[PATCH 3/8] libpvrdma: Add completion queue functions

[Adit Ranadive <aditr-pghWNbHTmq7QT0dZR+AlfA@public.gmane.org>]

Add support for completion queue creation, destruction, polling and
events.

Signed-off-by: Adit Ranadive <aditr-pghWNbHTmq7QT0dZR+AlfA@public.gmane.org>
---
 providers/pvrdma/cq.c | 287 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 287 insertions(+)
 create mode 100644 providers/pvrdma/cq.c

diff --git a/providers/pvrdma/cq.c b/providers/pvrdma/cq.c
new file mode 100644
index 0000000..f99873c
--- /dev/null
+++ b/providers/pvrdma/cq.c
@@ -0,0 +1,287 @@
+/*
+ * Copyright (c) 2012-2016 VMware, Inc.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of EITHER the GNU General Public License
+ * version 2 as published by the Free Software Foundation or the BSD
+ * 2-Clause License. This program is distributed in the hope that it
+ * will be useful, but WITHOUT ANY WARRANTY; WITHOUT EVEN THE IMPLIED
+ * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License version 2 for more details at
+ * http://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program available in the file COPYING in the main
+ * directory of this source tree.
+ *
+ * The BSD 2-Clause License
+ *
+ *     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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <infiniband/arch.h>
+
+#include "pvrdma.h"
+
+enum {
+	CQ_OK =  0,
+	CQ_EMPTY = -1,
+	CQ_POLL_ERR = -2,
+};
+
+enum {
+	PVRDMA_CQE_IS_SEND_MASK = 0x40,
+	PVRDMA_CQE_OPCODE_MASK = 0x1f,
+};
+
+int pvrdma_alloc_cq_buf(struct pvrdma_device *dev, struct pvrdma_cq *cq,
+			struct pvrdma_buf *buf, int entries)
+{
+	if (pvrdma_alloc_buf(buf, cq->offset +
+			     entries * (sizeof(struct pvrdma_cqe)),
+			     dev->page_size))
+		return -1;
+	memset(buf->buf, 0, buf->length);
+
+	return 0;
+}
+
+static struct pvrdma_cqe *get_cqe(struct pvrdma_cq *cq, int entry)
+{
+	return cq->buf.buf + cq->offset +
+	       entry * (sizeof(struct pvrdma_cqe));
+}
+
+static int pvrdma_poll_one(struct pvrdma_cq *cq,
+			   struct pvrdma_qp **cur_qp,
+			   struct ibv_wc *wc)
+{
+	struct pvrdma_context *ctx = to_vctx(cq->ibv_cq.context);
+	int has_data;
+	unsigned int head;
+	int tried = 0;
+	struct pvrdma_cqe *cqe;
+
+retry:
+	has_data = pvrdma_idx_ring_has_data(&cq->ring_state->rx,
+					    cq->cqe_cnt, &head);
+	if (has_data == 0) {
+		unsigned int val;
+
+		if (tried)
+			return CQ_EMPTY;
+
+		/* Pass down POLL to give physical HCA a chance to poll. */
+		val = cq->cqn | PVRDMA_UAR_CQ_POLL;
+		pvrdma_write_uar_cq(ctx->uar, val);
+
+		tried = 1;
+		goto retry;
+	} else if (has_data == -1) {
+		return CQ_POLL_ERR;
+	}
+
+	cqe = get_cqe(cq, head);
+	if (!cqe)
+		return CQ_EMPTY;
+
+	rmb();
+
+	if (ctx->qp_tbl[cqe->qp & 0xFFFF])
+		*cur_qp = (struct pvrdma_qp *)ctx->qp_tbl[cqe->qp & 0xFFFF];
+	 else
+		return CQ_POLL_ERR;
+
+	wc->opcode = pvrdma_wc_opcode_to_ibv(cqe->opcode);
+	wc->status = pvrdma_wc_status_to_ibv(cqe->status);
+	wc->wr_id = cqe->wr_id;
+	wc->qp_num = (*cur_qp)->ibv_qp.qp_num;
+	wc->byte_len = cqe->byte_len;
+	wc->imm_data = cqe->imm_data;
+	wc->src_qp = cqe->src_qp;
+	wc->wc_flags = cqe->wc_flags;
+	wc->pkey_index = cqe->pkey_index;
+	wc->slid = cqe->slid;
+	wc->sl = cqe->sl;
+	wc->dlid_path_bits = cqe->dlid_path_bits;
+	wc->vendor_err = 0;
+
+	/* Update shared ring state. */
+	pvrdma_idx_ring_inc(&(cq->ring_state->rx.cons_head), cq->cqe_cnt);
+
+	return CQ_OK;
+}
+
+int pvrdma_poll_cq(struct ibv_cq *ibcq, int num_entries, struct ibv_wc *wc)
+{
+	struct pvrdma_cq *cq = to_vcq(ibcq);
+	struct pvrdma_qp *qp;
+	int npolled = 0;
+
+	if (num_entries < 1 || wc == NULL)
+		return 0;
+
+	pthread_spin_lock(&cq->lock);
+
+	for (npolled = 0; npolled < num_entries; ++npolled) {
+		if (pvrdma_poll_one(cq, &qp, wc + npolled) != CQ_OK)
+			break;
+	}
+
+	pthread_spin_unlock(&cq->lock);
+
+	return npolled;
+}
+
+void __pvrdma_cq_clean(struct pvrdma_cq *cq, uint32_t qpn)
+{
+	/* Flush CQEs from specified QP */
+	int has_data;
+	unsigned int head;
+
+	/* Lock held */
+	has_data = pvrdma_idx_ring_has_data(&cq->ring_state->rx,
+					    cq->cqe_cnt, &head);
+
+	if (unlikely(has_data > 0)) {
+		int items;
+		int curr;
+		int tail = pvrdma_idx(&cq->ring_state->rx.prod_tail,
+				      cq->cqe_cnt);
+		struct pvrdma_cqe *cqe;
+		struct pvrdma_cqe *curr_cqe;
+
+		items = (tail > head) ? (tail - head) :
+			(cq->cqe_cnt - head + tail);
+		curr = --tail;
+		while (items-- > 0) {
+			if (curr < 0)
+				curr = cq->cqe_cnt - 1;
+			if (tail < 0)
+				tail = cq->cqe_cnt - 1;
+			curr_cqe = get_cqe(cq, curr);
+			rmb();
+			if ((curr_cqe->qp & 0xFFFF) != qpn) {
+				if (curr != tail) {
+					cqe = get_cqe(cq, tail);
+					rmb();
+					*cqe = *curr_cqe;
+				}
+				tail--;
+			} else {
+				pvrdma_idx_ring_inc(
+					&cq->ring_state->rx.cons_head,
+					cq->cqe_cnt);
+			}
+			curr--;
+		}
+	}
+}
+
+void pvrdma_cq_clean(struct pvrdma_cq *cq, uint32_t qpn)
+{
+	pthread_spin_lock(&cq->lock);
+	__pvrdma_cq_clean(cq, qpn);
+	pthread_spin_unlock(&cq->lock);
+}
+
+struct ibv_cq *pvrdma_create_cq(struct ibv_context *context, int cqe,
+				struct ibv_comp_channel *channel,
+				int comp_vector)
+{
+	struct pvrdma_device *dev = to_vdev(context->device);
+	struct pvrdma_create_cq cmd;
+	struct pvrdma_create_cq_resp resp;
+	struct pvrdma_cq *cq;
+	int ret;
+
+	if (cqe < 1)
+		return NULL;
+
+	cq = malloc(sizeof(*cq));
+	if (!cq)
+		return NULL;
+
+	/* Extra page for shared ring state */
+	cq->offset = dev->page_size;
+
+	if (pthread_spin_init(&cq->lock, PTHREAD_PROCESS_PRIVATE))
+		goto err;
+
+	cqe = align_next_power2(cqe);
+
+	if (pvrdma_alloc_cq_buf(dev, cq, &cq->buf, cqe))
+		goto err;
+
+	cq->ring_state = cq->buf.buf;
+
+	cmd.buf_addr = (uintptr_t) cq->buf.buf;
+	cmd.buf_size = cq->buf.length;
+	ret = ibv_cmd_create_cq(context, cqe, channel, comp_vector,
+				&cq->ibv_cq, &cmd.ibv_cmd, sizeof(cmd),
+				&resp.ibv_resp, sizeof(resp));
+	if (ret)
+		goto err_buf;
+
+	cq->cqn = resp.cqn;
+	cq->cqe_cnt = cq->ibv_cq.cqe;
+
+	return &cq->ibv_cq;
+
+err_buf:
+	pvrdma_free_buf(&cq->buf);
+err:
+	free(cq);
+
+	return NULL;
+}
+
+int pvrdma_destroy_cq(struct ibv_cq *cq)
+{
+	int ret;
+
+	ret = ibv_cmd_destroy_cq(cq);
+	if (ret)
+		return ret;
+
+	pvrdma_free_buf(&to_vcq(cq)->buf);
+	free(to_vcq(cq));
+
+	return 0;
+}
+
+int pvrdma_req_notify_cq(struct ibv_cq *ibcq, int solicited)
+{
+	struct pvrdma_context *ctx = to_vctx(ibcq->context);
+	struct pvrdma_cq *cq = to_vcq(ibcq);
+	unsigned int val = cq->cqn;
+
+	val |= solicited ? PVRDMA_UAR_CQ_ARM_SOL : PVRDMA_UAR_CQ_ARM;
+	pvrdma_write_uar_cq(ctx->uar, val);
+
+	return 0;
+}
-- 
2.7.4

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