When Core-0 handle SMP_ASK_C0COUNT IPI, we should make other cores to see the result as soon as possible (especially when Store-Fill-Buffer is enabled). Otherwise, C0_Count syncronization makes no sense.
BTW, there is a corner should be avoid: C0_Count of Core-0 is really 0. Cc: <[email protected]> Signed-off-by: Huacai Chen <[email protected]> --- arch/mips/loongson64/loongson-3/smp.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/mips/loongson64/loongson-3/smp.c b/arch/mips/loongson64/loongson-3/smp.c index 1a4738a..55d0f5f 100644 --- a/arch/mips/loongson64/loongson-3/smp.c +++ b/arch/mips/loongson64/loongson-3/smp.c @@ -275,8 +275,10 @@ void loongson3_ipi_interrupt(struct pt_regs *regs) if (action & SMP_ASK_C0COUNT) { BUG_ON(cpu != 0); c0count = read_c0_count(); + c0count = c0count ? c0count : 1; for (i = 1; i < num_possible_cpus(); i++) per_cpu(core0_c0count, i) = c0count; + __wbflush(); /* Let others see the result ASAP */ } } -- 2.4.6 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
