linux_dsm_epyc7002/include
Vladimir Oltean e1eea81120 net: dsa: introduce a dsa_port_from_netdev public helper
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-07 17:31:57 -07:00
..
acpi Additional ACPI updates for 5.7-rc1 2020-04-06 10:35:06 -07:00
asm-generic arch: split MODULE_ARCH_VERMAGIC definitions out to <asm/vermagic.h> 2020-04-23 10:50:26 +09:00
clocksource
crypto crypto: curve25519 - do not pollute dispatcher based on assembler 2020-04-09 00:01:59 +09:00
drm drm/bridge: analogix_dp: Split bind() into probe() and real bind() 2020-04-09 10:29:35 +02:00
dt-bindings RISC-V Patches for the 5.7 Merge Window, Part 1 2020-04-09 10:51:30 -07:00
keys
kunit
kvm
linux wireless-drivers-next patches for v5.8 2020-05-07 13:22:35 -07:00
math-emu
media
misc
net net: dsa: introduce a dsa_port_from_netdev public helper 2020-05-07 17:31:57 -07:00
pcmcia
ras
rdma
scsi SCSI misc on 20200402 2020-04-02 17:03:53 -07:00
soc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-06 22:10:13 -07:00
sound ASoC: Fixes for v5.7 2020-04-21 21:41:36 +02:00
target
trace Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-06 22:10:13 -07:00
uapi Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-06 22:10:13 -07:00
vdso vdso/datapage: Use correct clock mode name in comment 2020-04-20 19:19:52 +02:00
video
xen xen: Use evtchn_type_t as a type for event channels 2020-04-07 12:12:54 +02:00