Commit 6cccb3bb authored by Aswin Karuvally's avatar Aswin Karuvally Committed by Jakub Kicinski
Browse files

s390/net: Remove LCS driver 



The original Open Systems Adapter (OSA) was introduced by IBM in the
mid-90s. These were then superseded by OSA-Express in 1999 which used
Queued Direct IO to greatly improve throughput. The newer cards
retained the older, slower non-QDIO (OSE) modes for compatibility with
older systems. In Linux, the lcs driver was responsible for cards
operating in the older OSE mode and the qeth driver was introduced to
allow the OSA-Express cards to operate in the newer QDIO (OSD) mode.

For an S390 machine from 1998 or later, there is no reason to use the
OSE mode and lcs driver as all OSA cards since 1999 provide the faster
OSD mode. As a result, it's been years since we have heard of a
customer configuration involving the lcs driver.

This patch removes the lcs driver. The technology it supports has been
obsolete for past 25+ years and is irrelevant for current use cases.

Reviewed-by: default avatarAlexandra Winter <wintera@linux.ibm.com>
Acked-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Acked-by: default avatarPeter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: default avatarAswin Karuvally <aswin@linux.ibm.com>
Signed-off-by: default avatarAlexandra Winter <wintera@linux.ibm.com>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250204103135.1619097-1-wintera@linux.ibm.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 863257c2

Documentation/arch/s390/driver-model.rst

+1 −1
Original line number Diff line number Diff line
@@ -244,7 +244,7 @@ information about the interrupt from the irb parameter. 
--------------------



The ccwgroup mechanism is designed to handle devices consisting of multiple ccw

devices, like lcs or ctc.

devices, like qeth or ctc.



The ccw driver provides a 'group' attribute. Piping bus ids of ccw devices to

this attributes creates a ccwgroup device consisting of these ccw devices (if

arch/s390/include/asm/irq.h

+0 −1
Original line number Diff line number Diff line
@@ -54,7 +54,6 @@ enum interruption_class { 
	IRQIO_C70,

	IRQIO_TAP,

	IRQIO_VMR,

	IRQIO_LCS,

	IRQIO_CTC,

	IRQIO_ADM,

	IRQIO_CSC,

arch/s390/kernel/irq.c

+0 −1
Original line number Diff line number Diff line
@@ -84,7 +84,6 @@ static const struct irq_class irqclass_sub_desc[] = { 
	{.irq = IRQIO_C70,  .name = "C70", .desc = "[I/O] 3270"},

	{.irq = IRQIO_TAP,  .name = "TAP", .desc = "[I/O] Tape"},

	{.irq = IRQIO_VMR,  .name = "VMR", .desc = "[I/O] Unit Record Devices"},

	{.irq = IRQIO_LCS,  .name = "LCS", .desc = "[I/O] LCS"},

	{.irq = IRQIO_CTC,  .name = "CTC", .desc = "[I/O] CTC"},

	{.irq = IRQIO_ADM,  .name = "ADM", .desc = "[I/O] EADM Subchannel"},

	{.irq = IRQIO_CSC,  .name = "CSC", .desc = "[I/O] CHSC Subchannel"},

drivers/s390/net/Kconfig

+1 −10
Original line number Diff line number Diff line
@@ -2,15 +2,6 @@ 
menu "S/390 network device drivers"

	depends on NETDEVICES && S390



config LCS

	def_tristate m

	prompt "Lan Channel Station Interface"

	depends on CCW && NETDEVICES && ETHERNET

	help

	  Select this option if you want to use LCS networking on IBM System z.

	  To compile as a module, choose M. The module name is lcs.

	  If you do not use LCS, choose N.



config CTCM

	def_tristate m

	prompt "CTC and MPC SNA device support"
@@ -98,7 +89,7 @@ config QETH_OSX 


config CCWGROUP

	tristate

	default (LCS || CTCM || QETH || SMC)

	default (CTCM || QETH || SMC)



config ISM

	tristate "Support for ISM vPCI Adapter"

drivers/s390/net/Makefile

+0 −1
Original line number Diff line number Diff line
@@ -8,7 +8,6 @@ obj-$(CONFIG_CTCM) += ctcm.o fsm.o 
obj-$(CONFIG_NETIUCV) += netiucv.o fsm.o

obj-$(CONFIG_SMSGIUCV) += smsgiucv.o

obj-$(CONFIG_SMSGIUCV_EVENT) += smsgiucv_app.o

obj-$(CONFIG_LCS) += lcs.o

qeth-y += qeth_core_sys.o qeth_core_main.o qeth_core_mpc.o qeth_ethtool.o

obj-$(CONFIG_QETH) += qeth.o

qeth_l2-y += qeth_l2_main.o qeth_l2_sys.o