powerpc/64: implement spin loop primitives

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Nicholas Piggin 2017-06-06 23:08:31 +10:00 committed by Michael Ellerman
parent fd851a3cdc
commit ede8e2bbb0

View file

@ -428,6 +428,26 @@ static inline unsigned long __pack_fe01(unsigned int fpmode)
#ifdef CONFIG_PPC64
#define cpu_relax() do { HMT_low(); HMT_medium(); barrier(); } while (0)
#define spin_begin() HMT_low()
#define spin_cpu_relax() barrier()
#define spin_cpu_yield() spin_cpu_relax()
#define spin_end() HMT_medium()
#define spin_until_cond(cond) \
do { \
if (unlikely(!(cond))) { \
spin_begin(); \
do { \
spin_cpu_relax(); \
} while (!(cond)); \
spin_end(); \
} \
} while (0)
#else
#define cpu_relax() barrier()
#endif