On Tue, 2019-08-20 at 15:32 -0700, Matthew Wilcox wrote:
> From: "Matthew Wilcox (Oracle)" <wi...@infradead.org>
>
> Since mlx5_cq_table would have shrunk down to just the xarray,
> eliminate
> it and embed the xarray directly into mlx5_eq.
>
> Signed-off-by: Matthew Wilcox (Oracle) <wi...@infradead.org>
> ---
> drivers/net/ethernet/mellanox/mlx5/core/eq.c | 27 ++++-------------
> --
> .../net/ethernet/mellanox/mlx5/core/lib/eq.h | 7 +----
> 2 files changed, 6 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eq.c
> b/drivers/net/ethernet/mellanox/mlx5/core/eq.c
> index 09d4c64b6e73..c5953f6e0a69 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/eq.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/eq.c
> @@ -113,11 +113,10 @@ static int mlx5_cmd_destroy_eq(struct
> mlx5_core_dev *dev, u8 eqn)
> /* caller must eventually call mlx5_cq_put on the returned cq */
> static struct mlx5_core_cq *mlx5_eq_cq_get(struct mlx5_eq *eq, u32
> cqn)
> {
> - struct mlx5_cq_table *table = &eq->cq_table;
> - struct mlx5_core_cq *cq = NULL;
> + struct mlx5_core_cq *cq;
>
> rcu_read_lock();
> - cq = radix_tree_lookup(&table->tree, cqn);
> + cq = xa_load(&eq->cq_table, cqn);
> if (likely(cq))
> mlx5_cq_hold(cq);
> rcu_read_unlock();
> @@ -243,7 +242,6 @@ static int
> create_map_eq(struct mlx5_core_dev *dev, struct mlx5_eq *eq,
> struct mlx5_eq_param *param)
> {
> - struct mlx5_cq_table *cq_table = &eq->cq_table;
> u32 out[MLX5_ST_SZ_DW(create_eq_out)] = {0};
> struct mlx5_priv *priv = &dev->priv;
> u8 vecidx = param->irq_index;
> @@ -254,11 +252,7 @@ create_map_eq(struct mlx5_core_dev *dev, struct
> mlx5_eq *eq,
> int err;
> int i;
>
> - /* Init CQ table */
> - memset(cq_table, 0, sizeof(*cq_table));
> - spin_lock_init(&cq_table->lock);
> - INIT_RADIX_TREE(&cq_table->tree, GFP_ATOMIC);
> -
> + xa_init_flags(&eq->cq_table, XA_FLAGS_LOCK_IRQ);
Why the IRQ flag ? we are not going to modify the xarray in irq context
all we do is hold a ref count on the entry we looked up
mlx5_cq_hold(cq); and this is protected by rcu_lock.
> eq->nent = roundup_pow_of_two(param->nent +
> MLX5_NUM_SPARE_EQE);
> eq->cons_index = 0;
> err = mlx5_buf_alloc(dev, eq->nent * MLX5_EQE_SIZE, &eq->buf);
> @@ -378,25 +372,14 @@ static int destroy_unmap_eq(struct
> mlx5_core_dev *dev, struct mlx5_eq *eq)
>
> int mlx5_eq_add_cq(struct mlx5_eq *eq, struct mlx5_core_cq *cq)
> {
> - struct mlx5_cq_table *table = &eq->cq_table;
> - int err;
> -
> - spin_lock(&table->lock);
> - err = radix_tree_insert(&table->tree, cq->cqn, cq);
> - spin_unlock(&table->lock);
> -
> - return err;
> + return xa_err(xa_store(&eq->cq_table, cq->cqn, cq,
> GFP_KERNEL));
> }
>
> void mlx5_eq_del_cq(struct mlx5_eq *eq, struct mlx5_core_cq *cq)
> {
> - struct mlx5_cq_table *table = &eq->cq_table;
> struct mlx5_core_cq *tmp;
>
> - spin_lock(&table->lock);
> - tmp = radix_tree_delete(&table->tree, cq->cqn);
> - spin_unlock(&table->lock);
> -
> + tmp = xa_erase(&eq->cq_table, cq->cqn);
> if (!tmp) {
> mlx5_core_dbg(eq->dev, "cq 0x%x not found in eq 0x%x
> tree\n",
> eq->eqn, cq->cqn);
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/eq.h
> b/drivers/net/ethernet/mellanox/mlx5/core/lib/eq.h
> index 4be4d2d36218..a342cf78120e 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/lib/eq.h
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/eq.h
> @@ -16,14 +16,9 @@ struct mlx5_eq_tasklet {
> spinlock_t lock; /* lock completion tasklet list */
> };
>
> -struct mlx5_cq_table {
> - spinlock_t lock; /* protect radix tree */
> - struct radix_tree_root tree;
> -};
> -
> struct mlx5_eq {
> struct mlx5_core_dev *dev;
> - struct mlx5_cq_table cq_table;
> + struct xarray cq_table;
> __be32 __iomem *doorbell;
> u32 cons_index;
> struct mlx5_frag_buf buf;
