kernel-ark/drivers/tty/hvc/Kconfig
Joe Millenbach 4f73bc4dd3 tty: Added a CONFIG_TTY option to allow removal of TTY
The option allows you to remove TTY and compile without errors. This
saves space on systems that won't support TTY interfaces anyway.
bloat-o-meter output is below.

The bulk of this patch consists of Kconfig changes adding "depends on
TTY" to various serial devices and similar drivers that require the TTY
layer.  Ideally, these dependencies would occur on a common intermediate
symbol such as SERIO, but most drivers "select SERIO" rather than
"depends on SERIO", and "select" does not respect dependencies.

bloat-o-meter output comparing our previous minimal to new minimal by
removing TTY.  The list is filtered to not show removed entries with awk
'$3 != "-"' as the list was very long.

add/remove: 0/226 grow/shrink: 2/14 up/down: 6/-35356 (-35350)
function                                     old     new   delta
chr_dev_init                                 166     170      +4
allow_signal                                  80      82      +2
static.__warned                              143     142      -1
disallow_signal                               63      62      -1
__set_special_pids                            95      94      -1
unregister_console                           126     121      -5
start_kernel                                 546     541      -5
register_console                             593     588      -5
copy_from_user                                45      40      -5
sys_setsid                                   128     120      -8
sys_vhangup                                   32      19     -13
do_exit                                     1543    1526     -17
bitmap_zero                                   60      40     -20
arch_local_irq_save                          137     117     -20
release_task                                 674     652     -22
static.spin_unlock_irqrestore                308     260     -48

Signed-off-by: Joe Millenbach <jmillenbach@gmail.com>
Reviewed-by: Jamey Sharp <jamey@minilop.net>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-18 16:15:27 -08:00

125 lines
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if TTY
config HVC_DRIVER
bool
help
Generic "hypervisor virtual console" infrastructure for various
hypervisors (pSeries, iSeries, Xen, lguest).
It will automatically be selected if one of the back-end console drivers
is selected.
config HVC_IRQ
bool
config HVC_CONSOLE
bool "pSeries Hypervisor Virtual Console support"
depends on PPC_PSERIES
select HVC_DRIVER
select HVC_IRQ
help
pSeries machines when partitioned support a hypervisor virtual
console. This driver allows each pSeries partition to have a console
which is accessed via the HMC.
config HVC_OLD_HVSI
bool "Old driver for pSeries serial port (/dev/hvsi*)"
depends on HVC_CONSOLE
default n
config HVC_OPAL
bool "OPAL Console support"
depends on PPC_POWERNV
select HVC_DRIVER
select HVC_IRQ
default y
help
PowerNV machines running under OPAL need that driver to get a console
config HVC_RTAS
bool "IBM RTAS Console support"
depends on PPC_RTAS
select HVC_DRIVER
help
IBM Console device driver which makes use of RTAS
config HVC_BEAT
bool "Toshiba's Beat Hypervisor Console support"
depends on PPC_CELLEB
select HVC_DRIVER
help
Toshiba's Cell Reference Set Beat Console device driver
config HVC_IUCV
bool "z/VM IUCV Hypervisor console support (VM only)"
depends on S390
select HVC_DRIVER
select IUCV
default y
help
This driver provides a Hypervisor console (HVC) back-end to access
a Linux (console) terminal via a z/VM IUCV communication path.
config HVC_XEN
bool "Xen Hypervisor Console support"
depends on XEN
select HVC_DRIVER
select HVC_IRQ
default y
help
Xen virtual console device driver
config HVC_XEN_FRONTEND
bool "Xen Hypervisor Multiple Consoles support"
depends on HVC_XEN
select XEN_XENBUS_FRONTEND
default y
help
Xen driver for secondary virtual consoles
config HVC_UDBG
bool "udbg based fake hypervisor console"
depends on PPC
select HVC_DRIVER
default n
help
This is meant to be used during HW bring up or debugging when
no other console mechanism exist but udbg, to get you a quick
console for userspace. Do NOT enable in production kernels.
config HVC_DCC
bool "ARM JTAG DCC console"
depends on ARM
select HVC_DRIVER
help
This console uses the JTAG DCC on ARM to create a console under the HVC
driver. This console is used through a JTAG only on ARM. If you don't have
a JTAG then you probably don't want this option.
config HVC_BFIN_JTAG
bool "Blackfin JTAG console"
depends on BLACKFIN
select HVC_DRIVER
help
This console uses the Blackfin JTAG to create a console under the
the HVC driver. If you don't have JTAG, then you probably don't
want this option.
config HVCS
tristate "IBM Hypervisor Virtual Console Server support"
depends on PPC_PSERIES && HVC_CONSOLE
help
Partitionable IBM Power5 ppc64 machines allow hosting of
firmware virtual consoles from one Linux partition by
another Linux partition. This driver allows console data
from Linux partitions to be accessed through TTY device
interfaces in the device tree of a Linux partition running
this driver.
To compile this driver as a module, choose M here: the
module will be called hvcs. Additionally, this module
will depend on arch specific APIs exported from hvcserver.ko
which will also be compiled when this driver is built as a
module.
endif # TTY