From 15f93f46f31232da863316769182c699e364c45f Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Sat, 15 Apr 2023 20:05:45 +0300 Subject: net: mscc: ocelot: export a single ocelot_mm_irq() When the switch emits an IRQ, we don't know what caused it, and we iterate through all ports to check the MAC Merge status. Move that iteration inside the ocelot lib; we will change the locking in a future change and it would be good to encapsulate that lock completely within the ocelot lib. Signed-off-by: Vladimir Oltean Reviewed-by: Simon Horman Reviewed-by: Florian Fainelli Signed-off-by: Jakub Kicinski --- include/soc/mscc/ocelot.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/soc/mscc/ocelot.h b/include/soc/mscc/ocelot.h index 277e6d1f2096..eb8e3935375d 100644 --- a/include/soc/mscc/ocelot.h +++ b/include/soc/mscc/ocelot.h @@ -1148,7 +1148,7 @@ int ocelot_vcap_policer_add(struct ocelot *ocelot, u32 pol_ix, struct ocelot_policer *pol); int ocelot_vcap_policer_del(struct ocelot *ocelot, u32 pol_ix); -void ocelot_port_mm_irq(struct ocelot *ocelot, int port); +void ocelot_mm_irq(struct ocelot *ocelot); int ocelot_port_set_mm(struct ocelot *ocelot, int port, struct ethtool_mm_cfg *cfg, struct netlink_ext_ack *extack); -- cgit v1.2.3 From 3ff468ef987e38740de9ca0a811c55e11bfb2141 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Sat, 15 Apr 2023 20:05:46 +0300 Subject: net: mscc: ocelot: remove struct ocelot_mm_state :: lock Unfortunately, the workarounds for the hardware bugs make it pointless to keep fine-grained locking for the MAC Merge state of each port. Our vsc9959_cut_through_fwd() implementation requires ocelot->fwd_domain_lock to be held, in order to serialize with changes to the bridging domains and to port speed changes (which affect which ports can be cut-through). Simultaneously, the traffic classes which can be cut-through cannot be preemptible at the same time, and this will depend on the MAC Merge layer state (which changes from threaded interrupt context). Since vsc9959_cut_through_fwd() would have to hold the mm->lock of all ports for a correct and race-free implementation with respect to ocelot_mm_irq(), in practice it means that any time a port's mm->lock is held, it would potentially block holders of ocelot->fwd_domain_lock. In the interest of simple locking rules, make all MAC Merge layer state changes (and preemptible traffic class changes) be serialized by the ocelot->fwd_domain_lock. Signed-off-by: Vladimir Oltean Reviewed-by: Simon Horman Reviewed-by: Florian Fainelli Signed-off-by: Jakub Kicinski --- include/soc/mscc/ocelot.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include') diff --git a/include/soc/mscc/ocelot.h b/include/soc/mscc/ocelot.h index eb8e3935375d..9599be6a0a39 100644 --- a/include/soc/mscc/ocelot.h +++ b/include/soc/mscc/ocelot.h @@ -744,7 +744,6 @@ struct ocelot_mirror { }; struct ocelot_mm_state { - struct mutex lock; enum ethtool_mm_verify_status verify_status; bool tx_active; }; -- cgit v1.2.3 From 7bf4a5b071e59f48de8d39dfde07a3a65e7f6488 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Sat, 15 Apr 2023 20:05:47 +0300 Subject: net: mscc: ocelot: optimize ocelot_mm_irq() The MAC Merge IRQ of all ports is shared with the PTP TX timestamp IRQ of all ports, which means that currently, when a PTP TX timestamp is generated, felix_irq_handler() also polls for the MAC Merge layer status of all ports, looking for changes. This makes the kernel do more work, and under certain circumstances may make ptp4l require a tx_timestamp_timeout argument higher than before. Changes to the MAC Merge layer status are only to be expected under certain conditions - its TX direction needs to be enabled - so we can check early if that is the case, and omit register access otherwise. Make ocelot_mm_update_port_status() skip register access if mm->tx_enabled is unset, and also call it once more, outside IRQ context, from ocelot_port_set_mm(), when mm->tx_enabled transitions from true to false, because an IRQ is also expected in that case. Also, a port may have its MAC Merge layer enabled but it may not have generated the interrupt. In that case, there's no point in writing to DEV_MM_STATUS to acknowledge that IRQ. We can reduce the number of register writes per port with MM enabled by keeping an "ack" variable which writes the "write-one-to-clear" bits. Those are 3 in number: PRMPT_ACTIVE_STICKY, UNEXP_RX_PFRM_STICKY and UNEXP_TX_PFRM_STICKY. The other fields in DEV_MM_STATUS are read-only and it doesn't matter what is written to them, so writing zero is just fine. Signed-off-by: Vladimir Oltean Reviewed-by: Simon Horman Reviewed-by: Florian Fainelli Signed-off-by: Jakub Kicinski --- include/soc/mscc/ocelot.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/soc/mscc/ocelot.h b/include/soc/mscc/ocelot.h index 9599be6a0a39..ee8d43dc5c06 100644 --- a/include/soc/mscc/ocelot.h +++ b/include/soc/mscc/ocelot.h @@ -745,6 +745,7 @@ struct ocelot_mirror { struct ocelot_mm_state { enum ethtool_mm_verify_status verify_status; + bool tx_enabled; bool tx_active; }; -- cgit v1.2.3 From aac80140dc31963d818a65a522c2e2da81979857 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Sat, 15 Apr 2023 20:05:49 +0300 Subject: net: mscc: ocelot: add support for mqprio offload This doesn't apply anything to hardware and in general doesn't do anything that the software variant doesn't do, except for checking that there isn't more than 1 TXQ per TC (TXQs for a DSA switch are a dubious concept anyway). The reason we add this is to be able to parse one more field added to struct tc_mqprio_qopt_offload, namely preemptible_tcs. Signed-off-by: Vladimir Oltean Reviewed-by: Ferenc Fejes Reviewed-by: Simon Horman Reviewed-by: Florian Fainelli Signed-off-by: Jakub Kicinski --- include/soc/mscc/ocelot.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include') diff --git a/include/soc/mscc/ocelot.h b/include/soc/mscc/ocelot.h index ee8d43dc5c06..9596c79e9223 100644 --- a/include/soc/mscc/ocelot.h +++ b/include/soc/mscc/ocelot.h @@ -11,6 +11,8 @@ #include #include +struct tc_mqprio_qopt_offload; + /* Port Group IDs (PGID) are masks of destination ports. * * For L2 forwarding, the switch performs 3 lookups in the PGID table for each @@ -1154,6 +1156,8 @@ int ocelot_port_set_mm(struct ocelot *ocelot, int port, struct netlink_ext_ack *extack); int ocelot_port_get_mm(struct ocelot *ocelot, int port, struct ethtool_mm_state *state); +int ocelot_port_mqprio(struct ocelot *ocelot, int port, + struct tc_mqprio_qopt_offload *mqprio); #if IS_ENABLED(CONFIG_BRIDGE_MRP) int ocelot_mrp_add(struct ocelot *ocelot, int port, -- cgit v1.2.3 From 403ffc2c34de5297d007e0e169bf022094d444c2 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Sat, 15 Apr 2023 20:05:51 +0300 Subject: net: mscc: ocelot: add support for preemptible traffic classes In order to not transmit (preemptible) frames which will be received by the link partner as corrupted (because it doesn't support FP), the hardware requires the driver to program the QSYS_PREEMPTION_CFG_P_QUEUES register only after the MAC Merge layer becomes active (verification succeeds, or was disabled). There are some cases when FP is known (through experimentation) to be broken. Give priority to FP over cut-through switching, and disable FP for known broken link modes. Signed-off-by: Vladimir Oltean Reviewed-by: Simon Horman Signed-off-by: Jakub Kicinski --- include/soc/mscc/ocelot.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include') diff --git a/include/soc/mscc/ocelot.h b/include/soc/mscc/ocelot.h index 9596c79e9223..cb8fbb241879 100644 --- a/include/soc/mscc/ocelot.h +++ b/include/soc/mscc/ocelot.h @@ -749,6 +749,8 @@ struct ocelot_mm_state { enum ethtool_mm_verify_status verify_status; bool tx_enabled; bool tx_active; + u8 preemptible_tcs; + u8 active_preemptible_tcs; }; struct ocelot_port; @@ -1158,6 +1160,7 @@ int ocelot_port_get_mm(struct ocelot *ocelot, int port, struct ethtool_mm_state *state); int ocelot_port_mqprio(struct ocelot *ocelot, int port, struct tc_mqprio_qopt_offload *mqprio); +void ocelot_port_update_preemptible_tcs(struct ocelot *ocelot, int port); #if IS_ENABLED(CONFIG_BRIDGE_MRP) int ocelot_mrp_add(struct ocelot *ocelot, int port, -- cgit v1.2.3