netdevice: convert private flags > BIT(31) to bitfields

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>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

3 files changed, 7 insertions, 8 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 932d67b975f5..56aed88ceadf 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -9274,7 +9274,7 @@ 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;
@@ -11930,7 +11930,7 @@ 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 8592c052c0f4..473c437b6b53 100644
--- a/net/core/dev_ioctl.c
+++ b/net/core/dev_ioctl.c
@@ -317,8 +317,7 @@ 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,
@@ -332,13 +331,13 @@ 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)
@@ -347,7 +346,7 @@ 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 cd9487a12d1a..f0a520987085 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;
 	}