[PATCH 0/5] locking/atomic: generic arch__atomic_long_*() and arch_ bitops

From: Mark Rutland
Date: Tue Jul 13 2021 - 06:53:00 EST


These patches (based on v5.14-rc1) add arch_*() forms of the atomic_long_*()
operations for all architectures, and build atop this to have the generic
bitops provide arch_*() forms, allowing for safe usage in `noinstr` code. For
example, I'd like to be able to use these in arm64's entry code.

The first three patches cleanup the current code, simplifiying this by removing
some ARCH_ATOMIC remnants and centralizing the generated headers under
include/linux/atomic/ for consistency.

Patch four adds arch_atomic_long_*(). This is almost entirely scripted (adding
~600 lines), with the only manual change being to the order of includes in
include/linux/atomic.h, as we must now include atomic-long.h before
atomic-instrumented.h.

Patch five updates the generic bitop implementaton to provide arch_* forms.
Since the non-atomic ops can be implicitly instrumented, some logic is added to
omit the redundant checks.

I've pushed the patches to my atomics/arch-atomic-bitops branch [1,2].

I've given this some light build and boot testing so far.

Thanks,
Mark.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git/log/?h=atomics/arch-atomic-bitops
[2] git://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git atomics/arch-atomic-bitops

Mark Rutland (5):
locking/atomic: simplify ifdef generation
locking/atomic: remove ARCH_ATOMIC remanants
locking/atomic: centralize generated headers
locking/atomic: add arch_atomic_long*()
locking/atomic: add generic arch_*() bitops

include/asm-generic/atomic-long.h | 1014 --------------------
include/asm-generic/bitops/atomic.h | 32 +-
.../asm-generic/bitops/instrumented-non-atomic.h | 21 +-
include/asm-generic/bitops/lock.h | 39 +-
include/asm-generic/bitops/non-atomic.h | 41 +-
include/linux/atomic.h | 7 +-
include/linux/{ => atomic}/atomic-arch-fallback.h | 0
.../atomic}/atomic-instrumented.h | 586 ++++++++++-
include/linux/atomic/atomic-long.h | 1014 ++++++++++++++++++++
scripts/atomic/check-atomics.sh | 6 +-
scripts/atomic/fallbacks/acquire | 4 +-
scripts/atomic/fallbacks/add_negative | 6 +-
scripts/atomic/fallbacks/add_unless | 6 +-
scripts/atomic/fallbacks/andnot | 4 +-
scripts/atomic/fallbacks/dec | 4 +-
scripts/atomic/fallbacks/dec_and_test | 6 +-
scripts/atomic/fallbacks/dec_if_positive | 6 +-
scripts/atomic/fallbacks/dec_unless_positive | 6 +-
scripts/atomic/fallbacks/fence | 4 +-
scripts/atomic/fallbacks/fetch_add_unless | 8 +-
scripts/atomic/fallbacks/inc | 4 +-
scripts/atomic/fallbacks/inc_and_test | 6 +-
scripts/atomic/fallbacks/inc_not_zero | 6 +-
scripts/atomic/fallbacks/inc_unless_negative | 6 +-
scripts/atomic/fallbacks/read_acquire | 2 +-
scripts/atomic/fallbacks/release | 4 +-
scripts/atomic/fallbacks/set_release | 2 +-
scripts/atomic/fallbacks/sub_and_test | 6 +-
scripts/atomic/fallbacks/try_cmpxchg | 4 +-
scripts/atomic/gen-atomic-fallback.sh | 68 +-
scripts/atomic/gen-atomic-instrumented.sh | 11 +-
scripts/atomic/gen-atomic-long.sh | 10 +-
scripts/atomic/gen-atomics.sh | 6 +-
33 files changed, 1772 insertions(+), 1177 deletions(-)
delete mode 100644 include/asm-generic/atomic-long.h
rename include/linux/{ => atomic}/atomic-arch-fallback.h (100%)
rename include/{asm-generic => linux/atomic}/atomic-instrumented.h (68%)
create mode 100644 include/linux/atomic/atomic-long.h

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2.11.0