From b4b2917cc8babe8eaf4bc133bca31b11ed7dac13 Mon Sep 17 00:00:00 2001 From: Peter Watkins Date: Mon, 30 Jul 2007 18:01:29 -0400 Subject: [PATCH] [MIPS] Add smp_call_function_single() In the other archs, there is more factoring of smp call code, and more care in the use of get_cpu(). That can be a follow-up MIPS patch. Signed-off-by: Peter Watkins Signed-off-by: Ralf Baechle --- arch/mips/kernel/smp.c | 55 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c index 04bbbd8d91ab..73b0dab02668 100644 --- a/arch/mips/kernel/smp.c +++ b/arch/mips/kernel/smp.c @@ -194,6 +194,61 @@ void smp_call_function_interrupt(void) } } +int smp_call_function_single(int cpu, void (*func) (void *info), void *info, + int retry, int wait) +{ + struct call_data_struct data; + int me; + + /* + * Can die spectacularly if this CPU isn't yet marked online + */ + if (!cpu_online(cpu)) + return 0; + + me = get_cpu(); + BUG_ON(!cpu_online(me)); + + if (cpu == me) { + local_irq_disable(); + func(info); + local_irq_enable(); + put_cpu(); + return 0; + } + + /* Can deadlock when called with interrupts disabled */ + WARN_ON(irqs_disabled()); + + data.func = func; + data.info = info; + atomic_set(&data.started, 0); + data.wait = wait; + if (wait) + atomic_set(&data.finished, 0); + + spin_lock(&smp_call_lock); + call_data = &data; + smp_mb(); + + /* Send a message to the other CPU */ + core_send_ipi(cpu, SMP_CALL_FUNCTION); + + /* Wait for response */ + /* FIXME: lock-up detection, backtrace on lock-up */ + while (atomic_read(&data.started) != 1) + barrier(); + + if (wait) + while (atomic_read(&data.finished) != 1) + barrier(); + call_data = NULL; + spin_unlock(&smp_call_lock); + + put_cpu(); + return 0; +} + static void stop_this_cpu(void *dummy) { /* -- 2.30.2