arm64: atomics: prefetch the destination word for write prior to stxr

[cascardo/linux.git] / arch / arm64 / include / asm / futex.h

diff --git a/arch/arm64/include/asm/futex.h b/arch/arm64/include/asm/futex.h
index 775e85b..007a69f 100644 (file)
--- a/arch/arm64/include/asm/futex.h
+++ b/arch/arm64/include/asm/futex.h
@@ -30,6 +30,7 @@
        asm volatile(                                                   \
        ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_HAS_PAN,            \
                    CONFIG_ARM64_PAN)                                   \
+"      prfm    pstl1strm, %2\n"                                        \
 "1:    ldxr    %w1, %2\n"                                              \
        insn "\n"                                                       \
 "2:    stlxr   %w3, %w0, %2\n"                                         \
@@ -120,6 +121,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
                return -EFAULT;
 
        asm volatile("// futex_atomic_cmpxchg_inatomic\n"
+"      prfm    pstl1strm, %2\n"
 "1:    ldxr    %w1, %2\n"
 "      sub     %w3, %w1, %w4\n"
 "      cbnz    %w3, 3f\n"