Commit Graph

3 Commits

Author SHA1 Message Date
Jason A. Donenfeld
f5ed22e264 arm64: make label allocation style consistent in tishift
This is entirely cosmetic, but somehow it was missed when sending
differing versions of this patch. This just makes the file a bit more
uniform.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-02 14:22:18 +00:00
Jason A. Donenfeld
9bfe7553fa arm64: Implement __lshrti3 library function
Commit fb8722735f ("arm64: support __int128 on gcc 5+") added support
for the __int128 data type, but this breaks the build in some configurations
where GCC ends up emitting calls to the __lshrti3 helper in libgcc, which
results in a link error:

  kernel/sched/fair.o: In function `__calc_delta':
  fair.c:(.text+0xca0): undefined reference to `__lshrti3'
  kernel/time/timekeeping.o: In function `timekeeping_resume':
  timekeeping.c:(.text+0x3f60): undefined reference to `__lshrti3'
  make: *** [vmlinux] Error 1

Fix the build by providing an implementation of __lshrti3, like we do
already for __ashlti3 and __ashrti3.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-13 16:05:50 +00:00
Jason A. Donenfeld
fb8722735f arm64: support __int128 on gcc 5+
Versions of gcc prior to gcc 5 emitted a __multi3 function call when
dealing with TI types, resulting in failures when trying to link to
libgcc, and more generally, bad performance. However, since gcc 5,
the compiler supports actually emitting fast instructions, which means
we can at long last enable this option and receive the speedups.

The gcc commit that added proper Aarch64 support is:
https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=d1ae7bb994f49316f6f63e6173f2931e837a351d
This commit appears to be part of the gcc 5 release.

There are still a few instructions, __ashlti3 and __ashrti3, which
require libgcc, which is fine. Rather than linking to libgcc, we
simply provide them ourselves, since they're not that complicated.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03 15:24:21 +00:00