enetc: Add interrupt coalescing support

Enable programming of the interrupt coalescing registers
and allow manual configuration of the coalescing time
thresholds via ethtool.  Packet thresholds have been fixed
to predetermined values as there's no point in making them
run-time configurable, also anticipating the dynamic interrupt
moderation (DIM) algorithm which uses fixed packet thresholds
as well.  If the interface is up when the operation mode of
traffic interrupt events is changed by the user (i.e. switching
from default per-packet interrupts to coalesced interrupts),
the traffic needs to be paused in the process.
This patch also prepares the ground for introducing DIM on Rx.

Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index be594c7..f4593c0 100644 (file)
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -265,6 +265,7 @@ static irqreturn_t enetc_msix(int irq, void *data)
 
        /* disable interrupts */
        enetc_wr_reg(v->rbier, 0);
+       enetc_wr_reg(v->ricr1, v->rx_ictt);
 
        for_each_set_bit(i, &v->tx_rings_map, ENETC_MAX_NUM_TXQS)
                enetc_wr_reg(v->tbier_base + ENETC_BDR_OFF(i), 0);
@@ -1268,6 +1269,7 @@ static int enetc_setup_irqs(struct enetc_ndev_priv *priv)
 
                v->tbier_base = hw->reg + ENETC_BDR(TX, 0, ENETC_TBIER);
                v->rbier = hw->reg + ENETC_BDR(RX, i, ENETC_RBIER);
+               v->ricr1 = hw->reg + ENETC_BDR(RX, i, ENETC_RBICR1);
 
                enetc_wr(hw, ENETC_SIMSIRRV(i), entry);
 
@@ -1309,17 +1311,35 @@ static void enetc_free_irqs(struct enetc_ndev_priv *priv)
 
 static void enetc_setup_interrupts(struct enetc_ndev_priv *priv)
 {
+       struct enetc_hw *hw = &priv->si->hw;
+       u32 icpt, ictt;
        int i;
 
        /* enable Tx & Rx event indication */
+       if (priv->ic_mode & ENETC_IC_RX_MANUAL) {
+               icpt = ENETC_RBICR0_SET_ICPT(ENETC_RXIC_PKTTHR);
+               /* init to non-0 minimum, will be adjusted later */
+               ictt = 0x1;
+       } else {
+               icpt = 0x1; /* enable Rx ints by setting pkt thr to 1 */
+               ictt = 0;
+       }
+
        for (i = 0; i < priv->num_rx_rings; i++) {
-               enetc_rxbdr_wr(&priv->si->hw, i,
-                              ENETC_RBIER, ENETC_RBIER_RXTIE);
+               enetc_rxbdr_wr(hw, i, ENETC_RBICR1, ictt);
+               enetc_rxbdr_wr(hw, i, ENETC_RBICR0, ENETC_RBICR0_ICEN | icpt);
+               enetc_rxbdr_wr(hw, i, ENETC_RBIER, ENETC_RBIER_RXTIE);
        }
 
+       if (priv->ic_mode & ENETC_IC_TX_MANUAL)
+               icpt = ENETC_TBICR0_SET_ICPT(ENETC_TXIC_PKTTHR);
+       else
+               icpt = 0x1; /* enable Tx ints by setting pkt thr to 1 */
+
        for (i = 0; i < priv->num_tx_rings; i++) {
-               enetc_txbdr_wr(&priv->si->hw, i,
-                              ENETC_TBIER, ENETC_TBIER_TXTIE);
+               enetc_txbdr_wr(hw, i, ENETC_TBICR1, priv->tx_ictt);
+               enetc_txbdr_wr(hw, i, ENETC_TBICR0, ENETC_TBICR0_ICEN | icpt);
+               enetc_txbdr_wr(hw, i, ENETC_TBIER, ENETC_TBIER_TXTIE);
        }
 }
 
@@ -1370,7 +1390,7 @@ static int enetc_phy_connect(struct net_device *ndev)
        return 0;
 }
 
-static void enetc_start(struct net_device *ndev)
+void enetc_start(struct net_device *ndev)
 {
        struct enetc_ndev_priv *priv = netdev_priv(ndev);
        int i;
@@ -1440,7 +1460,7 @@ err_phy_connect:
        return err;
 }
 
-static void enetc_stop(struct net_device *ndev)
+void enetc_stop(struct net_device *ndev)
 {
        struct enetc_ndev_priv *priv = netdev_priv(ndev);
        int i;

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.h b/drivers/net/ethernet/freescale/enetc/enetc.h
index 81e9072..4e3af7f 100644 (file)
--- a/drivers/net/ethernet/freescale/enetc/enetc.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc.h
@@ -190,8 +190,10 @@ static inline bool enetc_si_is_pf(struct enetc_si *si)
 struct enetc_int_vector {
        void __iomem *rbier;
        void __iomem *tbier_base;
+       void __iomem *ricr1;
        unsigned long tx_rings_map;
        int count_tx_rings;
+       u32 rx_ictt;
        struct napi_struct napi;
        char name[ENETC_INT_NAME_MAX];
 
@@ -221,6 +223,18 @@ enum enetc_active_offloads {
        ENETC_F_QCI             = BIT(3),
 };
 
+/* interrupt coalescing modes */
+enum enetc_ic_mode {
+       /* one interrupt per frame */
+       ENETC_IC_NONE = 0,
+       /* activated when int coalescing time is set to a non-0 value */
+       ENETC_IC_RX_MANUAL = BIT(0),
+       ENETC_IC_TX_MANUAL = BIT(1),
+};
+
+#define ENETC_RXIC_PKTTHR      min_t(u32, 256, ENETC_RX_RING_DEFAULT_SIZE / 2)
+#define ENETC_TXIC_PKTTHR      min_t(u32, 128, ENETC_TX_RING_DEFAULT_SIZE / 2)
+
 struct enetc_ndev_priv {
        struct net_device *ndev;
        struct device *dev; /* dma-mapping device */
@@ -245,6 +259,8 @@ struct enetc_ndev_priv {
 
        struct device_node *phy_node;
        phy_interface_t if_mode;
+       int ic_mode;
+       u32 tx_ictt;
 };
 
 /* Messaging */
@@ -274,6 +290,8 @@ void enetc_free_si_resources(struct enetc_ndev_priv *priv);
 
 int enetc_open(struct net_device *ndev);
 int enetc_close(struct net_device *ndev);
+void enetc_start(struct net_device *ndev);
+void enetc_stop(struct net_device *ndev);
 netdev_tx_t enetc_xmit(struct sk_buff *skb, struct net_device *ndev);
 struct net_device_stats *enetc_get_stats(struct net_device *ndev);
 int enetc_set_features(struct net_device *ndev,

diff --git a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
index 8aeaa3d..521f3b4 100644 (file)
--- a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
@@ -14,12 +14,14 @@ static const u32 enetc_si_regs[] = {
 
 static const u32 enetc_txbdr_regs[] = {
        ENETC_TBMR, ENETC_TBSR, ENETC_TBBAR0, ENETC_TBBAR1,
-       ENETC_TBPIR, ENETC_TBCIR, ENETC_TBLENR, ENETC_TBIER
+       ENETC_TBPIR, ENETC_TBCIR, ENETC_TBLENR, ENETC_TBIER, ENETC_TBICR0,
+       ENETC_TBICR1
 };
 
 static const u32 enetc_rxbdr_regs[] = {
        ENETC_RBMR, ENETC_RBSR, ENETC_RBBSR, ENETC_RBCIR, ENETC_RBBAR0,
-       ENETC_RBBAR1, ENETC_RBPIR, ENETC_RBLENR, ENETC_RBICR0, ENETC_RBIER
+       ENETC_RBBAR1, ENETC_RBPIR, ENETC_RBLENR, ENETC_RBIER, ENETC_RBICR0,
+       ENETC_RBICR1
 };
 
 static const u32 enetc_port_regs[] = {
@@ -561,6 +563,65 @@ static void enetc_get_ringparam(struct net_device *ndev,
        }
 }
 
+static int enetc_get_coalesce(struct net_device *ndev,
+                             struct ethtool_coalesce *ic)
+{
+       struct enetc_ndev_priv *priv = netdev_priv(ndev);
+       struct enetc_int_vector *v = priv->int_vector[0];
+
+       ic->tx_coalesce_usecs = enetc_cycles_to_usecs(priv->tx_ictt);
+       ic->rx_coalesce_usecs = enetc_cycles_to_usecs(v->rx_ictt);
+
+       ic->tx_max_coalesced_frames = ENETC_TXIC_PKTTHR;
+       ic->rx_max_coalesced_frames = ENETC_RXIC_PKTTHR;
+
+       return 0;
+}
+
+static int enetc_set_coalesce(struct net_device *ndev,
+                             struct ethtool_coalesce *ic)
+{
+       struct enetc_ndev_priv *priv = netdev_priv(ndev);
+       u32 rx_ictt, tx_ictt;
+       int i, ic_mode;
+       bool changed;
+
+       tx_ictt = enetc_usecs_to_cycles(ic->tx_coalesce_usecs);
+       rx_ictt = enetc_usecs_to_cycles(ic->rx_coalesce_usecs);
+
+       if (ic->rx_max_coalesced_frames != ENETC_RXIC_PKTTHR)
+               return -EOPNOTSUPP;
+
+       if (ic->tx_max_coalesced_frames != ENETC_TXIC_PKTTHR)
+               return -EOPNOTSUPP;
+
+       ic_mode = ENETC_IC_NONE;
+       ic_mode |= tx_ictt ? ENETC_IC_TX_MANUAL : 0;
+       ic_mode |= rx_ictt ? ENETC_IC_RX_MANUAL : 0;
+
+       /* commit the settings */
+       changed = (ic_mode != priv->ic_mode);
+
+       priv->ic_mode = ic_mode;
+       priv->tx_ictt = tx_ictt;
+
+       for (i = 0; i < priv->bdr_int_num; i++) {
+               struct enetc_int_vector *v = priv->int_vector[i];
+
+               v->rx_ictt = rx_ictt;
+       }
+
+       if (netif_running(ndev) && changed) {
+               /* reconfigure the operation mode of h/w interrupts,
+                * traffic needs to be paused in the process
+                */
+               enetc_stop(ndev);
+               enetc_start(ndev);
+       }
+
+       return 0;
+}
+
 static int enetc_get_ts_info(struct net_device *ndev,
                             struct ethtool_ts_info *info)
 {
@@ -617,6 +678,8 @@ static int enetc_set_wol(struct net_device *dev,
 }
 
 static const struct ethtool_ops enetc_pf_ethtool_ops = {
+       .supported_coalesce_params = ETHTOOL_COALESCE_USECS |
+                                    ETHTOOL_COALESCE_MAX_FRAMES,
        .get_regs_len = enetc_get_reglen,
        .get_regs = enetc_get_regs,
        .get_sset_count = enetc_get_sset_count,
@@ -629,6 +692,8 @@ static const struct ethtool_ops enetc_pf_ethtool_ops = {
        .get_rxfh = enetc_get_rxfh,
        .set_rxfh = enetc_set_rxfh,
        .get_ringparam = enetc_get_ringparam,
+       .get_coalesce = enetc_get_coalesce,
+       .set_coalesce = enetc_set_coalesce,
        .get_link_ksettings = phy_ethtool_get_link_ksettings,
        .set_link_ksettings = phy_ethtool_set_link_ksettings,
        .get_link = ethtool_op_get_link,
@@ -638,6 +703,8 @@ static const struct ethtool_ops enetc_pf_ethtool_ops = {
 };
 
 static const struct ethtool_ops enetc_vf_ethtool_ops = {
+       .supported_coalesce_params = ETHTOOL_COALESCE_USECS |
+                                    ETHTOOL_COALESCE_MAX_FRAMES,
        .get_regs_len = enetc_get_reglen,
        .get_regs = enetc_get_regs,
        .get_sset_count = enetc_get_sset_count,
@@ -649,6 +716,8 @@ static const struct ethtool_ops enetc_vf_ethtool_ops = {
        .get_rxfh = enetc_get_rxfh,
        .set_rxfh = enetc_set_rxfh,
        .get_ringparam = enetc_get_ringparam,
+       .get_coalesce = enetc_get_coalesce,
+       .set_coalesce = enetc_set_coalesce,
        .get_link = ethtool_op_get_link,
        .get_ts_info = enetc_get_ts_info,
 };

diff --git a/drivers/net/ethernet/freescale/enetc/enetc_hw.h b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
index d70ee37..17cf7c9 100644 (file)
--- a/drivers/net/ethernet/freescale/enetc/enetc_hw.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
@@ -122,7 +122,10 @@ enum enetc_bdr_type {TX, RX};
 #define ENETC_RBIER_RXTIE      BIT(0)
 #define ENETC_RBIDR    0xa4
 #define ENETC_RBICR0   0xa8
-#define ENETC_RBICR0_ICEN      BIT(31)
+#define ENETC_RBICR0_ICEN              BIT(31)
+#define ENETC_RBICR0_ICPT_MASK         0x1ff
+#define ENETC_RBICR0_SET_ICPT(n)       ((n) & ENETC_RBICR0_ICPT_MASK)
+#define ENETC_RBICR1   0xac
 
 /* TX BDR reg offsets */
 #define ENETC_TBMR     0
@@ -142,7 +145,10 @@ enum enetc_bdr_type {TX, RX};
 #define ENETC_TBIER_TXTIE      BIT(0)
 #define ENETC_TBIDR    0xa4
 #define ENETC_TBICR0   0xa8
-#define ENETC_TBICR0_ICEN      BIT(31)
+#define ENETC_TBICR0_ICEN              BIT(31)
+#define ENETC_TBICR0_ICPT_MASK         0xf
+#define ENETC_TBICR0_SET_ICPT(n) ((ilog2(n) + 1) & ENETC_TBICR0_ICPT_MASK)
+#define ENETC_TBICR1   0xac
 
 #define ENETC_RTBLENR_LEN(n)   ((n) & ~0x7)
 
@@ -787,6 +793,15 @@ struct enetc_cbd {
 };
 
 #define ENETC_CLK  400000000ULL
+static inline u32 enetc_cycles_to_usecs(u32 cycles)
+{
+       return (u32)div_u64(cycles * 1000000ULL, ENETC_CLK);
+}
+
+static inline u32 enetc_usecs_to_cycles(u32 usecs)
+{
+       return (u32)div_u64(usecs * ENETC_CLK, 1000000ULL);
+}
 
 /* port time gating control register */
 #define ENETC_QBV_PTGCR_OFFSET         0x11a00