Commit Graph

5 Commits

Author SHA1 Message Date
Mark Rutland
abb77f3d96 arm64: tishift: use asm EXPORT_SYMBOL()
For a while now it's been possible to use EXPORT_SYMBOL() in assembly
files, which allows us to place exports immediately after assembly
functions, as we do for C functions.

As a step towards removing arm64ksyms.c, let's move the tishift exports
to the assembly file the functions are defined in.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-10 11:50:11 +00:00
Jason A. Donenfeld
255845fc43 arm64: export tishift functions to modules
Otherwise modules that use these arithmetic operations will fail to
link. We accomplish this with the usual EXPORT_SYMBOL, which on most
architectures goes in the .S file but the ARM64 maintainers prefer that
insead it goes into arm64ksyms.

While we're at it, we also fix this up to use SPDX, and I personally
choose to relicense this as GPL2||BSD so that these symbols don't need
to be export_symbol_gpl, so all modules can use the routines, since
these are important general purpose compiler-generated function calls.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reported-by: PaX Team <pageexec@freemail.hu>
Cc: stable@vger.kernel.org
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-05-21 19:00:48 +01:00
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