/*
* Copyright (c) 2012, 2013 Intel Corporation. All rights reserved.
* Copyright (c) 2006 - 2012 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 <linux/jhash.h>
#ifdef CONFIG_DEBUG_FS
#include <linux/seq_file.h>
#endif
#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(&qpt->lock);
if (map->page)
free_page(page);
else
map->page = (void *)page;
spin_unlock(&qpt->lock);
}
/*
* Allocate the next available QPN or
* zero/one for QP type IB_QPT_SMI/IB_QPT_GSI.
*/
static int alloc_qpn(struct qib_devdata *dd, struct qib_qpn_table *qpt,
enum ib_qp_type type, u8 port)
{
u32 i, offset, max_scan, qpn;
struct qpn_map *map;
u32 ret;
if (type == IB_QPT_SMI || type == IB_QPT_GSI) {
unsigned n;
ret = type == IB_QPT_GSI;
n = 1 << (ret + 2 * (port - 1));
spin_lock(&qpt->lock);
if (qpt->flags & n)
ret = -EINVAL;
else
qpt->flags |= n;
spin_unlock(&qpt->lock);
goto bail;
}
qpn = qpt->last + 2;
if (qpn >= QPN_MAX)
qpn = 2;
if (qpt->mask && ((qpn & qpt->mask) >> 1) >= dd->n_krcv_queues)
qpn = (qpn | qpt->mask) + 2;
offset = qpn & BITS_PER_PAGE_MASK;
map = &qpt->map[qpn / BITS_PER_PAGE];
max_scan = qpt->nmaps - !offset;
for (i = 0;;) {
if (unlikely(!map->page)) {
get_map_page(qpt, map);
if (unlikely(!map->page))
break;
}
do {
if (!test_and_set_bit(offset, map->page)) {
qpt->last = qpn;
ret = qpn;
goto bail;
}
offset = find_next_offset(qpt, map, offset,
dd->n_krcv_queues);
qpn = mk_qpn(qpt, map, offset);
/*
* This test differs from alloc_pidmap().
* If find_next_offset() does find a zero
* bit, we don't need to check for QPN
* wrapping around past our starting QPN.
* We just need to be sure we don't loop
* forever.
*/
} while (offset < BITS_PER_PAGE && qpn < QPN_MAX);
/*
* In order to keep the number of pages allocated to a
* minimum, we scan the all existing pages before increasing
* the size of the bitmap table.
*/
if (++i > max_scan) {
if (qpt->nmaps == QPNMAP_ENTRIES)
break;
map = &qpt->map[qpt->nmaps++];
offset = 0;
} else if (map < &qpt->map[qpt->nmaps]) {
++map;
offset = 0;
} else {
map = &qpt->map[0];
offset = 2;
}
qpn = mk_qpn(qpt, map, offset);
}
ret = -ENOMEM;
bail:
return ret;
}
static void free_qpn(struct qib_qpn_table *qpt, u32 qpn)
{
struct qpn_map *map;
map = qpt->map + qpn / BITS_PER_PAGE;
if (map->page)
clear_bit(qpn & BITS_PER_PAGE_MASK, map->page);
}
static inline unsigned qpn_hash(struct qib_ibdev *dev, u32 qpn)
{
return jhash_1word(qpn, dev->qp_rnd) &
(dev->qp_table_size - 1);
}
/*
* Put the QP into the hash table.
* The hash table holds a reference to the QP.
*/
static void insert_qp(struct qib_ibdev *dev, struct qib_qp *qp)
{
struct qib_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
unsigned long flags;
unsigned n = qpn_hash(dev, qp->ibqp.qp_num);
atomic_inc(&qp->refcount);
spin_lock_irqsave(&dev->qpt_lock, flags);
if (qp->ibqp.qp_num == 0)
rcu_assign_pointer(ibp->qp0, qp);
else if (qp->ibqp.qp_num == 1)
rcu_assign_pointer(ibp->qp1, qp);
else {
qp->next = dev->qp_table[n];
rcu_assign_pointer(dev->qp_table[n], qp);
}
spin_unlock_irqrestore(&dev->qpt_lock, flags);
}
/*
* Remove the QP from the table so it can't be found asynchronously by
* the receive interrupt routine.
*/
static void remove_qp(struct qib_ibdev *dev, struct qib_qp *qp)
{
struct qib_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
unsigned n = qpn_hash(dev, qp->ibqp.qp_num);
unsigned long flags;
int removed = 1;
spin_lock_irqsave(&dev->qpt_lock, flags);
if (rcu_dereference_protected(ibp->qp0,
lockdep_is_held(&dev->qpt_lock)) == qp) {
rcu_assign_pointer(ibp->qp0, NULL);
} else if (rcu_dereference_protected(ibp->qp1,
lockdep_is_held(&dev->qpt_lock)) == qp) {
rcu_assign_pointer(ibp->qp1, NULL);
} else {
struct qib_qp *q;
struct qib_qp __rcu **qpp;
removed = 0;
qpp = &dev->qp_table[n];
for (; (q = rcu_dereference_protected(*qpp,
lockdep_is_held(&dev->qpt_lock))) != NULL;
qpp = &q->next)
if (q == qp) {
rcu_assign_pointer(*qpp,
rcu_dereference_protected(qp->next,
lockdep_is_held(&dev->qpt_lock)));
removed = 1;
break;
}
}
spin_unlock_irqrestore(&dev->qpt_lock, flags);
if (removed) {
synchronize_rcu();
atomic_dec(&qp->refcount);
}
}
/**
* qib_free_all_qps - check for QPs still in use
* @qpt: the QP table to empty
*
* There should not be any QPs still in use.
* Free memory for table.
*/
unsigned qib_free_all_qps(struct qib_devdata *dd)
{
struct qib_ibdev *dev = &dd->
