path: root/drivers/infiniband/hw/qib/qib_qp.c

/*
 * Copyright (c) 2006, 2007, 2008, 2009, 2010 QLogic Corporation.
 * All rights reserved.
 * Copyright (c) 2005, 2006 PathScale, 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/err.h>
#include <linux/vmalloc.h>

#include "qib.h"

#define BITS_PER_PAGE           (PAGE_SIZE*BITS_PER_BYTE)
#define BITS_PER_PAGE_MASK      (BITS_PER_PAGE-1)

static inline unsigned mk_qpn(struct qib_qpn_table *qpt,
			      struct qpn_map *map, unsigned off)
{
	return (map - qpt->map) * BITS_PER_PAGE + off;
}

static inline unsigned find_next_offset(struct qib_qpn_table *qpt,
					struct qpn_map *map, unsigned off,
					unsigned n)
{
	if (qpt->mask) {
		off++;
		if (((off & qpt->mask) >> 1) >= n)
			off = (off | qpt->mask) + 2;
	} else
		off = find_next_zero_bit(map->page, BITS_PER_PAGE, off);
	return off;
}

/*
 * Convert the AETH credit code into the number of credits.
 */
static u32 credit_table[31] = {
	0,                      /* 0 */
	1,                      /* 1 */
	2,                      /* 2 */
	3,                      /* 3 */
	4,                      /* 4 */
	6,                      /* 5 */
	8,                      /* 6 */
	12,                     /* 7 */
	16,                     /* 8 */
	24,                     /* 9 */
	32,                     /* A */
	48,                     /* B */
	64,                     /* C */
	96,                     /* D */
	128,                    /* E */
	192,                    /* F */
	256,                    /* 10 */
	384,                    /* 11 */
	512,                    /* 12 */
	768,                    /* 13 */
	1024,                   /* 14 */
	1536,                   /* 15 */
	2048,                   /* 16 */
	3072,                   /* 17 */
	4096,                   /* 18 */
	6144,                   /* 19 */
	8192,                   /* 1A */
	12288,                  /* 1B */
	16384,                  /* 1C */
	24576,                  /* 1D */
	32768                   /* 1E */
};

static void get_map_page(struct qib_qpn_table *qpt, struct qpn_map *map)
{
	unsigned long page = get_zeroed_page(GFP_KERNEL);

	/*
	 * Free the page if someone raced with us installing it.
	 */

	spin_lock(&