Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6

[linux-2.6-omap-h63xx.git] / kernel / smp.c

diff --git a/kernel/smp.c b/kernel/smp.c
index 782e2b93e4652214ad5b6f21cd89935178e3b9f9..75c8dde58c55fcdd2f0ae71f75ceb05213e0985e 100644 (file)
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -51,10 +51,6 @@ static void csd_flag_wait(struct call_single_data *data)
 {
        /* Wait for response */
        do {
-               /*
-                * We need to see the flags store in the IPI handler
-                */
-               smp_mb();
                if (!(data->flags & CSD_FLAG_WAIT))
                        break;
                cpu_relax();
@@ -76,6 +72,11 @@ static void generic_exec_single(int cpu, struct call_single_data *data)
        list_add_tail(&data->list, &dst->list);
        spin_unlock_irqrestore(&dst->lock, flags);
 
+       /*
+        * Make the list addition visible before sending the ipi.
+        */
+       smp_mb();
+
        if (ipi)
                arch_send_call_function_single_ipi(cpu);
 
@@ -157,7 +158,7 @@ void generic_smp_call_function_single_interrupt(void)
         * Need to see other stores to list head for checking whether
         * list is empty without holding q->lock
         */
-       smp_mb();
+       smp_read_barrier_depends();
        while (!list_empty(&q->list)) {
                unsigned int data_flags;
 
@@ -191,7 +192,7 @@ void generic_smp_call_function_single_interrupt(void)
                /*
                 * See comment on outer loop
                 */
-               smp_mb();
+               smp_read_barrier_depends();
        }
 }
 
@@ -210,8 +211,10 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
 {
        struct call_single_data d;
        unsigned long flags;
-       /* prevent preemption and reschedule on another processor */
+       /* prevent preemption and reschedule on another processor,
+          as well as CPU removal */
        int me = get_cpu();
+       int err = 0;
 
        /* Can deadlock when called with interrupts disabled */
        WARN_ON(irqs_disabled());
@@ -220,7 +223,7 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
                local_irq_save(flags);
                func(info);
                local_irq_restore(flags);
-       } else {
+       } else if ((unsigned)cpu < NR_CPUS && cpu_online(cpu)) {
                struct call_single_data *data = NULL;
 
                if (!wait) {
@@ -236,10 +239,12 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
                data->func = func;
                data->info = info;
                generic_exec_single(cpu, data);
+       } else {
+               err = -ENXIO;   /* CPU not online */
        }
 
        put_cpu();
-       return 0;
+       return err;
 }
 EXPORT_SYMBOL(smp_call_function_single);
 
@@ -366,6 +371,11 @@ int smp_call_function_mask(cpumask_t mask, void (*func)(void *), void *info,
        list_add_tail_rcu(&data->csd.list, &call_function_queue);
        spin_unlock_irqrestore(&call_function_lock, flags);
 
+       /*
+        * Make the list addition visible before sending the ipi.
+        */
+       smp_mb();
+
        /* Send a message to all CPUs in the map */
        arch_send_call_function_ipi(mask);