cache.c

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/*
 * 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 <rdma/ib_cache.h>

#include "core_priv.h"

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

struct ib_gid_cache {
    int             table_len;
    union ib_gid    table[0];
};

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

static inline int start_port(struct ib_device *device)
{
    return (device->node_type == RDMA_NODE_IB_SWITCH) ? 0 : 1;
}

static inline int end_port(struct ib_device *device)
{
    return (device->node_type == RDMA_NODE_IB_SWITCH) ?
        0 : device->phys_port_cnt;
}

int ib_get_cached_gid(struct ib_device *device,
              u8                port_num,
              int               index,
              union ib_gid     *gid)
{
    struct ib_gid_cache *cache;
    unsigned long flags;
    int ret = 0;

    if (port_num < start_port(device) || port_num > end_port(device))
        return -EINVAL;

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

    cache = device->cache.gid_cache[port_num - start_port(device)];

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

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

    return ret;
}
EXPORT_SYMBOL(ib_get_cached_gid);

int ib_find_cached_gid(struct ib_device *device,
               union ib_gid *gid,
               u8               *port_num,
               u16              *index)
{
    struct ib_gid_cache *cache;
    unsigned long flags;
    int p, i;
    int ret = -ENOENT;

    *port_num = -1;
    if (index)
        *index = -1;

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

    for (p = 0; p <= end_port(device) - start_port(device); ++p) {
        cache = device->cache.gid_cache[p];
        for (i = 0; i < cache->table_len; ++i) {
            if (!memcmp(gid, &cache->table[i], sizeof *gid)) {
                *port_num = p + start_port(device);
                if (index)
                    *index = i;
                ret = 0;
                goto found;
            }
        }
    }
found:
    read_unlock_irqrestore(&device->cache.lock, flags);

    return ret;
}
EXPORT_SYMBOL(ib_find_cached_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 (port_num < start_port(device) || port_num > end_port(device))
        return -EINVAL;

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

    cache = device->cache.pkey_cache[port_num - 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 < start_port(device) || port_num > end_port(device))
        return -EINVAL;

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

    cache = device->cache.pkey_cache[port_num - 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 < start_port(device) || port_num > end_port(device))
        return -EINVAL;

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

    cache = device->cache.pkey_cache[port_num - 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 < start_port(device) || port_num > end_port(device))
        return -EINVAL;

    read_lock_irqsave(&device->cache.lock, flags);
    *lmc = device->cache.lmc_cache[port_num - 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       *gid_cache = NULL, *old_gid_cache;
    int                        i;
    int                        ret;

    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;

    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;
        }
    }

    for (i = 0; i < gid_cache->table_len; ++i) {
        ret = ib_query_gid(device, port, i, gid_cache->table + i);
        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 - start_port(device)];
    old_gid_cache  = device->cache.gid_cache [port - start_port(device)];

    device->cache.pkey_cache[port - start_port(device)] = pkey_cache;
    device->cache.gid_cache [port - start_port(device)] = gid_cache;

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

    write_unlock_irq(&device->cache.lock);

    kfree(old_pkey_cache);
    kfree(old_gid_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);
        }
    }
}

static void ib_cache_setup_one(struct ib_device *device)
{
    int p;

    rwlock_init(&device->cache.lock);

    device->cache.pkey_cache =
        kmalloc(sizeof *device->cache.pkey_cache *
            (end_port(device) - start_port(device) + 1), GFP_KERNEL);
    device->cache.gid_cache =
        kmalloc(sizeof *device->cache.gid_cache *
            (end_port(device) - start_port(device) + 1), GFP_KERNEL);

    device->cache.lmc_cache = kmalloc(sizeof *device->cache.lmc_cache *
                      (end_port(device) -
                       start_port(device) + 1),
                      GFP_KERNEL);

    if (!device->cache.pkey_cache || !device->cache.gid_cache ||
        !device->cache.lmc_cache) {
        printk(KERN_WARNING "Couldn't allocate cache "
               "for %s\n", device->name);
        goto err;
    }

    for (p = 0; p <= end_port(device) - start_port(device); ++p) {
        device->cache.pkey_cache[p] = NULL;
        device->cache.gid_cache [p] = NULL;
        ib_cache_update(device, p + start_port(device));
    }

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

    return;

err_cache:
    for (p = 0; p <= end_port(device) - start_port(device); ++p) {
        kfree(device->cache.pkey_cache[p]);
        kfree(device->cache.gid_cache[p]);
    }

err:
    kfree(device->cache.pkey_cache);
    kfree(device->cache.gid_cache);
    kfree(device->cache.lmc_cache);
}

static void ib_cache_cleanup_one(struct ib_device *device)
{
    int p;

    ib_unregister_event_handler(&device->cache.event_handler);
    flush_workqueue(ib_wq);

    for (p = 0; p <= end_port(device) - start_port(device); ++p) {
        kfree(device->cache.pkey_cache[p]);
        kfree(device->cache.gid_cache[p]);
    }

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

static struct ib_client cache_client = {
    .name   = "cache",
    .add    = ib_cache_setup_one,
    .remove = ib_cache_cleanup_one
};

int __init ib_cache_setup(void)
{
    return ib_register_client(&cache_client);
}

void __exit ib_cache_cleanup(void)
{
    ib_unregister_client(&cache_client);
}