[PATCH net-next v2 1/5] netdevice: convert private flags > BIT(31) to bitfields
From: Alexander Lobakin <aleksander.lobakin@intel.com>
Date: 2024-07-03 15:04:56
Also in:
lkml
Subsystem:
documentation, microchip lan966x ethernet driver, networking drivers, networking [general], the rest · Maintainers:
Jonathan Corbet, Horatiu Vultur, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Make dev->priv_flags `u32` back and define bits higher than 31 as bitfield booleans as per Jakub's suggestion. This simplifies code which accesses these bits with no optimization loss (testb both before/after), allows to not extend &netdev_priv_flags each time, but also scales better as bits > 63 in the future would only add a new u64 to the structure with no complications, comparing to that extending ::priv_flags would require converting it to a bitmap. Note that I picked `unsigned long :1` to not lose any potential optimizations comparing to `bool :1` etc. Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> --- .../networking/net_cachelines/net_device.rst | 4 ++- include/linux/netdevice.h | 30 ++++++++++++------- .../ethernet/microchip/lan966x/lan966x_main.c | 2 +- drivers/net/macvlan.c | 3 +- drivers/net/vxlan/vxlan_core.c | 3 +- net/8021q/vlanproc.c | 4 +-- net/core/dev.c | 4 +-- net/core/dev_ioctl.c | 9 +++--- net/core/rtnetlink.c | 2 +- 9 files changed, 37 insertions(+), 24 deletions(-)
diff --git a/Documentation/networking/net_cachelines/net_device.rst b/Documentation/networking/net_cachelines/net_device.rst
index 70c4fb9d4e5c..d7ba48ff5559 100644
--- a/Documentation/networking/net_cachelines/net_device.rst
+++ b/Documentation/networking/net_cachelines/net_device.rst@@ -7,6 +7,7 @@ net_device struct fast path usage breakdown Type Name fastpath_tx_access fastpath_rx_access Comments ..struct ..net_device +unsigned_long:32 priv_flags read_mostly - __dev_queue_xmit(tx) char name[16] - - struct_netdev_name_node* name_node struct_dev_ifalias* ifalias
@@ -23,7 +24,6 @@ struct_list_head ptype_specific struct adj_list unsigned_int flags read_mostly read_mostly __dev_queue_xmit,__dev_xmit_skb,ip6_output,__ip6_finish_output(tx);ip6_rcv_core(rx) xdp_features_t xdp_features -unsigned_long_long priv_flags read_mostly - __dev_queue_xmit(tx) struct_net_device_ops* netdev_ops read_mostly - netdev_core_pick_tx,netdev_start_xmit(tx) struct_xdp_metadata_ops* xdp_metadata_ops int ifindex - read_mostly ip6_rcv_core
@@ -163,6 +163,8 @@ struct_lock_class_key* qdisc_tx_busylock bool proto_down unsigned:1 wol_enabled unsigned:1 threaded - - napi_poll(napi_enable,dev_set_threaded) +unsigned_long:1 see_all_hwtstamp_requests +unsigned_long:1 change_proto_down struct_list_head net_notifier_list struct_macsec_ops* macsec_ops struct_udp_tunnel_nic_info* udp_tunnel_nic_info
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 3c719f0d5f5a..20ffc7a112da 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h@@ -1608,7 +1608,8 @@ struct net_device_ops { * userspace; this means that the order of these flags can change * during any kernel release. * - * You should have a pretty good reason to be extending these flags. + * You should add bitfield booleans after either net_device::priv_flags + * (hotpath) or ::threaded (slowpath) instead of extending these flags. * * @IFF_802_1Q_VLAN: 802.1Q VLAN device * @IFF_EBRIDGE: Ethernet bridging device
@@ -1647,10 +1648,6 @@ struct net_device_ops { * @IFF_NO_ADDRCONF: prevent ipv6 addrconf * @IFF_TX_SKB_NO_LINEAR: device/driver is capable of xmitting frames with * skb_headlen(skb) == 0 (data starts from frag0) - * @IFF_CHANGE_PROTO_DOWN: device supports setting carrier via IFLA_PROTO_DOWN - * @IFF_SEE_ALL_HWTSTAMP_REQUESTS: device wants to see calls to - * ndo_hwtstamp_set() for all timestamp requests regardless of source, - * even if those aren't HWTSTAMP_SOURCE_NETDEV. */ enum netdev_priv_flags { IFF_802_1Q_VLAN = 1<<0,
@@ -1685,8 +1682,6 @@ enum netdev_priv_flags { IFF_L3MDEV_RX_HANDLER = 1<<29, IFF_NO_ADDRCONF = BIT_ULL(30), IFF_TX_SKB_NO_LINEAR = BIT_ULL(31), - IFF_CHANGE_PROTO_DOWN = BIT_ULL(32), - IFF_SEE_ALL_HWTSTAMP_REQUESTS = BIT_ULL(33), }; #define IFF_802_1Q_VLAN IFF_802_1Q_VLAN
@@ -1750,6 +1745,11 @@ enum netdev_reg_state { * data with strictly "high-level" data, and it has to know about * almost every data structure used in the INET module. * + * @priv_flags_fast: both hotpath private flags as bits and as bitfield + * booleans combined, only to assert cacheline placement + * @priv_flags: flags invisible to userspace defined as bits, see + * enum netdev_priv_flags for the definitions + * * @name: This is the first field of the "visible" part of this structure * (i.e. as seen by users in the "Space.c" file). It is the name * of the interface.
@@ -1816,8 +1816,6 @@ enum netdev_reg_state { * * @flags: Interface flags (a la BSD) * @xdp_features: XDP capability supported by the device - * @priv_flags: Like 'flags' but invisible to userspace, - * see if.h for the definitions * @gflags: Global flags ( kept as legacy ) * @padded: How much padding added by alloc_netdev() * @operstate: RFC2863 operstate
@@ -1989,6 +1987,12 @@ enum netdev_reg_state { * * @threaded: napi threaded mode is enabled * + * @see_all_hwtstamp_requests: device wants to see calls to + * ndo_hwtstamp_set() for all timestamp requests + * regardless of source, even if those aren't + * HWTSTAMP_SOURCE_NETDEV + * @change_proto_down: device supports setting carrier via IFLA_PROTO_DOWN + * * @module_fw_flash_in_progress: Module firmware flashing is in progress. * * @net_notifier_list: List of per-net netdev notifier block
@@ -2041,7 +2045,9 @@ struct net_device { /* TX read-mostly hotpath */ __cacheline_group_begin(net_device_read_tx); - unsigned long long priv_flags; + struct_group(priv_flags_fast, + unsigned long priv_flags:32; + ); const struct net_device_ops *netdev_ops; const struct header_ops *header_ops; struct netdev_queue *_tx;
@@ -2376,6 +2382,10 @@ struct net_device { bool proto_down; bool threaded; + /* priv_flags_slow, ungrouped to save space */ + unsigned long see_all_hwtstamp_requests:1; + unsigned long change_proto_down:1; + unsigned module_fw_flash_in_progress:1; struct list_head net_notifier_list;
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
index ec672af12e25..534d4716d5f7 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c@@ -816,7 +816,7 @@ static int lan966x_probe_port(struct lan966x *lan966x, u32 p, NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_TC; dev->hw_features |= NETIF_F_HW_TC; - dev->priv_flags |= IFF_SEE_ALL_HWTSTAMP_REQUESTS; + dev->see_all_hwtstamp_requests = true; dev->needed_headroom = IFH_LEN_BYTES; eth_hw_addr_gen(dev, lan966x->base_mac, p + 1);
diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 67b7ef2d463f..3aa6d33efdf5 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c@@ -1213,7 +1213,8 @@ void macvlan_common_setup(struct net_device *dev) dev->max_mtu = ETH_MAX_MTU; dev->priv_flags &= ~IFF_TX_SKB_SHARING; netif_keep_dst(dev); - dev->priv_flags |= IFF_UNICAST_FLT | IFF_CHANGE_PROTO_DOWN; + dev->priv_flags |= IFF_UNICAST_FLT; + dev->change_proto_down = true; dev->netdev_ops = &macvlan_netdev_ops; dev->needs_free_netdev = true; dev->priv_destructor = macvlan_dev_free;
diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index ba59e92ab941..c1dedda4e6ba 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c@@ -3332,7 +3332,8 @@ static void vxlan_setup(struct net_device *dev) dev->hw_features |= NETIF_F_RXCSUM; dev->hw_features |= NETIF_F_GSO_SOFTWARE; netif_keep_dst(dev); - dev->priv_flags |= IFF_NO_QUEUE | IFF_CHANGE_PROTO_DOWN; + dev->priv_flags |= IFF_NO_QUEUE; + dev->change_proto_down = true; /* MTU range: 68 - 65535 */ dev->min_mtu = ETH_MIN_MTU;
diff --git a/net/8021q/vlanproc.c b/net/8021q/vlanproc.c
index 87b959da00cd..fa67374bda49 100644
--- a/net/8021q/vlanproc.c
+++ b/net/8021q/vlanproc.c@@ -238,9 +238,9 @@ static int vlandev_seq_show(struct seq_file *seq, void *offset) stats = dev_get_stats(vlandev, &temp); seq_printf(seq, - "%s VID: %d REORDER_HDR: %i dev->priv_flags: %llx\n", + "%s VID: %d REORDER_HDR: %i dev->priv_flags: %x\n", vlandev->name, vlan->vlan_id, - (int)(vlan->flags & 1), vlandev->priv_flags); + (int)(vlan->flags & 1), (u32)vlandev->priv_flags); seq_printf(seq, fmt64, "total frames received", stats->rx_packets); seq_printf(seq, fmt64, "total bytes received", stats->rx_bytes);
diff --git a/net/core/dev.c b/net/core/dev.c
index 385c4091aa77..a2ced6cd5138 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c@@ -9266,7 +9266,7 @@ EXPORT_SYMBOL(netdev_port_same_parent_id); */ int dev_change_proto_down(struct net_device *dev, bool proto_down) { - if (!(dev->priv_flags & IFF_CHANGE_PROTO_DOWN)) + if (!dev->change_proto_down) return -EOPNOTSUPP; if (!netif_device_present(dev)) return -ENODEV;
@@ -11909,7 +11909,7 @@ static struct pernet_operations __net_initdata default_device_ops = { static void __init net_dev_struct_check(void) { /* TX read-mostly hotpath */ - CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_tx, priv_flags); + CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_tx, priv_flags_fast); CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_tx, netdev_ops); CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_tx, header_ops); CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_tx, _tx);
diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c
index b9719ed3c3fd..3868486fb71f 100644
--- a/net/core/dev_ioctl.c
+++ b/net/core/dev_ioctl.c@@ -319,8 +319,7 @@ static int dev_get_hwtstamp(struct net_device *dev, struct ifreq *ifr) * should take precedence in front of hardware timestamping provided by the * netdev. If the netdev driver needs to perform specific actions even for PHY * timestamping to work properly (a switch port must trap the timestamped - * frames and not forward them), it must set IFF_SEE_ALL_HWTSTAMP_REQUESTS in - * dev->priv_flags. + * frames and not forward them), it must set dev->see_all_hwtstamp_requests. */ int dev_set_hwtstamp_phylib(struct net_device *dev, struct kernel_hwtstamp_config *cfg,
@@ -334,13 +333,13 @@ int dev_set_hwtstamp_phylib(struct net_device *dev, cfg->source = phy_ts ? HWTSTAMP_SOURCE_PHYLIB : HWTSTAMP_SOURCE_NETDEV; - if (phy_ts && (dev->priv_flags & IFF_SEE_ALL_HWTSTAMP_REQUESTS)) { + if (phy_ts && dev->see_all_hwtstamp_requests) { err = ops->ndo_hwtstamp_get(dev, &old_cfg); if (err) return err; } - if (!phy_ts || (dev->priv_flags & IFF_SEE_ALL_HWTSTAMP_REQUESTS)) { + if (!phy_ts || dev->see_all_hwtstamp_requests) { err = ops->ndo_hwtstamp_set(dev, cfg, extack); if (err) { if (extack->_msg)
@@ -349,7 +348,7 @@ int dev_set_hwtstamp_phylib(struct net_device *dev, } } - if (phy_ts && (dev->priv_flags & IFF_SEE_ALL_HWTSTAMP_REQUESTS)) + if (phy_ts && dev->see_all_hwtstamp_requests) changed = kernel_hwtstamp_config_changed(&old_cfg, cfg); if (phy_ts) {
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index eabfc8290f5e..cff172f0ff3d 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c@@ -2724,7 +2724,7 @@ static int do_set_proto_down(struct net_device *dev, bool proto_down; int err; - if (!(dev->priv_flags & IFF_CHANGE_PROTO_DOWN)) { + if (!dev->change_proto_down) { NL_SET_ERR_MSG(extack, "Protodown not supported by device"); return -EOPNOTSUPP; }
--
2.45.2