[S390] smp_call_function cleanup
Introduce __smp_call_function_map which calls a function on all cpus given with a cpumask_t. Use it to implement smp_call_function and smp_call_function_on. Replace smp_ext_bitcall_others with smp_ext_bitcall and a for_each_cpu_mask loop. Use a cpumask_t instead of an atomic_t for cpu counting and print a warning if preempt is on in __smp_call_function_map(). Signed-off-by: Jan Glauber <jan.glauber@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Jan Glauber
Martin Schwidefsky
Родитель
188596faf7
Коммит
63db6e8d41
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@ -54,19 +54,18 @@ cpumask_t cpu_possible_map = CPU_MASK_NONE;
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static struct task_struct *current_set[NR_CPUS];
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static void smp_ext_bitcall(int, ec_bit_sig);
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static void smp_ext_bitcall_others(ec_bit_sig);
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/*
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* Structure and data for smp_call_function(). This is designed to minimise
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* static memory requirements. It also looks cleaner.
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* Structure and data for __smp_call_function_map(). This is designed to
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* minimise static memory requirements. It also looks cleaner.
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*/
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static DEFINE_SPINLOCK(call_lock);
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struct call_data_struct {
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void (*func) (void *info);
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void *info;
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atomic_t started;
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atomic_t finished;
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cpumask_t started;
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cpumask_t finished;
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int wait;
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};
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@ -81,118 +80,113 @@ static void do_call_function(void)
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void *info = call_data->info;
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int wait = call_data->wait;
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atomic_inc(&call_data->started);
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cpu_set(smp_processor_id(), call_data->started);
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(*func)(info);
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if (wait)
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atomic_inc(&call_data->finished);
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cpu_set(smp_processor_id(), call_data->finished);;
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}
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/*
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* this function sends a 'generic call function' IPI to all other CPUs
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* in the system.
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*/
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int smp_call_function (void (*func) (void *info), void *info, int nonatomic,
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int wait)
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/*
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* [SUMMARY] Run a function on all other CPUs.
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* <func> The function to run. This must be fast and non-blocking.
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* <info> An arbitrary pointer to pass to the function.
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* <nonatomic> currently unused.
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* <wait> If true, wait (atomically) until function has completed on other CPUs.
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* [RETURNS] 0 on success, else a negative status code. Does not return until
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* remote CPUs are nearly ready to execute <<func>> or are or have executed.
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*
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* You must not call this function with disabled interrupts or from a
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* hardware interrupt handler.
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*/
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static void __smp_call_function_map(void (*func) (void *info), void *info,
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int nonatomic, int wait, cpumask_t map)
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{
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struct call_data_struct data;
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int cpus = num_online_cpus()-1;
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int cpu, local = 0;
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if (cpus <= 0)
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return 0;
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/*
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* Can deadlock when interrupts are disabled or if in wrong context,
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* caller must disable preemption
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*/
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WARN_ON(irqs_disabled() || in_irq() || preemptible());
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/* Can deadlock when interrupts are disabled or if in wrong context */
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WARN_ON(irqs_disabled() || in_irq());
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data.func = func;
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data.info = info;
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atomic_set(&data.started, 0);
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data.wait = wait;
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if (wait)
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atomic_set(&data.finished, 0);
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spin_lock_bh(&call_lock);
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call_data = &data;
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/* Send a message to all other CPUs and wait for them to respond */
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smp_ext_bitcall_others(ec_call_function);
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/* Wait for response */
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while (atomic_read(&data.started) != cpus)
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cpu_relax();
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if (wait)
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while (atomic_read(&data.finished) != cpus)
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cpu_relax();
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spin_unlock_bh(&call_lock);
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return 0;
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}
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/*
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* Call a function on one CPU
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* cpu : the CPU the function should be executed on
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*
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* You must not call this function with disabled interrupts or from a
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* hardware interrupt handler. You may call it from a bottom half.
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*
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* It is guaranteed that the called function runs on the specified CPU,
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* preemption is disabled.
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*/
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int smp_call_function_on(void (*func) (void *info), void *info,
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int nonatomic, int wait, int cpu)
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{
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struct call_data_struct data;
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int curr_cpu;
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if (!cpu_online(cpu))
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return -EINVAL;
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/* Can deadlock when interrupts are disabled or if in wrong context */
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WARN_ON(irqs_disabled() || in_irq());
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/* disable preemption for local function call */
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curr_cpu = get_cpu();
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if (curr_cpu == cpu) {
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/* direct call to function */
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func(info);
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put_cpu();
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return 0;
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/*
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* Check for local function call. We have to have the same call order
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* as in on_each_cpu() because of machine_restart_smp().
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*/
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if (cpu_isset(smp_processor_id(), map)) {
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local = 1;
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cpu_clear(smp_processor_id(), map);
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}
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cpus_and(map, map, cpu_online_map);
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if (cpus_empty(map))
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goto out;
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data.func = func;
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data.info = info;
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atomic_set(&data.started, 0);
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data.started = CPU_MASK_NONE;
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data.wait = wait;
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if (wait)
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atomic_set(&data.finished, 0);
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data.finished = CPU_MASK_NONE;
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spin_lock_bh(&call_lock);
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call_data = &data;
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smp_ext_bitcall(cpu, ec_call_function);
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for_each_cpu_mask(cpu, map)
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smp_ext_bitcall(cpu, ec_call_function);
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/* Wait for response */
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while (atomic_read(&data.started) != 1)
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while (!cpus_equal(map, data.started))
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cpu_relax();
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if (wait)
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while (atomic_read(&data.finished) != 1)
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while (!cpus_equal(map, data.finished))
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cpu_relax();
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spin_unlock_bh(&call_lock);
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put_cpu();
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out:
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local_irq_disable();
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if (local)
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func(info);
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local_irq_enable();
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}
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/*
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* smp_call_function:
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* @func: the function to run; this must be fast and non-blocking
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* @info: an arbitrary pointer to pass to the function
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* @nonatomic: unused
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* @wait: if true, wait (atomically) until function has completed on other CPUs
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*
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* Run a function on all other CPUs.
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*
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* You must not call this function with disabled interrupts or from a
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* hardware interrupt handler. Must be called with preemption disabled.
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* You may call it from a bottom half.
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*/
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int smp_call_function(void (*func) (void *info), void *info, int nonatomic,
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int wait)
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{
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cpumask_t map;
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map = cpu_online_map;
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cpu_clear(smp_processor_id(), map);
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__smp_call_function_map(func, info, nonatomic, wait, map);
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return 0;
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}
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EXPORT_SYMBOL(smp_call_function);
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/*
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* smp_call_function_on:
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* @func: the function to run; this must be fast and non-blocking
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* @info: an arbitrary pointer to pass to the function
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* @nonatomic: unused
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* @wait: if true, wait (atomically) until function has completed on other CPUs
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* @cpu: the CPU where func should run
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*
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* Run a function on one processor.
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*
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* You must not call this function with disabled interrupts or from a
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* hardware interrupt handler. Must be called with preemption disabled.
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* You may call it from a bottom half.
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*/
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int smp_call_function_on(void (*func) (void *info), void *info, int nonatomic,
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int wait, int cpu)
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{
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cpumask_t map = CPU_MASK_NONE;
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cpu_set(cpu, map);
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__smp_call_function_map(func, info, nonatomic, wait, map);
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return 0;
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}
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EXPORT_SYMBOL(smp_call_function_on);
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@ -325,26 +319,6 @@ static void smp_ext_bitcall(int cpu, ec_bit_sig sig)
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udelay(10);
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}
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/*
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* Send an external call sigp to every other cpu in the system and
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* return without waiting for its completion.
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*/
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static void smp_ext_bitcall_others(ec_bit_sig sig)
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{
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int cpu;
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for_each_online_cpu(cpu) {
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if (cpu == smp_processor_id())
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continue;
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/*
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* Set signaling bit in lowcore of target cpu and kick it
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*/
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set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast);
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while (signal_processor(cpu, sigp_emergency_signal) == sigp_busy)
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udelay(10);
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}
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}
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#ifndef CONFIG_64BIT
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/*
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* this function sends a 'purge tlb' signal to another CPU.
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@ -807,6 +781,5 @@ EXPORT_SYMBOL(cpu_possible_map);
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EXPORT_SYMBOL(lowcore_ptr);
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EXPORT_SYMBOL(smp_ctl_set_bit);
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EXPORT_SYMBOL(smp_ctl_clear_bit);
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EXPORT_SYMBOL(smp_call_function);
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EXPORT_SYMBOL(smp_get_cpu);
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EXPORT_SYMBOL(smp_put_cpu);
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