2 * Copyright (c) 2006 QLogic, Inc. All rights reserved.
3 * Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved.
5 * This software is available to you under a choice of one of two
6 * licenses. You may choose to be licensed under the terms of the GNU
7 * General Public License (GPL) Version 2, available from the file
8 * COPYING in the main directory of this source tree, or the
9 * OpenIB.org BSD license below:
11 * Redistribution and use in source and binary forms, with or
12 * without modification, are permitted provided that the following
15 * - Redistributions of source code must retain the above
16 * copyright notice, this list of conditions and the following
19 * - Redistributions in binary form must reproduce the above
20 * copyright notice, this list of conditions and the following
21 * disclaimer in the documentation and/or other materials
22 * provided with the distribution.
24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
34 #include <linux/err.h>
35 #include <linux/vmalloc.h>
37 #include "ipath_verbs.h"
38 #include "ipath_common.h"
40 #define BITS_PER_PAGE (PAGE_SIZE*BITS_PER_BYTE)
41 #define BITS_PER_PAGE_MASK (BITS_PER_PAGE-1)
42 #define mk_qpn(qpt, map, off) (((map) - (qpt)->map) * BITS_PER_PAGE + \
44 #define find_next_offset(map, off) find_next_zero_bit((map)->page, \
47 #define TRANS_INVALID 0
48 #define TRANS_ANY2RST 1
49 #define TRANS_RST2INIT 2
50 #define TRANS_INIT2INIT 3
51 #define TRANS_INIT2RTR 4
52 #define TRANS_RTR2RTS 5
53 #define TRANS_RTS2RTS 6
54 #define TRANS_SQERR2RTS 7
55 #define TRANS_ANY2ERR 8
56 #define TRANS_RTS2SQD 9 /* XXX Wait for expected ACKs & signal event */
57 #define TRANS_SQD2SQD 10 /* error if not drained & parameter change */
58 #define TRANS_SQD2RTS 11 /* error if not drained */
61 * Convert the AETH credit code into the number of credits.
63 static u32 credit_table[31] = {
97 static u32 alloc_qpn(struct ipath_qp_table *qpt)
99 u32 i, offset, max_scan, qpn;
106 offset = qpn & BITS_PER_PAGE_MASK;
107 map = &qpt->map[qpn / BITS_PER_PAGE];
108 max_scan = qpt->nmaps - !offset;
110 if (unlikely(!map->page)) {
111 unsigned long page = get_zeroed_page(GFP_KERNEL);
115 * Free the page if someone raced with us
118 spin_lock_irqsave(&qpt->lock, flags);
122 map->page = (void *)page;
123 spin_unlock_irqrestore(&qpt->lock, flags);
124 if (unlikely(!map->page))
127 if (likely(atomic_read(&map->n_free))) {
129 if (!test_and_set_bit(offset, map->page)) {
130 atomic_dec(&map->n_free);
135 offset = find_next_offset(map, offset);
136 qpn = mk_qpn(qpt, map, offset);
138 * This test differs from alloc_pidmap().
139 * If find_next_offset() does find a zero
140 * bit, we don't need to check for QPN
141 * wrapping around past our starting QPN.
142 * We just need to be sure we don't loop
145 } while (offset < BITS_PER_PAGE && qpn < QPN_MAX);
148 * In order to keep the number of pages allocated to a
149 * minimum, we scan the all existing pages before increasing
150 * the size of the bitmap table.
152 if (++i > max_scan) {
153 if (qpt->nmaps == QPNMAP_ENTRIES)
155 map = &qpt->map[qpt->nmaps++];
157 } else if (map < &qpt->map[qpt->nmaps]) {
164 qpn = mk_qpn(qpt, map, offset);
173 static void free_qpn(struct ipath_qp_table *qpt, u32 qpn)
177 map = qpt->map + qpn / BITS_PER_PAGE;
179 clear_bit(qpn & BITS_PER_PAGE_MASK, map->page);
180 atomic_inc(&map->n_free);
184 * ipath_alloc_qpn - allocate a QP number
187 * @type: the QP type (IB_QPT_SMI and IB_QPT_GSI are special)
189 * Allocate the next available QPN and put the QP into the hash table.
190 * The hash table holds a reference to the QP.
192 static int ipath_alloc_qpn(struct ipath_qp_table *qpt, struct ipath_qp *qp,
193 enum ib_qp_type type)
199 if (type == IB_QPT_SMI)
201 else if (type == IB_QPT_GSI)
204 /* Allocate the next available QPN */
205 qpn = alloc_qpn(qpt);
211 qp->ibqp.qp_num = qpn;
213 /* Add the QP to the hash table. */
214 spin_lock_irqsave(&qpt->lock, flags);
217 qp->next = qpt->table[qpn];
218 qpt->table[qpn] = qp;
219 atomic_inc(&qp->refcount);
221 spin_unlock_irqrestore(&qpt->lock, flags);
229 * ipath_free_qp - remove a QP from the QP table
231 * @qp: the QP to remove
233 * Remove the QP from the table so it can't be found asynchronously by
234 * the receive interrupt routine.
236 static void ipath_free_qp(struct ipath_qp_table *qpt, struct ipath_qp *qp)
238 struct ipath_qp *q, **qpp;
242 spin_lock_irqsave(&qpt->lock, flags);
244 /* Remove QP from the hash table. */
245 qpp = &qpt->table[qp->ibqp.qp_num % qpt->max];
246 for (; (q = *qpp) != NULL; qpp = &q->next) {
250 atomic_dec(&qp->refcount);
256 spin_unlock_irqrestore(&qpt->lock, flags);
261 /* If QPN is not reserved, mark QPN free in the bitmap. */
262 if (qp->ibqp.qp_num > 1)
263 free_qpn(qpt, qp->ibqp.qp_num);
265 wait_event(qp->wait, !atomic_read(&qp->refcount));
269 * ipath_free_all_qps - remove all QPs from the table
270 * @qpt: the QP table to empty
272 void ipath_free_all_qps(struct ipath_qp_table *qpt)
275 struct ipath_qp *qp, *nqp;
278 for (n = 0; n < qpt->max; n++) {
279 spin_lock_irqsave(&qpt->lock, flags);
281 qpt->table[n] = NULL;
282 spin_unlock_irqrestore(&qpt->lock, flags);
286 if (qp->ibqp.qp_num > 1)
287 free_qpn(qpt, qp->ibqp.qp_num);
288 if (!atomic_dec_and_test(&qp->refcount) ||
289 !ipath_destroy_qp(&qp->ibqp))
290 _VERBS_INFO("QP memory leak!\n");
295 for (n = 0; n < ARRAY_SIZE(qpt->map); n++) {
296 if (qpt->map[n].page)
297 free_page((unsigned long)qpt->map[n].page);
302 * ipath_lookup_qpn - return the QP with the given QPN
304 * @qpn: the QP number to look up
306 * The caller is responsible for decrementing the QP reference count
309 struct ipath_qp *ipath_lookup_qpn(struct ipath_qp_table *qpt, u32 qpn)
314 spin_lock_irqsave(&qpt->lock, flags);
316 for (qp = qpt->table[qpn % qpt->max]; qp; qp = qp->next) {
317 if (qp->ibqp.qp_num == qpn) {
318 atomic_inc(&qp->refcount);
323 spin_unlock_irqrestore(&qpt->lock, flags);
328 * ipath_reset_qp - initialize the QP state to the reset state
329 * @qp: the QP to reset
331 static void ipath_reset_qp(struct ipath_qp *qp)
335 qp->qp_access_flags = 0;
336 clear_bit(IPATH_S_BUSY, &qp->s_flags);
341 if (qp->ibqp.qp_type == IB_QPT_RC) {
342 qp->s_state = IB_OPCODE_RC_SEND_LAST;
343 qp->r_state = IB_OPCODE_RC_SEND_LAST;
345 qp->s_state = IB_OPCODE_UC_SEND_LAST;
346 qp->r_state = IB_OPCODE_UC_SEND_LAST;
348 qp->s_ack_state = IB_OPCODE_RC_ACKNOWLEDGE;
349 qp->r_ack_state = IB_OPCODE_RC_ACKNOWLEDGE;
351 qp->s_rnr_timeout = 0;
364 * ipath_error_qp - put a QP into an error state
365 * @qp: the QP to put into an error state
367 * Flushes both send and receive work queues.
368 * QP s_lock should be held and interrupts disabled.
371 void ipath_error_qp(struct ipath_qp *qp)
373 struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
376 _VERBS_INFO("QP%d/%d in error state\n",
377 qp->ibqp.qp_num, qp->remote_qpn);
379 spin_lock(&dev->pending_lock);
380 /* XXX What if its already removed by the timeout code? */
381 if (!list_empty(&qp->timerwait))
382 list_del_init(&qp->timerwait);
383 if (!list_empty(&qp->piowait))
384 list_del_init(&qp->piowait);
385 spin_unlock(&dev->pending_lock);
387 wc.status = IB_WC_WR_FLUSH_ERR;
391 wc.qp_num = qp->ibqp.qp_num;
397 wc.dlid_path_bits = 0;
400 while (qp->s_last != qp->s_head) {
401 struct ipath_swqe *wqe = get_swqe_ptr(qp, qp->s_last);
403 wc.wr_id = wqe->wr.wr_id;
404 wc.opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
405 if (++qp->s_last >= qp->s_size)
407 ipath_cq_enter(to_icq(qp->ibqp.send_cq), &wc, 1);
409 qp->s_cur = qp->s_tail = qp->s_head;
411 qp->s_ack_state = IB_OPCODE_RC_ACKNOWLEDGE;
413 wc.opcode = IB_WC_RECV;
414 spin_lock(&qp->r_rq.lock);
415 while (qp->r_rq.tail != qp->r_rq.head) {
416 wc.wr_id = get_rwqe_ptr(&qp->r_rq, qp->r_rq.tail)->wr_id;
417 if (++qp->r_rq.tail >= qp->r_rq.size)
419 ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc, 1);
421 spin_unlock(&qp->r_rq.lock);
425 * ipath_modify_qp - modify the attributes of a queue pair
426 * @ibqp: the queue pair who's attributes we're modifying
427 * @attr: the new attributes
428 * @attr_mask: the mask of attributes to modify
429 * @udata: user data for ipathverbs.so
431 * Returns 0 on success, otherwise returns an errno.
433 int ipath_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
434 int attr_mask, struct ib_udata *udata)
436 struct ipath_ibdev *dev = to_idev(ibqp->device);
437 struct ipath_qp *qp = to_iqp(ibqp);
438 enum ib_qp_state cur_state, new_state;
442 spin_lock_irqsave(&qp->s_lock, flags);
444 cur_state = attr_mask & IB_QP_CUR_STATE ?
445 attr->cur_qp_state : qp->state;
446 new_state = attr_mask & IB_QP_STATE ? attr->qp_state : cur_state;
448 if (!ib_modify_qp_is_ok(cur_state, new_state, ibqp->qp_type,
452 if (attr_mask & IB_QP_AV)
453 if (attr->ah_attr.dlid == 0 ||
454 attr->ah_attr.dlid >= IPATH_MULTICAST_LID_BASE)
457 if (attr_mask & IB_QP_PKEY_INDEX)
458 if (attr->pkey_index >= ipath_layer_get_npkeys(dev->dd))
461 if (attr_mask & IB_QP_MIN_RNR_TIMER)
462 if (attr->min_rnr_timer > 31)
479 if (attr_mask & IB_QP_PKEY_INDEX)
480 qp->s_pkey_index = attr->pkey_index;
482 if (attr_mask & IB_QP_DEST_QPN)
483 qp->remote_qpn = attr->dest_qp_num;
485 if (attr_mask & IB_QP_SQ_PSN) {
486 qp->s_next_psn = attr->sq_psn;
487 qp->s_last_psn = qp->s_next_psn - 1;
490 if (attr_mask & IB_QP_RQ_PSN)
491 qp->r_psn = attr->rq_psn;
493 if (attr_mask & IB_QP_ACCESS_FLAGS)
494 qp->qp_access_flags = attr->qp_access_flags;
496 if (attr_mask & IB_QP_AV)
497 qp->remote_ah_attr = attr->ah_attr;
499 if (attr_mask & IB_QP_PATH_MTU)
500 qp->path_mtu = attr->path_mtu;
502 if (attr_mask & IB_QP_RETRY_CNT)
503 qp->s_retry = qp->s_retry_cnt = attr->retry_cnt;
505 if (attr_mask & IB_QP_RNR_RETRY) {
506 qp->s_rnr_retry = attr->rnr_retry;
507 if (qp->s_rnr_retry > 7)
509 qp->s_rnr_retry_cnt = qp->s_rnr_retry;
512 if (attr_mask & IB_QP_MIN_RNR_TIMER)
513 qp->r_min_rnr_timer = attr->min_rnr_timer;
515 if (attr_mask & IB_QP_QKEY)
516 qp->qkey = attr->qkey;
518 qp->state = new_state;
519 spin_unlock_irqrestore(&qp->s_lock, flags);
525 spin_unlock_irqrestore(&qp->s_lock, flags);
532 int ipath_query_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
533 int attr_mask, struct ib_qp_init_attr *init_attr)
535 struct ipath_qp *qp = to_iqp(ibqp);
537 attr->qp_state = qp->state;
538 attr->cur_qp_state = attr->qp_state;
539 attr->path_mtu = qp->path_mtu;
540 attr->path_mig_state = 0;
541 attr->qkey = qp->qkey;
542 attr->rq_psn = qp->r_psn;
543 attr->sq_psn = qp->s_next_psn;
544 attr->dest_qp_num = qp->remote_qpn;
545 attr->qp_access_flags = qp->qp_access_flags;
546 attr->cap.max_send_wr = qp->s_size - 1;
547 attr->cap.max_recv_wr = qp->r_rq.size - 1;
548 attr->cap.max_send_sge = qp->s_max_sge;
549 attr->cap.max_recv_sge = qp->r_rq.max_sge;
550 attr->cap.max_inline_data = 0;
551 attr->ah_attr = qp->remote_ah_attr;
552 memset(&attr->alt_ah_attr, 0, sizeof(attr->alt_ah_attr));
553 attr->pkey_index = qp->s_pkey_index;
554 attr->alt_pkey_index = 0;
555 attr->en_sqd_async_notify = 0;
556 attr->sq_draining = 0;
557 attr->max_rd_atomic = 1;
558 attr->max_dest_rd_atomic = 1;
559 attr->min_rnr_timer = qp->r_min_rnr_timer;
562 attr->retry_cnt = qp->s_retry_cnt;
563 attr->rnr_retry = qp->s_rnr_retry;
564 attr->alt_port_num = 0;
565 attr->alt_timeout = 0;
567 init_attr->event_handler = qp->ibqp.event_handler;
568 init_attr->qp_context = qp->ibqp.qp_context;
569 init_attr->send_cq = qp->ibqp.send_cq;
570 init_attr->recv_cq = qp->ibqp.recv_cq;
571 init_attr->srq = qp->ibqp.srq;
572 init_attr->cap = attr->cap;
573 init_attr->sq_sig_type =
574 (qp->s_flags & (1 << IPATH_S_SIGNAL_REQ_WR))
575 ? IB_SIGNAL_REQ_WR : 0;
576 init_attr->qp_type = qp->ibqp.qp_type;
577 init_attr->port_num = 1;
582 * ipath_compute_aeth - compute the AETH (syndrome + MSN)
583 * @qp: the queue pair to compute the AETH for
587 __be32 ipath_compute_aeth(struct ipath_qp *qp)
589 u32 aeth = qp->r_msn & IPATH_MSN_MASK;
593 * Shared receive queues don't generate credits.
594 * Set the credit field to the invalid value.
596 aeth |= IPATH_AETH_CREDIT_INVAL << IPATH_AETH_CREDIT_SHIFT;
602 * Compute the number of credits available (RWQEs).
603 * XXX Not holding the r_rq.lock here so there is a small
604 * chance that the pair of reads are not atomic.
606 credits = qp->r_rq.head - qp->r_rq.tail;
607 if ((int)credits < 0)
608 credits += qp->r_rq.size;
610 * Binary search the credit table to find the code to
617 if (credit_table[x] == credits)
619 if (credit_table[x] > credits)
626 aeth |= x << IPATH_AETH_CREDIT_SHIFT;
628 return cpu_to_be32(aeth);
632 * ipath_create_qp - create a queue pair for a device
633 * @ibpd: the protection domain who's device we create the queue pair for
634 * @init_attr: the attributes of the queue pair
635 * @udata: unused by InfiniPath
637 * Returns the queue pair on success, otherwise returns an errno.
639 * Called by the ib_create_qp() core verbs function.
641 struct ib_qp *ipath_create_qp(struct ib_pd *ibpd,
642 struct ib_qp_init_attr *init_attr,
643 struct ib_udata *udata)
647 struct ipath_swqe *swq = NULL;
648 struct ipath_ibdev *dev;
652 if (init_attr->cap.max_send_sge > ib_ipath_max_sges ||
653 init_attr->cap.max_recv_sge > ib_ipath_max_sges ||
654 init_attr->cap.max_send_wr > ib_ipath_max_qp_wrs ||
655 init_attr->cap.max_recv_wr > ib_ipath_max_qp_wrs) {
656 ret = ERR_PTR(-ENOMEM);
660 if (init_attr->cap.max_send_sge +
661 init_attr->cap.max_recv_sge +
662 init_attr->cap.max_send_wr +
663 init_attr->cap.max_recv_wr == 0) {
664 ret = ERR_PTR(-EINVAL);
668 switch (init_attr->qp_type) {
671 sz = sizeof(struct ipath_sge) *
672 init_attr->cap.max_send_sge +
673 sizeof(struct ipath_swqe);
674 swq = vmalloc((init_attr->cap.max_send_wr + 1) * sz);
676 ret = ERR_PTR(-ENOMEM);
683 qp = kmalloc(sizeof(*qp), GFP_KERNEL);
686 ret = ERR_PTR(-ENOMEM);
689 if (init_attr->srq) {
691 qp->r_rq.max_sge = 0;
694 qp->r_rq.size = init_attr->cap.max_recv_wr + 1;
695 qp->r_rq.max_sge = init_attr->cap.max_recv_sge;
696 sz = (sizeof(struct ipath_sge) * qp->r_rq.max_sge) +
697 sizeof(struct ipath_rwqe);
698 qp->r_rq.wq = vmalloc(qp->r_rq.size * sz);
702 ret = ERR_PTR(-ENOMEM);
708 * ib_create_qp() will initialize qp->ibqp
709 * except for qp->ibqp.qp_num.
711 spin_lock_init(&qp->s_lock);
712 spin_lock_init(&qp->r_rq.lock);
713 atomic_set(&qp->refcount, 0);
714 init_waitqueue_head(&qp->wait);
715 tasklet_init(&qp->s_task, ipath_do_ruc_send,
717 INIT_LIST_HEAD(&qp->piowait);
718 INIT_LIST_HEAD(&qp->timerwait);
719 qp->state = IB_QPS_RESET;
721 qp->s_size = init_attr->cap.max_send_wr + 1;
722 qp->s_max_sge = init_attr->cap.max_send_sge;
723 qp->s_flags = init_attr->sq_sig_type == IB_SIGNAL_REQ_WR ?
724 1 << IPATH_S_SIGNAL_REQ_WR : 0;
725 dev = to_idev(ibpd->device);
726 err = ipath_alloc_qpn(&dev->qp_table, qp,
737 /* Tell the core driver that the kernel SMA is present. */
738 if (init_attr->qp_type == IB_QPT_SMI)
739 ipath_layer_set_verbs_flags(dev->dd,
740 IPATH_VERBS_KERNEL_SMA);
744 /* Don't support raw QPs */
745 ret = ERR_PTR(-ENOSYS);
749 init_attr->cap.max_inline_data = 0;
758 * ipath_destroy_qp - destroy a queue pair
759 * @ibqp: the queue pair to destroy
761 * Returns 0 on success.
763 * Note that this can be called while the QP is actively sending or
766 int ipath_destroy_qp(struct ib_qp *ibqp)
768 struct ipath_qp *qp = to_iqp(ibqp);
769 struct ipath_ibdev *dev = to_idev(ibqp->device);
772 /* Tell the core driver that the kernel SMA is gone. */
773 if (qp->ibqp.qp_type == IB_QPT_SMI)
774 ipath_layer_set_verbs_flags(dev->dd, 0);
776 spin_lock_irqsave(&qp->r_rq.lock, flags);
777 spin_lock(&qp->s_lock);
778 qp->state = IB_QPS_ERR;
779 spin_unlock(&qp->s_lock);
780 spin_unlock_irqrestore(&qp->r_rq.lock, flags);
782 /* Stop the sending tasklet. */
783 tasklet_kill(&qp->s_task);
785 /* Make sure the QP isn't on the timeout list. */
786 spin_lock_irqsave(&dev->pending_lock, flags);
787 if (!list_empty(&qp->timerwait))
788 list_del_init(&qp->timerwait);
789 if (!list_empty(&qp->piowait))
790 list_del_init(&qp->piowait);
791 spin_unlock_irqrestore(&dev->pending_lock, flags);
794 * Make sure that the QP is not in the QPN table so receive
795 * interrupts will discard packets for this QP. XXX Also remove QP
796 * from multicast table.
798 if (atomic_read(&qp->refcount) != 0)
799 ipath_free_qp(&dev->qp_table, qp);
808 * ipath_init_qp_table - initialize the QP table for a device
809 * @idev: the device who's QP table we're initializing
810 * @size: the size of the QP table
812 * Returns 0 on success, otherwise returns an errno.
814 int ipath_init_qp_table(struct ipath_ibdev *idev, int size)
819 idev->qp_table.last = 1; /* QPN 0 and 1 are special. */
820 idev->qp_table.max = size;
821 idev->qp_table.nmaps = 1;
822 idev->qp_table.table = kzalloc(size * sizeof(*idev->qp_table.table),
824 if (idev->qp_table.table == NULL) {
829 for (i = 0; i < ARRAY_SIZE(idev->qp_table.map); i++) {
830 atomic_set(&idev->qp_table.map[i].n_free, BITS_PER_PAGE);
831 idev->qp_table.map[i].page = NULL;
841 * ipath_sqerror_qp - put a QP's send queue into an error state
842 * @qp: QP who's send queue will be put into an error state
843 * @wc: the WC responsible for putting the QP in this state
845 * Flushes the send work queue.
846 * The QP s_lock should be held.
849 void ipath_sqerror_qp(struct ipath_qp *qp, struct ib_wc *wc)
851 struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
852 struct ipath_swqe *wqe = get_swqe_ptr(qp, qp->s_last);
854 _VERBS_INFO("Send queue error on QP%d/%d: err: %d\n",
855 qp->ibqp.qp_num, qp->remote_qpn, wc->status);
857 spin_lock(&dev->pending_lock);
858 /* XXX What if its already removed by the timeout code? */
859 if (!list_empty(&qp->timerwait))
860 list_del_init(&qp->timerwait);
861 if (!list_empty(&qp->piowait))
862 list_del_init(&qp->piowait);
863 spin_unlock(&dev->pending_lock);
865 ipath_cq_enter(to_icq(qp->ibqp.send_cq), wc, 1);
866 if (++qp->s_last >= qp->s_size)
869 wc->status = IB_WC_WR_FLUSH_ERR;
871 while (qp->s_last != qp->s_head) {
872 wc->wr_id = wqe->wr.wr_id;
873 wc->opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
874 ipath_cq_enter(to_icq(qp->ibqp.send_cq), wc, 1);
875 if (++qp->s_last >= qp->s_size)
877 wqe = get_swqe_ptr(qp, qp->s_last);
879 qp->s_cur = qp->s_tail = qp->s_head;
880 qp->state = IB_QPS_SQE;
884 * ipath_get_credit - flush the send work queue of a QP
885 * @qp: the qp who's send work queue to flush
886 * @aeth: the Acknowledge Extended Transport Header
888 * The QP s_lock should be held.
890 void ipath_get_credit(struct ipath_qp *qp, u32 aeth)
892 u32 credit = (aeth >> IPATH_AETH_CREDIT_SHIFT) & IPATH_AETH_CREDIT_MASK;
895 * If the credit is invalid, we can send
896 * as many packets as we like. Otherwise, we have to
897 * honor the credit field.
899 if (credit == IPATH_AETH_CREDIT_INVAL)
900 qp->s_lsn = (u32) -1;
901 else if (qp->s_lsn != (u32) -1) {
902 /* Compute new LSN (i.e., MSN + credit) */
903 credit = (aeth + credit_table[credit]) & IPATH_MSN_MASK;
904 if (ipath_cmp24(credit, qp->s_lsn) > 0)
908 /* Restart sending if it was blocked due to lack of credits. */
909 if (qp->s_cur != qp->s_head &&
910 (qp->s_lsn == (u32) -1 ||
911 ipath_cmp24(get_swqe_ptr(qp, qp->s_cur)->ssn,
912 qp->s_lsn + 1) <= 0))
913 tasklet_hi_schedule(&qp->s_task);