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7d49b28a80
Introduce a variant of on_each_cpu_cond that iterates only over the CPUs in a cpumask, in order to avoid making callbacks for every single CPU in the system when we only need to test a subset. Cc: npiggin@gmail.com Cc: mingo@kernel.org Cc: will.deacon@arm.com Cc: songliubraving@fb.com Cc: kernel-team@fb.com Cc: hpa@zytor.com Cc: luto@kernel.org Signed-off-by: Rik van Riel <riel@surriel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180926035844.1420-5-riel@surriel.com
110 lines
2.3 KiB
C
110 lines
2.3 KiB
C
/*
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* Uniprocessor-only support functions. The counterpart to kernel/smp.c
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*/
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#include <linux/interrupt.h>
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#include <linux/kernel.h>
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#include <linux/export.h>
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#include <linux/smp.h>
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#include <linux/hypervisor.h>
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int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
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int wait)
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{
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unsigned long flags;
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WARN_ON(cpu != 0);
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local_irq_save(flags);
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func(info);
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local_irq_restore(flags);
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return 0;
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}
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EXPORT_SYMBOL(smp_call_function_single);
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int smp_call_function_single_async(int cpu, call_single_data_t *csd)
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{
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unsigned long flags;
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local_irq_save(flags);
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csd->func(csd->info);
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local_irq_restore(flags);
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return 0;
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}
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EXPORT_SYMBOL(smp_call_function_single_async);
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int on_each_cpu(smp_call_func_t func, void *info, int wait)
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{
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unsigned long flags;
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local_irq_save(flags);
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func(info);
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local_irq_restore(flags);
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return 0;
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}
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EXPORT_SYMBOL(on_each_cpu);
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/*
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* Note we still need to test the mask even for UP
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* because we actually can get an empty mask from
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* code that on SMP might call us without the local
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* CPU in the mask.
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*/
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void on_each_cpu_mask(const struct cpumask *mask,
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smp_call_func_t func, void *info, bool wait)
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{
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unsigned long flags;
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if (cpumask_test_cpu(0, mask)) {
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local_irq_save(flags);
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func(info);
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local_irq_restore(flags);
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}
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}
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EXPORT_SYMBOL(on_each_cpu_mask);
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/*
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* Preemption is disabled here to make sure the cond_func is called under the
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* same condtions in UP and SMP.
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*/
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void on_each_cpu_cond_mask(bool (*cond_func)(int cpu, void *info),
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smp_call_func_t func, void *info, bool wait,
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gfp_t gfp_flags, const struct cpumask *mask)
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{
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unsigned long flags;
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preempt_disable();
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if (cond_func(0, info)) {
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local_irq_save(flags);
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func(info);
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local_irq_restore(flags);
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}
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preempt_enable();
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}
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EXPORT_SYMBOL(on_each_cpu_cond_mask);
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void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
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smp_call_func_t func, void *info, bool wait,
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gfp_t gfp_flags)
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{
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on_each_cpu_cond_mask(cond_func, func, info, wait, gfp_flags, NULL);
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}
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EXPORT_SYMBOL(on_each_cpu_cond);
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int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par, bool phys)
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{
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int ret;
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if (cpu != 0)
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return -ENXIO;
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if (phys)
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hypervisor_pin_vcpu(0);
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ret = func(par);
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if (phys)
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hypervisor_pin_vcpu(-1);
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return ret;
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}
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EXPORT_SYMBOL_GPL(smp_call_on_cpu);
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