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When I understood the pattern, it made sense for me to remove the duplications and create macros to make it easier to understand what exactly changes between the versions: Instruction sufixes & barriers. Also, did the same kind of work on atomic.c. After that, I noted both cmpxchg and xchg only accept variables of size 4 and 8, compared to x86 and arm64 which do 1,2,4,8. Now that deduplication is done, it is quite direct to implement them for variable sizes 1 and 2, so I did it. Then Guo Ren already presented me some possible users :) I did compare the generated asm on a test.c that contained usage for every changed function, and could not detect any change on patches 1 + 2 + 3 compared with upstream. Pathes 4 & 5 were compiled-tested, merged with guoren/qspinlock_v11 and booted just fine with qemu -machine virt -append "qspinlock". Thanks! Leo Changes since squashed cmpxchg RFCv3: - Fixed bug on cmpxchg macro for var size 1 & 2: now working - Macros for var size 1 & 2's lr.w and sc.w now are guaranteed to receive input of a 32-bit aligned address - Renamed internal macros from _mask to _masked for patches 4 & 5 - __rc variable on macros for var size 1 & 2 changed from register to ulong https://lore.kernel.org/all/20230804084900.1135660-2-leobras@redhat.com/ Changes since squashed cmpxchg RFCv2: - Removed rc parameter from the new macro: it can be internal to the macro - 2 new patches: cmpxchg size 1 and 2, xchg size 1 and 2 https://lore.kernel.org/all/20230803051401.710236-2-leobras@redhat.com/ Changes since squashed cmpxchg RFCv1: - Unified with atomic.c patchset - Rebased on top of torvalds/master (thanks Andrea Parri!) - Removed helper macros that were not being used elsewhere in the kernel. https://lore.kernel.org/all/20230419062505.257231-1-leobras@redhat.com/ https://lore.kernel.org/all/20230406082018.70367-1-leobras@redhat.com/ Changes since (cmpxchg) RFCv3: - Squashed the 6 original patches in 2: one for cmpxchg and one for xchg https://lore.kernel.org/all/20230404163741.2762165-1-leobras@redhat.com/ Changes since (cmpxchg) RFCv2: - Fixed macros that depend on having a local variable with a magic name - Previous cast to (long) is now only applied on 4-bytes cmpxchg https://lore.kernel.org/all/20230321074249.2221674-1-leobras@redhat.com/ Changes since (cmpxchg) RFCv1: - Fixed patch 4/6 suffix from 'w.aqrl' to '.w.aqrl', to avoid build error https://lore.kernel.org/all/20230318080059.1109286-1-leobras@redhat.com/ Leonardo Bras (5): riscv/cmpxchg: Deduplicate xchg() asm functions riscv/cmpxchg: Deduplicate cmpxchg() asm and macros riscv/atomic.h : Deduplicate arch_atomic.* riscv/cmpxchg: Implement cmpxchg for variables of size 1 and 2 riscv/cmpxchg: Implement xchg for variables of size 1 and 2 arch/riscv/include/asm/atomic.h | 164 ++++++------- arch/riscv/include/asm/cmpxchg.h | 394 ++++++++++--------------------- 2 files changed, 195 insertions(+), 363 deletions(-)