[PATCH net-next 10/14] mlxsw: spectrum_qdisc: Support offloading of TBF Qdisc

Ido Schimmel
2020-01-24T13:24:30Z

React to the TC messages that were introduced in a preceding patch and
configure egress maximum shaper as appropriate. TBF can be used as a root
qdisc or under one of PRIO or strict ETS bands.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
---
.../net/ethernet/mellanox/mlxsw/spectrum.c | 2 +
.../net/ethernet/mellanox/mlxsw/spectrum.h | 2 +
.../ethernet/mellanox/mlxsw/spectrum_qdisc.c | 199 ++++++++++++++++++
3 files changed, 203 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index 021664c62bba..7358b5bc7eb6 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -1796,6 +1796,8 @@ static int mlxsw_sp_setup_tc(struct net_device *dev, enum tc_setup_type type,
return mlxsw_sp_setup_tc_prio(mlxsw_sp_port, type_data);
case TC_SETUP_QDISC_ETS:
return mlxsw_sp_setup_tc_ets(mlxsw_sp_port, type_data);
+ case TC_SETUP_QDISC_TBF:
+ return mlxsw_sp_setup_tc_tbf(mlxsw_sp_port, type_data);
default:
return -EOPNOTSUPP;
}
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.h b/drivers/net/ethernet/mellanox/mlxsw/spectrum.h
index a2393c02a5e5..a0f1f9dceec5 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.h
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.h
@@ -862,6 +862,8 @@ int mlxsw_sp_setup_tc_prio(struct mlxsw_sp_port *mlxsw_sp_port,
struct tc_prio_qopt_offload *p);
int mlxsw_sp_setup_tc_ets(struct mlxsw_sp_port *mlxsw_sp_port,
struct tc_ets_qopt_offload *p);
+int mlxsw_sp_setup_tc_tbf(struct mlxsw_sp_port *mlxsw_sp_port,
+ struct tc_tbf_qopt_offload *p);

/* spectrum_fid.c */
bool mlxsw_sp_fid_is_dummy(struct mlxsw_sp *mlxsw_sp, u16 fid_index);
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c
index 57b014a95bc8..79a2801d59f6 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c
@@ -19,6 +19,7 @@ enum mlxsw_sp_qdisc_type {
MLXSW_SP_QDISC_RED,
MLXSW_SP_QDISC_PRIO,
MLXSW_SP_QDISC_ETS,
+ MLXSW_SP_QDISC_TBF,
};

struct mlxsw_sp_qdisc_ops {
@@ -540,6 +541,204 @@ int mlxsw_sp_setup_tc_red(struct mlxsw_sp_port *mlxsw_sp_port,
}
}

+static void
+mlxsw_sp_setup_tc_qdisc_leaf_clean_stats(struct mlxsw_sp_port *mlxsw_sp_port,
+ struct mlxsw_sp_qdisc *mlxsw_sp_qdisc)
+{
+ u64 backlog_cells = 0;
+ u64 tx_packets = 0;
+ u64 tx_bytes = 0;
+ u64 drops = 0;
+
+ mlxsw_sp_qdisc_collect_tc_stats(mlxsw_sp_port, mlxsw_sp_qdisc,
+ &tx_bytes, &tx_packets,
+ &drops, &backlog_cells);
+
+ mlxsw_sp_qdisc->stats_base.tx_packets = tx_packets;
+ mlxsw_sp_qdisc->stats_base.tx_bytes = tx_bytes;
+ mlxsw_sp_qdisc->stats_base.drops = drops;
+ mlxsw_sp_qdisc->stats_base.backlog = 0;
+}
+
+static int
+mlxsw_sp_qdisc_tbf_destroy(struct mlxsw_sp_port *mlxsw_sp_port,
+ struct mlxsw_sp_qdisc *mlxsw_sp_qdisc)
+{
+ struct mlxsw_sp_qdisc *root_qdisc = mlxsw_sp_port->root_qdisc;
+
+ if (root_qdisc != mlxsw_sp_qdisc)
+ root_qdisc->stats_base.backlog -=
+ mlxsw_sp_qdisc->stats_base.backlog;
+
+ return mlxsw_sp_port_ets_maxrate_set(mlxsw_sp_port,
+ MLXSW_REG_QEEC_HR_SUBGROUP,
+ mlxsw_sp_qdisc->tclass_num, 0,
+ MLXSW_REG_QEEC_MAS_DIS, 0);
+}
+
+static int
+mlxsw_sp_qdisc_tbf_bs(struct mlxsw_sp_port *mlxsw_sp_port,
+ u32 max_size, u8 *p_burst_size)
+{
+ /* TBF burst size is configured in bytes. The ASIC burst size value is
+ * ((2 ^ bs) * 512 bits. Convert the TBF bytes to 512-bit units.
+ */
+ u32 bs512 = max_size / 64;
+ u8 bs = fls(bs512);
+
+ if (!bs)
+ return -EINVAL;
+ --bs;
+
+ /* Demand a power of two. */
+ if ((1 << bs) != bs512)
+ return -EINVAL;
+
+ if (bs < mlxsw_sp_port->mlxsw_sp->lowest_shaper_bs ||
+ bs > MLXSW_REG_QEEC_HIGHEST_SHAPER_BS)
+ return -EINVAL;
+
+ *p_burst_size = bs;
+ return 0;
+}
+
+static u32
+mlxsw_sp_qdisc_tbf_max_size(u8 bs)
+{
+ return (1U << bs) * 64;
+}
+
+static u64
+mlxsw_sp_qdisc_tbf_rate_kbps(struct tc_tbf_qopt_offload_replace_params *p)
+{
+ /* TBF interface is in bytes/s, whereas Spectrum ASIC is configured in
+ * Kbits/s.
+ */
+ return p->rate.rate_bytes_ps / 1000 * 8;
+}
+
+static int
+mlxsw_sp_qdisc_tbf_check_params(struct mlxsw_sp_port *mlxsw_sp_port,
+ struct mlxsw_sp_qdisc *mlxsw_sp_qdisc,
+ void *params)
+{
+ struct tc_tbf_qopt_offload_replace_params *p = params;
+ struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
+ u64 rate_kbps = mlxsw_sp_qdisc_tbf_rate_kbps(p);
+ u8 burst_size;
+ int err;
+
+ if (rate_kbps >= MLXSW_REG_QEEC_MAS_DIS) {
+ dev_err(mlxsw_sp_port->mlxsw_sp->bus_info->dev,
+ "spectrum: TBF: rate of %lluKbps must be below %u\n",
+ rate_kbps, MLXSW_REG_QEEC_MAS_DIS);
+ return -EINVAL;
+ }
+
+ err = mlxsw_sp_qdisc_tbf_bs(mlxsw_sp_port, p->max_size, &burst_size);
+ if (err) {
+ u8 highest_shaper_bs = MLXSW_REG_QEEC_HIGHEST_SHAPER_BS;
+
+ dev_err(mlxsw_sp->bus_info->dev,
+ "spectrum: TBF: invalid burst size of %u, must be a power of two between %u and %u",
+ p->max_size,
+ mlxsw_sp_qdisc_tbf_max_size(mlxsw_sp->lowest_shaper_bs),
+ mlxsw_sp_qdisc_tbf_max_size(highest_shaper_bs));
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int
+mlxsw_sp_qdisc_tbf_replace(struct mlxsw_sp_port *mlxsw_sp_port,
+ struct mlxsw_sp_qdisc *mlxsw_sp_qdisc,
+ void *params)
+{
+ struct tc_tbf_qopt_offload_replace_params *p = params;
+ u64 rate_kbps = mlxsw_sp_qdisc_tbf_rate_kbps(p);
+ u8 burst_size;
+ int err;
+
+ err = mlxsw_sp_qdisc_tbf_bs(mlxsw_sp_port, p->max_size, &burst_size);
+ if (WARN_ON_ONCE(err))
+ /* check_params above was supposed to reject this value. */
+ return -EINVAL;
+
+ /* Configure subgroup shaper, so that both UC and MC traffic is subject
+ * to shaping. That is unlike RED, however UC queue lengths are going to
+ * be different than MC ones due to different pool and quota
+ * configurations, so the configuration is not applicable. For shaper on
+ * the other hand, subjecting the overall stream to the configured
+ * shaper makes sense. Also note that that is what we do for
+ * ieee_setmaxrate().
+ */
+ return mlxsw_sp_port_ets_maxrate_set(mlxsw_sp_port,
+ MLXSW_REG_QEEC_HR_SUBGROUP,
+ mlxsw_sp_qdisc->tclass_num, 0,
+ rate_kbps, burst_size);
+}
+
+static void
+mlxsw_sp_qdisc_tbf_unoffload(struct mlxsw_sp_port *mlxsw_sp_port,
+ struct mlxsw_sp_qdisc *mlxsw_sp_qdisc,
+ void *params)
+{
+ struct tc_tbf_qopt_offload_replace_params *p = params;
+
+ mlxsw_sp_qdisc_leaf_unoffload(mlxsw_sp_port, mlxsw_sp_qdisc, p->qstats);
+}
+
+static int
+mlxsw_sp_qdisc_get_tbf_stats(struct mlxsw_sp_port *mlxsw_sp_port,
+ struct mlxsw_sp_qdisc *mlxsw_sp_qdisc,
+ struct tc_qopt_offload_stats *stats_ptr)
+{
+ mlxsw_sp_qdisc_get_tc_stats(mlxsw_sp_port, mlxsw_sp_qdisc,
+ stats_ptr);
+ return 0;
+}
+
+static struct mlxsw_sp_qdisc_ops mlxsw_sp_qdisc_ops_tbf = {
+ .type = MLXSW_SP_QDISC_TBF,
+ .check_params = mlxsw_sp_qdisc_tbf_check_params,
+ .replace = mlxsw_sp_qdisc_tbf_replace,
+ .unoffload = mlxsw_sp_qdisc_tbf_unoffload,
+ .destroy = mlxsw_sp_qdisc_tbf_destroy,
+ .get_stats = mlxsw_sp_qdisc_get_tbf_stats,
+ .clean_stats = mlxsw_sp_setup_tc_qdisc_leaf_clean_stats,
+};
+
+int mlxsw_sp_setup_tc_tbf(struct mlxsw_sp_port *mlxsw_sp_port,
+ struct tc_tbf_qopt_offload *p)
+{
+ struct mlxsw_sp_qdisc *mlxsw_sp_qdisc;
+
+ mlxsw_sp_qdisc = mlxsw_sp_qdisc_find(mlxsw_sp_port, p->parent, false);
+ if (!mlxsw_sp_qdisc)
+ return -EOPNOTSUPP;
+
+ if (p->command == TC_TBF_REPLACE)
+ return mlxsw_sp_qdisc_replace(mlxsw_sp_port, p->handle,
+ mlxsw_sp_qdisc,
+ &mlxsw_sp_qdisc_ops_tbf,
+ &p->replace_params);
+
+ if (!mlxsw_sp_qdisc_compare(mlxsw_sp_qdisc, p->handle,
+ MLXSW_SP_QDISC_TBF))
+ return -EOPNOTSUPP;
+
+ switch (p->command) {
+ case TC_TBF_DESTROY:
+ return mlxsw_sp_qdisc_destroy(mlxsw_sp_port, mlxsw_sp_qdisc);
+ case TC_TBF_STATS:
+ return mlxsw_sp_qdisc_get_stats(mlxsw_sp_port, mlxsw_sp_qdisc,
+ &p->stats);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
static int
__mlxsw_sp_qdisc_ets_destroy(struct mlxsw_sp_port *mlxsw_sp_port)
{
--
2.24.1