[PATCH net-next 8/8] s390/qeth: support configurable RX copybreak

Julian Wiedmann
2020-02-27T17:08:16Z

Implement the ethtool hooks for the ETHTOOL_RX_COPYBREAK tunable.

The copybreak is stored into netdev_priv, so that we automatically go
back to the default value if the netdev is re-allocated.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
---
drivers/s390/net/qeth_core.h | 10 ++++++----
drivers/s390/net/qeth_core_main.c | 17 +++++++++++------
drivers/s390/net/qeth_ethtool.c | 31 +++++++++++++++++++++++++++++++
3 files changed, 48 insertions(+), 10 deletions(-)

diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h
index 9575a627a1e1..b7d64690ea38 100644
--- a/drivers/s390/net/qeth_core.h
+++ b/drivers/s390/net/qeth_core.h
@@ -189,6 +189,8 @@ struct qeth_vnicc_info {
#define QETH_IQD_MIN_TXQ 2 /* One for ucast, one for mcast. */
#define QETH_IQD_MCAST_TXQ 0
#define QETH_IQD_MIN_UCAST_TXQ 1
+
+#define QETH_RX_COPYBREAK (PAGE_SIZE >> 1)
#define QETH_IN_BUF_SIZE_DEFAULT 65536
#define QETH_IN_BUF_COUNT_DEFAULT 64
#define QETH_IN_BUF_COUNT_HSDEFAULT 128
@@ -219,9 +221,6 @@ struct qeth_vnicc_info {
#define QETH_HIGH_WATERMARK_PACK 5
#define QETH_WATERMARK_PACK_FUZZ 1

-/* large receive scatter gather copy break */
-#define QETH_RX_SG_CB (PAGE_SIZE >> 1)
-
struct qeth_hdr_layer3 {
__u8 id;
__u8 flags;
@@ -711,7 +710,6 @@ struct qeth_card_options {
struct qeth_vnicc_info vnicc; /* VNICC options */
int fake_broadcast;
enum qeth_discipline_id layer;
- int rx_sg_cb;
enum qeth_ipa_isolation_modes isolation;
enum qeth_ipa_isolation_modes prev_isolation;
int sniffer;
@@ -770,6 +768,10 @@ struct qeth_switch_info {
__u32 settings;
};

+struct qeth_priv {
+ unsigned int rx_copybreak;
+};
+
#define QETH_NAPI_WEIGHT NAPI_POLL_WEIGHT

struct qeth_card {
diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index cbd2b4c46ea4..1bcac50bb395 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -1257,7 +1257,6 @@ static void qeth_set_initial_options(struct qeth_card *card)
{
card->options.route4.type = NO_ROUTER;
card->options.route6.type = NO_ROUTER;
- card->options.rx_sg_cb = QETH_RX_SG_CB;
card->options.isolation = ISOLATION_MODE_NONE;
card->options.cq = QETH_CQ_DISABLED;
card->options.layer = QETH_DISCIPLINE_UNDETERMINED;
@@ -5268,6 +5267,7 @@ static int qeth_extract_skb(struct qeth_card *card,
int *__offset)
{
struct qdio_buffer_element *element = *__element;
+ struct qeth_priv *priv = netdev_priv(card->dev);
struct qdio_buffer *buffer = qethbuffer->buffer;
struct napi_struct *napi = &card->napi;
unsigned int linear_len = 0;
@@ -5343,7 +5343,7 @@ static int qeth_extract_skb(struct qeth_card *card,
}

use_rx_sg = (card->options.cq == QETH_CQ_ENABLED) ||
- (skb_len > card->options.rx_sg_cb &&
+ (skb_len > READ_ONCE(priv->rx_copybreak) &&
!atomic_read(&card->force_alloc_skb) &&
!IS_OSN(card));

@@ -5892,25 +5892,30 @@ static void qeth_clear_dbf_list(void)
static struct net_device *qeth_alloc_netdev(struct qeth_card *card)
{
struct net_device *dev;
+ struct qeth_priv *priv;

switch (card->info.type) {
case QETH_CARD_TYPE_IQD:
- dev = alloc_netdev_mqs(0, "hsi%d", NET_NAME_UNKNOWN,
+ dev = alloc_netdev_mqs(sizeof(*priv), "hsi%d", NET_NAME_UNKNOWN,
ether_setup, QETH_MAX_QUEUES, 1);
break;
case QETH_CARD_TYPE_OSM:
- dev = alloc_etherdev(0);
+ dev = alloc_etherdev(sizeof(*priv));
break;
case QETH_CARD_TYPE_OSN:
- dev = alloc_netdev(0, "osn%d", NET_NAME_UNKNOWN, ether_setup);
+ dev = alloc_netdev(sizeof(*priv), "osn%d", NET_NAME_UNKNOWN,
+ ether_setup);
break;
default:
- dev = alloc_etherdev_mqs(0, QETH_MAX_QUEUES, 1);
+ dev = alloc_etherdev_mqs(sizeof(*priv), QETH_MAX_QUEUES, 1);
}

if (!dev)
return NULL;

+ priv = netdev_priv(dev);
+ priv->rx_copybreak = QETH_RX_COPYBREAK;
+
dev->ml_priv = card;
dev->watchdog_timeo = QETH_TX_TIMEOUT;
dev->min_mtu = IS_OSN(card) ? 64 : 576;
diff --git a/drivers/s390/net/qeth_ethtool.c b/drivers/s390/net/qeth_ethtool.c
index ab59bc975719..9052c72d5b8f 100644
--- a/drivers/s390/net/qeth_ethtool.c
+++ b/drivers/s390/net/qeth_ethtool.c
@@ -175,6 +175,35 @@ static void qeth_get_channels(struct net_device *dev,
channels->combined_count = 0;
}

+static int qeth_get_tunable(struct net_device *dev,
+ const struct ethtool_tunable *tuna, void *data)
+{
+ struct qeth_priv *priv = netdev_priv(dev);
+
+ switch (tuna->id) {
+ case ETHTOOL_RX_COPYBREAK:
+ *(u32 *)data = priv->rx_copybreak;
+ return 0;
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int qeth_set_tunable(struct net_device *dev,
+ const struct ethtool_tunable *tuna,
+ const void *data)
+{
+ struct qeth_priv *priv = netdev_priv(dev);
+
+ switch (tuna->id) {
+ case ETHTOOL_RX_COPYBREAK:
+ WRITE_ONCE(priv->rx_copybreak, *(u32 *)data);
+ return 0;
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
/* Helper function to fill 'advertising' and 'supported' which are the same. */
/* Autoneg and full-duplex are supported and advertised unconditionally. */
/* Always advertise and support all speeds up to specified, and only one */
@@ -381,6 +410,8 @@ const struct ethtool_ops qeth_ethtool_ops = {
.get_sset_count = qeth_get_sset_count,
.get_drvinfo = qeth_get_drvinfo,
.get_channels = qeth_get_channels,
+ .get_tunable = qeth_get_tunable,
+ .set_tunable = qeth_set_tunable,
.get_link_ksettings = qeth_get_link_ksettings,
};

--
2.17.1