path: root/drivers/infiniband/core/cache.c

/*
 * Copyright (c) 2004 Topspin Communications.  All rights reserved.
 * Copyright (c) 2005 Intel Corporation. All rights reserved.
 * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
 * Copyright (c) 2005 Voltaire, Inc. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/netdevice.h>
#include <net/addrconf.h>

#include <rdma/ib_cache.h>

#include "core_priv.h"

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

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

union ib_gid zgid;
EXPORT_SYMBOL(zgid);

static const struct ib_gid_attr zattr;

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

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

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

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

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

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

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

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

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

	table->