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@@ -6,8 +6,6 @@
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#include <linux/list.h>
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#include <asm/system.h>
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-#if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP)
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-
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/*
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* stop_cpu[s]() is simplistic per-cpu maximum priority cpu
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* monopolization mechanism. The caller can specify a non-sleeping
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@@ -18,9 +16,10 @@
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* up and requests are guaranteed to be served as long as the target
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* cpus are online.
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*/
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-
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typedef int (*cpu_stop_fn_t)(void *arg);
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+#ifdef CONFIG_SMP
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+
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struct cpu_stop_work {
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struct list_head list; /* cpu_stopper->works */
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cpu_stop_fn_t fn;
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@@ -34,12 +33,70 @@ void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg,
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int stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg);
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int try_stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg);
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+#else /* CONFIG_SMP */
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+
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+#include <linux/workqueue.h>
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+
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+struct cpu_stop_work {
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+ struct work_struct work;
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+ cpu_stop_fn_t fn;
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+ void *arg;
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+};
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+
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+static inline int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg)
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+{
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+ int ret = -ENOENT;
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+ preempt_disable();
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+ if (cpu == smp_processor_id())
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+ ret = fn(arg);
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+ preempt_enable();
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+ return ret;
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+}
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+
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+static void stop_one_cpu_nowait_workfn(struct work_struct *work)
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+{
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+ struct cpu_stop_work *stwork =
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+ container_of(work, struct cpu_stop_work, work);
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+ preempt_disable();
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+ stwork->fn(stwork->arg);
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+ preempt_enable();
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+}
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+
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+static inline void stop_one_cpu_nowait(unsigned int cpu,
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+ cpu_stop_fn_t fn, void *arg,
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+ struct cpu_stop_work *work_buf)
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+{
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+ if (cpu == smp_processor_id()) {
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+ INIT_WORK(&work_buf->work, stop_one_cpu_nowait_workfn);
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+ work_buf->fn = fn;
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+ work_buf->arg = arg;
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+ schedule_work(&work_buf->work);
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+ }
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+}
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+
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+static inline int stop_cpus(const struct cpumask *cpumask,
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+ cpu_stop_fn_t fn, void *arg)
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+{
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+ if (cpumask_test_cpu(raw_smp_processor_id(), cpumask))
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+ return stop_one_cpu(raw_smp_processor_id(), fn, arg);
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+ return -ENOENT;
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+}
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+
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+static inline int try_stop_cpus(const struct cpumask *cpumask,
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+ cpu_stop_fn_t fn, void *arg)
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+{
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+ return stop_cpus(cpumask, fn, arg);
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+}
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+
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+#endif /* CONFIG_SMP */
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+
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/*
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* stop_machine "Bogolock": stop the entire machine, disable
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* interrupts. This is a very heavy lock, which is equivalent to
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* grabbing every spinlock (and more). So the "read" side to such a
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* lock is anything which disables preeempt.
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*/
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+#if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP)
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/**
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* stop_machine: freeze the machine on all CPUs and run this function
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@@ -67,7 +124,7 @@ int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus);
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*/
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int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus);
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-#else
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+#else /* CONFIG_STOP_MACHINE && CONFIG_SMP */
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static inline int stop_machine(int (*fn)(void *), void *data,
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const struct cpumask *cpus)
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@@ -79,5 +136,5 @@ static inline int stop_machine(int (*fn)(void *), void *data,
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return ret;
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}
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-#endif /* CONFIG_SMP */
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-#endif /* _LINUX_STOP_MACHINE */
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+#endif /* CONFIG_STOP_MACHINE && CONFIG_SMP */
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+#endif /* _LINUX_STOP_MACHINE */
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