path: root/drivers/infiniband/hw/mthca/mthca_mr.c

/*
 * Copyright (c) 2004 Topspin Communications.  All rights reserved.
 * Copyright (c) 2005 Mellanox Technologies. 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.
 *
 * $Id: mthca_mr.c 1349 2004-12-16 21:09:43Z roland $
 */

#include <linux/slab.h>
#include <linux/errno.h>

#include "mthca_dev.h"
#include "mthca_cmd.h"
#include "mthca_memfree.h"

struct mthca_mtt {
	struct mthca_buddy *buddy;
	int                 order;
	u32                 first_seg;
};

/*
 * Must be packed because mtt_seg is 64 bits but only aligned to 32 bits.
 */
struct mthca_mpt_entry {
	__be32 flags;
	__be32 page_size;
	__be32 key;
	__be32 pd;
	__be64 start;
	__be64 length;
	__be32 lkey;
	__be32 window_count;
	__be32 window_count_limit;
	__be64 mtt_seg;
	__be32 mtt_sz;		/* Arbel only */
	u32    reserved[2];
} __attribute__((packed));

#define MTHCA_MPT_FLAG_SW_OWNS       (0xfUL << 28)
#define MTHCA_MPT_FLAG_MIO           (1 << 17)
#define MTHCA_MPT_FLAG_BIND_ENABLE   (1 << 15)
#define MTHCA_MPT_FLAG_PHYSICAL      (1 <<  9)
#define MTHCA_MPT_FLAG_REGION        (1 <<  8)

#define MTHCA_MTT_FLAG_PRESENT       1

#define MTHCA_MPT_STATUS_SW 0xF0
#define MTHCA_MPT_STATUS_HW 0x00

#define SINAI_FMR_KEY_INC 0x1000000

/*
 * Buddy allocator for MTT segments (currently not very efficient
 * since it doesn't keep a free list and just searches linearly
 * through the bitmaps)
 */

static u32 mthca_buddy_alloc(struct mthca_buddy *buddy, int order)
{
	int o;
	int m;
	u32 seg;

	spin_lock(&buddy->lock);

	for (o = order; o <= buddy->max_order; ++o) {
		m = 1 << (buddy->max_order - o);
		seg = find_first_bit(buddy->bits[o], m);
		if (seg < m)
			goto found;
	}

	spin_unlock(&buddy->lock);
	return -1;

 found:
	clear_bit(seg, buddy->bits[o]);

	while (o > order) {
		--o;
		seg <<= 1;
		set_bit(seg ^ 1, buddy->bits[o]);
	}

	spin_unlock(&buddy->lock);

	seg <<= order;

	return seg;
}

static void mthca_buddy_free(struct mthca_buddy *buddy, u32 seg, int order)
{
	seg >>= order;

	spin_lock(&buddy->lock);

	while (test_bit(seg ^ 1, buddy->bits[order])) {
		clear_bit(seg ^ 1, buddy->bits[order]);
		seg >>= 1;
		++order;
	}

	set_bit(seg, buddy->bits[order]);

	spin_unlock(&buddy->lock);
}

static int mthca_buddy_init(struct mthca_buddy *buddy, int max_order)
{
	int i, s;

	buddy->max_order = max_order;
	spin_lock_init(&buddy->lock);

	buddy->bits = kzalloc((buddy->max_order + 1) * sizeof (long *),
			      GFP_KERNEL);
	if (!buddy->bits)
		goto err_out;

	for (i = 0; i <= buddy->max_order; ++i) {
		s = BITS_TO_LONGS(1 << (buddy->max_order - i));
		buddy->bits[i] = kmalloc(s * sizeof (long), GFP_KERNEL);
		if (!buddy->bits[i])
			goto err_out_free;
		bitmap_zero(buddy->bits[i],
			    1 << (buddy->max_order - i));
	}

	set_bit(0, buddy->bits[buddy->max_order]);

	return 0;

err_out_free:
	for (i = 0; i <= buddy->max_order; ++i)
		kfree(buddy->bits[i]);

	kfree(buddy->bits);

err_out:
	return -ENOMEM;
}

static void mthca_buddy_cleanup(struct mthca_buddy *buddy)
{
	int i;

	for (i = 0; i <= buddy->max_order; ++i)
		kfree(buddy->bits[i]);

	kfree(buddy->bits);