[PATCH 1/2] net: thunderx: Support to configure queue sizes from ethtool

From: sunil . kovvuri
Date: Wed Jan 25 2017 - 07:07:06 EST


From: Sunil Goutham <sgoutham@xxxxxxxxxx>

Adds support to set Rx/Tx queue sizes from ethtool. Fixes
an issue with retrieving queue size. Also sets SQ's CQ_LIMIT
based on configured Tx queue size such that HW doesn't process
SQEs when there is no sufficient space in CQ.

Signed-off-by: Sunil Goutham <sgoutham@xxxxxxxxxx>
---
.../net/ethernet/cavium/thunder/nicvf_ethtool.c | 39 ++++++++++++++++++++--
drivers/net/ethernet/cavium/thunder/nicvf_queues.c | 19 +++++++++--
drivers/net/ethernet/cavium/thunder/nicvf_queues.h | 16 ++++++---
3 files changed, 65 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_ethtool.c b/drivers/net/ethernet/cavium/thunder/nicvf_ethtool.c
index 5ac4746..02a986c 100644
--- a/drivers/net/ethernet/cavium/thunder/nicvf_ethtool.c
+++ b/drivers/net/ethernet/cavium/thunder/nicvf_ethtool.c
@@ -471,12 +471,46 @@ static void nicvf_get_ringparam(struct net_device *netdev,
struct nicvf *nic = netdev_priv(netdev);
struct queue_set *qs = nic->qs;

- ring->rx_max_pending = MAX_RCV_BUF_COUNT;
- ring->rx_pending = qs->rbdr_len;
+ ring->rx_max_pending = MAX_CMP_QUEUE_LEN;
+ ring->rx_pending = qs->cq_len;
ring->tx_max_pending = MAX_SND_QUEUE_LEN;
ring->tx_pending = qs->sq_len;
}

+static int nicvf_set_ringparam(struct net_device *netdev,
+ struct ethtool_ringparam *ring)
+{
+ struct nicvf *nic = netdev_priv(netdev);
+ struct queue_set *qs = nic->qs;
+ u32 rx_count, tx_count;
+
+ /* Due to HW errata this is not supported on T88 pass 1.x silicon */
+ if (pass1_silicon(nic->pdev))
+ return -EINVAL;
+
+ if ((ring->rx_mini_pending) || (ring->rx_jumbo_pending))
+ return -EINVAL;
+
+ tx_count = clamp_t(u32, ring->tx_pending,
+ MIN_SND_QUEUE_LEN, MAX_SND_QUEUE_LEN);
+ rx_count = clamp_t(u32, ring->rx_pending,
+ MIN_CMP_QUEUE_LEN, MAX_CMP_QUEUE_LEN);
+
+ if ((tx_count == qs->sq_len) && (rx_count == qs->cq_len))
+ return 0;
+
+ /* Permitted lengths are 1K, 2K, 4K, 8K, 16K, 32K, 64K */
+ qs->sq_len = rounddown_pow_of_two(tx_count);
+ qs->cq_len = rounddown_pow_of_two(rx_count);
+
+ if (netif_running(netdev)) {
+ nicvf_stop(netdev);
+ nicvf_open(netdev);
+ }
+
+ return 0;
+}
+
static int nicvf_get_rss_hash_opts(struct nicvf *nic,
struct ethtool_rxnfc *info)
{
@@ -787,6 +821,7 @@ static const struct ethtool_ops nicvf_ethtool_ops = {
.get_regs = nicvf_get_regs,
.get_coalesce = nicvf_get_coalesce,
.get_ringparam = nicvf_get_ringparam,
+ .set_ringparam = nicvf_set_ringparam,
.get_rxnfc = nicvf_get_rxnfc,
.set_rxnfc = nicvf_set_rxnfc,
.get_rxfh_key_size = nicvf_get_rxfh_key_size,
diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_queues.c b/drivers/net/ethernet/cavium/thunder/nicvf_queues.c
index d2ac133..ac0390b 100644
--- a/drivers/net/ethernet/cavium/thunder/nicvf_queues.c
+++ b/drivers/net/ethernet/cavium/thunder/nicvf_queues.c
@@ -603,7 +603,7 @@ void nicvf_cmp_queue_config(struct nicvf *nic, struct queue_set *qs,
cq_cfg.ena = 1;
cq_cfg.reset = 0;
cq_cfg.caching = 0;
- cq_cfg.qsize = CMP_QSIZE;
+ cq_cfg.qsize = ilog2(qs->cq_len >> 10);
cq_cfg.avg_con = 0;
nicvf_queue_reg_write(nic, NIC_QSET_CQ_0_7_CFG, qidx, *(u64 *)&cq_cfg);

@@ -652,9 +652,12 @@ static void nicvf_snd_queue_config(struct nicvf *nic, struct queue_set *qs,
sq_cfg.ena = 1;
sq_cfg.reset = 0;
sq_cfg.ldwb = 0;
- sq_cfg.qsize = SND_QSIZE;
+ sq_cfg.qsize = ilog2(qs->sq_len >> 10);
sq_cfg.tstmp_bgx_intf = 0;
- sq_cfg.cq_limit = 0;
+ /* CQ's level at which HW will stop processing SQEs to avoid
+ * transmitting a pkt with no space in CQ to post CQE_TX.
+ */
+ sq_cfg.cq_limit = (CMP_QUEUE_PIPELINE_RSVD * 256) / qs->cq_len;
nicvf_queue_reg_write(nic, NIC_QSET_SQ_0_7_CFG, qidx, *(u64 *)&sq_cfg);

/* Set threshold value for interrupt generation */
@@ -816,11 +819,21 @@ int nicvf_config_data_transfer(struct nicvf *nic, bool enable)
{
bool disable = false;
struct queue_set *qs = nic->qs;
+ struct queue_set *pqs = nic->pnicvf->qs;
int qidx;

if (!qs)
return 0;

+ /* Take primary VF's queue lengths.
+ * This is needed to take queue lengths set from ethtool
+ * into consideration.
+ */
+ if (nic->sqs_mode && pqs) {
+ qs->cq_len = pqs->cq_len;
+ qs->sq_len = pqs->sq_len;
+ }
+
if (enable) {
if (nicvf_alloc_resources(nic))
return -ENOMEM;
diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_queues.h b/drivers/net/ethernet/cavium/thunder/nicvf_queues.h
index 9e21046..5cb84da 100644
--- a/drivers/net/ethernet/cavium/thunder/nicvf_queues.h
+++ b/drivers/net/ethernet/cavium/thunder/nicvf_queues.h
@@ -59,8 +59,9 @@
/* Default queue count per QS, its lengths and threshold values */
#define DEFAULT_RBDR_CNT 1

-#define SND_QSIZE SND_QUEUE_SIZE2
+#define SND_QSIZE SND_QUEUE_SIZE0
#define SND_QUEUE_LEN (1ULL << (SND_QSIZE + 10))
+#define MIN_SND_QUEUE_LEN (1ULL << (SND_QUEUE_SIZE0 + 10))
#define MAX_SND_QUEUE_LEN (1ULL << (SND_QUEUE_SIZE6 + 10))
#define SND_QUEUE_THRESH 2ULL
#define MIN_SQ_DESC_PER_PKT_XMIT 2
@@ -70,11 +71,18 @@
/* Keep CQ and SQ sizes same, if timestamping
* is enabled this equation will change.
*/
-#define CMP_QSIZE CMP_QUEUE_SIZE2
+#define CMP_QSIZE CMP_QUEUE_SIZE0
#define CMP_QUEUE_LEN (1ULL << (CMP_QSIZE + 10))
+#define MIN_CMP_QUEUE_LEN (1ULL << (CMP_QUEUE_SIZE0 + 10))
+#define MAX_CMP_QUEUE_LEN (1ULL << (CMP_QUEUE_SIZE6 + 10))
#define CMP_QUEUE_CQE_THRESH (NAPI_POLL_WEIGHT / 2)
#define CMP_QUEUE_TIMER_THRESH 80 /* ~2usec */

+/* No of CQEs that might anyway gets used by HW due to pipelining
+ * effects irrespective of PASS/DROP/LEVELS being configured
+ */
+#define CMP_QUEUE_PIPELINE_RSVD 544
+
#define RBDR_SIZE RBDR_SIZE0
#define RCV_BUF_COUNT (1ULL << (RBDR_SIZE + 13))
#define MAX_RCV_BUF_COUNT (1ULL << (RBDR_SIZE6 + 13))
@@ -93,8 +101,8 @@
* RED accepts pkt if unused CQE < 2304 & >= 2560
* DROPs pkts if unused CQE < 2304
*/
-#define RQ_PASS_CQ_LVL 160ULL
-#define RQ_DROP_CQ_LVL 144ULL
+#define RQ_PASS_CQ_LVL 192ULL
+#define RQ_DROP_CQ_LVL 184ULL

/* RED and Backpressure levels of RBDR for pkt reception
* For RBDR, level is a measure of fullness i.e 0x0 means empty
--
2.7.4