[PATCH] Add Multiple TX/RX Queues Support for WWAN Network Device
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STALE1766d
From: <hidden>
Date: 2021-12-08 04:04:24
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lkml
Subsystem:
networking drivers, the rest, wwan drivers · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Loic Poulain, Sergey Ryazanov
From: Xiayu Zhang <redacted>
This patch adds 2 callback functions get_num_tx_queues() and
get_num_rx_queues() to let WWAN network device driver customize its own
TX and RX queue numbers. It gives WWAN driver a chance to implement its
own software strategies, such as TX Qos.
Currently, if WWAN device driver creates default bearer interface when
calling wwan_register_ops(), there will be only 1 TX queue and 1 RX queue
for the WWAN network device. In this case, driver is not able to enlarge
the queue numbers by calling netif_set_real_num_tx_queues() or
netif_set_real_num_rx_queues() to take advantage of the network device's
capability of supporting multiple TX/RX queues.
As for additional interfaces of secondary bearers, if userspace service
doesn't specify the num_tx_queues or num_rx_queues in netlink message or
iproute2 command, there also will be only 1 TX queue and 1 RX queue for
each additional interface. If userspace service specifies the num_tx_queues
and num_rx_queues, however, these numbers could be not able to match the
capabilities of network device.
Besides, userspace service is hard to learn every WWAN network device's
TX/RX queue numbers.
In order to let WWAN driver determine the queue numbers, this patch adds
below callback functions in wwan_ops:
struct wwan_ops {
unsigned int priv_size;
...
unsigned int (*get_num_tx_queues)(unsigned int hint_num);
unsigned int (*get_num_rx_queues)(unsigned int hint_num);
};
WWAN subsystem uses the input parameters num_tx_queues and num_rx_queues of
wwan_rtnl_alloc() as hint values, and passes the 2 values to the two
callback functions. WWAN device driver should determine the actual numbers
of network device's TX and RX queues according to the hint value and
device's capabilities.
Signed-off-by: Xiayu Zhang <redacted>
---
drivers/net/wwan/wwan_core.c | 25 ++++++++++++++++++++++++-
include/linux/wwan.h | 6 ++++++
2 files changed, 30 insertions(+), 1 deletion(-)
diff --git a/drivers/net/wwan/wwan_core.c b/drivers/net/wwan/wwan_core.c
index d293ab688044..00095c6987be 100644
--- a/drivers/net/wwan/wwan_core.c
+++ b/drivers/net/wwan/wwan_core.c@@ -823,6 +823,7 @@ static struct net_device *wwan_rtnl_alloc(struct nlattr *tb[], struct wwan_device *wwandev = wwan_dev_get_by_name(devname); struct net_device *dev; unsigned int priv_size; + unsigned int num_txqs, num_rxqs; if (IS_ERR(wwandev)) return ERR_CAST(wwandev);
@@ -833,9 +834,31 @@ static struct net_device *wwan_rtnl_alloc(struct nlattr *tb[], goto out; } + /* let wwan device driver determine TX queue number if it wants */ + if (wwandev->ops->get_num_tx_queues) { + num_txqs = wwandev->ops->get_num_tx_queues(num_tx_queues); + if (num_txqs < 1 || num_txqs > 4096) { + dev = ERR_PTR(-EINVAL); + goto out; + } + } else { + num_txqs = num_tx_queues; + } + + /* let wwan device driver determine RX queue number if it wants */ + if (wwandev->ops->get_num_rx_queues) { + num_rxqs = wwandev->ops->get_num_rx_queues(num_rx_queues); + if (num_rxqs < 1 || num_rxqs > 4096) { + dev = ERR_PTR(-EINVAL); + goto out; + } + } else { + num_rxqs = num_rx_queues; + } + priv_size = sizeof(struct wwan_netdev_priv) + wwandev->ops->priv_size; dev = alloc_netdev_mqs(priv_size, ifname, name_assign_type, - wwandev->ops->setup, num_tx_queues, num_rx_queues); + wwandev->ops->setup, num_txqs, num_rxqs); if (dev) { SET_NETDEV_DEV(dev, &wwandev->dev);
diff --git a/include/linux/wwan.h b/include/linux/wwan.h
index 9fac819f92e3..69c0af7ab6af 100644
--- a/include/linux/wwan.h
+++ b/include/linux/wwan.h@@ -156,6 +156,10 @@ static inline void *wwan_netdev_drvpriv(struct net_device *dev) * @setup: set up a new netdev * @newlink: register the new netdev * @dellink: remove the given netdev + * @get_num_tx_queues: determine number of transmit queues + * to create when creating a new device. + * @get_num_rx_queues: determine number of receive queues + * to create when creating a new device. */ struct wwan_ops { unsigned int priv_size;
@@ -164,6 +168,8 @@ struct wwan_ops { u32 if_id, struct netlink_ext_ack *extack); void (*dellink)(void *ctxt, struct net_device *dev, struct list_head *head); + unsigned int (*get_num_tx_queues)(unsigned int hint_num); + unsigned int (*get_num_rx_queues)(unsigned int hint_num); }; int wwan_register_ops(struct device *parent, const struct wwan_ops *ops,
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2.17.0