* anything. Worst case is that we lose a reschedule ...
*/
-void smp_send_reschedule(int cpu)
+static void native_smp_send_reschedule(int cpu)
{
+ WARN_ON(cpu_is_offline(cpu));
send_IPI_mask(cpumask_of_cpu(cpu), RESCHEDULE_VECTOR);
}
spin_unlock_irq(&call_lock);
}
-/*
- * this function sends a 'generic call function' IPI to all other CPU
- * of the system defined in the mask.
- */
-static int __smp_call_function_mask(cpumask_t mask,
- void (*func)(void *), void *info,
- int wait)
+static void __smp_call_function(void (*func) (void *info), void *info,
+ int nonatomic, int wait)
+{
+ struct call_data_struct data;
+ int cpus = num_online_cpus() - 1;
+
+ if (!cpus)
+ return;
+
+ data.func = func;
+ data.info = info;
+ atomic_set(&data.started, 0);
+ data.wait = wait;
+ if (wait)
+ atomic_set(&data.finished, 0);
+
+ call_data = &data;
+ mb();
+
+ /* Send a message to all other CPUs and wait for them to respond */
+ send_IPI_allbutself(CALL_FUNCTION_VECTOR);
+
+ /* Wait for response */
+ while (atomic_read(&data.started) != cpus)
+ cpu_relax();
+
+ if (wait)
+ while (atomic_read(&data.finished) != cpus)
+ cpu_relax();
+}
+
+
+int native_smp_call_function_mask(cpumask_t mask,
+ void (*func)(void *), void *info,
+ int wait)
{
struct call_data_struct data;
cpumask_t allbutself;
int cpus;
+ /* Can deadlock when called with interrupts disabled */
+ WARN_ON(irqs_disabled());
+
+ /* Holding any lock stops cpus from going down. */
+ spin_lock(&call_lock);
+
allbutself = cpu_online_map;
cpu_clear(smp_processor_id(), allbutself);
cpus_and(mask, mask, allbutself);
cpus = cpus_weight(mask);
- if (!cpus)
+ if (!cpus) {
+ spin_unlock(&call_lock);
return 0;
+ }
data.func = func;
data.info = info;
while (atomic_read(&data.started) != cpus)
cpu_relax();
- if (!wait)
- return 0;
-
- while (atomic_read(&data.finished) != cpus)
- cpu_relax();
-
- return 0;
-}
-/**
- * smp_call_function_mask(): Run a function on a set of other CPUs.
- * @mask: The set of cpus to run on. Must not include the current cpu.
- * @func: The function to run. This must be fast and non-blocking.
- * @info: An arbitrary pointer to pass to the function.
- * @wait: If true, wait (atomically) until function has completed on other CPUs.
- *
- * Returns 0 on success, else a negative status code.
- *
- * If @wait is true, then returns once @func has returned; otherwise
- * it returns just before the target cpu calls @func.
- *
- * You must not call this function with disabled interrupts or from a
- * hardware interrupt handler or from a bottom half handler.
- */
-int smp_call_function_mask(cpumask_t mask,
- void (*func)(void *), void *info,
- int wait)
-{
- int ret;
-
- /* Can deadlock when called with interrupts disabled */
- WARN_ON(irqs_disabled());
+ if (wait)
+ while (atomic_read(&data.finished) != cpus)
+ cpu_relax();
- spin_lock(&call_lock);
- ret = __smp_call_function_mask(mask, func, info, wait);
spin_unlock(&call_lock);
- return ret;
-}
-EXPORT_SYMBOL(smp_call_function_mask);
-
-/*
- * smp_call_function_single - Run a function on a specific 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 ret, me = get_cpu();
-
- /* Can deadlock when called with interrupts disabled */
- WARN_ON(irqs_disabled());
-
- if (cpu == me) {
- local_irq_disable();
- func(info);
- local_irq_enable();
- put_cpu();
- return 0;
- }
-
- ret = smp_call_function_mask(cpumask_of_cpu(cpu), func, info, wait);
-
- put_cpu();
- return ret;
-}
-EXPORT_SYMBOL(smp_call_function_single);
-
-/*
- * smp_call_function - run a function on all other CPUs.
- * @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 (atomically) until function has completed on other
- * CPUs.
- *
- * Returns 0 on success, else a negative status code. Does not return until
- * remote CPUs are nearly ready to execute func or are or have executed.
- *
- * You must not call this function with disabled interrupts or from a
- * hardware interrupt handler or from a bottom half handler.
- * Actually there are a few legal cases, like panic.
- */
-int smp_call_function (void (*func) (void *info), void *info, int nonatomic,
- int wait)
-{
- return smp_call_function_mask(cpu_online_map, func, info, wait);
+ return 0;
}
-EXPORT_SYMBOL(smp_call_function);
static void stop_this_cpu(void *dummy)
{
*/
cpu_clear(smp_processor_id(), cpu_online_map);
disable_local_APIC();
- for (;;)
- halt();
+ if (hlt_works(smp_processor_id()))
+ for (;;) halt();
+ for (;;);
}
void smp_send_stop(void)
/* Don't deadlock on the call lock in panic */
nolock = !spin_trylock(&call_lock);
local_irq_save(flags);
- __smp_call_function_mask(cpu_online_map, stop_this_cpu, NULL, 0);
+ __smp_call_function(stop_this_cpu, NULL, 0, 0);
if (!nolock)
spin_unlock(&call_lock);
disable_local_APIC();
}
}
+struct smp_ops smp_ops = {
+ .smp_prepare_boot_cpu = native_smp_prepare_boot_cpu,
+ .smp_prepare_cpus = native_smp_prepare_cpus,
+ .smp_cpus_done = native_smp_cpus_done,
+
+ .smp_send_reschedule = native_smp_send_reschedule,
+ .smp_call_function_mask = native_smp_call_function_mask,
+ .cpu_up = native_cpu_up,
+};
+EXPORT_SYMBOL_GPL(smp_ops);