bnxt_en: add support for software dynamic interrupt moderation

This implements the changes needed for the bnxt_en driver to add support
for dynamic interrupt moderation per ring.

This does add additional counters in the receive path, but testing shows
that any additional instructions are offset by throughput gain when the
default configuration is for low latency.

Signed-off-by: Andy Gospodarek <gospo@broadcom.com>
Acked-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/broadcom/bnxt/Makefile b/drivers/net/ethernet/broadcom/bnxt/Makefile
index 59c8ec9c1cad58f43f87f426601ce321f4cddd66..7c560d545c038100a7af3492cb816ac03348d278 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnxt/Makefile
+++ b/drivers/net/ethernet/broadcom/bnxt/Makefile
@@ -1,4 +1,4 @@
 obj-$(CONFIG_BNXT) += bnxt_en.o
 
-bnxt_en-y := bnxt.o bnxt_sriov.o bnxt_ethtool.o bnxt_dcb.o bnxt_ulp.o bnxt_xdp.o bnxt_vfr.o bnxt_devlink.o
+bnxt_en-y := bnxt.o bnxt_sriov.o bnxt_ethtool.o bnxt_dcb.o bnxt_ulp.o bnxt_xdp.o bnxt_vfr.o bnxt_devlink.o bnxt_dim.o
 bnxt_en-$(CONFIG_BNXT_FLOWER_OFFLOAD) += bnxt_tc.o

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 89c3c8760a7822a53230b302cdd31e92688c8265..cf6ebf1e324b79300e3c4d723721b8660e6713f9 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -1645,6 +1645,8 @@ next_rx:
        rxr->rx_next_cons = NEXT_RX(cons);
 
 next_rx_no_prod:
+       cpr->rx_packets += 1;
+       cpr->rx_bytes += len;
        *raw_cons = tmp_raw_cons;
 
        return rc;
@@ -1802,6 +1804,7 @@ static irqreturn_t bnxt_msix(int irq, void *dev_instance)
        struct bnxt_cp_ring_info *cpr = &bnapi->cp_ring;
        u32 cons = RING_CMP(cpr->cp_raw_cons);
 
+       cpr->event_ctr++;
        prefetch(&cpr->cp_desc_ring[CP_RING(cons)][CP_IDX(cons)]);
        napi_schedule(&bnapi->napi);
        return IRQ_HANDLED;
@@ -2025,6 +2028,15 @@ static int bnxt_poll(struct napi_struct *napi, int budget)
                        break;
                }
        }
+       if (bp->flags & BNXT_FLAG_DIM) {
+               struct net_dim_sample dim_sample;
+
+               net_dim_sample(cpr->event_ctr,
+                              cpr->rx_packets,
+                              cpr->rx_bytes,
+                              &dim_sample);
+               net_dim(&cpr->dim, dim_sample);
+       }
        mmiowb();
        return work_done;
 }
@@ -2617,6 +2629,8 @@ static void bnxt_init_cp_rings(struct bnxt *bp)
                struct bnxt_ring_struct *ring = &cpr->cp_ring_struct;
 
                ring->fw_ring_id = INVALID_HW_RING_ID;
+               cpr->rx_ring_coal.coal_ticks = bp->rx_coal.coal_ticks;
+               cpr->rx_ring_coal.coal_bufs = bp->rx_coal.coal_bufs;
        }
 }
 
@@ -4593,6 +4607,36 @@ static void bnxt_hwrm_set_coal_params(struct bnxt_coal *hw_coal,
        req->flags = cpu_to_le16(flags);
 }
 
+int bnxt_hwrm_set_ring_coal(struct bnxt *bp, struct bnxt_napi *bnapi)
+{
+       struct hwrm_ring_cmpl_ring_cfg_aggint_params_input req_rx = {0};
+       struct bnxt_cp_ring_info *cpr = &bnapi->cp_ring;
+       struct bnxt_coal coal;
+       unsigned int grp_idx;
+
+       /* Tick values in micro seconds.
+        * 1 coal_buf x bufs_per_record = 1 completion record.
+        */
+       memcpy(&coal, &bp->rx_coal, sizeof(struct bnxt_coal));
+
+       coal.coal_ticks = cpr->rx_ring_coal.coal_ticks;
+       coal.coal_bufs = cpr->rx_ring_coal.coal_bufs;
+
+       if (!bnapi->rx_ring)
+               return -ENODEV;
+
+       bnxt_hwrm_cmd_hdr_init(bp, &req_rx,
+                              HWRM_RING_CMPL_RING_CFG_AGGINT_PARAMS, -1, -1);
+
+       bnxt_hwrm_set_coal_params(&coal, &req_rx);
+
+       grp_idx = bnapi->index;
+       req_rx.ring_id = cpu_to_le16(bp->grp_info[grp_idx].cp_fw_ring_id);
+
+       return hwrm_send_message(bp, &req_rx, sizeof(req_rx),
+                                HWRM_CMD_TIMEOUT);
+}
+
 int bnxt_hwrm_set_coal(struct bnxt *bp)
 {
        int i, rc = 0;
@@ -5715,7 +5759,13 @@ static void bnxt_enable_napi(struct bnxt *bp)
        int i;
 
        for (i = 0; i < bp->cp_nr_rings; i++) {
+               struct bnxt_cp_ring_info *cpr = &bp->bnapi[i]->cp_ring;
                bp->bnapi[i]->in_reset = false;
+
+               if (bp->bnapi[i]->rx_ring) {
+                       INIT_WORK(&cpr->dim.work, bnxt_dim_work);
+                       cpr->dim.mode = NET_DIM_CQ_PERIOD_MODE_START_FROM_EQE;
+               }
                napi_enable(&bp->bnapi[i]->napi);
        }
 }

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index 2d268fc26f5efc4a7e225bb0ec40a3b692a77e44..89887a88b1bd52c4bfa1fc71e5cf28fdbd8c302c 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -24,6 +24,7 @@
 #include <net/dst_metadata.h>
 #include <net/switchdev.h>
 #include <net/xdp.h>
+#include <linux/net_dim.h>
 
 struct tx_bd {
        __le32 tx_bd_len_flags_type;
@@ -608,6 +609,17 @@ struct bnxt_tx_ring_info {
        struct bnxt_ring_struct tx_ring_struct;
 };
 
+struct bnxt_coal {
+       u16                     coal_ticks;
+       u16                     coal_ticks_irq;
+       u16                     coal_bufs;
+       u16                     coal_bufs_irq;
+                       /* RING_IDLE enabled when coal ticks < idle_thresh  */
+       u16                     idle_thresh;
+       u8                      bufs_per_record;
+       u8                      budget;
+};
+
 struct bnxt_tpa_info {
        void                    *data;
        u8                      *data_ptr;
@@ -672,6 +684,13 @@ struct bnxt_cp_ring_info {
        u32                     cp_raw_cons;
        void __iomem            *cp_doorbell;
 
+       struct bnxt_coal        rx_ring_coal;
+       u64                     rx_packets;
+       u64                     rx_bytes;
+       u64                     event_ctr;
+
+       struct net_dim          dim;
+
        struct tx_cmp           *cp_desc_ring[MAX_CP_PAGES];
 
        dma_addr_t              cp_desc_mapping[MAX_CP_PAGES];
@@ -946,17 +965,6 @@ struct bnxt_test_info {
 #define BNXT_CAG_REG_LEGACY_INT_STATUS 0x4014
 #define BNXT_CAG_REG_BASE              0x300000
 
-struct bnxt_coal {
-       u16                     coal_ticks;
-       u16                     coal_ticks_irq;
-       u16                     coal_bufs;
-       u16                     coal_bufs_irq;
-                       /* RING_IDLE enabled when coal ticks < idle_thresh  */
-       u16                     idle_thresh;
-       u8                      bufs_per_record;
-       u8                      budget;
-};
-
 struct bnxt_tc_flow_stats {
        u64             packets;
        u64             bytes;
@@ -1128,6 +1136,7 @@ struct bnxt {
        #define BNXT_FLAG_DOUBLE_DB     0x400000
        #define BNXT_FLAG_FW_DCBX_AGENT 0x800000
        #define BNXT_FLAG_CHIP_NITRO_A0 0x1000000
+       #define BNXT_FLAG_DIM           0x2000000
 
        #define BNXT_FLAG_ALL_CONFIG_FEATS (BNXT_FLAG_TPA |             \
                                            BNXT_FLAG_RFS |             \
@@ -1425,4 +1434,7 @@ int bnxt_setup_mq_tc(struct net_device *dev, u8 tc);
 int bnxt_get_max_rings(struct bnxt *, int *, int *, bool);
 void bnxt_restore_pf_fw_resources(struct bnxt *bp);
 int bnxt_port_attr_get(struct bnxt *bp, struct switchdev_attr *attr);
+void bnxt_dim_work(struct work_struct *work);
+int bnxt_hwrm_set_ring_coal(struct bnxt *bp, struct bnxt_napi *bnapi);
+
 #endif

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_dim.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_dim.c
new file mode 100644 (file)
index 0000000..408dd19
--- /dev/null
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_dim.c
@@ -0,0 +1,32 @@
+/* Broadcom NetXtreme-C/E network driver.
+ *
+ * Copyright (c) 2017-2018 Broadcom Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/net_dim.h>
+#include "bnxt_hsi.h"
+#include "bnxt.h"
+
+void bnxt_dim_work(struct work_struct *work)
+{
+       struct net_dim *dim = container_of(work, struct net_dim,
+                                          work);
+       struct bnxt_cp_ring_info *cpr = container_of(dim,
+                                                    struct bnxt_cp_ring_info,
+                                                    dim);
+       struct bnxt_napi *bnapi = container_of(cpr,
+                                              struct bnxt_napi,
+                                              cp_ring);
+       struct net_dim_cq_moder cur_profile = net_dim_get_profile(dim->mode,
+                                                                 dim->profile_ix);
+
+       cpr->rx_ring_coal.coal_ticks = cur_profile.usec;
+       cpr->rx_ring_coal.coal_bufs = cur_profile.pkts;
+
+       bnxt_hwrm_set_ring_coal(bnapi->bp, bnapi);
+       dim->state = NET_DIM_START_MEASURE;
+}

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
index fe7599f404bf7381b1a412ef51fa7b86b4ae9263..1801582076be4ba8be9541b2679dddb2a491557d 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
@@ -49,6 +49,8 @@ static int bnxt_get_coalesce(struct net_device *dev,
 
        memset(coal, 0, sizeof(*coal));
 
+       coal->use_adaptive_rx_coalesce = bp->flags & BNXT_FLAG_DIM;
+
        hw_coal = &bp->rx_coal;
        mult = hw_coal->bufs_per_record;
        coal->rx_coalesce_usecs = hw_coal->coal_ticks;
@@ -77,6 +79,15 @@ static int bnxt_set_coalesce(struct net_device *dev,
        int rc = 0;
        u16 mult;
 
+       if (coal->use_adaptive_rx_coalesce) {
+               bp->flags |= BNXT_FLAG_DIM;
+       } else {
+               if (bp->flags & BNXT_FLAG_DIM) {
+                       bp->flags &= ~(BNXT_FLAG_DIM);
+                       goto reset_coalesce;
+               }
+       }
+
        hw_coal = &bp->rx_coal;
        mult = hw_coal->bufs_per_record;
        hw_coal->coal_ticks = coal->rx_coalesce_usecs;
@@ -104,6 +115,7 @@ static int bnxt_set_coalesce(struct net_device *dev,
                update_stats = true;
        }
 
+reset_coalesce:
        if (netif_running(dev)) {
                if (update_stats) {
                        rc = bnxt_close_nic(bp, true, false);