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| author | Will Deacon <will@kernel.org> | 2019-08-29 13:52:47 +0300 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2019-08-30 13:18:33 +0300 |
| commit | b32baf91f60fb9c7010bff87e68132f2ce31d9a8 (patch) | |
| tree | 5a8f8ad256abb2b33e5c4c7efc59ce98ea7bbed2 /arch/arm64/Kconfig | |
| parent | 0533f97b4356bfa8af5d4758c6c3fe703bb010d9 (diff) | |
| download | linux-b32baf91f60fb9c7010bff87e68132f2ce31d9a8.tar.xz | |
arm64: lse: Make ARM64_LSE_ATOMICS depend on JUMP_LABEL
Support for LSE atomic instructions (CONFIG_ARM64_LSE_ATOMICS) relies on
a static key to select between the legacy LL/SC implementation which is
available on all arm64 CPUs and the super-duper LSE implementation which
is available on CPUs implementing v8.1 and later.
Unfortunately, when building a kernel with CONFIG_JUMP_LABEL disabled
(e.g. because the toolchain doesn't support 'asm goto'), the static key
inside the atomics code tries to use atomics itself. This results in a
mess of circular includes and a build failure:
In file included from ./arch/arm64/include/asm/lse.h:11,
from ./arch/arm64/include/asm/atomic.h:16,
from ./include/linux/atomic.h:7,
from ./include/asm-generic/bitops/atomic.h:5,
from ./arch/arm64/include/asm/bitops.h:26,
from ./include/linux/bitops.h:19,
from ./include/linux/kernel.h:12,
from ./include/asm-generic/bug.h:18,
from ./arch/arm64/include/asm/bug.h:26,
from ./include/linux/bug.h:5,
from ./include/linux/page-flags.h:10,
from kernel/bounds.c:10:
./include/linux/jump_label.h: In function ‘static_key_count’:
./include/linux/jump_label.h:254:9: error: implicit declaration of function ‘atomic_read’ [-Werror=implicit-function-declaration]
return atomic_read(&key->enabled);
^~~~~~~~~~~
[ ... more of the same ... ]
Since LSE atomic instructions are not critical to the operation of the
kernel, make them depend on JUMP_LABEL at compile time.
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/Kconfig')
| -rw-r--r-- | arch/arm64/Kconfig | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 3adcec05b1f6..27405ac94228 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1263,6 +1263,7 @@ config ARM64_PAN config ARM64_LSE_ATOMICS bool "Atomic instructions" + depends on JUMP_LABEL default y help As part of the Large System Extensions, ARMv8.1 introduces new |