Messages in this thread Patch in this message | | | From | Nicholas Piggin <> | Subject | [PATCH v4 6/6] powerpc: implement smp_cond_load_relaxed | Date | Fri, 24 Jul 2020 23:14:23 +1000 |
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This implements smp_cond_load_relaed with the slowpath busy loop using the preferred SMT priority pattern.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- arch/powerpc/include/asm/barrier.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/arch/powerpc/include/asm/barrier.h b/arch/powerpc/include/asm/barrier.h index 123adcefd40f..9b4671d38674 100644 --- a/arch/powerpc/include/asm/barrier.h +++ b/arch/powerpc/include/asm/barrier.h @@ -76,6 +76,20 @@ do { \ ___p1; \ }) +#define smp_cond_load_relaxed(ptr, cond_expr) ({ \ + typeof(ptr) __PTR = (ptr); \ + __unqual_scalar_typeof(*ptr) VAL; \ + VAL = READ_ONCE(*__PTR); \ + if (unlikely(!(cond_expr))) { \ + spin_begin(); \ + do { \ + VAL = READ_ONCE(*__PTR); \ + } while (!(cond_expr)); \ + spin_end(); \ + } \ + (typeof(*ptr))VAL; \ +}) + #ifdef CONFIG_PPC_BOOK3S_64 #define NOSPEC_BARRIER_SLOT nop #elif defined(CONFIG_PPC_FSL_BOOK3E) -- 2.23.0
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