linux/arch/c6x/Kconfig
Arnd Bergmann 0774a6ed29 timekeeping: default GENERIC_CLOCKEVENTS to enabled
Almost all machines use GENERIC_CLOCKEVENTS, so it feels wrong to
require each one to select that symbol manually.

Instead, enable it whenever CONFIG_LEGACY_TIMER_TICK is disabled as
a simplification. It should be possible to select both
GENERIC_CLOCKEVENTS and LEGACY_TIMER_TICK from an architecture now
and decide at runtime between the two.

For the clockevents arch-support.txt file, this means that additional
architectures are marked as TODO when they have at least one machine
that still uses LEGACY_TIMER_TICK, rather than being marked 'ok' when
at least one machine has been converted. This means that both m68k and
arm (for riscpc) revert to TODO.

At this point, we could just always enable CONFIG_GENERIC_CLOCKEVENTS
rather than leaving it off when not needed. I built an m68k
defconfig kernel (using gcc-10.1.0) and found that this would add
around 5.5KB in kernel image size:

   text	   data	    bss	    dec	    hex	filename
3861936	1092236	 196656	5150828	 4e986c	obj-m68k/vmlinux-no-clockevent
3866201	1093832	 196184	5156217	 4ead79	obj-m68k/vmlinux-clockevent

On Arm (MACH_RPC), that difference appears to be twice as large,
around 11KB on top of an 6MB vmlinux.

Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2020-10-30 21:57:07 +01:00

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# SPDX-License-Identifier: GPL-2.0
#
# For a description of the syntax of this configuration file,
# see Documentation/kbuild/kconfig-language.rst.
#
config C6X
def_bool y
select ARCH_32BIT_OFF_T
select ARCH_HAS_BINFMT_FLAT
select ARCH_HAS_SYNC_DMA_FOR_CPU
select ARCH_HAS_SYNC_DMA_FOR_DEVICE
select CLKDEV_LOOKUP
select HAVE_LEGACY_CLK
select GENERIC_ATOMIC64
select GENERIC_IRQ_SHOW
select HAVE_ARCH_TRACEHOOK
select SPARSE_IRQ
select IRQ_DOMAIN
select OF
select OF_EARLY_FLATTREE
select MODULES_USE_ELF_RELA
select MMU_GATHER_NO_RANGE if MMU
select SET_FS
config MMU
def_bool n
config FPU
def_bool n
config GENERIC_CALIBRATE_DELAY
def_bool y
config GENERIC_HWEIGHT
def_bool y
config GENERIC_BUG
def_bool y
depends on BUG
config C6X_BIG_KERNEL
bool "Build a big kernel"
help
The C6X function call instruction has a limited range of +/- 2MiB.
This is sufficient for most kernels, but some kernel configurations
with lots of compiled-in functionality may require a larger range
for function calls. Use this option to have the compiler generate
function calls with 32-bit range. This will make the kernel both
larger and slower.
If unsure, say N.
# Use the generic interrupt handling code in kernel/irq/
config CMDLINE_BOOL
bool "Default bootloader kernel arguments"
config CMDLINE
string "Kernel command line"
depends on CMDLINE_BOOL
default "console=ttyS0,57600"
help
On some architectures there is currently no way for the boot loader
to pass arguments to the kernel. For these architectures, you should
supply some command-line options at build time by entering them
here.
config CMDLINE_FORCE
bool "Force default kernel command string"
depends on CMDLINE_BOOL
default n
help
Set this to have arguments from the default kernel command string
override those passed by the boot loader.
config CPU_BIG_ENDIAN
bool "Build big-endian kernel"
default n
help
Say Y if you plan on running a kernel in big-endian mode.
Note that your board must be properly built and your board
port must properly enable any big-endian related features
of your chipset/board/processor.
config FORCE_MAX_ZONEORDER
int "Maximum zone order"
default "13"
help
The kernel memory allocator divides physically contiguous memory
blocks into "zones", where each zone is a power of two number of
pages. This option selects the largest power of two that the kernel
keeps in the memory allocator. If you need to allocate very large
blocks of physically contiguous memory, then you may need to
increase this value.
This config option is actually maximum order plus one. For example,
a value of 11 means that the largest free memory block is 2^10 pages.
menu "Processor type and features"
source "arch/c6x/platforms/Kconfig"
config KERNEL_RAM_BASE_ADDRESS
hex "Virtual address of memory base"
default 0xe0000000 if SOC_TMS320C6455
default 0xe0000000 if SOC_TMS320C6457
default 0xe0000000 if SOC_TMS320C6472
default 0x80000000
source "kernel/Kconfig.hz"
endmenu