/**
* alloc_qpn - Allocate the next available qpn or zero/one for QP type
* IB_QPT_SMI/IB_QPT_GSI
*@rdi: rvt device info structure
*@qpt: queue pair number table pointer
*@port_num: IB port number, 1 based, comes from core
*
* Return: The queue pair number
*/
static int alloc_qpn(struct rvt_dev_info *rdi, struct rvt_qpn_table *qpt,
enum ib_qp_type type, u8 port_num, gfp_t gfp)
{
u32 i, offset, max_scan, qpn;
struct rvt_qpn_map *map;
u32 ret;
if (rdi->driver_f.alloc_qpn)
return rdi->driver_f.alloc_qpn(rdi, qpt, type, port_num, gfp);
if (type == IB_QPT_SMI || type == IB_QPT_GSI) {
unsigned n;
ret = type == IB_QPT_GSI;
n = 1 << (ret + 2 * (port_num - 1));
spin_lock(&qpt->lock);
if (qpt->flags & n)
ret = -EINVAL;
else
qpt->flags |= n;
spin_unlock(&qpt->lock);
goto bail;
}
qpn = qpt->last + qpt->incr;
if (qpn >= RVT_QPN_MAX)
qpn = qpt->incr | ((qpt->last & 1) ^ 1);
/* offset carries bit 0 */
offset = qpn & RVT_BITS_PER_PAGE_MASK;
map = &qpt->map[qpn / RVT_BITS_PER_PAGE];
max_scan = qpt->nmaps - !offset;
for (i = 0;;) {
if (unlikely(!map->page)) {
get_map_page(qpt, map, gfp);
if (unlikely(!map->page))
break;
}
do {
if (!test_and_set_bit(offset, map->page)) {
qpt->last = qpn;
ret = qpn;
goto bail;
}
offset += qpt->incr;
/*
* This qpn might be bogus if offset >= BITS_PER_PAGE.
* That is OK. It gets re-assigned below
*/
qpn = mk_qpn(qpt, map, offset);
} while (offset < RVT_BITS_PER_PAGE && qpn < RVT_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 == RVT_QPNMAP_ENTRIES)
break;
map = &qpt->map[qpt->nmaps++];
/* start at incr with current bit 0 */
offset = qpt->incr | (offset & 1);
} else if (map < &qpt->map[qpt->nmaps]) {
++map;
/* start at incr with current bit 0 */
offset = qpt->incr | (offset & 1);
} else {
map = &qpt->map[0];
/* wrap to first map page, invert bit 0 */
offset = qpt->incr | ((offset & 1) ^ 1);
}
/* there can be no bits at shift and below */
WARN_ON(offset & (rdi->dparms.qos_shift - 1));
qpn = mk_qpn(qpt, map, offset);
}
ret = -ENOMEM;
bail:
return ret;
}
static int alloc_qpn(struct ipath_qp_table *qpt, enum ib_qp_type type)
{
u32 i, offset, max_scan, qpn;
struct qpn_map *map;
u32 ret = -1;
if (type == IB_QPT_SMI)
ret = 0;
else if (type == IB_QPT_GSI)
ret = 1;
if (ret != -1) {
map = &qpt->map[0];
if (unlikely(!map->page)) {
get_map_page(qpt, map);
if (unlikely(!map->page)) {
ret = -ENOMEM;
goto bail;
}
}
if (!test_and_set_bit(ret, map->page))
atomic_dec(&map->n_free);
else
ret = -EBUSY;
goto bail;
}
qpn = qpt->last + 1;
if (qpn >= QPN_MAX)
qpn = 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;
}
if (likely(atomic_read(&map->n_free))) {
do {
if (!test_and_set_bit(offset, map->page)) {
atomic_dec(&map->n_free);
qpt->last = qpn;
ret = qpn;
goto bail;
}
offset = find_next_offset(map, offset);
qpn = mk_qpn(qpt, map, offset);
/*
*/
} while (offset < BITS_PER_PAGE && qpn < QPN_MAX);
}
/*
*/
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 int alloc_qpn(struct ipath_qp_table *qpt, enum ib_qp_type type)
{
u32 i, offset, max_scan, qpn;
struct qpn_map *map;
u32 ret = -1;
if (type == IB_QPT_SMI)
ret = 0;
else if (type == IB_QPT_GSI)
ret = 1;
if (ret != -1) {
map = &qpt->map[0];
if (unlikely(!map->page)) {
get_map_page(qpt, map);
if (unlikely(!map->page)) {
ret = -ENOMEM;
goto bail;
}
}
if (!test_and_set_bit(ret, map->page))
atomic_dec(&map->n_free);
else
ret = -EBUSY;
goto bail;
}
qpn = qpt->last + 1;
if (qpn >= QPN_MAX)
qpn = 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;
}
if (likely(atomic_read(&map->n_free))) {
do {
if (!test_and_set_bit(offset, map->page)) {
atomic_dec(&map->n_free);
qpt->last = qpn;
ret = qpn;
goto bail;
}
offset = find_next_offset(map, offset);
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;
}