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linux-next/arch/openrisc/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 OPENRISC
def_bool y
select ARCH_32BIT_OFF_T
select ARCH_HAS_DMA_SET_UNCACHED
select ARCH_HAS_DMA_CLEAR_UNCACHED
select ARCH_HAS_SYNC_DMA_FOR_DEVICE
select OF
select OF_EARLY_FLATTREE
select IRQ_DOMAIN
select HANDLE_DOMAIN_IRQ
select GPIOLIB
select HAVE_ARCH_TRACEHOOK
select SPARSE_IRQ
select GENERIC_IRQ_CHIP
select GENERIC_IRQ_PROBE
select GENERIC_IRQ_SHOW
select GENERIC_IOMAP
select GENERIC_CPU_DEVICES
select HAVE_UID16
select GENERIC_ATOMIC64
select GENERIC_CLOCKEVENTS_BROADCAST
select GENERIC_STRNCPY_FROM_USER
select GENERIC_STRNLEN_USER
select GENERIC_SMP_IDLE_THREAD
select MODULES_USE_ELF_RELA
select HAVE_DEBUG_STACKOVERFLOW
select OR1K_PIC
select CPU_NO_EFFICIENT_FFS if !OPENRISC_HAVE_INST_FF1
select ARCH_USE_QUEUED_SPINLOCKS
select ARCH_USE_QUEUED_RWLOCKS
select OMPIC if SMP
select ARCH_WANT_FRAME_POINTERS
select GENERIC_IRQ_MULTI_HANDLER
select MMU_GATHER_NO_RANGE if MMU
select SET_FS
config CPU_BIG_ENDIAN
def_bool y
config MMU
def_bool y
config GENERIC_HWEIGHT
def_bool y
config NO_IOPORT_MAP
def_bool y
config TRACE_IRQFLAGS_SUPPORT
def_bool y
# For now, use generic checksum functions
#These can be reimplemented in assembly later if so inclined
config GENERIC_CSUM
def_bool y
config STACKTRACE_SUPPORT
def_bool y
config LOCKDEP_SUPPORT
def_bool y
menu "Processor type and features"
choice
prompt "Subarchitecture"
default OR1K_1200
config OR1K_1200
bool "OR1200"
help
Generic OpenRISC 1200 architecture
endchoice
config DCACHE_WRITETHROUGH
bool "Have write through data caches"
default n
help
Select this if your implementation features write through data caches.
Selecting 'N' here will allow the kernel to force flushing of data
caches at relevant times. Most OpenRISC implementations support write-
through data caches.
If unsure say N here
config OPENRISC_BUILTIN_DTB
string "Builtin DTB"
default ""
menu "Class II Instructions"
config OPENRISC_HAVE_INST_FF1
bool "Have instruction l.ff1"
default y
help
Select this if your implementation has the Class II instruction l.ff1
config OPENRISC_HAVE_INST_FL1
bool "Have instruction l.fl1"
default y
help
Select this if your implementation has the Class II instruction l.fl1
config OPENRISC_HAVE_INST_MUL
bool "Have instruction l.mul for hardware multiply"
default y
help
Select this if your implementation has a hardware multiply instruction
config OPENRISC_HAVE_INST_DIV
bool "Have instruction l.div for hardware divide"
default y
help
Select this if your implementation has a hardware divide instruction
endmenu
config NR_CPUS
int "Maximum number of CPUs (2-32)"
range 2 32
depends on SMP
default "2"
config SMP
bool "Symmetric Multi-Processing support"
help
This enables support for systems with more than one CPU. If you have
a system with only one CPU, say N. If you have a system with more
than one CPU, say Y.
If you don't know what to do here, say N.
source "kernel/Kconfig.hz"
config OPENRISC_NO_SPR_SR_DSX
bool "use SPR_SR_DSX software emulation" if OR1K_1200
default y
help
SPR_SR_DSX bit is status register bit indicating whether
the last exception has happened in delay slot.
OpenRISC architecture makes it optional to have it implemented
in hardware and the OR1200 does not have it.
Say N here if you know that your OpenRISC processor has
SPR_SR_DSX bit implemented. Say Y if you are unsure.
config OPENRISC_HAVE_SHADOW_GPRS
bool "Support for shadow gpr files" if !SMP
default y if SMP
help
Say Y here if your OpenRISC processor features shadowed
register files. They will in such case be used as a
scratch reg storage on exception entry.
On SMP systems, this feature is mandatory.
On a unicore system it's safe to say N here if you are unsure.
config CMDLINE
string "Default kernel command string"
default ""
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.
menu "Debugging options"
config JUMP_UPON_UNHANDLED_EXCEPTION
bool "Try to die gracefully"
default y
help
Now this puts kernel into infinite loop after first oops. Till
your kernel crashes this doesn't have any influence.
Say Y if you are unsure.
config OPENRISC_ESR_EXCEPTION_BUG_CHECK
bool "Check for possible ESR exception bug"
default n
help
This option enables some checks that might expose some problems
in kernel.
Say N if you are unsure.
endmenu
endmenu