net/mlx5e: Use multiple TX doorbells

First, allocate more doorbells in mlx5e_create_mdev_resources:
- one doorbell remains 'global' and will be used by all non-channel
  associated SQs (e.g. ASO, HWS, PTP, ...).
- allocate additional 'num_doorbells' doorbells. This defaults to
  minimum between 8 and max number of channels.

mlx5e_channel_pick_doorbell() now spreads out channel SQs across
available doorbells.

Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_common.c b/drivers/net/ethernet/mellanox/mlx5/core/en_common.c
index e9e36358c39d1647ec32ddcbc52bf4a4c4a7dc59..d13cebbc763a450cfe96e0d2d8e0a8da77e1ff4c 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_common.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_common.c
@@ -143,6 +143,7 @@ err_close_tises:
 int mlx5e_create_mdev_resources(struct mlx5_core_dev *mdev, bool create_tises)
 {
        struct mlx5e_hw_objs *res = &mdev->mlx5e_res.hw_objs;
+       unsigned int num_doorbells, i;
        int err;
 
        err = mlx5_core_alloc_pd(mdev, &res->pdn);
@@ -163,11 +164,30 @@ int mlx5e_create_mdev_resources(struct mlx5_core_dev *mdev, bool create_tises)
                goto err_dealloc_transport_domain;
        }
 
+       num_doorbells = min(MLX5_DEFAULT_NUM_DOORBELLS,
+                           mlx5e_get_max_num_channels(mdev));
+       res->bfregs = kcalloc(num_doorbells, sizeof(*res->bfregs), GFP_KERNEL);
+       if (!res->bfregs) {
+               err = -ENOMEM;
+               goto err_destroy_mkey;
+       }
+
+       for (i = 0; i < num_doorbells; i++) {
+               err = mlx5_alloc_bfreg(mdev, res->bfregs + i, false, false);
+               if (err) {
+                       mlx5_core_warn(mdev,
+                                      "could only allocate %d/%d doorbells, err %d.\n",
+                                      i, num_doorbells, err);
+                       break;
+               }
+       }
+       res->num_bfregs = i;
+
        if (create_tises) {
                err = mlx5e_create_tises(mdev, res->tisn);
                if (err) {
                        mlx5_core_err(mdev, "alloc tises failed, %d\n", err);
-                       goto err_destroy_mkey;
+                       goto err_destroy_bfregs;
                }
                res->tisn_valid = true;
        }
@@ -184,6 +204,10 @@ int mlx5e_create_mdev_resources(struct mlx5_core_dev *mdev, bool create_tises)
 
        return 0;
 
+err_destroy_bfregs:
+       for (i = 0; i < res->num_bfregs; i++)
+               mlx5_free_bfreg(mdev, res->bfregs + i);
+       kfree(res->bfregs);
 err_destroy_mkey:
        mlx5_core_destroy_mkey(mdev, res->mkey);
 err_dealloc_transport_domain:
@@ -201,6 +225,9 @@ void mlx5e_destroy_mdev_resources(struct mlx5_core_dev *mdev)
        mdev->mlx5e_res.dek_priv = NULL;
        if (res->tisn_valid)
                mlx5e_destroy_tises(mdev, res->tisn);
+       for (unsigned int i = 0; i < res->num_bfregs; i++)
+               mlx5_free_bfreg(mdev, res->bfregs + i);
+       kfree(res->bfregs);
        mlx5_core_destroy_mkey(mdev, res->mkey);
        mlx5_core_dealloc_transport_domain(mdev, res->td.tdn);
        mlx5_core_dealloc_pd(mdev, res->pdn);

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 93505c82d6f0118af6af930b51edf0ab26721619..0700656b3c3eb54761d9e2163ec05465fe8afb9e 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -2752,7 +2752,16 @@ void mlx5e_trigger_napi_sched(struct napi_struct *napi)
 
 static void mlx5e_channel_pick_doorbell(struct mlx5e_channel *c)
 {
-       c->bfreg = &c->mdev->priv.bfreg;
+       struct mlx5e_hw_objs *hw_objs = &c->mdev->mlx5e_res.hw_objs;
+
+       /* No dedicated Ethernet doorbells, use the global one. */
+       if (hw_objs->num_bfregs == 0) {
+               c->bfreg = &c->mdev->priv.bfreg;
+               return;
+       }
+
+       /* Round-robin between doorbells. */
+       c->bfreg = hw_objs->bfregs + c->vec_ix % hw_objs->num_bfregs;
 }
 
 static int mlx5e_open_channel(struct mlx5e_priv *priv, int ix,

diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h
index 15c434fedff770aae8fe663e7231e0f623399125..99b34e4809aeb4966f2abfd54b948192b6c0d3da 100644 (file)
--- a/include/linux/mlx5/driver.h
+++ b/include/linux/mlx5/driver.h
@@ -658,6 +658,8 @@ struct mlx5e_resources {
                u32                        pdn;
                struct mlx5_td             td;
                u32                        mkey;
+               struct mlx5_sq_bfreg      *bfregs;
+               unsigned int               num_bfregs;
 #define MLX5_MAX_NUM_TC 8
                u32                        tisn[MLX5_MAX_PORTS][MLX5_MAX_NUM_TC];
                bool                       tisn_valid;
@@ -801,6 +803,8 @@ struct mlx5_db {
        int                     index;
 };
 
+#define MLX5_DEFAULT_NUM_DOORBELLS 8
+
 enum {
        MLX5_COMP_EQ_SIZE = 1024,
 };