cxgb4: tune burst buffer size for TC-MQPRIO offload

For each traffic class, firmware handles up to 4 * MTU amount of data
per burst cycle. Under heavy load, this small buffer size is a
bottleneck when buffering large TSO packets in <= 1500 MTU case.
Increase the burst buffer size to 8 * MTU when supported.

Also, keep the driver's traffic class configuration API similar to
the firmware API counterpart.

Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h b/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h
index 30d25a3..fc1405a 100644 (file)
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h
@@ -1125,19 +1125,20 @@ struct adapter {
  * programmed with various parameters.
  */
 struct ch_sched_params {
-       s8   type;                     /* packet or flow */
+       u8   type;                     /* packet or flow */
        union {
                struct {
-                       s8   level;    /* scheduler hierarchy level */
-                       s8   mode;     /* per-class or per-flow */
-                       s8   rateunit; /* bit or packet rate */
-                       s8   ratemode; /* %port relative or kbps absolute */
-                       s8   channel;  /* scheduler channel [0..N] */
-                       s8   class;    /* scheduler class [0..N] */
-                       s32  minrate;  /* minimum rate */
-                       s32  maxrate;  /* maximum rate */
-                       s16  weight;   /* percent weight */
-                       s16  pktsize;  /* average packet size */
+                       u8   level;    /* scheduler hierarchy level */
+                       u8   mode;     /* per-class or per-flow */
+                       u8   rateunit; /* bit or packet rate */
+                       u8   ratemode; /* %port relative or kbps absolute */
+                       u8   channel;  /* scheduler channel [0..N] */
+                       u8   class;    /* scheduler class [0..N] */
+                       u32  minrate;  /* minimum rate */
+                       u32  maxrate;  /* maximum rate */
+                       u16  weight;   /* percent weight */
+                       u16  pktsize;  /* average packet size */
+                       u16  burstsize;  /* burst buffer size */
                } params;
        } u;
 };
@@ -1952,9 +1953,10 @@ int t4_sge_ctxt_rd(struct adapter *adap, unsigned int mbox, unsigned int cid,
                   enum ctxt_type ctype, u32 *data);
 int t4_sge_ctxt_rd_bd(struct adapter *adap, unsigned int cid,
                      enum ctxt_type ctype, u32 *data);
-int t4_sched_params(struct adapter *adapter, int type, int level, int mode,
-                   int rateunit, int ratemode, int channel, int class,
-                   int minrate, int maxrate, int weight, int pktsize);
+int t4_sched_params(struct adapter *adapter, u8 type, u8 level, u8 mode,
+                   u8 rateunit, u8 ratemode, u8 channel, u8 class,
+                   u32 minrate, u32 maxrate, u16 weight, u16 pktsize,
+                   u16 burstsize);
 void t4_sge_decode_idma_state(struct adapter *adapter, int state);
 void t4_idma_monitor_init(struct adapter *adapter,
                          struct sge_idma_monitor_state *idma);

diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
index a70018f..196451f 100644 (file)
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
@@ -3021,7 +3021,7 @@ static int cxgb4_mgmt_set_vf_rate(struct net_device *dev, int vf,
                              SCHED_CLASS_RATEUNIT_BITS,
                              SCHED_CLASS_RATEMODE_ABS,
                              pi->tx_chan, class_id, 0,
-                             max_tx_rate * 1000, 0, pktsize);
+                             max_tx_rate * 1000, 0, pktsize, 0);
        if (ret) {
                dev_err(adap->pdev_dev, "Err %d for Traffic Class config\n",
                        ret);

diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_tc_mqprio.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_tc_mqprio.c
index e6af490..56079c9 100644 (file)
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_tc_mqprio.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_tc_mqprio.c
@@ -342,6 +342,13 @@ static int cxgb4_mqprio_alloc_tc(struct net_device *dev,
                p.u.params.minrate = div_u64(mqprio->min_rate[i] * 8, 1000);
                p.u.params.maxrate = div_u64(mqprio->max_rate[i] * 8, 1000);
 
+               /* Request larger burst buffer for smaller MTU, so
+                * that hardware can work on more data per burst
+                * cycle.
+                */
+               if (dev->mtu <= ETH_DATA_LEN)
+                       p.u.params.burstsize = 8 * dev->mtu;
+
                e = cxgb4_sched_class_alloc(dev, &p);
                if (!e) {
                        ret = -ENOMEM;

diff --git a/drivers/net/ethernet/chelsio/cxgb4/sched.c b/drivers/net/ethernet/chelsio/cxgb4/sched.c
index cebe141..fde93c5 100644 (file)
--- a/drivers/net/ethernet/chelsio/cxgb4/sched.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/sched.c
@@ -57,7 +57,8 @@ static int t4_sched_class_fw_cmd(struct port_info *pi,
                                      p->u.params.ratemode,
                                      p->u.params.channel, e->idx,
                                      p->u.params.minrate, p->u.params.maxrate,
-                                     p->u.params.weight, p->u.params.pktsize);
+                                     p->u.params.weight, p->u.params.pktsize,
+                                     p->u.params.burstsize);
                break;
        default:
                err = -ENOTSUPP;

diff --git a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c
index 2a3480f..1c8068c 100644 (file)
--- a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c
@@ -10361,9 +10361,10 @@ int t4_sge_ctxt_rd_bd(struct adapter *adap, unsigned int cid,
        return ret;
 }
 
-int t4_sched_params(struct adapter *adapter, int type, int level, int mode,
-                   int rateunit, int ratemode, int channel, int class,
-                   int minrate, int maxrate, int weight, int pktsize)
+int t4_sched_params(struct adapter *adapter, u8 type, u8 level, u8 mode,
+                   u8 rateunit, u8 ratemode, u8 channel, u8 class,
+                   u32 minrate, u32 maxrate, u16 weight, u16 pktsize,
+                   u16 burstsize)
 {
        struct fw_sched_cmd cmd;
 
@@ -10385,6 +10386,7 @@ int t4_sched_params(struct adapter *adapter, int type, int level, int mode,
        cmd.u.params.max = cpu_to_be32(maxrate);
        cmd.u.params.weight = cpu_to_be16(weight);
        cmd.u.params.pktsize = cpu_to_be16(pktsize);
+       cmd.u.params.burstsize = cpu_to_be16(burstsize);
 
        return t4_wr_mbox_meat(adapter, adapter->mbox, &cmd, sizeof(cmd),
                               NULL, 1);