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Message-Id: <20230127001516.592984-16-vladimir.oltean@nxp.com>
Date: Fri, 27 Jan 2023 02:15:16 +0200
From: Vladimir Oltean <vladimir.oltean@....com>
To: netdev@...r.kernel.org
Cc: "David S. Miller" <davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>,
Claudiu Manoil <claudiu.manoil@....com>,
Vinicius Costa Gomes <vinicius.gomes@...el.com>,
Kurt Kanzenbach <kurt@...utronix.de>,
Jacob Keller <jacob.e.keller@...el.com>,
Jamal Hadi Salim <jhs@...atatu.com>,
Cong Wang <xiyou.wangcong@...il.com>,
Jiri Pirko <jiri@...nulli.us>,
Horatiu Vultur <horatiu.vultur@...rochip.com>,
Siddharth Vadapalli <s-vadapalli@...com>,
Roger Quadros <rogerq@...nel.org>,
Gerhard Engleder <gerhard@...leder-embedded.com>
Subject: [PATCH v3 net-next 15/15] net/sched: taprio: only calculate gate mask per TXQ for igc, stmmac and tsnep
There are 2 classes of in-tree drivers currently:
- those who act upon struct tc_taprio_sched_entry :: gate_mask as if it
holds a bit mask of TXQs
- those who act upon the gate_mask as if it holds a bit mask of TCs
When it comes to the standard, IEEE 802.1Q-2018 does say this in the
second paragraph of section 8.6.8.4 Enhancements for scheduled traffic:
| A gate control list associated with each Port contains an ordered list
| of gate operations. Each gate operation changes the transmission gate
| state for the gate associated with each of the Port's traffic class
| queues and allows associated control operations to be scheduled.
In typically obtuse language, it refers to a "traffic class queue"
rather than a "traffic class" or a "queue". But careful reading of
802.1Q clarifies that "traffic class" and "queue" are in fact
synonymous (see 8.6.6 Queuing frames):
| A queue in this context is not necessarily a single FIFO data structure.
| A queue is a record of all frames of a given traffic class awaiting
| transmission on a given Bridge Port. The structure of this record is not
| specified.
i.o.w. their definition of "queue" isn't the Linux TX queue.
The gate_mask really is input into taprio via its UAPI as a mask of
traffic classes, but taprio_sched_to_offload() converts it into a TXQ
mask.
The breakdown of drivers which handle TC_SETUP_QDISC_TAPRIO is:
- hellcreek, felix, sja1105: these are DSA switches, it's not even very
clear what TXQs correspond to, other than purely software constructs.
Only the mqprio configuration with 8 TCs and 1 TXQ per TC makes sense.
So it's fine to convert these to a gate mask per TC.
- enetc: I have the hardware and can confirm that the gate mask is per
TC, and affects all TXQs (BD rings) configured for that priority.
- igc: in igc_save_qbv_schedule(), the gate_mask is clearly interpreted
to be per-TXQ.
- tsnep: Gerhard Engleder clarifies that even though this hardware
supports at most 1 TXQ per TC, the TXQ indices may be different from
the TC values themselves, and it is the TXQ indices that matter to
this hardware. So keep it per-TXQ as well.
- stmmac: I have a GMAC datasheet, and in the EST section it does
specify that the gate events are per TXQ rather than per TC.
- lan966x: again, this is a switch, and while not a DSA one, the way in
which it implements lan966x_mqprio_add() - by only allowing num_tc ==
NUM_PRIO_QUEUES (8) - makes it clear to me that TXQs are a purely
software construct here as well. They seem to map 1:1 with TCs.
- am65_cpsw: from looking at am65_cpsw_est_set_sched_cmds(), I get the
impression that the fetch_allow variable is treated like a prio_mask.
I haven't studied this driver's interpretation of the prio_tc_map, but
that definitely sounds closer to a per-TC gate mask rather than a
per-TXQ one.
Based on this breakdown, we have 6 drivers with a gate mask per TC and
3 with a gate mask per TXQ. So let's make the gate mask per TXQ the
opt-in and the gate mask per TC the default.
Benefit from the TC_QUERY_CAPS feature that Jakub suggested we add, and
query the device driver before calling the proper ndo_setup_tc(), and
figure out if it expects one or the other format.
Cc: Horatiu Vultur <horatiu.vultur@...rochip.com>
Cc: Siddharth Vadapalli <s-vadapalli@...com>
Cc: Roger Quadros <rogerq@...nel.org>
Signed-off-by: Vladimir Oltean <vladimir.oltean@....com>
Acked-by: Kurt Kanzenbach <kurt@...utronix.de> # hellcreek
Reviewed-by: Gerhard Engleder <gerhard@...leder-embedded.com>
---
v2->v3: adjust commit message in light of what Kurt has said
v1->v2:
- rewrite commit message
- also opt in stmmac and tsnep
drivers/net/ethernet/engleder/tsnep_tc.c | 21 +++++++++++++++++
drivers/net/ethernet/intel/igc/igc_main.c | 23 +++++++++++++++++++
drivers/net/ethernet/stmicro/stmmac/hwif.h | 5 ++++
.../net/ethernet/stmicro/stmmac/stmmac_main.c | 2 ++
.../net/ethernet/stmicro/stmmac/stmmac_tc.c | 20 ++++++++++++++++
include/net/pkt_sched.h | 1 +
net/sched/sch_taprio.c | 11 ++++++---
7 files changed, 80 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/engleder/tsnep_tc.c b/drivers/net/ethernet/engleder/tsnep_tc.c
index c4c6e1357317..d083e6684f12 100644
--- a/drivers/net/ethernet/engleder/tsnep_tc.c
+++ b/drivers/net/ethernet/engleder/tsnep_tc.c
@@ -403,12 +403,33 @@ static int tsnep_taprio(struct tsnep_adapter *adapter,
return 0;
}
+static int tsnep_tc_query_caps(struct tsnep_adapter *adapter,
+ struct tc_query_caps_base *base)
+{
+ switch (base->type) {
+ case TC_SETUP_QDISC_TAPRIO: {
+ struct tc_taprio_caps *caps = base->caps;
+
+ if (!adapter->gate_control)
+ return -EOPNOTSUPP;
+
+ caps->gate_mask_per_txq = true;
+
+ return 0;
+ }
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
int tsnep_tc_setup(struct net_device *netdev, enum tc_setup_type type,
void *type_data)
{
struct tsnep_adapter *adapter = netdev_priv(netdev);
switch (type) {
+ case TC_QUERY_CAPS:
+ return tsnep_tc_query_caps(adapter, type_data);
case TC_SETUP_QDISC_TAPRIO:
return tsnep_taprio(adapter, type_data);
default:
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index e86b15efaeb8..cce1dea51f76 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -6205,12 +6205,35 @@ static int igc_tsn_enable_cbs(struct igc_adapter *adapter,
return igc_tsn_offload_apply(adapter);
}
+static int igc_tc_query_caps(struct igc_adapter *adapter,
+ struct tc_query_caps_base *base)
+{
+ struct igc_hw *hw = &adapter->hw;
+
+ switch (base->type) {
+ case TC_SETUP_QDISC_TAPRIO: {
+ struct tc_taprio_caps *caps = base->caps;
+
+ if (hw->mac.type != igc_i225)
+ return -EOPNOTSUPP;
+
+ caps->gate_mask_per_txq = true;
+
+ return 0;
+ }
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
static int igc_setup_tc(struct net_device *dev, enum tc_setup_type type,
void *type_data)
{
struct igc_adapter *adapter = netdev_priv(dev);
switch (type) {
+ case TC_QUERY_CAPS:
+ return igc_tc_query_caps(adapter, type_data);
case TC_SETUP_QDISC_TAPRIO:
return igc_tsn_enable_qbv_scheduling(adapter, type_data);
diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.h b/drivers/net/ethernet/stmicro/stmmac/hwif.h
index 592b4067f9b8..16a7421715cb 100644
--- a/drivers/net/ethernet/stmicro/stmmac/hwif.h
+++ b/drivers/net/ethernet/stmicro/stmmac/hwif.h
@@ -567,6 +567,7 @@ struct tc_cbs_qopt_offload;
struct flow_cls_offload;
struct tc_taprio_qopt_offload;
struct tc_etf_qopt_offload;
+struct tc_query_caps_base;
struct stmmac_tc_ops {
int (*init)(struct stmmac_priv *priv);
@@ -580,6 +581,8 @@ struct stmmac_tc_ops {
struct tc_taprio_qopt_offload *qopt);
int (*setup_etf)(struct stmmac_priv *priv,
struct tc_etf_qopt_offload *qopt);
+ int (*query_caps)(struct stmmac_priv *priv,
+ struct tc_query_caps_base *base);
};
#define stmmac_tc_init(__priv, __args...) \
@@ -594,6 +597,8 @@ struct stmmac_tc_ops {
stmmac_do_callback(__priv, tc, setup_taprio, __args)
#define stmmac_tc_setup_etf(__priv, __args...) \
stmmac_do_callback(__priv, tc, setup_etf, __args)
+#define stmmac_tc_query_caps(__priv, __args...) \
+ stmmac_do_callback(__priv, tc, query_caps, __args)
struct stmmac_counters;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index b7e5af58ab75..17a7ea1cb961 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -5991,6 +5991,8 @@ static int stmmac_setup_tc(struct net_device *ndev, enum tc_setup_type type,
struct stmmac_priv *priv = netdev_priv(ndev);
switch (type) {
+ case TC_QUERY_CAPS:
+ return stmmac_tc_query_caps(priv, priv, type_data);
case TC_SETUP_BLOCK:
return flow_block_cb_setup_simple(type_data,
&stmmac_block_cb_list,
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
index 2cfb18cef1d4..9d55226479b4 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
@@ -1107,6 +1107,25 @@ static int tc_setup_etf(struct stmmac_priv *priv,
return 0;
}
+static int tc_query_caps(struct stmmac_priv *priv,
+ struct tc_query_caps_base *base)
+{
+ switch (base->type) {
+ case TC_SETUP_QDISC_TAPRIO: {
+ struct tc_taprio_caps *caps = base->caps;
+
+ if (!priv->dma_cap.estsel)
+ return -EOPNOTSUPP;
+
+ caps->gate_mask_per_txq = true;
+
+ return 0;
+ }
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
const struct stmmac_tc_ops dwmac510_tc_ops = {
.init = tc_init,
.setup_cls_u32 = tc_setup_cls_u32,
@@ -1114,4 +1133,5 @@ const struct stmmac_tc_ops dwmac510_tc_ops = {
.setup_cls = tc_setup_cls,
.setup_taprio = tc_setup_taprio,
.setup_etf = tc_setup_etf,
+ .query_caps = tc_query_caps,
};
diff --git a/include/net/pkt_sched.h b/include/net/pkt_sched.h
index ace8be520fb0..fd889fc4912b 100644
--- a/include/net/pkt_sched.h
+++ b/include/net/pkt_sched.h
@@ -176,6 +176,7 @@ struct tc_mqprio_qopt_offload {
struct tc_taprio_caps {
bool supports_queue_max_sdu:1;
+ bool gate_mask_per_txq:1;
};
struct tc_taprio_sched_entry {
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
index 0415f0dbfcc8..f2c585bb0519 100644
--- a/net/sched/sch_taprio.c
+++ b/net/sched/sch_taprio.c
@@ -1217,7 +1217,8 @@ static u32 tc_map_to_queue_mask(struct net_device *dev, u32 tc_mask)
static void taprio_sched_to_offload(struct net_device *dev,
struct sched_gate_list *sched,
- struct tc_taprio_qopt_offload *offload)
+ struct tc_taprio_qopt_offload *offload,
+ const struct tc_taprio_caps *caps)
{
struct sched_entry *entry;
int i = 0;
@@ -1231,7 +1232,11 @@ static void taprio_sched_to_offload(struct net_device *dev,
e->command = entry->command;
e->interval = entry->interval;
- e->gate_mask = tc_map_to_queue_mask(dev, entry->gate_mask);
+ if (caps->gate_mask_per_txq)
+ e->gate_mask = tc_map_to_queue_mask(dev,
+ entry->gate_mask);
+ else
+ e->gate_mask = entry->gate_mask;
i++;
}
@@ -1295,7 +1300,7 @@ static int taprio_enable_offload(struct net_device *dev,
}
offload->enable = 1;
taprio_mqprio_qopt_reconstruct(dev, &offload->mqprio);
- taprio_sched_to_offload(dev, sched, offload);
+ taprio_sched_to_offload(dev, sched, offload, &caps);
for (tc = 0; tc < TC_MAX_QUEUE; tc++)
offload->max_sdu[tc] = q->max_sdu[tc];
--
2.34.1
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