From 1d78814d41701c216e28fcf2656526146dec4a1a Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 5 Jun 2023 08:01:20 +0100 Subject: locking/atomic: scripts: simplify raw_atomic*() definitions Currently each ordering variant has several potential definitions, with a mixture of preprocessor and C definitions, including several copies of its C prototype, e.g. | #if defined(arch_atomic_fetch_andnot_acquire) | #define raw_atomic_fetch_andnot_acquire arch_atomic_fetch_andnot_acquire | #elif defined(arch_atomic_fetch_andnot_relaxed) | static __always_inline int | raw_atomic_fetch_andnot_acquire(int i, atomic_t *v) | { | int ret = arch_atomic_fetch_andnot_relaxed(i, v); | __atomic_acquire_fence(); | return ret; | } | #elif defined(arch_atomic_fetch_andnot) | #define raw_atomic_fetch_andnot_acquire arch_atomic_fetch_andnot | #else | static __always_inline int | raw_atomic_fetch_andnot_acquire(int i, atomic_t *v) | { | return raw_atomic_fetch_and_acquire(~i, v); | } | #endif Make this a bit simpler by defining the C prototype once, and writing the various potential definitions as plain C code guarded by ifdeffery. For example, the above becomes: | static __always_inline int | raw_atomic_fetch_andnot_acquire(int i, atomic_t *v) | { | #if defined(arch_atomic_fetch_andnot_acquire) | return arch_atomic_fetch_andnot_acquire(i, v); | #elif defined(arch_atomic_fetch_andnot_relaxed) | int ret = arch_atomic_fetch_andnot_relaxed(i, v); | __atomic_acquire_fence(); | return ret; | #elif defined(arch_atomic_fetch_andnot) | return arch_atomic_fetch_andnot(i, v); | #else | return raw_atomic_fetch_and_acquire(~i, v); | #endif | } Which is far easier to read. As we now always have a single copy of the C prototype wrapping all the potential definitions, we now have an obvious single location for kerneldoc comments. At the same time, the fallbacks for raw_atomic*_xhcg() are made to use 'new' rather than 'i' as the name of the new value. This is what the existing fallback template used, and is more consistent with the raw_atomic{_try,}cmpxchg() fallbacks. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20230605070124.3741859-24-mark.rutland@arm.com --- scripts/atomic/fallbacks/add_unless | 4 ---- 1 file changed, 4 deletions(-) (limited to 'scripts/atomic/fallbacks/add_unless') diff --git a/scripts/atomic/fallbacks/add_unless b/scripts/atomic/fallbacks/add_unless index 88593e28b163..95ecb2b7405b 100755 --- a/scripts/atomic/fallbacks/add_unless +++ b/scripts/atomic/fallbacks/add_unless @@ -1,7 +1,3 @@ cat << EOF -static __always_inline bool -raw_${atomic}_add_unless(${atomic}_t *v, ${int} a, ${int} u) -{ return raw_${atomic}_fetch_add_unless(v, a, u) != u; -} EOF -- cgit v1.2.3