Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/juhl/trivial

[safe/jmp/linux-2.6] / kernel / stop_machine.c

diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index b3d4dc8..0101aee 100644 (file)
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -1,11 +1,16 @@
-#include <linux/stop_machine.h>
-#include <linux/kthread.h>
-#include <linux/sched.h>
+/* Copyright 2005 Rusty Russell rusty@rustcorp.com.au IBM Corporation.
+ * GPL v2 and any later version.
+ */
 #include <linux/cpu.h>
 #include <linux/err.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/stop_machine.h>
 #include <linux/syscalls.h>
+#include <linux/interrupt.h>
+
 #include <asm/atomic.h>
-#include <asm/semaphore.h>
 #include <asm/uaccess.h>
 
 /* Since we effect priority and affinity (both of which are visible
@@ -23,14 +28,13 @@ enum stopmachine_state {
 static enum stopmachine_state stopmachine_state;
 static unsigned int stopmachine_num_threads;
 static atomic_t stopmachine_thread_ack;
-static DECLARE_MUTEX(stopmachine_mutex);
 
 static int stopmachine(void *cpu)
 {
        int irqs_disabled = 0;
        int prepared = 0;
 
-       set_cpus_allowed(current, cpumask_of_cpu((int)(long)cpu));
+       set_cpus_allowed_ptr(current, &cpumask_of_cpu((int)(long)cpu));
 
        /* Ack: we are alive */
        smp_mb(); /* Theoretically the ack = 0 might not be on this CPU yet. */
@@ -41,6 +45,7 @@ static int stopmachine(void *cpu)
                if (stopmachine_state == STOPMACHINE_DISABLE_IRQ 
                    && !irqs_disabled) {
                        local_irq_disable();
+                       hard_irq_disable();
                        irqs_disabled = 1;
                        /* Ack: irqs disabled. */
                        smp_mb(); /* Must read state first. */
@@ -86,14 +91,6 @@ static void stopmachine_set_state(enum stopmachine_state state)
 static int stop_machine(void)
 {
        int i, ret = 0;
-       struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
-       mm_segment_t old_fs = get_fs();
-
-       /* One high-prio thread per cpu.  We'll do this one. */
-       set_fs(KERNEL_DS);
-       sys_sched_setscheduler(current->pid, SCHED_FIFO,
-                               (struct sched_param __user *)&param);
-       set_fs(old_fs);
 
        atomic_set(&stopmachine_thread_ack, 0);
        stopmachine_num_threads = 0;
@@ -115,7 +112,6 @@ static int stop_machine(void)
        /* If some failed, kill them all. */
        if (ret < 0) {
                stopmachine_set_state(STOPMACHINE_EXIT);
-               up(&stopmachine_mutex);
                return ret;
        }
 
@@ -125,6 +121,7 @@ static int stop_machine(void)
 
        /* Make them disable irqs. */
        local_irq_disable();
+       hard_irq_disable();
        stopmachine_set_state(STOPMACHINE_DISABLE_IRQ);
 
        return 0;
@@ -137,8 +134,7 @@ static void restart_machine(void)
        preempt_enable_no_resched();
 }
 
-struct stop_machine_data
-{
+struct stop_machine_data {
        int (*fn)(void *);
        void *data;
        struct completion done;
@@ -171,6 +167,7 @@ static int do_stop(void *_smdata)
 struct task_struct *__stop_machine_run(int (*fn)(void *), void *data,
                                       unsigned int cpu)
 {
+       static DEFINE_MUTEX(stopmachine_mutex);
        struct stop_machine_data smdata;
        struct task_struct *p;
 
@@ -178,7 +175,7 @@ struct task_struct *__stop_machine_run(int (*fn)(void *), void *data,
        smdata.data = data;
        init_completion(&smdata.done);
 
-       down(&stopmachine_mutex);
+       mutex_lock(&stopmachine_mutex);
 
        /* If they don't care which CPU fn runs on, bind to any online one. */
        if (cpu == NR_CPUS)
@@ -186,11 +183,15 @@ struct task_struct *__stop_machine_run(int (*fn)(void *), void *data,
 
        p = kthread_create(do_stop, &smdata, "kstopmachine");
        if (!IS_ERR(p)) {
+               struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
+
+               /* One high-prio thread per cpu.  We'll do this one. */
+               sched_setscheduler(p, SCHED_FIFO, &param);
                kthread_bind(p, cpu);
                wake_up_process(p);
                wait_for_completion(&smdata.done);
        }
-       up(&stopmachine_mutex);
+       mutex_unlock(&stopmachine_mutex);
        return p;
 }
 
@@ -200,13 +201,14 @@ int stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu)
        int ret;
 
        /* No CPUs can come up or down during this. */
-       lock_cpu_hotplug();
+       get_online_cpus();
        p = __stop_machine_run(fn, data, cpu);
        if (!IS_ERR(p))
                ret = kthread_stop(p);
        else
                ret = PTR_ERR(p);
-       unlock_cpu_hotplug();
+       put_online_cpus();
 
        return ret;
 }
+EXPORT_SYMBOL_GPL(stop_machine_run);