| Message ID | 20200505192057.9086-2-olteanv@gmail.com |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | tc-gate offload for SJA1105 DSA switch | expand |
On Tue, 5 May 2020 22:20:52 +0300, Vladimir Oltean <olteanv@gmail.com> wrote: > From: Vladimir Oltean <vladimir.oltean@nxp.com> > > As its implementation shows, this is synonimous with calling > dsa_slave_dev_check followed by dsa_slave_to_port, so it is quite simple > already and provides functionality which is already there. > > However there is now a need for these functions outside dsa_priv.h, for > example in drivers that perform mirroring and redirection through > tc-flower offloads (they are given raw access to the flow_cls_offload > structure), where they need to call this function on act->dev. > > But simply exporting dsa_slave_to_port would make it non-inline and > would result in an extra function call in the hotpath, as can be seen > for example in sja1105: > > Before: > > 000006dc <sja1105_xmit>: > { > 6dc: e92d4ff0 push {r4, r5, r6, r7, r8, r9, sl, fp, lr} > 6e0: e1a04000 mov r4, r0 > 6e4: e591958c ldr r9, [r1, #1420] ; 0x58c <- Inline dsa_slave_to_port > 6e8: e1a05001 mov r5, r1 > 6ec: e24dd004 sub sp, sp, #4 > u16 tx_vid = dsa_8021q_tx_vid(dp->ds, dp->index); > 6f0: e1c901d8 ldrd r0, [r9, #24] > 6f4: ebfffffe bl 0 <dsa_8021q_tx_vid> > 6f4: R_ARM_CALL dsa_8021q_tx_vid > u8 pcp = netdev_txq_to_tc(netdev, queue_mapping); > 6f8: e1d416b0 ldrh r1, [r4, #96] ; 0x60 > u16 tx_vid = dsa_8021q_tx_vid(dp->ds, dp->index); > 6fc: e1a08000 mov r8, r0 > > After: > > 000006e4 <sja1105_xmit>: > { > 6e4: e92d4ff0 push {r4, r5, r6, r7, r8, r9, sl, fp, lr} > 6e8: e1a04000 mov r4, r0 > 6ec: e24dd004 sub sp, sp, #4 > struct dsa_port *dp = dsa_slave_to_port(netdev); > 6f0: e1a00001 mov r0, r1 > { > 6f4: e1a05001 mov r5, r1 > struct dsa_port *dp = dsa_slave_to_port(netdev); > 6f8: ebfffffe bl 0 <dsa_slave_to_port> > 6f8: R_ARM_CALL dsa_slave_to_port > 6fc: e1a09000 mov r9, r0 > u16 tx_vid = dsa_8021q_tx_vid(dp->ds, dp->index); > 700: e1c001d8 ldrd r0, [r0, #24] > 704: ebfffffe bl 0 <dsa_8021q_tx_vid> > 704: R_ARM_CALL dsa_8021q_tx_vid > > Because we want to avoid possible performance regressions, introduce > this new function which is designed to be public. > > Suggested-by: Vivien Didelot <vivien.didelot@gmail.com> > Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Vivien Didelot <vivien.didelot@gmail.com>
diff --git a/include/net/dsa.h b/include/net/dsa.h index fb3f9222f2a1..6dfc8c2f68b8 100644 --- a/include/net/dsa.h +++ b/include/net/dsa.h @@ -637,6 +637,7 @@ void dsa_devlink_resource_occ_get_register(struct dsa_switch *ds, void *occ_get_priv); void dsa_devlink_resource_occ_get_unregister(struct dsa_switch *ds, u64 resource_id); +struct dsa_port *dsa_port_from_netdev(struct net_device *netdev); struct dsa_devlink_priv { struct dsa_switch *ds; diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c index 0384a911779e..1ce9ba8cf545 100644 --- a/net/dsa/dsa.c +++ b/net/dsa/dsa.c @@ -412,6 +412,15 @@ void dsa_devlink_resource_occ_get_unregister(struct dsa_switch *ds, } EXPORT_SYMBOL_GPL(dsa_devlink_resource_occ_get_unregister); +struct dsa_port *dsa_port_from_netdev(struct net_device *netdev) +{ + if (!netdev || !dsa_slave_dev_check(netdev)) + return ERR_PTR(-ENODEV); + + return dsa_slave_to_port(netdev); +} +EXPORT_SYMBOL_GPL(dsa_port_from_netdev); + static int __init dsa_init_module(void) { int rc;