[ofa-general] [PATCH v1] libmlx4: Added resize CQ capability.

[Vladimir Sokolovsky]

 From 012952a11c8e984a7ab70a5f85ad4ac845a25220 Mon Sep 17 00:00:00 2001
From: Vladimir Sokolovsky <vlad at mellanox.co.il>
Date: Tue, 25 Mar 2008 17:09:08 +0200
Subject: [PATCH] Added resize CQ capability.

Signed-off-by: Vladimir Sokolovsky <vlad at mellanox.co.il>
---
  src/cq.c    |   38 ++++++++++++++++++++++++++++++++++++++
  src/mlx4.h  |    3 +++
  src/verbs.c |   55 +++++++++++++++++++++++++++++++++++++++++++++++++++++--
  3 files changed, 94 insertions(+), 2 deletions(-)

diff --git a/src/cq.c b/src/cq.c
index 91297e4..e5436d4 100644
--- a/src/cq.c
+++ b/src/cq.c
@@ -201,6 +201,7 @@ static int mlx4_poll_one(struct mlx4_cq *cq,
  	int is_error;
  	int is_send;

+repoll:
  	cqe = next_cqe_sw(cq);
  	if (!cqe)
  		return CQ_EMPTY;
@@ -215,6 +216,9 @@ static int mlx4_poll_one(struct mlx4_cq *cq,
  	 */
  	rmb();

+	if ((cqe->owner_sr_opcode & MLX4_CQE_OPCODE_MASK) == MLX4_CQE_OPCODE_RESIZE)
+		goto repoll;
+
  	qpn = ntohl(cqe->my_qpn);

  	is_send  = cqe->owner_sr_opcode & MLX4_CQE_IS_SEND_MASK;
@@ -433,6 +437,40 @@ void mlx4_cq_clean(struct mlx4_cq *cq, uint32_t qpn, struct mlx4_srq *srq)
  	pthread_spin_unlock(&cq->lock);
  }

+int mlx4_get_outstanding_cqes(struct mlx4_cq *cq)
+{
+	int i;
+
+	for (i = cq->cons_index; get_sw_cqe(cq, (i & cq->ibv_cq.cqe)); ++i)
+		;
+
+	return i - cq->cons_index;
+}
+
  void mlx4_cq_resize_copy_cqes(struct mlx4_cq *cq, void *buf, int old_cqe)
  {
+	struct mlx4_cqe *cqe;
+	int i;
+
+	i = cq->cons_index;
+	cqe = get_cqe(cq, (i & old_cqe));
+
+	while ((cqe->owner_sr_opcode & MLX4_CQE_OPCODE_MASK) != MLX4_CQE_OPCODE_RESIZE) {
+		memcpy(buf + ((i + 1) & cq->ibv_cq.cqe) * MLX4_CQ_ENTRY_SIZE,
+		       cqe, MLX4_CQ_ENTRY_SIZE);
+		++i;
+		cqe = get_cqe(cq, (i & old_cqe));
+	}
+
+	++cq->cons_index;
+}
+
+int mlx4_alloc_cq_buf(struct mlx4_device *dev, struct mlx4_buf *buf, int nent)
+{
+	if (mlx4_alloc_buf(buf, align(nent * MLX4_CQ_ENTRY_SIZE, dev->page_size),
+		    dev->page_size))
+		return -1;
+	memset(buf->buf, 0, nent * MLX4_CQ_ENTRY_SIZE);
+
+	return 0;
  }
diff --git a/src/mlx4.h b/src/mlx4.h
index 3710a17..7d88f74 100644
--- a/src/mlx4.h
+++ b/src/mlx4.h
@@ -174,6 +174,7 @@ struct mlx4_pd {
  struct mlx4_cq {
  	struct ibv_cq			ibv_cq;
  	struct mlx4_buf			buf;
+	struct mlx4_buf			resize_buf;
  	pthread_spinlock_t		lock;
  	uint32_t			cqn;
  	uint32_t			cons_index;
@@ -307,6 +308,7 @@ int mlx4_dereg_mr(struct ibv_mr *mr);
  struct ibv_cq *mlx4_create_cq(struct ibv_context *context, int cqe,
  			       struct ibv_comp_channel *channel,
  			       int comp_vector);
+int mlx4_alloc_cq_buf(struct mlx4_device *dev, struct mlx4_buf *buf, int nent);
  int mlx4_resize_cq(struct ibv_cq *cq, int cqe);
  int mlx4_destroy_cq(struct ibv_cq *cq);
  int mlx4_poll_cq(struct ibv_cq *cq, int ne, struct ibv_wc *wc);
@@ -314,6 +316,7 @@ int mlx4_arm_cq(struct ibv_cq *cq, int solicited);
  void mlx4_cq_event(struct ibv_cq *cq);
  void mlx4_cq_clean(struct mlx4_cq *cq, uint32_t qpn,
  		    struct mlx4_srq *srq);
+int mlx4_get_outstanding_cqes(struct mlx4_cq *cq);
  void mlx4_cq_resize_copy_cqes(struct mlx4_cq *cq, void *buf, int new_cqe);

  struct ibv_srq *mlx4_create_srq(struct ibv_pd *pd,
diff --git a/src/verbs.c b/src/verbs.c
index 50e0947..6e0b479 100644
--- a/src/verbs.c
+++ b/src/verbs.c
@@ -226,8 +226,59 @@ err:

  int mlx4_resize_cq(struct ibv_cq *ibcq, int cqe)
  {
-	/* XXX resize CQ not implemented */
-	return ENOSYS;
+	struct mlx4_cq *cq = to_mcq(ibcq);
+	struct mlx4_resize_cq cmd;
+	struct mlx4_buf buf;
+	int old_cqe, outst_cqe, ret;
+
+	/* Sanity check CQ size before proceeding */
+	if (cqe > 0x3fffff)
+		return EINVAL;
+
+	pthread_spin_lock(&cq->lock);
+
+	cqe = align_queue_size(cqe);
+	if (cqe == ibcq->cqe + 1) {
+		ret = 0;
+		goto out;
+	}
+
+	/* Can't be smaller then the number of outstanding CQEs */
+	outst_cqe = mlx4_get_outstanding_cqes(cq);
+	if (cqe < outst_cqe + 1) {
+		ret = 0;
+		goto out;
+	}
+
+	ret = mlx4_alloc_cq_buf(to_mdev(ibcq->context->device), &buf, cqe);
+	if (ret)
+		goto out;
+
+	old_cqe = ibcq->cqe;
+	cmd.buf_addr = (uintptr_t) buf.buf;
+
+#ifdef IBV_CMD_RESIZE_CQ_HAS_RESP_PARAMS
+	{
+		struct ibv_resize_cq_resp resp;
+		ret = ibv_cmd_resize_cq(ibcq, cqe - 1, &cmd.ibv_cmd, sizeof cmd,
+					&resp, sizeof resp);
+	}
+#else
+	ret = ibv_cmd_resize_cq(ibcq, cqe - 1, &cmd.ibv_cmd, sizeof cmd);
+#endif
+	if (ret) {
+		mlx4_free_buf(&buf);
+		goto out;
+	}
+
+	mlx4_cq_resize_copy_cqes(cq, buf.buf, old_cqe);
+	mlx4_free_buf(&cq->buf);
+
+	cq->buf = buf;
+
+out:
+	pthread_spin_unlock(&cq->lock);
+	return ret;
  }

  int mlx4_destroy_cq(struct ibv_cq *cq)
-- 
1.5.4.2