Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

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

diff --git a/kernel/cpu.c b/kernel/cpu.c
index cfb1d43ab801b69f24c47c0cdb17332c25f6f99e..f17e9854c24612e1e3f83b389f48224eb2d7b807 100644 (file)
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -64,6 +64,8 @@ void __init cpu_hotplug_init(void)
        cpu_hotplug.refcount = 0;
 }
 
+cpumask_t cpu_active_map;
+
 #ifdef CONFIG_HOTPLUG_CPU
 
 void get_online_cpus(void)
@@ -214,7 +216,6 @@ static int __ref take_cpu_down(void *_param)
 static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
 {
        int err, nr_calls = 0;
-       struct task_struct *p;
        cpumask_t old_allowed, tmp;
        void *hcpu = (void *)(long)cpu;
        unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
@@ -247,21 +248,18 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
        cpus_setall(tmp);
        cpu_clear(cpu, tmp);
        set_cpus_allowed_ptr(current, &tmp);
+       tmp = cpumask_of_cpu(cpu);
 
-       p = __stop_machine_run(take_cpu_down, &tcd_param, cpu);
-
-       if (IS_ERR(p) || cpu_online(cpu)) {
+       err = __stop_machine(take_cpu_down, &tcd_param, &tmp);
+       if (err) {
                /* CPU didn't die: tell everyone.  Can't complain. */
                if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod,
                                            hcpu) == NOTIFY_BAD)
                        BUG();
 
-               if (IS_ERR(p)) {
-                       err = PTR_ERR(p);
-                       goto out_allowed;
-               }
-               goto out_thread;
+               goto out_allowed;
        }
+       BUG_ON(cpu_online(cpu));
 
        /* Wait for it to sleep (leaving idle task). */
        while (!idle_cpu(cpu))
@@ -277,12 +275,15 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
 
        check_for_tasks(cpu);
 
-out_thread:
-       err = kthread_stop(p);
 out_allowed:
        set_cpus_allowed_ptr(current, &old_allowed);
 out_release:
        cpu_hotplug_done();
+       if (!err) {
+               if (raw_notifier_call_chain(&cpu_chain, CPU_POST_DEAD | mod,
+                                           hcpu) == NOTIFY_BAD)
+                       BUG();
+       }
        return err;
 }
 
@@ -291,11 +292,30 @@ int __ref cpu_down(unsigned int cpu)
        int err = 0;
 
        cpu_maps_update_begin();
-       if (cpu_hotplug_disabled)
+
+       if (cpu_hotplug_disabled) {
                err = -EBUSY;
-       else
-               err = _cpu_down(cpu, 0);
+               goto out;
+       }
+
+       cpu_clear(cpu, cpu_active_map);
+
+       /*
+        * Make sure the all cpus did the reschedule and are not
+        * using stale version of the cpu_active_map.
+        * This is not strictly necessary becuase stop_machine()
+        * that we run down the line already provides the required
+        * synchronization. But it's really a side effect and we do not
+        * want to depend on the innards of the stop_machine here.
+        */
+       synchronize_sched();
+
+       err = _cpu_down(cpu, 0);
+
+       if (cpu_online(cpu))
+               cpu_set(cpu, cpu_active_map);
 
+out:
        cpu_maps_update_done();
        return err;
 }
@@ -329,6 +349,8 @@ static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen)
                goto out_notify;
        BUG_ON(!cpu_online(cpu));
 
+       cpu_set(cpu, cpu_active_map);
+
        /* Now call notifier in preparation. */
        raw_notifier_call_chain(&cpu_chain, CPU_ONLINE | mod, hcpu);
 
@@ -347,7 +369,7 @@ int __cpuinit cpu_up(unsigned int cpu)
        if (!cpu_isset(cpu, cpu_possible_map)) {
                printk(KERN_ERR "can't online cpu %d because it is not "
                        "configured as may-hotadd at boot time\n", cpu);
-#if defined(CONFIG_IA64) || defined(CONFIG_X86_64) || defined(CONFIG_S390)
+#if defined(CONFIG_IA64) || defined(CONFIG_X86_64)
                printk(KERN_ERR "please check additional_cpus= boot "
                                "parameter\n");
 #endif
@@ -355,11 +377,15 @@ int __cpuinit cpu_up(unsigned int cpu)
        }
 
        cpu_maps_update_begin();
-       if (cpu_hotplug_disabled)
+
+       if (cpu_hotplug_disabled) {
                err = -EBUSY;
-       else
-               err = _cpu_up(cpu, 0);
+               goto out;
+       }
+
+       err = _cpu_up(cpu, 0);
 
+out:
        cpu_maps_update_done();
        return err;
 }
@@ -413,7 +439,7 @@ void __ref enable_nonboot_cpus(void)
                goto out;
 
        printk("Enabling non-boot CPUs ...\n");
-       for_each_cpu_mask(cpu, frozen_cpus) {
+       for_each_cpu_mask_nr(cpu, frozen_cpus) {
                error = _cpu_up(cpu, 1);
                if (!error) {
                        printk("CPU%d is up\n", cpu);
@@ -428,3 +454,28 @@ out:
 #endif /* CONFIG_PM_SLEEP_SMP */
 
 #endif /* CONFIG_SMP */
+
+/*
+ * cpu_bit_bitmap[] is a special, "compressed" data structure that
+ * represents all NR_CPUS bits binary values of 1<<nr.
+ *
+ * It is used by cpumask_of_cpu() to get a constant address to a CPU
+ * mask value that has a single bit set only.
+ */
+
+/* cpu_bit_bitmap[0] is empty - so we can back into it */
+#define MASK_DECLARE_1(x)      [x+1][0] = 1UL << (x)
+#define MASK_DECLARE_2(x)      MASK_DECLARE_1(x), MASK_DECLARE_1(x+1)
+#define MASK_DECLARE_4(x)      MASK_DECLARE_2(x), MASK_DECLARE_2(x+2)
+#define MASK_DECLARE_8(x)      MASK_DECLARE_4(x), MASK_DECLARE_4(x+4)
+
+const unsigned long cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)] = {
+
+       MASK_DECLARE_8(0),      MASK_DECLARE_8(8),
+       MASK_DECLARE_8(16),     MASK_DECLARE_8(24),
+#if BITS_PER_LONG > 32
+       MASK_DECLARE_8(32),     MASK_DECLARE_8(40),
+       MASK_DECLARE_8(48),     MASK_DECLARE_8(56),
+#endif
+};
+EXPORT_SYMBOL_GPL(cpu_bit_bitmap);