igc: Change Tx mode for MQPRIO offloading

The current MQPRIO offload implementation uses the legacy TSN Tx mode. In
this mode the hardware uses four packet buffers and considers queue
priorities.

In order to harmonize the TAPRIO implementation with MQPRIO, switch to the
regular TSN Tx mode. This mode also uses four packet buffers and considers
queue priorities. In addition to the legacy mode, transmission is always
coupled to Qbv. The driver already has mechanisms to use a dummy schedule
of 1 second with all gates open for ETF. Simply use this for MQPRIO too.

This reduces code and makes it easier to add support for frame preemption
later.

Tested on i225 with real time application using high priority queue, iperf3
using low priority queue and network TAP device.

Acked-by: Faizal Rahim <faizal.abdul.rahim@linux.intel.com>
Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Mor Bar-Gabay <morx.bar.gabay@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
index 9bd243f23b469e32024a3465f0bf963e54c2fb9c..859a15e4ccbab577bb25ec158ac1aef4fbfa95c7 100644 (file)
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -394,12 +394,11 @@ extern char igc_driver_name[];
 #define IGC_FLAG_RX_LEGACY             BIT(16)
 #define IGC_FLAG_TSN_QBV_ENABLED       BIT(17)
 #define IGC_FLAG_TSN_QAV_ENABLED       BIT(18)
-#define IGC_FLAG_TSN_LEGACY_ENABLED    BIT(19)
-#define IGC_FLAG_TSN_PREEMPT_ENABLED   BIT(20)
+#define IGC_FLAG_TSN_PREEMPT_ENABLED   BIT(19)
 
 #define IGC_FLAG_TSN_ANY_ENABLED                               \
        (IGC_FLAG_TSN_QBV_ENABLED | IGC_FLAG_TSN_QAV_ENABLED |  \
-        IGC_FLAG_TSN_LEGACY_ENABLED | IGC_FLAG_TSN_PREEMPT_ENABLED)
+        IGC_FLAG_TSN_PREEMPT_ENABLED)
 
 #define IGC_FLAG_RSS_FIELD_IPV4_UDP    BIT(6)
 #define IGC_FLAG_RSS_FIELD_IPV6_UDP    BIT(7)

diff --git a/drivers/net/ethernet/intel/igc/igc_tsn.c b/drivers/net/ethernet/intel/igc/igc_tsn.c
index cbc49cdcaf6b6194c7dcc2f1d29a3ac627ded9dd..f22cc4d4f459d5549edd960b9ba66e0851d8c597 100644 (file)
--- a/drivers/net/ethernet/intel/igc/igc_tsn.c
+++ b/drivers/net/ethernet/intel/igc/igc_tsn.c
@@ -171,18 +171,14 @@ static unsigned int igc_tsn_new_flags(struct igc_adapter *adapter)
 {
        unsigned int new_flags = adapter->flags & ~IGC_FLAG_TSN_ANY_ENABLED;
 
-       if (adapter->taprio_offload_enable)
-               new_flags |= IGC_FLAG_TSN_QBV_ENABLED;
 
-       if (is_any_launchtime(adapter))
+       if (adapter->taprio_offload_enable || is_any_launchtime(adapter) ||
+           adapter->strict_priority_enable)
                new_flags |= IGC_FLAG_TSN_QBV_ENABLED;
 
        if (is_cbs_enabled(adapter))
                new_flags |= IGC_FLAG_TSN_QAV_ENABLED;
 
-       if (adapter->strict_priority_enable)
-               new_flags |= IGC_FLAG_TSN_LEGACY_ENABLED;
-
        if (adapter->fpe.mmsv.pmac_enabled)
                new_flags |= IGC_FLAG_TSN_PREEMPT_ENABLED;
 
@@ -326,7 +322,6 @@ static int igc_tsn_disable_offload(struct igc_adapter *adapter)
        igc_tsn_tx_arb(adapter, queue_per_tc);
 
        adapter->flags &= ~IGC_FLAG_TSN_QBV_ENABLED;
-       adapter->flags &= ~IGC_FLAG_TSN_LEGACY_ENABLED;
 
        return 0;
 }
@@ -395,16 +390,6 @@ static int igc_tsn_enable_offload(struct igc_adapter *adapter)
                 * mapping.
                 */
                igc_tsn_tx_arb(adapter, adapter->queue_per_tc);
-
-               /* Enable legacy TSN mode which will do strict priority without
-                * any other TSN features.
-                */
-               tqavctrl = rd32(IGC_TQAVCTRL);
-               tqavctrl |= IGC_TQAVCTRL_TRANSMIT_MODE_TSN;
-               tqavctrl &= ~IGC_TQAVCTRL_ENHANCED_QAV;
-               wr32(IGC_TQAVCTRL, tqavctrl);
-
-               return 0;
        }
 
        for (i = 0; i < adapter->num_tx_queues; i++) {