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![Linus Torvalds](/assets/img/avatar_default.png)
It may shut up gcc, but it also incorrectly changes the semantics of the smp_call_function() helpers. You can fix the warning other ways if you are interested (create another inline function that takes no arguments and returns zero), but preferably gcc just shouldn't complain about unused return values from statement expressions in the first place.
131 lines
3.3 KiB
C
131 lines
3.3 KiB
C
#ifndef __LINUX_SMP_H
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#define __LINUX_SMP_H
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/*
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* Generic SMP support
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* Alan Cox. <alan@redhat.com>
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*/
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#include <linux/config.h>
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extern void cpu_idle(void);
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#ifdef CONFIG_SMP
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#include <linux/preempt.h>
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#include <linux/kernel.h>
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#include <linux/compiler.h>
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#include <linux/thread_info.h>
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#include <asm/smp.h>
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#include <asm/bug.h>
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/*
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* main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
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* (defined in asm header):
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*/
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/*
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* stops all CPUs but the current one:
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*/
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extern void smp_send_stop(void);
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/*
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* sends a 'reschedule' event to another CPU:
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*/
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extern void smp_send_reschedule(int cpu);
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/*
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* Prepare machine for booting other CPUs.
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*/
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extern void smp_prepare_cpus(unsigned int max_cpus);
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/*
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* Bring a CPU up
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*/
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extern int __cpu_up(unsigned int cpunum);
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/*
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* Final polishing of CPUs
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*/
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extern void smp_cpus_done(unsigned int max_cpus);
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/*
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* Call a function on all other processors
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*/
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extern int smp_call_function (void (*func) (void *info), void *info,
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int retry, int wait);
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/*
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* Call a function on all processors
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*/
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static inline int on_each_cpu(void (*func) (void *info), void *info,
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int retry, int wait)
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{
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int ret = 0;
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preempt_disable();
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ret = smp_call_function(func, info, retry, wait);
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func(info);
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preempt_enable();
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return ret;
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}
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#define MSG_ALL_BUT_SELF 0x8000 /* Assume <32768 CPU's */
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#define MSG_ALL 0x8001
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#define MSG_INVALIDATE_TLB 0x0001 /* Remote processor TLB invalidate */
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#define MSG_STOP_CPU 0x0002 /* Sent to shut down slave CPU's
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* when rebooting
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*/
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#define MSG_RESCHEDULE 0x0003 /* Reschedule request from master CPU*/
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#define MSG_CALL_FUNCTION 0x0004 /* Call function on all other CPUs */
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/*
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* Mark the boot cpu "online" so that it can call console drivers in
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* printk() and can access its per-cpu storage.
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*/
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void smp_prepare_boot_cpu(void);
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#else /* !SMP */
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/*
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* These macros fold the SMP functionality into a single CPU system
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*/
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#define raw_smp_processor_id() 0
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#define hard_smp_processor_id() 0
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#define smp_call_function(func,info,retry,wait) ({ 0; })
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#define on_each_cpu(func,info,retry,wait) ({ func(info); 0; })
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static inline void smp_send_reschedule(int cpu) { }
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#define num_booting_cpus() 1
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#define smp_prepare_boot_cpu() do {} while (0)
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#endif /* !SMP */
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/*
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* smp_processor_id(): get the current CPU ID.
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*
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* if DEBUG_PREEMPT is enabled the we check whether it is
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* used in a preemption-safe way. (smp_processor_id() is safe
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* if it's used in a preemption-off critical section, or in
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* a thread that is bound to the current CPU.)
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*
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* NOTE: raw_smp_processor_id() is for internal use only
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* (smp_processor_id() is the preferred variant), but in rare
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* instances it might also be used to turn off false positives
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* (i.e. smp_processor_id() use that the debugging code reports but
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* which use for some reason is legal). Don't use this to hack around
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* the warning message, as your code might not work under PREEMPT.
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*/
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#ifdef CONFIG_DEBUG_PREEMPT
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extern unsigned int debug_smp_processor_id(void);
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# define smp_processor_id() debug_smp_processor_id()
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#else
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# define smp_processor_id() raw_smp_processor_id()
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#endif
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#define get_cpu() ({ preempt_disable(); smp_processor_id(); })
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#define put_cpu() preempt_enable()
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#define put_cpu_no_resched() preempt_enable_no_resched()
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#endif /* __LINUX_SMP_H */
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