net: enetc: add support for preemptible traffic classes

PFs which support the MAC Merge layer also have a set of 8 registers
called "Port traffic class N frame preemption register (PTC0FPR - PTC7FPR)".
Through these, a traffic class (group of TX rings of same dequeue
priority) can be mapped to the eMAC or to the pMAC.

There's nothing particularly spectacular here. We should probably only
commit the preemptible TCs to hardware once the MAC Merge layer became
active, but unlike Felix, we don't have an IRQ that notifies us of that.
We'd have to sleep for up to verifyTime (127 ms) to wait for a
resolution coming from the verification state machine; not only from the
ndo_setup_tc() code path, but also from enetc_mm_link_state_update().
Since it's relatively complicated and has a relatively small benefit,
I'm not doing it.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ferenc Fejes <fejes@inf.elte.hu>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index e0207b01ddd6edc184c1795e101edb64e3e7fcc1..41c194c1672d1adc88ad52de606055244f597520 100644 (file)
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -25,6 +25,24 @@ void enetc_port_mac_wr(struct enetc_si *si, u32 reg, u32 val)
 }
 EXPORT_SYMBOL_GPL(enetc_port_mac_wr);
 
+void enetc_set_ptcfpr(struct enetc_hw *hw, unsigned long preemptible_tcs)
+{
+       u32 val;
+       int tc;
+
+       for (tc = 0; tc < 8; tc++) {
+               val = enetc_port_rd(hw, ENETC_PTCFPR(tc));
+
+               if (preemptible_tcs & BIT(tc))
+                       val |= ENETC_PTCFPR_FPE;
+               else
+                       val &= ~ENETC_PTCFPR_FPE;
+
+               enetc_port_wr(hw, ENETC_PTCFPR(tc), val);
+       }
+}
+EXPORT_SYMBOL_GPL(enetc_set_ptcfpr);
+
 static int enetc_num_stack_tx_queues(struct enetc_ndev_priv *priv)
 {
        int num_tx_rings = priv->num_tx_rings;
@@ -2640,6 +2658,8 @@ static void enetc_reset_tc_mqprio(struct net_device *ndev)
        }
 
        enetc_debug_tx_ring_prios(priv);
+
+       enetc_set_ptcfpr(hw, 0);
 }
 
 int enetc_setup_tc_mqprio(struct net_device *ndev, void *type_data)
@@ -2694,6 +2714,8 @@ int enetc_setup_tc_mqprio(struct net_device *ndev, void *type_data)
 
        enetc_debug_tx_ring_prios(priv);
 
+       enetc_set_ptcfpr(hw, mqprio->preemptible_tcs);
+
        return 0;
 
 err_reset_tc:

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.h b/drivers/net/ethernet/freescale/enetc/enetc.h
index 8010f31cd10daed72a97d1463dffcf710d8a6297..143078a9ef16b59005fdad8ebddfbac3a004d7d2 100644 (file)
--- a/drivers/net/ethernet/freescale/enetc/enetc.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc.h
@@ -486,6 +486,7 @@ static inline void enetc_cbd_free_data_mem(struct enetc_si *si, int size,
 
 void enetc_reset_ptcmsdur(struct enetc_hw *hw);
 void enetc_set_ptcmsdur(struct enetc_hw *hw, u32 *queue_max_sdu);
+void enetc_set_ptcfpr(struct enetc_hw *hw, unsigned long preemptible_tcs);
 
 #ifdef CONFIG_FSL_ENETC_QOS
 int enetc_qos_query_caps(struct net_device *ndev, void *type_data);

diff --git a/drivers/net/ethernet/freescale/enetc/enetc_hw.h b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
index de2e0ee8cdcb5be333e82ce23f7d117bdd1dbcb8..36bb2d6d56584cc01a1a5b2fed95be932cfdcb22 100644 (file)
--- a/drivers/net/ethernet/freescale/enetc/enetc_hw.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
@@ -965,6 +965,10 @@ static inline u32 enetc_usecs_to_cycles(u32 usecs)
        return (u32)div_u64(usecs * ENETC_CLK, 1000000ULL);
 }
 
+/* Port traffic class frame preemption register */
+#define ENETC_PTCFPR(n)                        (0x1910 + (n) * 4) /* n = [0 ..7] */
+#define ENETC_PTCFPR_FPE               BIT(31)
+
 /* port time gating control register */
 #define ENETC_PTGCR                    0x11a00
 #define ENETC_PTGCR_TGE                        BIT(31)