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Diffstat (limited to 'arch/arm64/include/asm/percpu.h')
-rw-r--r--arch/arm64/include/asm/percpu.h15
1 files changed, 11 insertions, 4 deletions
diff --git a/arch/arm64/include/asm/percpu.h b/arch/arm64/include/asm/percpu.h
index 9abcc8ef3087..b57b2bb00967 100644
--- a/arch/arm64/include/asm/percpu.h
+++ b/arch/arm64/include/asm/percpu.h
@@ -77,7 +77,7 @@ __percpu_##name##_case_##sz(void *ptr, unsigned long val) \
" stxr" #sfx "\t%w[loop], %" #w "[tmp], %[ptr]\n" \
" cbnz %w[loop], 1b", \
/* LSE atomics */ \
- #op_lse "\t%" #w "[val], %[ptr]\n" \
+ #op_lse "\t%" #w "[val], %" #w "[tmp], %[ptr]\n" \
__nops(3)) \
: [loop] "=&r" (loop), [tmp] "=&r" (tmp), \
[ptr] "+Q"(*(u##sz *)ptr) \
@@ -124,9 +124,16 @@ PERCPU_RW_OPS(8)
PERCPU_RW_OPS(16)
PERCPU_RW_OPS(32)
PERCPU_RW_OPS(64)
-PERCPU_OP(add, add, stadd)
-PERCPU_OP(andnot, bic, stclr)
-PERCPU_OP(or, orr, stset)
+
+/*
+ * Use value-returning atomics for CPU-local ops as they are more likely
+ * to execute "near" to the CPU (e.g. in L1$).
+ *
+ * https://lore.kernel.org/r/e7d539ed-ced0-4b96-8ecd-048a5b803b85@paulmck-laptop
+ */
+PERCPU_OP(add, add, ldadd)
+PERCPU_OP(andnot, bic, ldclr)
+PERCPU_OP(or, orr, ldset)
PERCPU_RET_OP(add, add, ldadd)
#undef PERCPU_RW_OPS