linux/drivers/infiniband/hw/cxgb4/cq.c

/*
 * Copyright (c) 2009-2010 Chelsio, 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 "iw_cxgb4.h"

static int destroy_cq(struct c4iw_rdev *rdev, struct t4_cq *cq,
		      struct c4iw_dev_ucontext *uctx, struct sk_buff *skb,
		      struct c4iw_wr_wait *wr_waitp)
{
	struct fw_ri_res_wr *res_wr;
	struct fw_ri_res *res;
	int wr_len;
	int ret;

	wr_len = sizeof *res_wr + sizeof *res;
	set_wr_txq(skb, CPL_PRIORITY_CONTROL, 0);

	res_wr = __skb_put_zero(skb, wr_len);
	res_wr->op_nres = cpu_to_be32(
			FW_WR_OP_V(FW_RI_RES_WR) |
			FW_RI_RES_WR_NRES_V(1) |
			FW_WR_COMPL_F);
	res_wr->len16_pkd = cpu_to_be32(DIV_ROUND_UP(wr_len, 16));
	res_wr->cookie = (uintptr_t)wr_waitp;
	res = res_wr->res;
	res->u.cq.restype = FW_RI_RES_TYPE_CQ;
	res->u.cq.op = FW_RI_RES_OP_RESET;
	res->u.cq.iqid = cpu_to_be32(cq->cqid);

	c4iw_init_wr_wait(wr_waitp);
	ret = c4iw_ref_send_wait(rdev, skb, wr_waitp, 0, 0, __func__);

	kfree(cq->sw_queue);
	dma_free_coherent(&(rdev->lldi.pdev->dev),
			  cq->memsize, cq->queue,
			  dma_unmap_addr(cq, mapping));
	c4iw_put_cqid(rdev, cq->cqid, uctx);
	return ret;
}

static int create_cq(struct c4iw_rdev *rdev, struct t4_cq *cq,
		     struct c4iw_dev_ucontext *uctx,
		     struct c4iw_wr_wait *wr_waitp)
{
	struct fw_ri_res_wr *res_wr;
	struct fw_ri_res *res;
	int wr_len;
	int user = (uctx != &rdev->uctx);
	int ret;
	struct sk_buff *skb;
	struct c4iw_ucontext *ucontext = NULL;

	if (user)
		ucontext = container_of(uctx, struct c4iw_ucontext, uctx);

	cq->cqid = c4iw_get_cqid(rdev, uctx);
	if (!cq->cqid) {
		ret = -ENOMEM;
		goto err1;
	}

	if (!user) {
		cq->sw_queue = kzalloc(cq->memsize, GFP_KERNEL);
		if (!cq->sw_queue) {
			ret = -ENOMEM;
			goto err2;
		}
	}
	cq->queue = dma_alloc_coherent(&rdev->lldi.pdev->dev, cq->memsize,
				       &cq->dma_addr, GFP_KERNEL);
	if (!cq->queue) {
		ret = -ENOMEM;
		goto err3;
	}
	dma_unmap_addr_set(cq, mapping, cq->dma_addr);
	memset(cq->queue, 0, cq->memsize);

	if (user && ucontext->is_32b_cqe) {
		cq->qp_errp = &((struct t4_status_page *)
		((u8 *)cq->queue + (cq->size - 1) *
		 (sizeof(*cq->queue) / 2)))->qp_err;
	} else {
		cq->qp_errp = &((struct t4_status_page *)
		((u8 *)cq->queue + (cq->size - 1) *
		 sizeof(*cq->queue)))->qp_err;
	}

	/* build fw_ri_res_wr */
	wr_len = sizeof *res_wr + sizeof *res;

	skb = alloc_skb(wr_len, GFP_KERNEL);
	if (!skb) {
		ret = -ENOMEM;
		goto err4;
	}
	set_wr_txq(skb, CPL_PRIORITY_CONTROL, 0);

	res_wr = __skb_put_zero(skb, wr_len);
	res_wr->op_nres = cpu_to_be32(
			FW_WR_OP_V(FW_RI_RES_WR) |
			FW_RI_RES_WR_NRES_V(1) |
			FW_WR_COMPL_F);
	res_wr->len16_pkd = cpu_to_be32(DIV_ROUND_UP(wr_len, 16));
	res_wr->cookie = (uintptr_t)wr_waitp;
	res = res_wr->res;
	res->u.cq.restype = FW_RI_RES_TYPE_CQ;
	res->u.cq.op = FW_RI_RES_OP_WRITE;
	res->u.cq.iqid = cpu_to_be32(cq->cqid);
	res->u.cq.iqandst_to_iqandstindex = cpu_to_be32(
			FW_RI_RES_WR_IQANUS_V(0) |
			FW_RI_RES_WR_IQANUD_V(1) |
			FW_RI_RES_WR_IQANDST_F |
			FW_RI_RES_WR_IQANDSTINDEX_V(
				rdev->lldi.ciq_ids[cq->vector]));
	res->u.cq.iqdroprss_to_iqesize = cpu_to_be16(
			FW_RI_RES_WR_IQDROPRSS_F |
			FW_RI_RES_WR_IQPCIECH_V(2) |
			FW_RI_RES_WR_IQINTCNTTHRESH_V(0) |
			FW_RI_RES_WR_IQO_F |
			((user && ucontext->is_32b_cqe) ?
			 FW_RI_RES_WR_IQESIZE_V(1) :
			 FW_RI_RES_WR_IQESIZE_V(2)));
	res->u.cq.iqsize = cpu_to_be16(cq->size);
	res->u.cq.iqaddr = cpu_to_be64(cq->dma_addr);

	c4iw_init_wr_wait(wr_waitp);
	ret = c4iw_ref_send_wait(rdev, skb, wr_waitp, 0, 0, __func__);
	if (ret)
		goto err4;

	cq->gen = 1;
	cq->gts = rdev->lldi.gts_reg;
	cq->rdev = rdev;

	cq->bar2_va = c4iw_bar2_addrs(rdev, cq->cqid, CXGB4_BAR2_QTYPE_INGRESS,
				      &cq->bar2_qid,
				      user ? &cq->bar2_pa : NULL);
	if (user && !cq->bar2_pa) {
		pr_warn("%s: cqid %u not in BAR2 range\n",
			pci_name(rdev->lldi.pdev), cq->cqid);
		ret = -EINVAL;
		goto err4;
	}
	return 0;
err4:
	dma_free_coherent(&rdev->lldi.pdev->dev, cq->memsize, cq->queue,
			  dma_unmap_addr(cq, mapping));
err3:
	kfree(cq->sw_queue);
err2:
	c4iw_put_cqid(rdev, cq->cqid, uctx);
err1:
	return ret;
}

static void insert_recv_cqe(struct t4_wq *wq, struct t4_cq *cq, u32 srqidx)
{
	struct t4_cqe cqe;

	pr_debug("wq %p cq %p sw_cidx %u sw_pidx %u\n",
		 wq, cq, cq->sw_cidx, cq->sw_pidx);
	memset(&cqe, 0, sizeof(cqe));
	cqe.header = cpu_to_be32(CQE_STATUS_V(T4_ERR_SWFLUSH) |
				 CQE_OPCODE_V(FW_RI_SEND) |
				 CQE_TYPE_V(0) |
				 CQE_SWCQE_V(1) |
				 CQE_QPID_V(wq->sq.qid));
	cqe.bits_type_ts = cpu_to_be64(CQE_GENBIT_V((u64)cq->gen));
	if (srqidx)
		cqe.u.srcqe.abs_rqe_idx = cpu_to_be32(srqidx);
	cq->sw_queue[cq->sw_pidx] = cqe;
	t4_swcq_produce(cq);
}

int c4iw_flush_rq(struct t4_wq *wq, struct t4_cq *cq, int count)
{
	int flushed = 0;
	int in_use = wq->rq.in_use - count;

	pr_debug("wq %p cq %p rq.in_use %u skip count %u\n",
		 wq, cq, wq->rq.in_use, count);
	while (in_use--) {
		insert_recv_cqe(wq, cq, 0);
		flushed++;
	}
	return flushed;
}

static void insert_sq_cqe(struct t4_wq *wq, struct t4_cq *cq,
			  struct t4_swsqe *swcqe)
{
	struct t4_cqe cqe;

	pr_debug("wq %p cq %p sw_cidx %u sw_pidx %u\n",
		 wq, cq, cq->sw_cidx, cq->sw_pidx);
	memset(&cqe, 0, sizeof(cqe));
	cqe.header = cpu_to_be32(CQE_STATUS_V(T4_ERR_SWFLUSH) |
				 CQE_OPCODE_V(swcqe->opcode) |
				 CQE_TYPE_V(1) |
				 CQE_SWCQE_V(1) |
				 CQE_QPID_V(wq->sq.qid));
	CQE_WRID_SQ_IDX(&cqe) = swcqe->idx;
	cqe.bits_type_ts = cpu_to_be64(CQE_GENBIT_V((u64)cq->gen));
	cq->sw_queue[cq->sw_pidx] = cqe;
	t4_swcq_produce(cq);
}

static void advance_oldest_read(struct t4_wq *wq);

int c4iw_flush_sq(struct c4iw_qp *qhp)
{
	int flushed = 0;
	struct t4_wq *wq = &qhp->wq;
	struct c4iw_cq *chp = to_c4iw_cq(qhp->ibqp.send_cq);
	struct t4_cq *cq = &chp->cq;
	int idx;
	struct t4_swsqe *swsqe;

	if (wq->sq.flush_cidx == -1)
		wq->sq.flush_cidx = wq->sq.cidx;
	idx = wq->sq.flush_cidx;
	while (idx != wq->sq.pidx) {
		swsqe = &wq->sq.sw_sq[idx];
		swsqe->flushed = 1;
		insert_sq_cqe(wq, cq, swsqe);
		if (wq->sq.oldest_read == swsqe) {
			advance_oldest_read(wq);
		}
		flushed++;
		if (++idx == wq->sq.size)
			idx = 0;
	}
	wq->sq.flush_cidx += flushed;
	if (wq->sq.flush_cidx >= wq->sq.size)
		wq->sq.flush_cidx -= wq->sq.size;
	return flushed;
}

static void flush_completed_wrs(struct t4_wq *wq, struct t4_cq *cq)
{
	struct t4_swsqe *swsqe;
	int cidx;

	if (wq->sq.flush_cidx == -1)
		wq->sq.flush_cidx = wq->sq.cidx;
	cidx = wq->sq.flush_cidx;

	while (cidx != wq->sq.pidx) {
		swsqe = &wq->sq.sw_sq[cidx];
		if (!swsqe->signaled) {
			if (++cidx == wq->sq.size)
				cidx = 0;
		} else if (swsqe->complete) {

			/*
			 * Insert this completed cqe into the swcq.
			 */
			pr_debug("moving cqe into swcq sq idx %u cq idx %u\n",
				 cidx, cq->sw_pidx);
			swsqe->cqe.header |= htonl(CQE_SWCQE_V(1));
			cq->sw_queue[cq->sw_pidx] = swsqe->cqe;
			t4_swcq_produce(cq);
			swsqe->flushed = 1;
			if (++cidx == wq->sq.size)
				cidx = 0;
			wq->sq.flush_cidx = cidx;
		} else
			break;
	}
}

static void create_read_req_cqe(struct t4_wq *wq, struct t4_cqe *hw_cqe,
		struct t4_cqe *read_cqe)
{
	read_cqe->u.scqe.cidx = wq->sq.oldest_read->idx;
	read_cqe->len = htonl(wq->sq.oldest_read->read_len);
	read_cqe->header = htonl(CQE_QPID_V(CQE_QPID(hw_cqe)) |
			CQE_SWCQE_V(SW_CQE(hw_cqe)) |
			CQE_OPCODE_V(FW_RI_READ_REQ) |
			CQE_TYPE_V(1));
	read_cqe->bits_type_ts = hw_cqe->bits_type_ts;
}

static void advance_oldest_read(struct t4_wq *wq)
{

	u32 rptr = wq->sq.oldest_read - wq->sq.sw_sq + 1;

	if (rptr == wq->sq.size)
		rptr = 0;
	while (rptr != wq->sq.pidx) {
		wq->sq.oldest_read = &wq->sq.sw_sq[rptr];

		if (wq->sq.oldest_read->opcode == FW_RI_READ_REQ)
			return;
		if (++rptr == wq->sq.size)
			rptr = 0;
	}
	wq->sq.oldest_read = NULL;
}

/*
 * Move all CQEs from the HWCQ into the SWCQ.
 * Deal with out-of-order and/or completions that complete
 * prior unsignalled WRs.
 */
void c4iw_flush_hw_cq(struct c4iw_cq *chp, struct c4iw_qp *flush_qhp)
{
	struct t4_cqe *hw_cqe, *swcqe, read_cqe;
	struct c4iw_qp *qhp;
	struct t4_swsqe *swsqe;
	int ret;

	pr_debug("cqid 0x%x\n", chp->cq.cqid);
	ret = t4_next_hw_cqe(&chp->cq, &hw_cqe);

	/*
	 * This logic is similar to poll_cq(), but not quite the same
	 * unfortunately.  Need to move pertinent HW CQEs to the SW CQ but
	 * also do any translation magic that poll_cq() normally does.
	 */
	while (!ret) {
		qhp = get_qhp(chp->rhp, CQE_QPID(hw_cqe));

		/*
		 * drop CQEs with no associated QP
		 */
		if (qhp == NULL)
			goto next_cqe;

		if (flush_qhp != qhp) {
			spin_lock(&qhp->lock);

			if (qhp->wq.flushed == 1)
				goto next_cqe;
		}

		if (CQE_OPCODE(hw_cqe) == FW_RI_TERMINATE)
			goto next_cqe;

		if (CQE_OPCODE(hw_cqe) == FW_RI_READ_RESP) {

			/* If we have reached here because of async
			 * event or other error, and have egress error
			 * then drop
			 */
			if (CQE_TYPE(hw_cqe) == 1)
				goto next_cqe;

			/* drop peer2peer RTR reads.
			 */
			if (CQE_WRID_STAG(hw_cqe) == 1)
				goto next_cqe;

			/*
			 * Eat completions for unsignaled read WRs.
			 */
			if (!qhp->wq.sq.oldest_read->signaled) {
				advance_oldest_read(&qhp->wq);
				goto next_cqe;
			}

			/*
			 * Don't write to the HWCQ, create a new read req CQE
			 * in local memory and move it into the swcq.
			 */
			create_read_req_cqe(&qhp->wq, hw_cqe, &read_cqe);
			hw_cqe = &read_cqe;
			advance_oldest_read(&qhp->wq);
		}

		/* if its a SQ completion, then do the magic to move all the
		 * unsignaled and now in-order completions into the swcq.
		 */
		if (SQ_TYPE(hw_cqe)) {
			swsqe = &qhp->wq.sq.sw_sq[CQE_WRID_SQ_IDX(hw_cqe)];
			swsqe->cqe = *hw_cqe;
			swsqe->complete = 1;
			flush_completed_wrs(&qhp->wq, &chp->cq);
		} else {
			swcqe = &chp->cq.sw_queue[chp->cq.sw_pidx];
			*swcqe = *hw_cqe;
			swcqe->header |= cpu_to_be32(CQE_SWCQE_V(1));
			t4_swcq_produce(&chp->cq);
		}
next_cqe:
		t4_hwcq_consume(&chp->cq);
		ret = t4_next_hw_cqe(&chp->cq, &hw_cqe);
		if (qhp && flush_qhp != qhp)
			spin_unlock(&qhp->lock);
	}
}

static int cqe_completes_wr(struct t4_cqe *cqe, struct t4_wq *wq)
{
	if (DRAIN_CQE(cqe)) {
		WARN_ONCE(1, "Unexpected DRAIN CQE qp id %u!\n", wq->sq.qid);
		return 0;
	}

	if (CQE_OPCODE(cqe) == FW_RI_TERMINATE)
		return 0;

	if ((CQE_OPCODE(cqe) == FW_RI_RDMA_WRITE) && RQ_TYPE(cqe))
		return 0;

	if ((CQE_OPCODE(cqe) == FW_RI_READ_RESP) && SQ_TYPE(cqe))
		return 0;

	if (CQE_SEND_OPCODE(cqe) && RQ_TYPE(cqe) && t4_rq_empty(wq))
		return 0;
	return 1;
}

void c4iw_count_rcqes(struct t4_cq *cq, struct t4_wq *wq, int *count)
{
	struct t4_cqe *cqe;
	u32 ptr;

	*count = 0;
	pr_debug("count zero %d\n", *count);
	ptr = cq->sw_cidx;
	while (ptr != cq->sw_pidx) {
		cqe = &cq->sw_queue[ptr];
		if (RQ_TYPE(cqe) && (CQE_OPCODE(cqe) != FW_RI_READ_RESP) &&
		    (CQE_QPID(cqe) == wq->sq.qid) && cqe_completes_wr(cqe, wq))
			(*count)++;
		if (++ptr == cq->size)
			ptr = 0;
	}
	pr_debug("cq %p count %d\n", cq, *count);
}

static void post_pending_srq_wrs(struct t4_srq *srq)
{
	struct t4_srq_pending_wr *pwr;
	u16 idx = 0;

	while (srq->pending_in_use) {
		pwr = &srq->pending_wrs[srq->pending_cidx];
		srq->sw_rq[srq->pidx].wr_id = pwr->wr_id;
		srq->sw_rq[srq->pidx].valid = 1;

		pr_debug("%s posting pending cidx %u pidx %u wq_pidx %u in_use %u rq_size %u wr_id %llx\n",
			 __func__,
			 srq->cidx, srq->pidx, srq->wq_pidx,
			 srq->in_use, srq->size,
			 (unsigned long long)pwr->wr_id);

		c4iw_copy_wr_to_srq(srq, &pwr->wqe, pwr->len16);
		t4_srq_consume_pending_wr(srq);
		t4_srq_produce(srq, pwr->len16);
		idx += DIV_ROUND_UP(pwr->len16 * 16, T4_EQ_ENTRY_SIZE);
	}

	if (idx) {
		t4_ring_srq_db(srq, idx, pwr->len16, &pwr->wqe);
		srq->queue[srq->size].status.host_wq_pidx =
			srq->wq_pidx;
	}
}

static u64 reap_srq_cqe(struct t4_cqe *hw_cqe, struct t4_srq *srq)
{
	int rel_idx = CQE_ABS_RQE_IDX(hw_cqe) - srq->rqt_abs_idx;
	u64 wr_id;

	srq->sw_rq[rel_idx].valid = 0;
	wr_id = srq->sw_rq[rel_idx].wr_id;

	if (rel_idx == srq->cidx) {
		pr_debug("%s in order cqe rel_idx %u cidx %u pidx %u wq_pidx %u in_use %u rq_size %u wr_id %llx\n",
			 __func__, rel_idx, srq->cidx, srq->pidx,
			 srq->wq_pidx, srq->in_use, srq->size,
			 (unsigned long long)srq->sw_rq[rel_idx].wr_id);
		t4_srq_consume(srq);
		while (srq->ooo_count && !srq->sw_rq[srq->cidx].valid) {
			pr_debug("%s eat ooo cidx %u pidx %u wq_pidx %u in_use %u rq_size %u ooo_count %u wr_id %llx\n",
				 __func__, srq->cidx, srq->pidx,
				 srq->wq_pidx, srq->in_use,
				 srq->size, srq->ooo_count,
				 (unsigned long long)
				 srq->sw_rq[srq->cidx].wr_id);
			t4_srq_consume_ooo(srq);
		}
		if (srq->ooo_count == 0 && srq->pending_in_use)
			post_pending_srq_wrs(srq);
	} else {
		pr_debug("%s ooo cqe rel_idx %u cidx %u pidx %u wq_pidx %u in_use %u rq_size %u ooo_count %u wr_id %llx\n",
			 __func__, rel_idx, srq->cidx,
			 srq->pidx, srq->wq_pidx,
			 srq->in_use, srq->size,
			 srq->ooo_count,
			 (unsigned long long)srq->sw_rq[rel_idx].wr_id);
		t4_srq_produce_ooo(srq);
	}
	return wr_id;
}

/*
 * poll_cq
 *
 * Caller must:
 *     check the validity of the first CQE,
 *     supply the wq assicated with the qpid.
 *
 * credit: cq credit to return to sge.
 * cqe_flushed: 1 iff the CQE is flushed.
 * cqe: copy of the polled CQE.
 *
 * return value:
 *    0		    CQE returned ok.
 *    -EAGAIN       CQE skipped, try again.
 *    -EOVERFLOW    CQ overflow detected.
 */
static int poll_cq(struct t4_wq *wq, struct t4_cq *cq, struct t4_cqe *cqe,
		   u8 *cqe_flushed, u64 *cookie, u32 *credit,
		   struct t4_srq *srq)
{
	int ret = 0;
	struct t4_cqe *hw_cqe, read_cqe;

	*cqe_flushed = 0;
	*credit = 0;
	ret = t4_next_cqe(cq, &hw_cqe);
	if (ret)
		return ret;

	pr_debug("CQE OVF %u qpid 0x%0x genbit %u type %u status 0x%0x opcode 0x%0x len 0x%0x wrid_hi_stag 0x%x wrid_low_msn 0x%x\n",
		 CQE_OVFBIT(hw_cqe), CQE_QPID(hw_cqe),
		 CQE_GENBIT(hw_cqe), CQE_TYPE(hw_cqe), CQE_STATUS(hw_cqe),
		 CQE_OPCODE(hw_cqe), CQE_LEN(hw_cqe), CQE_WRID_HI(hw_cqe),
		 CQE_WRID_LOW(hw_cqe));

	/*
	 * skip cqe's not affiliated with a QP.
	 */
	if (wq == NULL) {
		ret = -EAGAIN;
		goto skip_cqe;
	}

	/*
	* skip hw cqe's if the wq is flushed.
	*/
	if (wq->flushed && !SW_CQE(hw_cqe)) {
		ret = -EAGAIN;
		goto skip_cqe;
	}

	/*
	 * skip TERMINATE cqes...
	 */
	if (CQE_OPCODE(hw_cqe) == FW_RI_TERMINATE) {
		ret = -EAGAIN;
		goto skip_cqe;
	}

	/*
	 * Special cqe for drain WR completions...
	 */
	if (DRAIN_CQE(hw_cqe)) {
		*cookie = CQE_DRAIN_COOKIE(hw_cqe);
		*cqe = *hw_cqe;
		goto skip_cqe;
	}

	/*
	 * Gotta tweak READ completions:
	 *	1) the cqe doesn't contain the sq_wptr from the wr.
	 *	2) opcode not reflected from the wr.
	 *	3) read_len not reflected from the wr.
	 *	4) cq_type is RQ_TYPE not SQ_TYPE.
	 */
	if (RQ_TYPE(hw_cqe) && (CQE_OPCODE(hw_cqe) == FW_RI_READ_RESP)) {

		/* If we have reached here because of async
		 * event or other error, and have egress error
		 * then drop
		 */
		if (CQE_TYPE(hw_cqe) == 1) {
			if (CQE_STATUS(hw_cqe))
				t4_set_wq_in_error(wq, 0);
			ret = -EAGAIN;
			goto skip_cqe;
		}

		/* If this is an unsolicited read response, then the read
		 * was generated by the kernel driver as part of peer-2-peer
		 * connection setup.  So ignore the completion.
		 */
		if (CQE_WRID_STAG(hw_cqe) == 1) {
			if (CQE_STATUS(hw_cqe))
				t4_set_wq_in_error(wq, 0);
			ret = -EAGAIN;
			goto skip_cqe;
		}

		/*
		 * Eat completions for unsignaled read WRs.
		 */
		if (!wq->sq.oldest_read->signaled) {
			advance_oldest_read(wq);
			ret = -EAGAIN;
			goto skip_cqe;
		}

		/*
		 * Don't write to the HWCQ, so create a new read req CQE
		 * in local memory.
		 */
		create_read_req_cqe(wq, hw_cqe, &read_cqe);
		hw_cqe = &read_cqe;
		advance_oldest_read(wq);
	}

	if (CQE_STATUS(hw_cqe) || t4_wq_in_error(wq)) {
		*cqe_flushed = (CQE_STATUS(hw_cqe) == T4_ERR_SWFLUSH);
		t4_set_wq_in_error(wq, 0);
	}

	/*
	 * RECV completion.
	 */
	if (RQ_TYPE(hw_cqe)) {

		/*
		 * HW only validates 4 bits of MSN.  So we must validate that
		 * the MSN in the SEND is the next expected MSN.  If its not,
		 * then we complete this with T4_ERR_MSN and mark the wq in
		 * error.
		 */
		if (unlikely(!CQE_STATUS(hw_cqe) &&
			     CQE_WRID_MSN(hw_cqe) != wq->rq.msn)) {
			t4_set_wq_in_error(wq, 0);
			hw_cqe->header |= cpu_to_be32(CQE_STATUS_V(T4_ERR_MSN));
		}
		goto proc_cqe;
	}

	/*
	 * If we get here its a send completion.
	 *
	 * Handle out of order completion. These get stuffed
	 * in the SW SQ. Then the SW SQ is walked to move any
	 * now in-order completions into the SW CQ.  This handles
	 * 2 cases:
	 *	1) reaping unsignaled WRs when the first subsequent
	 *	   signaled WR is completed.
	 *	2) out of order read completions.
	 */
	if (!SW_CQE(hw_cqe) && (CQE_WRID_SQ_IDX(hw_cqe) != wq->sq.cidx)) {
		struct t4_swsqe *swsqe;

		pr_debug("out of order completion going in sw_sq at idx %u\n",
			 CQE_WRID_SQ_IDX(hw_cqe));
		swsqe = &wq->sq.sw_sq[CQE_WRID_SQ_IDX(hw_cqe)];
		swsqe->cqe = *hw_cqe;
		swsqe->complete = 1;
		ret = -EAGAIN;
		goto flush_wq;
	}

proc_cqe:
	*cqe = *hw_cqe;

	/*
	 * Reap the associated WR(s) that are freed up with this
	 * completion.
	 */
	if (SQ_TYPE(hw_cqe)) {
		int idx = CQE_WRID_SQ_IDX(hw_cqe);

		/*
		* Account for any unsignaled completions completed by
		* this signaled completion.  In this case, cidx points
		* to the first unsignaled one, and idx points to the
		* signaled one.  So adjust in_use based on this delta.
		* if this is not completing any unsigned wrs, then the
		* delta will be 0. Handle wrapping also!
		*/
		if (idx < wq->sq.cidx)
			wq->sq.in_use -= wq->sq.size + idx - wq->sq.cidx;
		else
			wq->sq.in_use -= idx - wq->sq.cidx;

		wq->sq.cidx = (uint16_t)idx;
		pr_debug("completing sq idx %u\n", wq->sq.cidx);
		*cookie = wq->sq.sw_sq[wq->sq.cidx].wr_id;
		if (c4iw_wr_log)
			c4iw_log_wr_stats(wq, hw_cqe);
		t4_sq_consume(wq);
	} else {
		if (!srq) {
			pr_debug("completing rq idx %u\n", wq->rq.cidx);
			*cookie = wq->rq.sw_rq[wq->rq.cidx].wr_id;
			if (c4iw_wr_log)
				c4iw_log_wr_stats(wq, hw_cqe);
			t4_rq_consume(wq);
		} else {
			*cookie = reap_srq_cqe(hw_cqe, srq);
		}
		wq->rq.msn++;
		goto skip_cqe;
	}

flush_wq:
	/*
	 * Flush any completed cqes that are now in-order.
	 */
	flush_completed_wrs(wq, cq);

skip_cqe:
	if (SW_CQE(hw_cqe)) {
		pr_debug("cq %p cqid 0x%x skip sw cqe cidx %u\n",
			 cq, cq->cqid, cq->sw_cidx);
		t4_swcq_consume(cq);
	} else {
		pr_debug("cq %p cqid 0x%x skip hw cqe cidx %u\n",
			 cq, cq->cqid, cq->cidx);
		t4_hwcq_consume(cq);
	}
	return ret;
}

static int __c4iw_poll_cq_one(struct c4iw_cq *chp, struct c4iw_qp *qhp,
			      struct ib_wc *wc, struct c4iw_srq *srq)
{
	struct t4_cqe uninitialized_var(cqe);
	struct t4_wq *wq = qhp ? &qhp->wq : NULL;
	u32 credit = 0;
	u8 cqe_flushed;
	u64 cookie = 0;
	int ret;

	ret = poll_cq(wq, &(chp->cq), &cqe, &cqe_flushed, &cookie, &credit,
		      srq ? &srq->wq : NULL);
	if (ret)
		goto out;

	wc->wr_id = cookie;
	wc->qp = qhp ? &qhp->ibqp : NULL;
	wc->vendor_err = CQE_STATUS(&cqe);
	wc->wc_flags = 0;

	/*
	 * Simulate a SRQ_LIMIT_REACHED HW notification if required.
	 */
	if (srq && !(srq->flags & T4_SRQ_LIMIT_SUPPORT) && srq->armed &&
	    srq->wq.in_use < srq->srq_limit)
		c4iw_dispatch_srq_limit_reached_event(srq);

	pr_debug("qpid 0x%x type %d opcode %d status 0x%x len %u wrid hi 0x%x lo 0x%x cookie 0x%llx\n",
		 CQE_QPID(&cqe),
		 CQE_TYPE(&cqe), CQE_OPCODE(&cqe),
		 CQE_STATUS(&cqe), CQE_LEN(&cqe),
		 CQE_WRID_HI(&cqe), CQE_WRID_LOW(&cqe),
		 (unsigned long long)cookie);

	if (CQE_TYPE(&cqe) == 0) {
		if (!CQE_STATUS(&cqe))
			wc->byte_len = CQE_LEN(&cqe);
		else
			wc->byte_len = 0;

		switch (CQE_OPCODE(&cqe)) {
		case FW_RI_SEND:
			wc->opcode = IB_WC_RECV;
			break;
		case FW_RI_SEND_WITH_INV:
		case FW_RI_SEND_WITH_SE_INV:
			wc->opcode = IB_WC_RECV;
			wc->ex.invalidate_rkey = CQE_WRID_STAG(&cqe);
			wc->wc_flags |= IB_WC_WITH_INVALIDATE;
			c4iw_invalidate_mr(qhp->rhp, wc->ex.invalidate_rkey);
			break;
		case FW_RI_WRITE_IMMEDIATE:
			wc->opcode = IB_WC_RECV_RDMA_WITH_IMM;
			wc->ex.imm_data = CQE_IMM_DATA(&cqe);
			wc->wc_flags |= IB_WC_WITH_IMM;
			break;
		default:
			pr_err("Unexpected opcode %d in the CQE received for QPID=0x%0x\n",
			       CQE_OPCODE(&cqe), CQE_QPID(&cqe));
			ret = -EINVAL;
			goto out;
		}
	} else {
		switch (CQE_OPCODE(&cqe)) {
		case FW_RI_WRITE_IMMEDIATE:
		case FW_RI_RDMA_WRITE:
			wc->opcode = IB_WC_RDMA_WRITE;
			break;
		case FW_RI_READ_REQ:
			wc->opcode = IB_WC_RDMA_READ;
			wc->byte_len = CQE_LEN(&cqe);
			break;
		case FW_RI_SEND_WITH_INV:
		case FW_RI_SEND_WITH_SE_INV:
			wc->opcode = IB_WC_SEND;
			wc->wc_flags |= IB_WC_WITH_INVALIDATE;
			break;
		case FW_RI_SEND:
		case FW_RI_SEND_WITH_SE:
			wc->opcode = IB_WC_SEND;
			break;

		case FW_RI_LOCAL_INV:
			wc->opcode = IB_WC_LOCAL_INV;
			break;
		case FW_RI_FAST_REGISTER:
			wc->opcode = IB_WC_REG_MR;

			/* Invalidate the MR if the fastreg failed */
			if (CQE_STATUS(&cqe) != T4_ERR_SUCCESS)
				c4iw_invalidate_mr(qhp->rhp,
						   CQE_WRID_FR_STAG(&cqe));
			break;
		default:
			pr_err("Unexpected opcode %d in the CQE received for QPID=0x%0x\n",
			       CQE_OPCODE(&cqe), CQE_QPID(&cqe));
			ret = -EINVAL;
			goto out;
		}
	}

	if (cqe_flushed)
		wc->status = IB_WC_WR_FLUSH_ERR;
	else {

		switch (CQE_STATUS(&cqe)) {
		case T4_ERR_SUCCESS:
			wc->status = IB_WC_SUCCESS;
			break;
		case T4_ERR_STAG:
			wc->status = IB_WC_LOC_ACCESS_ERR;
			break;
		case T4_ERR_PDID:
			wc->status = IB_WC_LOC_PROT_ERR;
			break;
		case T4_ERR_QPID:
		case T4_ERR_ACCESS:
			wc->status = IB_WC_LOC_ACCESS_ERR;
			break;
		case T4_ERR_WRAP:
			wc->status = IB_WC_GENERAL_ERR;
			break;
		case T4_ERR_BOUND:
			wc->status = IB_WC_LOC_LEN_ERR;
			break;
		case T4_ERR_INVALIDATE_SHARED_MR:
		case T4_ERR_INVALIDATE_MR_WITH_MW_BOUND:
			wc->status = IB_WC_MW_BIND_ERR;
			break;
		case T4_ERR_CRC:
		case T4_ERR_MARKER:
		case T4_ERR_PDU_LEN_ERR:
		case T4_ERR_OUT_OF_RQE:
		case T4_ERR_DDP_VERSION:
		case T4_ERR_RDMA_VERSION:
		case T4_ERR_DDP_QUEUE_NUM:
		case T4_ERR_MSN:
		case T4_ERR_TBIT:
		case T4_ERR_MO:
		case T4_ERR_MSN_RANGE:
		case T4_ERR_IRD_OVERFLOW:
		case T4_ERR_OPCODE:
		case T4_ERR_INTERNAL_ERR:
			wc->status = IB_WC_FATAL_ERR;
			break;
		case T4_ERR_SWFLUSH:
			wc->status = IB_WC_WR_FLUSH_ERR;
			break;
		default:
			pr_err("Unexpected cqe_status 0x%x for QPID=0x%0x\n",
			       CQE_STATUS(&cqe), CQE_QPID(&cqe));
			wc->status = IB_WC_FATAL_ERR;
		}
	}
out:
	return ret;
}

/*
 * Get one cq entry from c4iw and map it to openib.
 *
 * Returns:
 *	0			cqe returned
 *	-ENODATA		EMPTY;
 *	-EAGAIN			caller must try again
 *	any other -errno	fatal error
 */
static int c4iw_poll_cq_one(struct c4iw_cq *chp, struct ib_wc *wc)
{
	struct c4iw_srq *srq = NULL;
	struct c4iw_qp *qhp = NULL;
	struct t4_cqe *rd_cqe;
	int ret;

	ret = t4_next_cqe(&chp->cq, &rd_cqe);

	if (ret)
		return ret;

	qhp = get_qhp(chp->rhp, CQE_QPID(rd_cqe));
	if (qhp) {
		spin_lock(&qhp->lock);
		srq = qhp->srq;
		if (srq)
			spin_lock(&srq->lock);
		ret = __c4iw_poll_cq_one(chp, qhp, wc, srq);
		spin_unlock(&qhp->lock);
		if (srq)
			spin_unlock(&srq->lock);
	} else {
		ret = __c4iw_poll_cq_one(chp, NULL, wc, NULL);
	}
	return ret;
}

int c4iw_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *wc)
{
	struct c4iw_cq *chp;
	unsigned long flags;
	int npolled;
	int err = 0;

	chp = to_c4iw_cq(ibcq);

	spin_lock_irqsave(&chp->lock, flags);
	for (npolled = 0; npolled < num_entries; ++npolled) {
		do {
			err = c4iw_poll_cq_one(chp, wc + npolled);
		} while (err == -EAGAIN);
		if (err)
			break;
	}
	spin_unlock_irqrestore(&chp->lock, flags);
	return !err || err == -ENODATA ? npolled : err;
}

int c4iw_destroy_cq(struct ib_cq *ib_cq)
{
	struct c4iw_cq *chp;
	struct c4iw_ucontext *ucontext;

	pr_debug("ib_cq %p\n", ib_cq);
	chp = to_c4iw_cq(ib_cq);

	remove_handle(chp->rhp, &chp->rhp->cqidr, chp->cq.cqid);
	atomic_dec(&chp->refcnt);
	wait_event(chp->wait, !atomic_read(&chp->refcnt));

	ucontext = ib_cq->uobject ? to_c4iw_ucontext(ib_cq->uobject->context)
				  : NULL;
	destroy_cq(&chp->rhp->rdev, &chp->cq,
		   ucontext ? &ucontext->uctx : &chp->cq.rdev->uctx,
		   chp->destroy_skb, chp->wr_waitp);
	c4iw_put_wr_wait(chp->wr_waitp);
	kfree(chp);
	return 0;
}

struct ib_cq *c4iw_create_cq(struct ib_device *ibdev,
			     const struct ib_cq_init_attr *attr,
			     struct ib_ucontext *ib_context,
			     struct ib_udata *udata)
{
	int entries = attr->cqe;
	int vector = attr->comp_vector;
	struct c4iw_dev *rhp;
	struct c4iw_cq *chp;
	struct c4iw_create_cq ucmd;
	struct c4iw_create_cq_resp uresp;
	struct c4iw_ucontext *ucontext = NULL;
	int ret, wr_len;
	size_t memsize, hwentries;
	struct c4iw_mm_entry *mm, *mm2;

	pr_debug("ib_dev %p entries %d\n", ibdev, entries);
	if (attr->flags)
		return ERR_PTR(-EINVAL);

	rhp = to_c4iw_dev(ibdev);

	if (vector >= rhp->rdev.lldi.nciq)
		return ERR_PTR(-EINVAL);

	if (ib_context) {
		ucontext = to_c4iw_ucontext(ib_context);
		if (udata->inlen < sizeof(ucmd))
			ucontext->is_32b_cqe = 1;
	}

	chp = kzalloc(sizeof(*chp), GFP_KERNEL);
	if (!chp)
		return ERR_PTR(-ENOMEM);

	chp->wr_waitp = c4iw_alloc_wr_wait(GFP_KERNEL);
	if (!chp->wr_waitp) {
		ret = -ENOMEM;
		goto err_free_chp;
	}
	c4iw_init_wr_wait(chp->wr_waitp);

	wr_len = sizeof(struct fw_ri_res_wr) + sizeof(struct fw_ri_res);
	chp->destroy_skb = alloc_skb(wr_len, GFP_KERNEL);
	if (!chp->destroy_skb) {
		ret = -ENOMEM;
		goto err_free_wr_wait;
	}

	/* account for the status page. */
	entries++;

	/* IQ needs one extra entry to differentiate full vs empty. */
	entries++;

	/*
	 * entries must be multiple of 16 for HW.
	 */
	entries = roundup(entries, 16);

	/*
	 * Make actual HW queue 2x to avoid cdix_inc overflows.
	 */
	hwentries = min(entries * 2, rhp->rdev.hw_queue.t4_max_iq_size);

	/*
	 * Make HW queue at least 64 entries so GTS updates aren't too
	 * frequent.
	 */
	if (hwentries < 64)
		hwentries = 64;

	memsize = hwentries * ((ucontext && ucontext->is_32b_cqe) ?
			(sizeof(*chp->cq.queue) / 2) : sizeof(*chp->cq.queue));

	/*
	 * memsize must be a multiple of the page size if its a user cq.
	 */
	if (ucontext)
		memsize = roundup(memsize, PAGE_SIZE);

	chp->cq.size = hwentries;
	chp->cq.memsize = memsize;
	chp->cq.vector = vector;

	ret = create_cq(&rhp->rdev, &chp->cq,
			ucontext ? &ucontext->uctx : &rhp->rdev.uctx,
			chp->wr_waitp);
	if (ret)
		goto err_free_skb;

	chp->rhp = rhp;
	chp->cq.size--;				/* status page */
	chp->ibcq.cqe = entries - 2;
	spin_lock_init(&chp->lock);
	spin_lock_init(&chp->comp_handler_lock);
	atomic_set(&chp->refcnt, 1);
	init_waitqueue_head(&chp->wait);
	ret = insert_handle(rhp, &rhp->cqidr, chp, chp->cq.cqid);
	if (ret)
		goto err_destroy_cq;

	if (ucontext) {
		ret = -ENOMEM;
		mm = kmalloc(sizeof *mm, GFP_KERNEL);
		if (!mm)
			goto err_remove_handle;
		mm2 = kmalloc(sizeof *mm2, GFP_KERNEL);
		if (!mm2)
			goto err_free_mm;

		memset(&uresp, 0, sizeof(uresp));
		uresp.qid_mask = rhp->rdev.cqmask;
		uresp.cqid = chp->cq.cqid;
		uresp.size = chp->cq.size;
		uresp.memsize = chp->cq.memsize;
		spin_lock(&ucontext->mmap_lock);
		uresp.key = ucontext->key;
		ucontext->key += PAGE_SIZE;
		uresp.gts_key = ucontext->key;
		ucontext->key += PAGE_SIZE;
		/* communicate to the userspace that
		 * kernel driver supports 64B CQE
		 */
		uresp.flags |= C4IW_64B_CQE;

		spin_unlock(&ucontext->mmap_lock);
		ret = ib_copy_to_udata(udata, &uresp,
				       ucontext->is_32b_cqe ?
				       sizeof(uresp) - sizeof(uresp.flags) :
				       sizeof(uresp));
		if (ret)
			goto err_free_mm2;

		mm->key = uresp.key;
		mm->addr = virt_to_phys(chp->cq.queue);
		mm->len = chp->cq.memsize;
		insert_mmap(ucontext, mm);

		mm2->key = uresp.gts_key;
		mm2->addr = chp->cq.bar2_pa;
		mm2->len = PAGE_SIZE;
		insert_mmap(ucontext, mm2);
	}
	pr_debug("cqid 0x%0x chp %p size %u memsize %zu, dma_addr 0x%0llx\n",
		 chp->cq.cqid, chp, chp->cq.size,
		 chp->cq.memsize, (unsigned long long)chp->cq.dma_addr);
	return &chp->ibcq;
err_free_mm2:
	kfree(mm2);
err_free_mm:
	kfree(mm);
err_remove_handle:
	remove_handle(rhp, &rhp->cqidr, chp->cq.cqid);
err_destroy_cq:
	destroy_cq(&chp->rhp->rdev, &chp->cq,
		   ucontext ? &ucontext->uctx : &rhp->rdev.uctx,
		   chp->destroy_skb, chp->wr_waitp);
err_free_skb:
	kfree_skb(chp->destroy_skb);
err_free_wr_wait:
	c4iw_put_wr_wait(chp->wr_waitp);
err_free_chp:
	kfree(chp);
	return ERR_PTR(ret);
}

int c4iw_arm_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags flags)
{
	struct c4iw_cq *chp;
	int ret = 0;
	unsigned long flag;

	chp = to_c4iw_cq(ibcq);
	spin_lock_irqsave(&chp->lock, flag);
	t4_arm_cq(&chp->cq,
		  (flags & IB_CQ_SOLICITED_MASK) == IB_CQ_SOLICITED);
	if (flags & IB_CQ_REPORT_MISSED_EVENTS)
		ret = t4_cq_notempty(&chp->cq);
	spin_unlock_irqrestore(&chp->lock, flag);
	return ret;
}

void c4iw_flush_srqidx(struct c4iw_qp *qhp, u32 srqidx)
{
	struct c4iw_cq *rchp = to_c4iw_cq(qhp->ibqp.recv_cq);
	unsigned long flag;

	/* locking heirarchy: cq lock first, then qp lock. */
	spin_lock_irqsave(&rchp->lock, flag);
	spin_lock(&qhp->lock);

	/* create a SRQ RECV CQE for srqidx */
	insert_recv_cqe(&qhp->wq, &rchp->cq, srqidx);

	spin_unlock(&qhp->lock);
	spin_unlock_irqrestore(&rchp->lock, flag);
}