mirror of https://gitee.com/openkylin/linux.git
83 lines
2.4 KiB
C
83 lines
2.4 KiB
C
/*
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* SMP stuff which is common to all sub-architectures.
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*/
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#include <linux/module.h>
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#include <asm/smp.h>
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DEFINE_PER_CPU(unsigned long, this_cpu_off);
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EXPORT_PER_CPU_SYMBOL(this_cpu_off);
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/* Initialize the CPU's GDT. This is either the boot CPU doing itself
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(still using the master per-cpu area), or a CPU doing it for a
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secondary which will soon come up. */
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__cpuinit void init_gdt(int cpu)
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{
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struct desc_struct *gdt = get_cpu_gdt_table(cpu);
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pack_descriptor(&gdt[GDT_ENTRY_PERCPU],
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__per_cpu_offset[cpu], 0xFFFFF,
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0x2 | DESCTYPE_S, 0x8);
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gdt[GDT_ENTRY_PERCPU].s = 1;
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per_cpu(this_cpu_off, cpu) = __per_cpu_offset[cpu];
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per_cpu(cpu_number, cpu) = cpu;
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}
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/**
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* smp_call_function(): 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: 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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* Returns 0 on success, else a negative status code.
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*
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* If @wait is true, then returns once @func has returned; otherwise
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* it returns just before the target cpu calls @func.
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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 or from a bottom half handler.
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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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return smp_call_function_mask(cpu_online_map, func, info, wait);
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}
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EXPORT_SYMBOL(smp_call_function);
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/**
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* smp_call_function_single - Run a function on a specific CPU
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* @cpu: The target CPU. Cannot be the calling CPU.
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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 until function has completed on other CPUs.
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*
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* Returns 0 on success, else a negative status code.
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*
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* If @wait is true, then returns once @func has returned; otherwise
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* it returns just before the target cpu calls @func.
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*/
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int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
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int nonatomic, int wait)
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{
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/* prevent preemption and reschedule on another processor */
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int ret;
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int me = get_cpu();
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if (cpu == me) {
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local_irq_disable();
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func(info);
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local_irq_enable();
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put_cpu();
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return 0;
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}
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ret = smp_call_function_mask(cpumask_of_cpu(cpu), func, info, wait);
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put_cpu();
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return ret;
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}
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EXPORT_SYMBOL(smp_call_function_single);
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