0,
      .size_bits    = 128 },
    { MCMEMBER_REC_FIELD(qkey),
      .offset_words = 8,
      .offset_bits  = 0,
      .size_bits    = 32 },
    { MCMEMBER_REC_FIELD(mlid),
      .offset_words = 9,
      .offset_bits  = 0,
      .size_bits    = 16 },
    { MCMEMBER_REC_FIELD(mtu_selector),
      .offset_words = 9,
      .offset_bits  = 16,
      .size_bits    = 2 },
    { MCMEMBER_REC_FIELD(mtu),
      .offset_words = 9,
      .offset_bits  = 18,
      .size_bits    = 6 },
    { MCMEMBER_REC_FIELD(traffic_class),
      .offset_words = 9,
      .offset_bits  = 24,
      .size_bits    = 8 },
    { MCMEMBER_REC_FIELD(pkey),
      .offset_words = 10,
      .offset_bits  = 0,
      .size_bits    = 16 },
    { MCMEMBER_REC_FIELD(rate_selector),
      .offset_words = 10,
      .offset_bits  = 16,
      .size_bits    = 2 },
    { MCMEMBER_REC_FIELD(rate),
      .offset_words = 10,
      .offset_bits  = 18,
      .size_bits    = 6 },
    { MCMEMBER_REC_FIELD(packet_life_time_selector),
      .offset_words = 10,
      .offset_bits  = 24,
      .size_bits    = 2 },
    { MCMEMBER_REC_FIELD(packet_life_time),
      .offset_words = 10,
      .offset_bits  = 26,
      .size_bits    = 6 },
    { MCMEMBER_REC_FIELD(sl),
      .offset_words = 11,
      .offset_bits  = 0,
      .size_bits    = 4 },
    { MCMEMBER_REC_FIELD(flow_label),
      .offset_words = 11,
      .offset_bits  = 4,
      .size_bits    = 20 },
    { MCMEMBER_REC_FIELD(hop_limit),
      .offset_words = 11,
      .offset_bits  = 24,
      .size_bits    = 8 },
    { MCMEMBER_REC_FIELD(scope),
      .offset_words = 12,
      .offset_bits  = 0,
      .size_bits    = 4 },
    { MCMEMBER_REC_FIELD(join_state),
      .offset_words = 12,
      .offset_bits  = 4,
      .size_bits    = 4 },
    { MCMEMBER_REC_FIELD(proxy_join),
      .offset_words = 12,
      .offset_bits  = 8,
      .size_bits    = 1 },
    { RESERVED,
      .offset_words = 12,
      .offset_bits  = 9,
      .size_bits    = 23 },
};

#define SERVICE_REC_FIELD(field) \
    .struct_offset_bytes = offsetof(struct ib_sa_service_rec, field),   \
    .struct_size_bytes   = sizeof ((struct ib_sa_service_rec *) 0)->field,  \
    .field_name          = "sa_service_rec:" #field

static const struct ib_field service_rec_table[] = {
    { SERVICE_REC_FIELD(id),
      .offset_words = 0,
      .offset_bits  = 0,
      .size_bits    = 64 },
    { SERVICE_REC_FIELD(gid),
      .offset_words = 2,
      .offset_bits  = 0,
      .size_bits    = 128 },
    { SERVICE_REC_FIELD(pkey),
      .offset_words = 6,
      .offset_bits  = 0,
      .size_bits    = 16 },
    { SERVICE_REC_FIELD(lease),
      .offset_words = 7,
      .offset_bits  = 0,
      .size_bits    = 32 },
    { SERVICE_REC_FIELD(key),
      .offset_words = 8,
      .offset_bits  = 0,
      .size_bits    = 128 },
    { SERVICE_REC_FIELD(name),
      .offset_words = 12,
      .offset_bits  = 0,
      .size_bits    = 64*8 },
    { SERVICE_REC_FIELD(data8),
      .offset_words = 28,
      .offset_bits  = 0,
      .size_bits    = 16*8 },
    { SERVICE_REC_FIELD(data16),
      .offset_words = 32,
      .offset_bits  = 0,
      .size_bits    = 8*16 },
    { SERVICE_REC_FIELD(data32),
      .offset_words = 36,
      .offset_bits  = 0,
      .size_bits    = 4*32 },
    { SERVICE_REC_FIELD(data64),
      .offset_words = 40,
      .offset_bits  = 0,
      .size_bits    = 2*64 },
};

#define GUIDINFO_REC_FIELD(field) \
    .struct_offset_bytes = offsetof(struct ib_sa_guidinfo_rec, field),  \
    .struct_size_bytes   = sizeof((struct ib_sa_guidinfo_rec *) 0)->field,  \
    .field_name          = "sa_guidinfo_rec:" #field

static const struct ib_field guidinfo_rec_table[] = {
    { GUIDINFO_REC_FIELD(lid),
      .offset_words = 0,
      .offset_bits  = 0,
      .size_bits    = 16 },
    { GUIDINFO_REC_FIELD(block_num),
      .offset_words = 0,
      .offset_bits  = 16,
      .size_bits    = 8 },
    { GUIDINFO_REC_FIELD(res1),
      .offset_words = 0,
      .offset_bits  = 24,
      .size_bits    = 8 },
    { GUIDINFO_REC_FIELD(res2),
      .offset_words = 1,
      .offset_bits  = 0,
      .size_bits    = 32 },
    { GUIDINFO_REC_FIELD(guid_info_list),
      .offset_words = 2,
      .offset_bits  = 0,
      .size_bits    = 512 },
};

static void free_sm_ah(struct kref *kref)
{
    struct ib_sa_sm_ah *sm_ah = container_of(kref, struct ib_sa_sm_ah, ref);

    ib_destroy_ah(sm_ah->ah);
    kfree(sm_ah);
}

static void update_sm_ah(struct work_struct *work)
{
    struct ib_sa_port *port =
        container_of(work, struct ib_sa_port, update_task);
    struct ib_sa_sm_ah *new_ah;
    struct ib_port_attr port_attr;
    struct ib_ah_attr   ah_attr;

    if (ib_query_port(port->agent->device, port->port_num, &port_attr)) {
        printk(KERN_WARNING "Couldn't query port\n");
        return;
    }

    new_ah = kmalloc(sizeof *new_ah, GFP_KERNEL);
    if (!new_ah) {
        printk(KERN_WARNING "Couldn't allocate new SM AH\n");
        return;
    }

    kref_init(&new_ah->ref);
    new_ah->src_path_mask = (1 << port_attr.lmc) - 1;

    new_ah->pkey_index = 0;
    if (ib_find_pkey(port->agent->device, port->port_num,
             IB_DEFAULT_PKEY_FULL, &new_ah->pkey_index))
        printk(KERN_ERR "Couldn't find index for default PKey\n");

    memset(&ah_attr, 0, sizeof ah_attr);
    ah_attr.dlid     = port_attr.sm_lid;
    ah_attr.sl       = port_attr.sm_sl;
    ah_attr.port_num = port->port_num;

    new_ah->ah = ib_create_ah(port->agent->qp->pd, &ah_attr);
    if (IS_ERR(new_ah->ah)) {
        printk(KERN_WARNING "Couldn't create new SM AH\n");
        kfree(new_ah);
        return;
    }

    spin_lock_irq(&port->ah_lock);
    if (port->sm_ah)
        kref_put(&port->sm_ah->ref, free_sm_ah);
    port->sm_ah = new_ah;
    spin_unlock_irq(&port->ah_lock);

}

static void ib_sa_event(struct ib_event_handler *handler, struct ib_event *event)
{
    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) {
        unsigned long flags;
        struct ib_sa_device *sa_dev =
            container_of(handler, typeof(*sa_dev), event_handler);
        struct ib_sa_port *port =
            &sa_dev->port[event->element.port_num - sa_dev->start_port];

        if (rdma_port_get_link_layer(handler->device, port->port_num) != IB_LINK_LAYER_INFINIBAND)
            return;

        spin_lock_irqsave(&port->ah_lock, flags);
        if (port->sm_ah)
            kref_put(&port->sm_ah->ref, free_sm_ah);
        port->sm_ah = NULL;
        spin_unlock_irqrestore(&port->ah_lock, flags);

        queue_work(ib_wq, &sa_dev->port[event->element.port_num -
                        sa_dev->start_port].update_task);
    }
}

void ib_sa_register_client(struct ib_sa_client *client)
{
    atomic_set(&client->users, 1);
    init_completion(&client->comp);
}
EXPORT_SYMBOL(ib_sa_register_client);

void ib_sa_unregister_client(struct ib_sa_client *client)
{
    ib_sa_client_put(client);
    wait_for_completion(&client->comp);
}
EXPORT_SYMBOL(ib_sa_unregister_client);

void ib_sa_cancel_query(int id, struct ib_sa_query *query)
{
    unsigned long flags;
    struct ib_mad_agent *agent;
    struct ib_mad_send_buf *mad_buf;

    spin_lock_irqsave(&idr_lock, flags);
    if (idr_find(&query_idr, id) != query) {
        spin_unlock_irqrestore(&idr_lock, flags);
        return;
    }
    agent = query->port->agent;
    mad_buf = query->mad_buf;
    spin_unlock_irqrestore(&idr_lock, flags);

    ib_cancel_mad(agent, mad_buf);
}
EXPORT_SYMBOL(ib_sa_cancel_query);

static u8 get_src_path_mask(struct ib_device *device, u8 port_num)
{
    struct ib_sa_device *sa_dev;
    struct ib_sa_port   *port;
    unsigned long flags;
    u8 src_path_mask;

    sa_dev = ib_get_client_data(device, &sa_client);
    if (!sa_dev)
        return 0x7f;

    port  = &sa_dev->port[port_num - sa_dev->start_port];
    spin_lock_irqsave(&port->ah_lock, flags);
    src_path_mask = port->sm_ah ? port->sm_ah->src_path_mask : 0x7f;
    spin_unlock_irqrestore(&port->ah_lock, flags);

    return src_path_mask;
}

int ib_init_ah_from_path(struct ib_device *device, u8 port_num,
             struct ib_sa_path_rec *rec, struct ib_ah_attr *ah_attr)
{
    int ret;
    u16 gid_index;
    int force_grh;

    memset(ah_attr, 0, sizeof *ah_attr);
    ah_attr->dlid = be16_to_cpu(rec->dlid);
    ah_attr->sl = rec->sl;
    ah_attr->src_path_bits = be16_to_cpu(rec->slid) &
                 get_src_path_mask(device, port_num);
    ah_attr->port_num = port_num;
    ah_attr->static_rate = rec->rate;

    force_grh = rdma_port_get_link_layer(device, port_num) == IB_LINK_LAYER_ETHERNET;

    if (rec->hop_limit > 1 || force_grh) {
        ah_attr->ah_flags = IB_AH_GRH;
        ah_attr->grh.dgid = rec->dgid;

        ret = ib_find_cached_gid(device, &rec->sgid, &port_num,
                     &gid_index);
        if (ret)
            return ret;

        ah_attr->grh.sgid_index    = gid_index;
        ah_attr->grh.flow_label    = be32_to_cpu(rec->flow_label);
        ah_attr->grh.hop_limit     = rec->hop_limit;
        ah_attr->grh.traffic_class = rec->traffic_class;
    }
    return 0;
}
EXPORT_SYMBOL(ib_init_ah_from_path);

static int alloc_mad(struct ib_sa_query *query, gfp_t gfp_mask)
{
    unsigned long flags;

    spin_lock_irqsave(&query->port->ah_lock, flags);
    if (!query->port->sm_ah) {
        spin_unlock_irqrestore(&query->port->ah_lock, flags);
        return -EAGAIN;
    }
    kref_get(&query->port->sm_ah->ref);
    query->sm_ah = query->port->sm_ah;
    spin_unlock_irqrestore(&query->port->ah_lock, flags);

    query->mad_buf = ib_create_send_mad(query->port->agent, 1,
                        query->sm_ah->pkey_index,
                        0, IB_MGMT_SA_HDR, IB_MGMT_SA_DATA,
                        gfp_mask);
    if (IS_ERR(query->mad_buf)) {
        kref_put(&query->sm_ah->ref, free_sm_ah);
        return -ENOMEM;
    }

    query->mad_buf->ah = query->sm_ah->ah;

    return 0;
}

static void free_mad(struct ib_sa_query *query)
{
    ib_free_send_mad(query->mad_buf);
    kref_put(&query->sm_ah->ref, free_sm_ah);
}

static void init_mad(struct ib_sa_mad *mad, struct ib_mad_agent *agent)
{
    unsigned long flags;

    memset(mad, 0, sizeof *mad);

    mad->mad_hdr.base_version  = IB_MGMT_BASE_VERSION;
    mad->mad_hdr.mgmt_class    = IB_MGMT_CLASS_SUBN_ADM;
    mad->mad_hdr.class_version = IB_SA_CLASS_VERSION;

    spin_lock_irqsave(&tid_lock, flags);
    mad->mad_hdr.tid           =
        cpu_to_be64(((u64) agent->hi_tid) << 32 | tid++);
    spin_unlock_irqrestore(&tid_lock, flags);
}

static int send_mad(struct ib_sa_query *query, int timeout_ms, gfp_t gfp_mask)
{
    unsigned long flags;
    int ret, id;

retry:
    if (!idr_pre_get(&query_idr, gfp_mask))
        return -ENOMEM;
    spin_lock_irqsave(&idr_lock, flags);
    ret = idr_get_new(&query_idr, query, &id);
    spin_unlock_irqrestore(&idr_lock, flags);
    if (ret == -EAGAIN)
        goto retry;
    if (ret)
        return ret;

    query->mad_buf->timeout_ms  = timeout_ms;
    query->mad_buf->context[0] = query;
    query->id = id;

    ret = ib_post_send_mad(query->mad_buf, NULL);
    if (ret) {
        spin_lock_irqsave(&idr_lock, flags);
        idr_remove(&query_idr, id);
        spin_unlock_irqrestore(&idr_lock, flags);
    }

    /*
     * It's not safe to dereference query any more, because the
     * send may already have completed and freed the query in
     * another context.
     */
    return ret ? ret : id;
}

void ib_sa_unpack_path(void *attribute, struct ib_sa_path_rec *rec)
{
    ib_unpack(path_rec_table, ARRAY_SIZE(path_rec_table), attribute, rec);
}
EXPORT_SYMBOL(ib_sa_unpack_path);

static void ib_sa_path_rec_callback(struct ib_sa_query *sa_query,
                    int status,
                    struct ib_sa_mad *mad)
{
    struct ib_sa_path_query *query =
        container_of(sa_query, struct ib_sa_path_query, sa_query);

    if (mad) {
        struct ib_sa_path_rec rec;

        ib_unpack(path_rec_table, ARRAY_SIZE(path_rec_table),
              mad->data, &rec);
        query->callback(status, &rec, query->context);
    } else
        query->callback(status, NULL, query->context);
}

static void ib_sa_path_rec_release(struct ib_sa_query *sa_query)
{
    kfree(container_of(sa_query, struct ib_sa_path_query, sa_query));
}

int ib_sa_path_rec_get(struct ib_sa_client *client,
               struct ib_device *device, u8 port_num,
               struct ib_sa_path_rec *rec,
               ib_sa_comp_mask comp_mask,
               int timeout_ms, gfp_t gfp_mask,
               void (*callback)(int status,
                    struct ib_sa_path_rec *resp,
                    void *context),
               void *context,
               struct ib_sa_query **sa_query)
{
    struct ib_sa_path_query *query;
    struct ib_sa_device *sa_dev = ib_get_client_data(device, &sa_client);
    struct ib_sa_port   *port;
    struct ib_mad_agent *agent;
    struct ib_sa_mad *mad;
    int ret;

    if (!sa_dev)
        return -ENODEV;

    port  = &sa_dev->port[port_num - sa_dev->start_port];
    agent = port->agent;

    query = kmalloc(sizeof *query, gfp_mask);
    if (!query)
        return -ENOMEM;

    query->sa_query.port     = port;
    ret = alloc_mad(&query->sa_query, gfp_mask);
    if (ret)
        goto err1;

    ib_sa_client_get(client);
    query->sa_query.client = client;
    query->callback        = callback;
    query->context         = context;

    mad = query->sa_query.mad_buf->mad;
    init_mad(mad, agent);

    query->sa_query.callback = callback ? ib_sa_path_rec_callback : NULL;
    query->sa_query.release  = ib_sa_path_rec_release;
    mad->mad_hdr.method  = IB_MGMT_METHOD_GET;
    mad->mad_hdr.attr_id     = cpu_to_be16(IB_SA_ATTR_PATH_REC);
    mad->sa_hdr.comp_mask    = comp_mask;

    ib_pack(path_rec_table, ARRAY_SIZE(path_rec_table), rec, mad->data);

    *sa_query = &query->sa_query;

    ret = send_mad(&query->sa_query, timeout_ms, gfp_mask);
    if (ret < 0)
        goto err2;

    return ret;

err2:
    *sa_query = NULL;
    ib_sa_client_put(query->sa_query.client);
    free_mad(&query->sa_query);

err1:
    kfree(query);
    return ret;
}
EXPORT_SYMBOL(ib_sa_path_rec_get);

static void ib_sa_service_rec_callback(struct ib_sa_query *sa_query,
                    int status,
                    struct ib_sa_mad *mad)
{
    struct ib_sa_service_query *query =
        container_of(sa_query, struct ib_sa_service_query, sa_query);

    if (mad) {
        struct ib_sa_service_rec rec;

        ib_unpack(service_rec_table, ARRAY_SIZE(service_rec_table),
              mad->data, &rec);
        query->callback(status, &rec, query->context);
    } else
        query->callback(status, NULL, query->context);
}

static void ib_sa_service_rec_release(struct ib_sa_query *sa_query)
{
    kfree(container_of(sa_query, struct ib_sa_service_query, sa_query));
}

int ib_sa_service_rec_query(struct ib_sa_client *client,
                struct ib_device *device, u8 port_num, u8 method,
                struct ib_sa_service_rec *rec,
                ib_sa_comp_mask comp_mask,
                int timeout_ms, gfp_t gfp_mask,
                void (*callback)(int status,
                         struct ib_sa_service_rec *resp,
                         void *context),
                void *context,
                struct ib_sa_query **sa_query)
{
    struct ib_sa_service_query *query;
    struct ib_sa_device *sa_dev = ib_get_client_data(device, &sa_client);
    struct ib_sa_port   *port;
    struct ib_mad_agent *agent;
    struct ib_sa_mad *mad;
    int ret;

    if (!sa_dev)
        return -ENODEV;

    port  = &sa_dev->port[port_num - sa_dev->start_port];
    agent = port->agent;

    if (method != IB_MGMT_METHOD_GET &&
        method != IB_MGMT_METHOD_SET &&
        method != IB_SA_METHOD_DELETE)
        return -EINVAL;

    query = kmalloc(sizeof *query, gfp_mask);
    if (!query)
        return -ENOMEM;

    query->sa_query.port     = port;
    ret = alloc_mad(&query->sa_query, gfp_mask);
    if (ret)
        goto err1;

    ib_sa_client_get(client);
    query->sa_query.client = client;
    query->callback        = callback;
    query->context         = context;

    mad = query->sa_query.mad_buf->mad;
    init_mad(mad, agent);

    query->sa_query.callback = callback ? ib_sa_service_rec_callback : NULL;
    query->sa_query.release  = ib_sa_service_rec_release;
    mad->mad_hdr.method  = method;
    mad->mad_hdr.attr_id     = cpu_to_be16(IB_SA_ATTR_SERVICE_REC);
    mad->sa_hdr.comp_mask    = comp_mask;

    ib_pack(service_rec_table, ARRAY_SIZE(service_rec_table),
        rec, mad->data);

    *sa_query = &query->sa_query;

    ret = send_mad(&query->sa_query, timeout_ms, gfp_mask);
    if (ret < 0)
        goto err2;

    return ret;

err2:
    *sa_query = NULL;
    ib_sa_client_put(query->sa_query.client);
    free_mad(&query->sa_query);

err1:
    kfree(query);
    return ret;
}
EXPORT_SYMBOL(ib_sa_service_rec_query);

static void ib_sa_mcmember_rec_callback(struct ib_sa_query *sa_query,
                    int status,
                    struct ib_sa_mad *mad)
{
    struct ib_sa_mcmember_query *query =
        container_of(sa_query, struct ib_sa_mcmember_query, sa_query);

    if (mad) {
        struct ib_sa_mcmember_rec rec;

        ib_unpack(mcmember_rec_table, ARRAY_SIZE(mcmember_rec_table),
              mad->data, &rec);
        query->callback(status, &rec, query->context);
    } else
        query->callback(status, NULL, query->context);
}

static void ib_sa_mcmember_rec_release(struct ib_sa_query *sa_query)
{
    kfree(container_of(sa_query, struct ib_sa_mcmember_query, sa_query));
}

int ib_sa_mcmember_rec_query(struct ib_sa_client *client,
                 struct ib_device *device, u8 port_num,
                 u8 method,
                 struct ib_sa_mcmember_rec *rec,
                 ib_sa_comp_mask comp_mask,
                 int timeout_ms, gfp_t gfp_mask,
                 void (*callback)(int status,
                          struct ib_sa_mcmember_rec *resp,
                          void *context),
                 void *context,
                 struct ib_sa_query **sa_query)
{
    struct ib_sa_mcmember_query *query;
    struct ib_sa_device *sa_dev = ib_get_client_data(device, &sa_client);
    struct ib_sa_port   *port;
    struct ib_mad_agent *agent;
    struct ib_sa_mad *mad;
    int ret;

    if (!sa_dev)
        return -ENODEV;

    port  = &sa_dev->port[port_num - sa_dev->start_port];
    agent = port->agent;

    query = kmalloc(sizeof *query, gfp_mask);
    if (!query)
        return -ENOMEM;

    query->sa_query.port     = port;
    ret = alloc_mad(&query->sa_query, gfp_mask);
    if (ret)
        goto err1;

    ib_sa_client_get(client);
    query->sa_query.client = client;
    query->callback        = callback;
    query->context         = context;

    mad = query->sa_query.mad_buf->mad;
    init_mad(mad, agent);

    query->sa_query.callback = callback ? ib_sa_mcmember_rec_callback : NULL;
    query->sa_query.release  = ib_sa_mcmember_rec_release;
    mad->mad_hdr.method  = method;
    mad->mad_hdr.attr_id     = cpu_to_be16(IB_SA_ATTR_MC_MEMBER_REC);
    mad->sa_hdr.comp_mask    = comp_mask;

    ib_pack(mcmember_rec_table, ARRAY_SIZE(mcmember_rec_table),
        rec, mad->data);

    *sa_query = &query->sa_query;

    ret = send_mad(&query->sa_query, timeout_ms, gfp_mask);
    if (ret < 0)
        goto err2;

    return ret;

err2:
    *sa_query = NULL;
    ib_sa_client_put(query->sa_query.client);
    free_mad(&query->sa_query);

err1:
    kfree(query);
    return ret;
}

/* Support GuidInfoRecord */
static void ib_sa_guidinfo_rec_callback(struct ib_sa_query *sa_query,
                    int status,
                    struct ib_sa_mad *mad)
{
    struct ib_sa_guidinfo_query *query =
        container_of(sa_query, struct ib_sa_guidinfo_query, sa_query);

    if (mad) {
        struct ib_sa_guidinfo_rec rec;

        ib_unpack(guidinfo_rec_table, ARRAY_SIZE(guidinfo_rec_table),
              mad->data, &rec);
        query->callback(status, &rec, query->context);
    } else
        query->callback(status, NULL, query->context);
}

static void ib_sa_guidinfo_rec_release(struct ib_sa_query *sa_query)
{
    kfree(container_of(sa_query, struct ib_sa_guidinfo_query, sa_query));
}

int ib_sa_guid_info_rec_query(struct ib_sa_client *client,
                  struct ib_device *device, u8 port_num,
                  struct ib_sa_guidinfo_rec *rec,
                  ib_sa_comp_mask comp_mask, u8 method,
                  int timeout_ms, gfp_t gfp_mask,
                  void (*callback)(int status,
                           struct ib_sa_guidinfo_rec *resp,
                           void *context),
                  void *context,
                  struct ib_sa_query **sa_query)
{
    struct ib_sa_guidinfo_query *query;
    struct ib_sa_device *sa_dev = ib_get_client_data(device, &sa_client);
    struct ib_sa_port *port;
    struct ib_mad_agent *agent;
    struct ib_sa_mad *mad;
    int ret;

    if (!sa_dev)
        return -ENODEV;

    if (method != IB_MGMT_METHOD_GET &&
        method != IB_MGMT_METHOD_SET &&
        method != IB_SA_METHOD_DELETE) {
        return -EINVAL;
    }

    port  = &sa_dev->port[port_num - sa_dev->start_port];
    agent = port->agent;

    query = kmalloc(sizeof *query, gfp_mask);
    if (!query)
        return -ENOMEM;

    query->sa_query.port = port;
    ret = alloc_mad(&query->sa_query, gfp_mask);
    if (ret)
        goto err1;

    ib_sa_client_get(client);
    query->sa_query.client = client;
    query->callback        = callback;
    query->context         = context;

    mad = query->sa_query.mad_buf->mad;
    init_mad(mad, agent);

    query->sa_query.callback = callback ? ib_sa_guidinfo_rec_callback : NULL;
    query->sa_query.release  = ib_sa_guidinfo_rec_release;

    mad->mad_hdr.method  = method;
    mad->mad_hdr.attr_id     = cpu_to_be16(IB_SA_ATTR_GUID_INFO_REC);
    mad->sa_hdr.comp_mask    = comp_mask;

    ib_pack(guidinfo_rec_table, ARRAY_SIZE(guidinfo_rec_table), rec,
        mad->data);

    *sa_query = &query->sa_query;

    ret = send_mad(&query->sa_query, timeout_ms, gfp_mask);
    if (ret < 0)
        goto err2;

    return ret;

err2:
    *sa_query = NULL;
    ib_sa_client_put(query->sa_query.client);
    free_mad(&query->sa_query);

err1:
    kfree(query);
    return ret;
}
EXPORT_SYMBOL(ib_sa_guid_info_rec_query);

static void send_handler(struct ib_mad_agent *agent,
             struct ib_mad_send_wc *mad_send_wc)
{
    struct ib_sa_query *query = mad_send_wc->send_buf->context[0];
    unsigned long flags;

    if (query->callback)
        switch (mad_send_wc->status) {
        case IB_WC_SUCCESS:
            /* No callback -- already got recv */
            break;
        case IB_WC_RESP_TIMEOUT_ERR:
            query->callback(query, -ETIMEDOUT, NULL);
            break;
        case IB_WC_WR_FLUSH_ERR:
            query->callback(query, -EINTR, NULL);
            break;
        default:
            query->callback(query, -EIO, NULL);
            break;
        }

    spin_lock_irqsave(&idr_lock, flags);
    idr_remove(&query_idr, query->id);
    spin_unlock_irqrestore(&idr_lock, flags);

    free_mad(query);
    ib_sa_client_put(query->client);
    query->release(query);
}

static void recv_handler(struct ib_mad_agent *mad_agent,
             struct ib_mad_recv_wc *mad_recv_wc)
{
    struct ib_sa_query *query;
    struct ib_mad_send_buf *mad_buf;

    mad_buf = (void *) (unsigned long) mad_recv_wc->wc->wr_id;
    query = mad_buf->context[0];

    if (query->callback) {
        if (mad_recv_wc->wc->status == IB_WC_SUCCESS)
            query->callback(query,
                    mad_recv_wc->recv_buf.mad->mad_hdr.status ?
                    -EINVAL : 0,
                    (struct ib_sa_mad *) mad_recv_wc->recv_buf.mad);
        else
            query->callback(query, -EIO, NULL);
    }

    ib_free_recv_mad(mad_recv_wc);
}

static void ib_sa_add_one(struct ib_device *device)
{
    struct ib_sa_device *sa_dev;
    int s, e, i;

    if (rdma_node_get_transport(device->node_type) != RDMA_TRANSPORT_IB)
        return;

    if (device->node_type == RDMA_NODE_IB_SWITCH)
        s = e = 0;
    else {
        s = 1;
        e = device->phys_port_cnt;
    }

    sa_dev = kzalloc(sizeof *sa_dev +
             (e - s + 1) * sizeof (struct ib_sa_port),
             GFP_KERNEL);
    if (!sa_dev)
        return;

    sa_dev->start_port = s;
    sa_dev->end_port   = e;

    for (i = 0; i <= e - s; ++i) {
        spin_lock_init(&sa_dev->port[i].ah_lock);
        if (rdma_port_get_link_layer(device, i + 1) != IB_LINK_LAYER_INFINIBAND)
            continue;

        sa_dev->port[i].sm_ah    = NULL;
        sa_dev->port[i].port_num = i + s;

        sa_dev->port[i].agent =
            ib_register_mad_agent(device, i + s, IB_QPT_GSI,
                          NULL, 0, send_handler,
                          recv_handler, sa_dev);
        if (IS_ERR(sa_dev->port[i].agent))
            goto err;

        INIT_WORK(&sa_dev->port[i].update_task, update_sm_ah);
    }

    ib_set_client_data(device, &sa_client, sa_dev);

    /*
     * We register our event handler after everything is set up,
     * and then update our cached info after the event handler is
     * registered to avoid any problems if a port changes state
     * during our initialization.
     */

    INIT_IB_EVENT_HANDLER(&sa_dev->event_handler, device, ib_sa_event);
    if (ib_register_event_handler(&sa_dev->event_handler))
        goto err;

    for (i = 0; i <= e - s; ++i)
        if (rdma_port_get_link_layer(device, i + 1) == IB_LINK_LAYER_INFINIBAND)
            update_sm_ah(&sa_dev->port[i].update_task);

    return;

err:
    while (--i >= 0)
        if (rdma_port_get_link_layer(device, i + 1) == IB_LINK_LAYER_INFINIBAND)
            ib_unregister_mad_agent(sa_dev->port[i].agent);

    kfree(sa_dev);

    return;
}

static void ib_sa_remove_one(struct ib_device *device)
{
    struct ib_sa_device *sa_dev = ib_get_client_data(device, &sa_client);
    int i;

    if (!sa_dev)
        return;

    ib_unregister_event_handler(&sa_dev->event_handler);

    flush_workqueue(ib_wq);

    for (i = 0; i <= sa_dev->end_port - sa_dev->start_port; ++i) {
        if (rdma_port_get_link_layer(device, i + 1) == IB_LINK_LAYER_INFINIBAND) {
            ib_unregister_mad_agent(sa_dev->port[i].agent);
            if (sa_dev->port[i].sm_ah)
                kref_put(&sa_dev->port[i].sm_ah->ref, free_sm_ah);
        }

    }

    kfree(sa_dev);
}

static int __init ib_sa_init(void)
{
    int ret;

    get_random_bytes(&tid, sizeof tid);

    ret = ib_register_client(&sa_client);
    if (ret) {
        printk(KERN_ERR "Couldn't register ib_sa client\n");
        goto err1;
    }

    ret = mcast_init();
    if (ret) {
        printk(KERN_ERR "Couldn't initialize multicast handling\n");
        goto err2;
    }

    return 0;
err2:
    ib_unregister_client(&sa_client);
err1:
    return ret;
}

static void __exit ib_sa_cleanup(void)
{
    mcast_cleanup();
    ib_unregister_client(&sa_client);
    idr_destroy(&query_idr);
}

module_init(ib_sa_init);
module_exit(ib_sa_cleanup);