Commit 49a7d46a authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman

powerpc: Implement smp_cond_load_relaxed()

This implements smp_cond_load_relaxed() with the slowpath busy loop
using the preferred SMT priority pattern.
Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Acked-by: default avatarWaiman Long <longman@redhat.com>
[mpe: Make it 64-bit only to fix build errors on 32-bit]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200724131423.1362108-7-npiggin@gmail.com
parent 2f6560e6
...@@ -80,6 +80,22 @@ do { \ ...@@ -80,6 +80,22 @@ do { \
___p1; \ ___p1; \
}) })
#ifdef CONFIG_PPC64
#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; \
})
#endif
#ifdef CONFIG_PPC_BOOK3S_64 #ifdef CONFIG_PPC_BOOK3S_64
#define NOSPEC_BARRIER_SLOT nop #define NOSPEC_BARRIER_SLOT nop
#elif defined(CONFIG_PPC_FSL_BOOK3E) #elif defined(CONFIG_PPC_FSL_BOOK3E)
......
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