diff options
| author | Greg Ungerer <gerg@linux-m68k.org> | 2020-09-09 11:27:27 +1000 |
|---|---|---|
| committer | Greg Ungerer <gerg@linux-m68k.org> | 2020-10-05 21:51:31 +1000 |
| commit | a27bc11f4b7c54a95a977a8e8b15c84dac804bd4 (patch) | |
| tree | 5f33c52bfe54812bd1bcad330135b2311ccb3ac6 /arch/m68k/Kconfig | |
| parent | 549738f15da0e5a00275977623be199fbbf7df50 (diff) | |
m68knommu: switch to using asm-generic/uaccess.h
Switch to using the asm-generic/uaccess functions for non-MMU builds.
Remove all the m68knommu local specific uaccess defines and macros.
There is nothing so special about the m68knommu targets that they cannot
use all of the asm-generic uaccess support. Using the asm-generic
uaccess definitions also resolves some of the existing problems with
missing __user annotations in the m68knommu specific functions.
The elimination of all of the contents of uaccess_no.h means we can fold
the uaccess_mm.h back into uaccess.h - and just have the single file
now.
The resulting generated code ends up being slightly smaller (by a few
hundred bytes) due to the compilers ability to better optimize load
and stores without forcing its hand with asm statements.
Specifically trivial cases like this contrived example:
get_user(x, ptr);
x++;
put_user(x, ptr);
end up now being optimized to a single instruction on m68k. More
generally the compiler can avoid using a temporary register in many
cases as well.
Reported-by: kernel test robot <lkp@intel.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
Diffstat (limited to 'arch/m68k/Kconfig')
| -rw-r--r-- | arch/m68k/Kconfig | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig index 6f2f38d05772..aefffebc0afa 100644 --- a/arch/m68k/Kconfig +++ b/arch/m68k/Kconfig @@ -24,6 +24,7 @@ config M68K select GENERIC_IOMAP select GENERIC_STRNCPY_FROM_USER if MMU select GENERIC_STRNLEN_USER if MMU + select UACCESS_MEMCPY if !MMU select ARCH_WANT_IPC_PARSE_VERSION select HAVE_FUTEX_CMPXCHG if MMU && FUTEX select HAVE_MOD_ARCH_SPECIFIC |