x86: change x86_64 smp_call_function_mask to look alike i386

the two versions (the inner version, and the outer version, that takes
the locks) of smp_call_function_mask are made into one. With the changes,
i386 and x86_64 versions look exactly the same.

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/smp_32.c b/arch/x86/kernel/smp_32.c
index dc0cde9..e4a6b66 100644 (file)
--- a/arch/x86/kernel/smp_32.c
+++ b/arch/x86/kernel/smp_32.c
@@ -583,7 +583,7 @@ native_smp_call_function_mask(cpumask_t mask,
                atomic_set(&data.finished, 0);
 
        call_data = &data;
-       mb();
+       wmb();
 
        /* Send a message to other CPUs */
        if (cpus_equal(mask, allbutself))

diff --git a/arch/x86/kernel/smp_64.c b/arch/x86/kernel/smp_64.c
index aa2edb7..e4494e8 100644 (file)
--- a/arch/x86/kernel/smp_64.c
+++ b/arch/x86/kernel/smp_64.c
@@ -354,26 +354,30 @@ static void __smp_call_function(void (*func) (void *info), void *info,
 }
 
 
-/*
- * 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)
+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;
@@ -395,43 +399,14 @@ static int __smp_call_function_mask(cpumask_t mask,
        while (atomic_read(&data.started) != cpus)
                cpu_relax();
 
-       if (!wait)
-               return 0;
+       if (wait)
+                while (atomic_read(&data.finished) != cpus)
+                       cpu_relax();
 
-       while (atomic_read(&data.finished) != cpus)
-               cpu_relax();
+       spin_unlock(&call_lock);
 
        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 native_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());
-
-       spin_lock(&call_lock);
-       ret = __smp_call_function_mask(mask, func, info, wait);
-       spin_unlock(&call_lock);
-       return ret;
-}
 
 static void stop_this_cpu(void *dummy)
 {