[PATCH v3 5/5] net: ethernet: ti: cpsw: add ethtool channels support

From: Ivan Khoronzhuk
Date: Mon Aug 15 2016 - 19:26:18 EST


These ops allow to control number of channels driver is allowed to
work with at cpdma level. The maximum number of channels is 8 for
rx and 8 for tx. In dual_emac mode the h/w channels are shared
between two interfaces and changing number on one interface changes
number of channels on another.

How many channels are supported and enabled:
$ ethtool -l ethX

Change number of channels (up to 8)
$ ethtool -L ethX rx 6 tx 6

Per-channel statistic:
$ ethtool -S ethX

Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx>
---
drivers/net/ethernet/ti/cpsw.c | 180 ++++++++++++++++++++++++++++++++++++++++-
1 file changed, 176 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index 6dcbd8a..f02e577 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -735,6 +735,11 @@ static void cpsw_rx_handler(void *token, int len, int status)
}

requeue:
+ if (netif_dormant(ndev)) {
+ dev_kfree_skb_any(new_skb);
+ return;
+ }
+
ch = cpsw->rxch[skb_get_queue_mapping(new_skb)];
ret = cpdma_chan_submit(ch, new_skb, new_skb->data,
skb_tailroom(new_skb), 0);
@@ -1267,9 +1272,8 @@ static void cpsw_init_host_port(struct cpsw_priv *priv)
}
}

-static int cpsw_fill_rx_channels(struct net_device *ndev)
+static int cpsw_fill_rx_channels(struct cpsw_priv *priv)
{
- struct cpsw_priv *priv = netdev_priv(ndev);
struct cpsw_common *cpsw = priv->cpsw;
struct sk_buff *skb;
int ch, i, ret;
@@ -1279,7 +1283,7 @@ static int cpsw_fill_rx_channels(struct net_device *ndev)

ch_buf_num = cpdma_chan_get_rx_buf_num(cpsw->rxch[ch]);
for (i = 0; i < ch_buf_num; i++) {
- skb = __netdev_alloc_skb_ip_align(ndev,
+ skb = __netdev_alloc_skb_ip_align(priv->ndev,
cpsw->rx_packet_max,
GFP_KERNEL);
if (!skb) {
@@ -1397,7 +1401,7 @@ static int cpsw_ndo_open(struct net_device *ndev)
enable_irq(cpsw->irqs_table[0]);
}

- ret = cpsw_fill_rx_channels(ndev);
+ ret = cpsw_fill_rx_channels(priv);
if (ret < 0)
goto err_cleanup;

@@ -2060,6 +2064,172 @@ static void cpsw_ethtool_op_complete(struct net_device *ndev)
cpsw_err(priv, drv, "ethtool complete failed %d\n", ret);
}

+static void cpsw_get_channels(struct net_device *ndev,
+ struct ethtool_channels *ch)
+{
+ struct cpsw_common *cpsw = ndev_to_cpsw(ndev);
+
+ ch->max_combined = 0;
+ ch->max_rx = CPSW_MAX_QUEUES;
+ ch->max_tx = CPSW_MAX_QUEUES;
+ ch->max_other = 0;
+ ch->other_count = 0;
+ ch->rx_count = cpsw->rx_ch_num;
+ ch->tx_count = cpsw->tx_ch_num;
+ ch->combined_count = 0;
+}
+
+static int cpsw_check_ch_settings(struct cpsw_common *cpsw,
+ struct ethtool_channels *ch)
+{
+ if (ch->combined_count)
+ return -EINVAL;
+
+ /* verify we have at least one channel in each direction */
+ if (!ch->rx_count || !ch->tx_count)
+ return -EINVAL;
+
+ if (ch->rx_count > cpsw->data.channels ||
+ ch->tx_count > cpsw->data.channels)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int cpsw_update_channels_res(struct cpsw_priv *priv, int ch_num, int rx)
+{
+ int (*poll)(struct napi_struct *, int);
+ struct cpsw_common *cpsw = priv->cpsw;
+ void (*handler)(void *, int, int);
+ struct cpdma_chan **chan;
+ int ret, *ch;
+
+ if (rx) {
+ ch = &cpsw->rx_ch_num;
+ chan = cpsw->rxch;
+ handler = cpsw_rx_handler;
+ poll = cpsw_rx_poll;
+ } else {
+ ch = &cpsw->tx_ch_num;
+ chan = cpsw->txch;
+ handler = cpsw_tx_handler;
+ poll = cpsw_tx_poll;
+ }
+
+ while (*ch < ch_num) {
+ chan[*ch] = cpdma_chan_create(cpsw->dma, *ch, handler, rx);
+
+ if (IS_ERR(chan[*ch]))
+ return PTR_ERR(chan[*ch]);
+
+ if (!chan[*ch])
+ return -EINVAL;
+
+ cpsw_info(priv, ifup, "created new %d %s channel\n", *ch,
+ (rx ? "rx" : "tx"));
+ (*ch)++;
+ }
+
+ while (*ch > ch_num) {
+ (*ch)--;
+
+ ret = cpdma_chan_destroy(chan[*ch]);
+ if (ret)
+ return ret;
+
+ cpsw_info(priv, ifup, "destroyed %d %s channel\n", *ch,
+ (rx ? "rx" : "tx"));
+ }
+
+ return 0;
+}
+
+static int cpsw_update_channels(struct cpsw_priv *priv,
+ struct ethtool_channels *ch)
+{
+ int ret;
+
+ ret = cpsw_update_channels_res(priv, ch->rx_count, 1);
+ if (ret)
+ return ret;
+
+ ret = cpsw_update_channels_res(priv, ch->tx_count, 0);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int cpsw_set_channels(struct net_device *ndev,
+ struct ethtool_channels *chs)
+{
+ struct cpsw_priv *priv = netdev_priv(ndev);
+ struct cpsw_common *cpsw = priv->cpsw;
+ struct cpsw_slave *slave;
+ int i, ret;
+
+ ret = cpsw_check_ch_settings(cpsw, chs);
+ if (ret < 0)
+ return ret;
+
+ cpsw_intr_disable(cpsw);
+
+ for (i = cpsw->data.slaves, slave = cpsw->slaves; i; i--, slave++) {
+ if (!(slave->ndev && netif_running(slave->ndev)))
+ continue;
+
+ netif_tx_stop_all_queues(slave->ndev);
+ netif_dormant_on(slave->ndev);
+ }
+
+ cpdma_ctlr_stop(cpsw->dma);
+ ret = cpsw_update_channels(priv, chs);
+ if (ret)
+ goto err;
+
+ for (i = cpsw->data.slaves, slave = cpsw->slaves; i; i--, slave++) {
+ if (!(slave->ndev && netif_running(slave->ndev)))
+ continue;
+
+ /* inform stack about new count of queues */
+ ret = netif_set_real_num_tx_queues(slave->ndev,
+ cpsw->tx_ch_num);
+ if (ret) {
+ dev_err(priv->dev, "cannot set real number of tx queues\n");
+ goto err;
+ }
+
+ ret = netif_set_real_num_rx_queues(slave->ndev,
+ cpsw->rx_ch_num);
+ if (ret) {
+ dev_err(priv->dev, "cannot set real number of rx queues\n");
+ goto err;
+ }
+
+ netif_dormant_off(slave->ndev);
+ }
+
+ if (cpsw_common_res_usage_state(cpsw)) {
+ if (cpsw_fill_rx_channels(priv))
+ goto err;
+
+ cpdma_ctlr_start(cpsw->dma);
+ cpsw_intr_enable(cpsw);
+ }
+
+ for (i = cpsw->data.slaves, slave = cpsw->slaves; i; i--, slave++) {
+ if (!(slave->ndev && netif_running(slave->ndev)))
+ continue;
+ netif_tx_start_all_queues(slave->ndev);
+ }
+
+ return 0;
+err:
+ dev_err(priv->dev, "cannot update channels number, closing device\n");
+ dev_close(ndev);
+ return ret;
+}
+
static const struct ethtool_ops cpsw_ethtool_ops = {
.get_drvinfo = cpsw_get_drvinfo,
.get_msglevel = cpsw_get_msglevel,
@@ -2081,6 +2251,8 @@ static const struct ethtool_ops cpsw_ethtool_ops = {
.get_regs = cpsw_get_regs,
.begin = cpsw_ethtool_op_begin,
.complete = cpsw_ethtool_op_complete,
+ .get_channels = cpsw_get_channels,
+ .set_channels = cpsw_set_channels,
};

static void cpsw_slave_init(struct cpsw_slave *slave, struct cpsw_common *cpsw,
--
1.9.1