net/mlx5: Refactor fragmented buffer struct fields and init flow

Take struct mlx5_frag_buf out of mlx5_frag_buf_ctrl, as it is not
needed to manage and control the datapath of the fragmented buffers API.

struct mlx5_frag_buf contains control info to manage the allocation
and de-allocation of the fragmented buffer.
Its fields are not relevant for datapath, so here I take them out of the
struct mlx5_frag_buf_ctrl, except for the fragments array itself.

In addition, modified mlx5_fill_fbc to initialise the frags pointers
as well. This implies that the buffer must be allocated before the
function is called.

A set of type-specific *_get_byte_size() functions are replaced by
a generic one.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

drivers/infiniband/hw/mlx5/cq.c

@@ -393,7 +393,7 @@ static void handle_atomics(struct mlx5_ib_qp *qp, struct mlx5_cqe64 *cqe64,
 
 static void free_cq_buf(struct mlx5_ib_dev *dev, struct mlx5_ib_cq_buf *buf)
 {
-	mlx5_frag_buf_free(dev->mdev, &buf->fbc.frag_buf);
+	mlx5_frag_buf_free(dev->mdev, &buf->frag_buf);
 }
 
 static void get_sig_err_item(struct mlx5_sig_err_cqe *cqe,
@@ -728,16 +728,11 @@ static int alloc_cq_frag_buf(struct mlx5_ib_dev *dev,
 			     int nent,
 			     int cqe_size)
 {
-	struct mlx5_frag_buf_ctrl *c = &buf->fbc;
-	struct mlx5_frag_buf *frag_buf = &c->frag_buf;
-	u32 cqc_buff[MLX5_ST_SZ_DW(cqc)] = {0};
+	struct mlx5_frag_buf *frag_buf = &buf->frag_buf;
+	u8 log_wq_stride = 6 + (cqe_size == 128 ? 1 : 0);
+	u8 log_wq_sz     = ilog2(cqe_size);
 	int err;
 
-	MLX5_SET(cqc, cqc_buff, log_cq_size, ilog2(cqe_size));
-	MLX5_SET(cqc, cqc_buff, cqe_sz, (cqe_size == 128) ? 1 : 0);
-
-	mlx5_core_init_cq_frag_buf(&buf->fbc, cqc_buff);
-
 	err = mlx5_frag_buf_alloc_node(dev->mdev,
 				       nent * cqe_size,
 				       frag_buf,
@@ -745,6 +740,8 @@ static int alloc_cq_frag_buf(struct mlx5_ib_dev *dev,
 	if (err)
 		return err;
 
+	mlx5_init_fbc(frag_buf->frags, log_wq_stride, log_wq_sz, &buf->fbc);
+
 	buf->cqe_size = cqe_size;
 	buf->nent = nent;
 
@@ -934,7 +931,7 @@ static int create_cq_kernel(struct mlx5_ib_dev *dev, struct mlx5_ib_cq *cq,
 
 	*inlen = MLX5_ST_SZ_BYTES(create_cq_in) +
 		 MLX5_FLD_SZ_BYTES(create_cq_in, pas[0]) *
-		 cq->buf.fbc.frag_buf.npages;
+		 cq->buf.frag_buf.npages;
 	*cqb = kvzalloc(*inlen, GFP_KERNEL);
 	if (!*cqb) {
 		err = -ENOMEM;
@@ -942,11 +939,11 @@ static int create_cq_kernel(struct mlx5_ib_dev *dev, struct mlx5_ib_cq *cq,
 	}
 
 	pas = (__be64 *)MLX5_ADDR_OF(create_cq_in, *cqb, pas);
-	mlx5_fill_page_frag_array(&cq->buf.fbc.frag_buf, pas);
+	mlx5_fill_page_frag_array(&cq->buf.frag_buf, pas);
 
 	cqc = MLX5_ADDR_OF(create_cq_in, *cqb, cq_context);
 	MLX5_SET(cqc, cqc, log_page_size,
-		 cq->buf.fbc.frag_buf.page_shift -
+		 cq->buf.frag_buf.page_shift -
 		 MLX5_ADAPTER_PAGE_SHIFT);
 
 	*index = dev->mdev->priv.uar->index;
@@ -1365,11 +1362,10 @@ int mlx5_ib_resize_cq(struct ib_cq *ibcq, int entries, struct ib_udata *udata)
 		cqe_size = 64;
 		err = resize_kernel(dev, cq, entries, cqe_size);
 		if (!err) {
-			struct mlx5_frag_buf_ctrl *c;
+			struct mlx5_frag_buf *frag_buf = &cq->resize_buf->frag_buf;
 
-			c = &cq->resize_buf->fbc;
-			npas = c->frag_buf.npages;
-			page_shift = c->frag_buf.page_shift;
+			npas = frag_buf->npages;
+			page_shift = frag_buf->page_shift;
 		}
 	}
 
@@ -1390,8 +1386,7 @@ int mlx5_ib_resize_cq(struct ib_cq *ibcq, int entries, struct ib_udata *udata)
 		mlx5_ib_populate_pas(dev, cq->resize_umem, page_shift,
 				     pas, 0);
 	else
-		mlx5_fill_page_frag_array(&cq->resize_buf->fbc.frag_buf,
-					  pas);
+		mlx5_fill_page_frag_array(&cq->resize_buf->frag_buf, pas);
 
 	MLX5_SET(modify_cq_in, in,
 		 modify_field_select_resize_field_select.resize_field_select.resize_field_select,

drivers/infiniband/hw/mlx5/mlx5_ib.h

@@ -435,6 +435,7 @@ struct mlx5_ib_qp {
 
 struct mlx5_ib_cq_buf {
 	struct mlx5_frag_buf_ctrl fbc;
+	struct mlx5_frag_buf    frag_buf;
 	struct ib_umem		*umem;
 	int			cqe_size;
 	int			nent;

drivers/net/ethernet/mellanox/mlx5/core/wq.c

@@ -54,54 +54,37 @@ u32 mlx5_wq_ll_get_size(struct mlx5_wq_ll *wq)
 	return (u32)wq->fbc.sz_m1 + 1;
 }
 
-static u32 mlx5_wq_cyc_get_byte_size(struct mlx5_wq_cyc *wq)
+static u32 wq_get_byte_sz(u8 log_sz, u8 log_stride)
 {
-	return mlx5_wq_cyc_get_size(wq) << wq->fbc.log_stride;
-}
-
-static u32 mlx5_wq_qp_get_byte_size(struct mlx5_wq_qp *wq)
-{
-	return mlx5_wq_cyc_get_byte_size(&wq->rq) +
-	       mlx5_wq_cyc_get_byte_size(&wq->sq);
-}
-
-static u32 mlx5_cqwq_get_byte_size(struct mlx5_cqwq *wq)
-{
-	return mlx5_cqwq_get_size(wq) << wq->fbc.log_stride;
-}
-
-static u32 mlx5_wq_ll_get_byte_size(struct mlx5_wq_ll *wq)
-{
-	return mlx5_wq_ll_get_size(wq) << wq->fbc.log_stride;
+	return ((u32)1 << log_sz) << log_stride;
 }
 
 int mlx5_wq_cyc_create(struct mlx5_core_dev *mdev, struct mlx5_wq_param *param,
 		       void *wqc, struct mlx5_wq_cyc *wq,
 		       struct mlx5_wq_ctrl *wq_ctrl)
 {
+	u8 log_wq_stride = MLX5_GET(wq, wqc, log_wq_stride);
+	u8 log_wq_sz     = MLX5_GET(wq, wqc, log_wq_sz);
 	struct mlx5_frag_buf_ctrl *fbc = &wq->fbc;
 	int err;
 
-	mlx5_fill_fbc(MLX5_GET(wq, wqc, log_wq_stride),
-		      MLX5_GET(wq, wqc, log_wq_sz),
-		      fbc);
-	wq->sz    = wq->fbc.sz_m1 + 1;
-
 	err = mlx5_db_alloc_node(mdev, &wq_ctrl->db, param->db_numa_node);
 	if (err) {
 		mlx5_core_warn(mdev, "mlx5_db_alloc_node() failed, %d\n", err);
 		return err;
 	}
 
-	err = mlx5_frag_buf_alloc_node(mdev, mlx5_wq_cyc_get_byte_size(wq),
+	wq->db  = wq_ctrl->db.db;
+
+	err = mlx5_frag_buf_alloc_node(mdev, wq_get_byte_sz(log_wq_sz, log_wq_stride),
 				       &wq_ctrl->buf, param->buf_numa_node);
 	if (err) {
 		mlx5_core_warn(mdev, "mlx5_frag_buf_alloc_node() failed, %d\n", err);
 		goto err_db_free;
 	}
 
-	fbc->frag_buf = wq_ctrl->buf;
-	wq->db  = wq_ctrl->db.db;
+	mlx5_init_fbc(wq_ctrl->buf.frags, log_wq_stride, log_wq_sz, fbc);
+	wq->sz = mlx5_wq_cyc_get_size(wq);
 
 	wq_ctrl->mdev = mdev;
 
@@ -113,46 +96,19 @@ int mlx5_wq_cyc_create(struct mlx5_core_dev *mdev, struct mlx5_wq_param *param,
 	return err;
 }
 
-static void mlx5_qp_set_frag_buf(struct mlx5_frag_buf *buf,
-				 struct mlx5_wq_qp *qp)
-{
-	struct mlx5_frag_buf_ctrl *sq_fbc;
-	struct mlx5_frag_buf *rqb, *sqb;
-
-	rqb  = &qp->rq.fbc.frag_buf;
-	*rqb = *buf;
-	rqb->size   = mlx5_wq_cyc_get_byte_size(&qp->rq);
-	rqb->npages = DIV_ROUND_UP(rqb->size, PAGE_SIZE);
-
-	sq_fbc = &qp->sq.fbc;
-	sqb    = &sq_fbc->frag_buf;
-	*sqb   = *buf;
-	sqb->size   = mlx5_wq_cyc_get_byte_size(&qp->sq);
-	sqb->npages = DIV_ROUND_UP(sqb->size, PAGE_SIZE);
-	sqb->frags += rqb->npages; /* first part is for the rq */
-	if (sq_fbc->strides_offset)
-		sqb->frags--;
-}
-
 int mlx5_wq_qp_create(struct mlx5_core_dev *mdev, struct mlx5_wq_param *param,
 		      void *qpc, struct mlx5_wq_qp *wq,
 		      struct mlx5_wq_ctrl *wq_ctrl)
 {
-	u16 sq_strides_offset;
-	u32 rq_pg_remainder;
-	int err;
+	u8 log_rq_stride = MLX5_GET(qpc, qpc, log_rq_stride) + 4;
+	u8 log_rq_sz     = MLX5_GET(qpc, qpc, log_rq_size);
+	u8 log_sq_stride = ilog2(MLX5_SEND_WQE_BB);
+	u8 log_sq_sz     = MLX5_GET(qpc, qpc, log_sq_size);
 
-	mlx5_fill_fbc(MLX5_GET(qpc, qpc, log_rq_stride) + 4,
-		      MLX5_GET(qpc, qpc, log_rq_size),
-		      &wq->rq.fbc);
+	u32 rq_byte_size;
+	int err;
 
-	rq_pg_remainder   = mlx5_wq_cyc_get_byte_size(&wq->rq) % PAGE_SIZE;
-	sq_strides_offset = rq_pg_remainder / MLX5_SEND_WQE_BB;
 
-	mlx5_fill_fbc_offset(ilog2(MLX5_SEND_WQE_BB),
-			     MLX5_GET(qpc, qpc, log_sq_size),
-			     sq_strides_offset,
-			     &wq->sq.fbc);
 
 	err = mlx5_db_alloc_node(mdev, &wq_ctrl->db, param->db_numa_node);
 	if (err) {
@@ -160,14 +116,32 @@ int mlx5_wq_qp_create(struct mlx5_core_dev *mdev, struct mlx5_wq_param *param,
 		return err;
 	}
 
-	err = mlx5_frag_buf_alloc_node(mdev, mlx5_wq_qp_get_byte_size(wq),
+	err = mlx5_frag_buf_alloc_node(mdev,
+				       wq_get_byte_sz(log_rq_sz, log_rq_stride) +
+				       wq_get_byte_sz(log_sq_sz, log_sq_stride),
 				       &wq_ctrl->buf, param->buf_numa_node);
 	if (err) {
 		mlx5_core_warn(mdev, "mlx5_frag_buf_alloc_node() failed, %d\n", err);
 		goto err_db_free;
 	}
 
-	mlx5_qp_set_frag_buf(&wq_ctrl->buf, wq);
+	mlx5_init_fbc(wq_ctrl->buf.frags, log_rq_stride, log_rq_sz, &wq->rq.fbc);
+
+	rq_byte_size = wq_get_byte_sz(log_rq_sz, log_rq_stride);
+
+	if (rq_byte_size < PAGE_SIZE) {
+		/* SQ starts within the same page of the RQ */
+		u16 sq_strides_offset = rq_byte_size / MLX5_SEND_WQE_BB;
+
+		mlx5_init_fbc_offset(wq_ctrl->buf.frags,
+				     log_sq_stride, log_sq_sz, sq_strides_offset,
+				     &wq->sq.fbc);
+	} else {
+		u16 rq_npages = rq_byte_size >> PAGE_SHIFT;
+
+		mlx5_init_fbc(wq_ctrl->buf.frags + rq_npages,
+			      log_sq_stride, log_sq_sz, &wq->sq.fbc);
+	}
 
 	wq->rq.db  = &wq_ctrl->db.db[MLX5_RCV_DBR];
 	wq->sq.db  = &wq_ctrl->db.db[MLX5_SND_DBR];
@@ -186,17 +160,19 @@ int mlx5_cqwq_create(struct mlx5_core_dev *mdev, struct mlx5_wq_param *param,
 		     void *cqc, struct mlx5_cqwq *wq,
 		     struct mlx5_wq_ctrl *wq_ctrl)
 {
+	u8 log_wq_stride = MLX5_GET(cqc, cqc, cqe_sz) + 6;
+	u8 log_wq_sz     = MLX5_GET(cqc, cqc, log_cq_size);
 	int err;
 
-	mlx5_core_init_cq_frag_buf(&wq->fbc, cqc);
-
 	err = mlx5_db_alloc_node(mdev, &wq_ctrl->db, param->db_numa_node);
 	if (err) {
 		mlx5_core_warn(mdev, "mlx5_db_alloc_node() failed, %d\n", err);
 		return err;
 	}
 
-	err = mlx5_frag_buf_alloc_node(mdev, mlx5_cqwq_get_byte_size(wq),
+	wq->db  = wq_ctrl->db.db;
+
+	err = mlx5_frag_buf_alloc_node(mdev, wq_get_byte_sz(log_wq_sz, log_wq_stride),
 				       &wq_ctrl->buf,
 				       param->buf_numa_node);
 	if (err) {
@@ -205,8 +181,7 @@ int mlx5_cqwq_create(struct mlx5_core_dev *mdev, struct mlx5_wq_param *param,
 		goto err_db_free;
 	}
 
-	wq->fbc.frag_buf = wq_ctrl->buf;
-	wq->db  = wq_ctrl->db.db;
+	mlx5_init_fbc(wq_ctrl->buf.frags, log_wq_stride, log_wq_sz, &wq->fbc);
 
 	wq_ctrl->mdev = mdev;
 
@@ -222,30 +197,29 @@ int mlx5_wq_ll_create(struct mlx5_core_dev *mdev, struct mlx5_wq_param *param,
 		      void *wqc, struct mlx5_wq_ll *wq,
 		      struct mlx5_wq_ctrl *wq_ctrl)
 {
+	u8 log_wq_stride = MLX5_GET(wq, wqc, log_wq_stride);
+	u8 log_wq_sz     = MLX5_GET(wq, wqc, log_wq_sz);
 	struct mlx5_frag_buf_ctrl *fbc = &wq->fbc;
 	struct mlx5_wqe_srq_next_seg *next_seg;
 	int err;
 	int i;
 
-	mlx5_fill_fbc(MLX5_GET(wq, wqc, log_wq_stride),
-		      MLX5_GET(wq, wqc, log_wq_sz),
-		      fbc);
-
 	err = mlx5_db_alloc_node(mdev, &wq_ctrl->db, param->db_numa_node);
 	if (err) {
 		mlx5_core_warn(mdev, "mlx5_db_alloc_node() failed, %d\n", err);
 		return err;
 	}
 
-	err = mlx5_frag_buf_alloc_node(mdev, mlx5_wq_ll_get_byte_size(wq),
+	wq->db  = wq_ctrl->db.db;
+
+	err = mlx5_frag_buf_alloc_node(mdev, wq_get_byte_sz(log_wq_sz, log_wq_stride),
 				       &wq_ctrl->buf, param->buf_numa_node);
 	if (err) {
 		mlx5_core_warn(mdev, "mlx5_frag_buf_alloc_node() failed, %d\n", err);
 		goto err_db_free;
 	}
 
-	wq->fbc.frag_buf = wq_ctrl->buf;
-	wq->db  = wq_ctrl->db.db;
+	mlx5_init_fbc(wq_ctrl->buf.frags, log_wq_stride, log_wq_sz, fbc);
 
 	for (i = 0; i < fbc->sz_m1; i++) {
 		next_seg = mlx5_wq_ll_get_wqe(wq, i);

include/linux/mlx5/driver.h

@@ -357,7 +357,7 @@ struct mlx5_frag_buf {
 };
 
 struct mlx5_frag_buf_ctrl {
-	struct mlx5_frag_buf	frag_buf;
+	struct mlx5_buf_list   *frags;
 	u32			sz_m1;
 	u16			frag_sz_m1;
 	u16			strides_offset;
@@ -994,10 +994,12 @@ static inline u32 mlx5_base_mkey(const u32 key)
 	return key & 0xffffff00u;
 }
 
-static inline void mlx5_fill_fbc_offset(u8 log_stride, u8 log_sz,
+static inline void mlx5_init_fbc_offset(struct mlx5_buf_list *frags,
+					u8 log_stride, u8 log_sz,
 					u16 strides_offset,
 					struct mlx5_frag_buf_ctrl *fbc)
 {
+	fbc->frags      = frags;
 	fbc->log_stride = log_stride;
 	fbc->log_sz     = log_sz;
 	fbc->sz_m1	= (1 << fbc->log_sz) - 1;
@@ -1006,18 +1008,11 @@ static inline void mlx5_fill_fbc_offset(u8 log_stride, u8 log_sz,
 	fbc->strides_offset = strides_offset;
 }
 
-static inline void mlx5_fill_fbc(u8 log_stride, u8 log_sz,
+static inline void mlx5_init_fbc(struct mlx5_buf_list *frags,
+				 u8 log_stride, u8 log_sz,
 				 struct mlx5_frag_buf_ctrl *fbc)
 {
-	mlx5_fill_fbc_offset(log_stride, log_sz, 0, fbc);
-}
-
-static inline void mlx5_core_init_cq_frag_buf(struct mlx5_frag_buf_ctrl *fbc,
-					      void *cqc)
-{
-	mlx5_fill_fbc(6 + MLX5_GET(cqc, cqc, cqe_sz),
-		      MLX5_GET(cqc, cqc, log_cq_size),
-		      fbc);
+	mlx5_init_fbc_offset(frags, log_stride, log_sz, 0, fbc);
 }
 
 static inline void *mlx5_frag_buf_get_wqe(struct mlx5_frag_buf_ctrl *fbc,
@@ -1028,8 +1023,7 @@ static inline void *mlx5_frag_buf_get_wqe(struct mlx5_frag_buf_ctrl *fbc,
 	ix  += fbc->strides_offset;
 	frag = ix >> fbc->log_frag_strides;
 
-	return fbc->frag_buf.frags[frag].buf +
-		((fbc->frag_sz_m1 & ix) << fbc->log_stride);
+	return fbc->frags[frag].buf + ((fbc->frag_sz_m1 & ix) << fbc->log_stride);
 }
 
 int mlx5_cmd_init(struct mlx5_core_dev *dev);