diff options
| -rw-r--r-- | arch/i386/kernel/smp.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/arch/i386/kernel/smp.c b/arch/i386/kernel/smp.c index c10789d7a9d..304243ed7a3 100644 --- a/arch/i386/kernel/smp.c +++ b/arch/i386/kernel/smp.c @@ -634,3 +634,69 @@ fastcall void smp_call_function_interrupt(struct pt_regs *regs) } } +/* + * this function sends a 'generic call function' IPI to one other CPU + * in the system. + * + * cpu is a standard Linux logical CPU number. + */ +static void +__smp_call_function_single(int cpu, void (*func) (void *info), void *info, + int nonatomic, int wait) +{ + struct call_data_struct data; + int cpus = 1; + + data.func = func; + data.info = info; + atomic_set(&data.started, 0); + data.wait = wait; + if (wait) + atomic_set(&data.finished, 0); + + call_data = &data; + wmb(); + /* Send a message to all other CPUs and wait for them to respond */ + send_IPI_mask(cpumask_of_cpu(cpu), CALL_FUNCTION_VECTOR); + + /* Wait for response */ + while (atomic_read(&data.started) != cpus) + cpu_relax(); + + if (!wait) + return; + + while (atomic_read(&data.finished) != cpus) + cpu_relax(); +} + +/* + * smp_call_function_single - Run a function on another CPU + * @func: The function to run. This must be fast and non-blocking. + * @info: An arbitrary pointer to pass to the function. + * @nonatomic: Currently unused. + * @wait: If true, wait until function has completed on other CPUs. + * + * Retrurns 0 on success, else a negative status code. + * + * Does not return until the remote CPU is nearly ready to execute <func> + * or is or has executed. + */ + +int smp_call_function_single (int cpu, void (*func) (void *info), void *info, + int nonatomic, int wait) +{ + /* prevent preemption and reschedule on another processor */ + int me = get_cpu(); + if (cpu == me) { + WARN_ON(1); + put_cpu(); + return -EBUSY; + } + spin_lock_bh(&call_lock); + __smp_call_function_single(cpu, func, info, nonatomic, wait); + spin_unlock_bh(&call_lock); + put_cpu(); + return 0; +} +EXPORT_SYMBOL(smp_call_function_single); |