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alpha: convert to generic helpers for IPI function calls
This converts alpha to use the new helpers for smp_call_function() and friends, and adds support for smp_call_function_single(). Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Jens Axboe
parent
f27b433ef3
commit
c524a1d891
@ -528,6 +528,7 @@ config ARCH_MAY_HAVE_PC_FDC
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config SMP
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bool "Symmetric multi-processing support"
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depends on ALPHA_SABLE || ALPHA_LYNX || ALPHA_RAWHIDE || ALPHA_DP264 || ALPHA_WILDFIRE || ALPHA_TITAN || ALPHA_GENERIC || ALPHA_SHARK || ALPHA_MARVEL
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select USE_GENERIC_SMP_HELPERS
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---help---
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This enables support for systems with more than one CPU. If you have
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a system with only one CPU, like most personal computers, say N. If
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@ -660,9 +660,9 @@ __marvel_rtc_io(u8 b, unsigned long addr, int write)
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#ifdef CONFIG_SMP
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if (smp_processor_id() != boot_cpuid)
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smp_call_function_on_cpu(__marvel_access_rtc,
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&rtc_access, 1, 1,
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cpumask_of_cpu(boot_cpuid));
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smp_call_function_single(boot_cpuid,
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__marvel_access_rtc,
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&rtc_access, 1, 1);
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else
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__marvel_access_rtc(&rtc_access);
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#else
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@ -62,6 +62,7 @@ static struct {
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enum ipi_message_type {
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IPI_RESCHEDULE,
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IPI_CALL_FUNC,
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IPI_CALL_FUNC_SINGLE,
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IPI_CPU_STOP,
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};
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@ -558,51 +559,6 @@ send_ipi_message(cpumask_t to_whom, enum ipi_message_type operation)
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wripir(i);
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}
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/* Structure and data for smp_call_function. This is designed to
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minimize static memory requirements. Plus it looks cleaner. */
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struct smp_call_struct {
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void (*func) (void *info);
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void *info;
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long wait;
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atomic_t unstarted_count;
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atomic_t unfinished_count;
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};
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static struct smp_call_struct *smp_call_function_data;
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/* Atomicly drop data into a shared pointer. The pointer is free if
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it is initially locked. If retry, spin until free. */
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static int
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pointer_lock (void *lock, void *data, int retry)
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{
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void *old, *tmp;
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mb();
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again:
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/* Compare and swap with zero. */
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asm volatile (
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"1: ldq_l %0,%1\n"
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" mov %3,%2\n"
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" bne %0,2f\n"
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" stq_c %2,%1\n"
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" beq %2,1b\n"
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"2:"
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: "=&r"(old), "=m"(*(void **)lock), "=&r"(tmp)
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: "r"(data)
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: "memory");
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if (old == 0)
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return 0;
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if (! retry)
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return -EBUSY;
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while (*(void **)lock)
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barrier();
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goto again;
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}
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void
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handle_ipi(struct pt_regs *regs)
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{
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@ -632,31 +588,12 @@ handle_ipi(struct pt_regs *regs)
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break;
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case IPI_CALL_FUNC:
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{
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struct smp_call_struct *data;
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void (*func)(void *info);
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void *info;
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int wait;
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data = smp_call_function_data;
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func = data->func;
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info = data->info;
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wait = data->wait;
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/* Notify the sending CPU that the data has been
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received, and execution is about to begin. */
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mb();
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atomic_dec (&data->unstarted_count);
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/* At this point the structure may be gone unless
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wait is true. */
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(*func)(info);
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/* Notify the sending CPU that the task is done. */
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mb();
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if (wait) atomic_dec (&data->unfinished_count);
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generic_smp_call_function_interrupt();
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break;
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case IPI_CALL_FUNC_SINGLE:
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generic_smp_call_function_single_interrupt();
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break;
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}
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case IPI_CPU_STOP:
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halt();
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@ -700,102 +637,15 @@ smp_send_stop(void)
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send_ipi_message(to_whom, IPI_CPU_STOP);
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}
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/*
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* 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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* <retry> If true, keep retrying until ready.
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* <wait> If true, wait until function has completed on other CPUs.
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* [RETURNS] 0 on success, else a negative status code.
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*
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* Does not return until remote CPUs are nearly ready to execute <func>
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* or are or have executed.
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* You must not call this function with disabled interrupts or from a
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* hardware interrupt handler or from a bottom half handler.
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*/
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int
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smp_call_function_on_cpu (void (*func) (void *info), void *info, int retry,
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int wait, cpumask_t to_whom)
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void arch_send_call_function_ipi(cpumask_t mask)
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{
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struct smp_call_struct data;
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unsigned long timeout;
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int num_cpus_to_call;
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/* Can deadlock when called with interrupts disabled */
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WARN_ON(irqs_disabled());
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data.func = func;
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data.info = info;
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data.wait = wait;
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cpu_clear(smp_processor_id(), to_whom);
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num_cpus_to_call = cpus_weight(to_whom);
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atomic_set(&data.unstarted_count, num_cpus_to_call);
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atomic_set(&data.unfinished_count, num_cpus_to_call);
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/* Acquire the smp_call_function_data mutex. */
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if (pointer_lock(&smp_call_function_data, &data, retry))
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return -EBUSY;
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/* Send a message to the requested CPUs. */
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send_ipi_message(to_whom, IPI_CALL_FUNC);
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/* Wait for a minimal response. */
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timeout = jiffies + HZ;
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while (atomic_read (&data.unstarted_count) > 0
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&& time_before (jiffies, timeout))
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barrier();
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/* If there's no response yet, log a message but allow a longer
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* timeout period -- if we get a response this time, log
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* a message saying when we got it..
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*/
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if (atomic_read(&data.unstarted_count) > 0) {
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long start_time = jiffies;
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printk(KERN_ERR "%s: initial timeout -- trying long wait\n",
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__func__);
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timeout = jiffies + 30 * HZ;
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while (atomic_read(&data.unstarted_count) > 0
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&& time_before(jiffies, timeout))
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barrier();
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if (atomic_read(&data.unstarted_count) <= 0) {
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long delta = jiffies - start_time;
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printk(KERN_ERR
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"%s: response %ld.%ld seconds into long wait\n",
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__func__, delta / HZ,
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(100 * (delta - ((delta / HZ) * HZ))) / HZ);
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}
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}
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/* We either got one or timed out -- clear the lock. */
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mb();
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smp_call_function_data = NULL;
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/*
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* If after both the initial and long timeout periods we still don't
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* have a response, something is very wrong...
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*/
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BUG_ON(atomic_read (&data.unstarted_count) > 0);
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/* Wait for a complete response, if needed. */
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if (wait) {
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while (atomic_read (&data.unfinished_count) > 0)
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barrier();
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}
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return 0;
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send_ipi_message(mask, IPI_CALL_FUNC);
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}
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EXPORT_SYMBOL(smp_call_function_on_cpu);
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int
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smp_call_function (void (*func) (void *info), void *info, int retry, int wait)
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void arch_send_call_function_single_ipi(int cpu)
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{
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return smp_call_function_on_cpu (func, info, retry, wait,
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cpu_online_map);
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send_ipi_message(cpumask_of_cpu(cpu), IPI_CALL_FUNC_SINGLE);
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}
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EXPORT_SYMBOL(smp_call_function);
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static void
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ipi_imb(void *ignored)
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@ -47,7 +47,8 @@ extern struct cpuinfo_alpha cpu_data[NR_CPUS];
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extern int smp_num_cpus;
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#define cpu_possible_map cpu_present_map
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int smp_call_function_on_cpu(void (*func) (void *info), void *info,int retry, int wait, cpumask_t cpu);
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extern void arch_send_call_function_single_ipi(int cpu);
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extern void arch_send_call_function_ipi(cpumask_t mask);
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#else /* CONFIG_SMP */
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