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authorMark Rutland <mark.rutland@arm.com>2023-06-05 09:01:00 +0200
committerPeter Zijlstra <peterz@infradead.org>2023-06-05 09:57:13 +0200
commita7bafa7969da1c0e9c342c792d8224078d1c491c (patch)
tree6bc8363a7e055e935ecd6b5e55c793581de871b6 /arch/hexagon/include/asm/atomic.h
parentlocking/atomic: remove fallback comments (diff)
downloadlinux-a7bafa7969da1c0e9c342c792d8224078d1c491c.tar.xz
linux-a7bafa7969da1c0e9c342c792d8224078d1c491c.zip
locking/atomic: hexagon: remove redundant arch_atomic_cmpxchg
Hexagon's implementation of arch_atomic_cmpxchg() is identical to its implementation of arch_cmpxchg(). Have it define arch_atomic_cmpxchg() in terms of arch_cmpxchg(), matching what it does for arch_atomic_xchg() and arch_xchg(). At the same time, remove the kerneldoc comments for hexagon's arch_atomic_xchg() and arch_atomic_cmpxchg(). The arch_atomic_*() namespace is shared by all architectures and the API should be documented centrally, and the comments aren't all that helpful as-is. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20230605070124.3741859-4-mark.rutland@arm.com
Diffstat (limited to 'arch/hexagon/include/asm/atomic.h')
-rw-r--r--arch/hexagon/include/asm/atomic.h46
1 files changed, 4 insertions, 42 deletions
diff --git a/arch/hexagon/include/asm/atomic.h b/arch/hexagon/include/asm/atomic.h
index 6e94f8d04146..738857e10d6e 100644
--- a/arch/hexagon/include/asm/atomic.h
+++ b/arch/hexagon/include/asm/atomic.h
@@ -36,49 +36,11 @@ static inline void arch_atomic_set(atomic_t *v, int new)
*/
#define arch_atomic_read(v) READ_ONCE((v)->counter)
-/**
- * arch_atomic_xchg - atomic
- * @v: pointer to memory to change
- * @new: new value (technically passed in a register -- see xchg)
- */
-#define arch_atomic_xchg(v, new) (arch_xchg(&((v)->counter), (new)))
-
-
-/**
- * arch_atomic_cmpxchg - atomic compare-and-exchange values
- * @v: pointer to value to change
- * @old: desired old value to match
- * @new: new value to put in
- *
- * Parameters are then pointer, value-in-register, value-in-register,
- * and the output is the old value.
- *
- * Apparently this is complicated for archs that don't support
- * the memw_locked like we do (or it's broken or whatever).
- *
- * Kind of the lynchpin of the rest of the generically defined routines.
- * Remember V2 had that bug with dotnew predicate set by memw_locked.
- *
- * "old" is "expected" old val, __oldval is actual old value
- */
-static inline int arch_atomic_cmpxchg(atomic_t *v, int old, int new)
-{
- int __oldval;
+#define arch_atomic_xchg(v, new) \
+ (arch_xchg(&((v)->counter), (new)))
- asm volatile(
- "1: %0 = memw_locked(%1);\n"
- " { P0 = cmp.eq(%0,%2);\n"
- " if (!P0.new) jump:nt 2f; }\n"
- " memw_locked(%1,P0) = %3;\n"
- " if (!P0) jump 1b;\n"
- "2:\n"
- : "=&r" (__oldval)
- : "r" (&v->counter), "r" (old), "r" (new)
- : "memory", "p0"
- );
-
- return __oldval;
-}
+#define arch_atomic_cmpxchg(v, old, new) \
+ (arch_cmpxchg(&((v)->counter), (old), (new)))
#define ATOMIC_OP(op) \
static inline void arch_atomic_##op(int i, atomic_t *v) \