cpu_stop: implement stop_cpu[s]()

[net-next-2.6.git] / include / linux / stop_machine.h

diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h
index baba3a23a8145c6106177f924dd712b63e7b2f17..efcbd6c379474877b30b69176a7954a2dad14587 100644 (file)
--- a/include/linux/stop_machine.h
+++ b/include/linux/stop_machine.h
@@ -1,15 +1,46 @@
 #ifndef _LINUX_STOP_MACHINE
 #define _LINUX_STOP_MACHINE
-/* "Bogolock": stop the entire machine, disable interrupts.  This is a
-   very heavy lock, which is equivalent to grabbing every spinlock
-   (and more).  So the "read" side to such a lock is anything which
-   disables preeempt. */
+
 #include <linux/cpu.h>
 #include <linux/cpumask.h>
+#include <linux/list.h>
 #include <asm/system.h>
 
 #if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP)
 
+/*
+ * stop_cpu[s]() is simplistic per-cpu maximum priority cpu
+ * monopolization mechanism.  The caller can specify a non-sleeping
+ * function to be executed on a single or multiple cpus preempting all
+ * other processes and monopolizing those cpus until it finishes.
+ *
+ * Resources for this mechanism are preallocated when a cpu is brought
+ * up and requests are guaranteed to be served as long as the target
+ * cpus are online.
+ */
+
+typedef int (*cpu_stop_fn_t)(void *arg);
+
+struct cpu_stop_work {
+       struct list_head        list;           /* cpu_stopper->works */
+       cpu_stop_fn_t           fn;
+       void                    *arg;
+       struct cpu_stop_done    *done;
+};
+
+int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg);
+void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg,
+                        struct cpu_stop_work *work_buf);
+int stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg);
+int try_stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg);
+
+/*
+ * stop_machine "Bogolock": stop the entire machine, disable
+ * interrupts.  This is a very heavy lock, which is equivalent to
+ * grabbing every spinlock (and more).  So the "read" side to such a
+ * lock is anything which disables preeempt.
+ */
+
 /**
  * stop_machine: freeze the machine on all CPUs and run this function
  * @fn: the function to run