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      1 #ifndef __LINUX_SMP_H
      2 #define __LINUX_SMP_H
      3 
      4 /*
      5  *	Generic SMP support
      6  *		Alan Cox. <alan (at) redhat.com>
      7  */
      8 
      9 
     10 extern void cpu_idle(void);
     11 
     12 #ifdef CONFIG_SMP
     13 
     14 #include <linux/preempt.h>
     15 #include <linux/kernel.h>
     16 #include <linux/compiler.h>
     17 #include <linux/thread_info.h>
     18 #include <asm/smp.h>
     19 
     20 /*
     21  * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
     22  * (defined in asm header):
     23  */
     24 
     25 /*
     26  * stops all CPUs but the current one:
     27  */
     28 extern void smp_send_stop(void);
     29 
     30 /*
     31  * sends a 'reschedule' event to another CPU:
     32  */
     33 extern void smp_send_reschedule(int cpu);
     34 
     35 
     36 /*
     37  * Prepare machine for booting other CPUs.
     38  */
     39 extern void smp_prepare_cpus(unsigned int max_cpus);
     40 
     41 /*
     42  * Bring a CPU up
     43  */
     44 extern int __cpu_up(unsigned int cpunum);
     45 
     46 /*
     47  * Final polishing of CPUs
     48  */
     49 extern void smp_cpus_done(unsigned int max_cpus);
     50 
     51 /*
     52  * Call a function on all other processors
     53  */
     54 int smp_call_function(void(*func)(void *info), void *info, int retry, int wait);
     55 
     56 /*
     57  * Call a function on all processors
     58  */
     59 int on_each_cpu(void (*func) (void *info), void *info, int retry, int wait);
     60 
     61 #define MSG_ALL_BUT_SELF	0x8000	/* Assume <32768 CPU's */
     62 #define MSG_ALL			0x8001
     63 
     64 #define MSG_INVALIDATE_TLB	0x0001	/* Remote processor TLB invalidate */
     65 #define MSG_STOP_CPU		0x0002	/* Sent to shut down slave CPU's
     66 					 * when rebooting
     67 					 */
     68 #define MSG_RESCHEDULE		0x0003	/* Reschedule request from master CPU*/
     69 #define MSG_CALL_FUNCTION       0x0004  /* Call function on all other CPUs */
     70 
     71 /*
     72  * Mark the boot cpu "online" so that it can call console drivers in
     73  * printk() and can access its per-cpu storage.
     74  */
     75 void smp_prepare_boot_cpu(void);
     76 
     77 #else /* !SMP */
     78 
     79 /*
     80  *	These macros fold the SMP functionality into a single CPU system
     81  */
     82 #define raw_smp_processor_id()			0
     83 #define hard_smp_processor_id()			0
     84 static inline int up_smp_call_function(void)
     85 {
     86 	return 0;
     87 }
     88 #define smp_call_function(func,info,retry,wait)	(up_smp_call_function())
     89 #define on_each_cpu(func,info,retry,wait)	\
     90 	({					\
     91 		local_irq_disable();		\
     92 		func(info);			\
     93 		local_irq_enable();		\
     94 		0;				\
     95 	})
     96 static inline void smp_send_reschedule(int cpu) { }
     97 #define num_booting_cpus()			1
     98 #define smp_prepare_boot_cpu()			do {} while (0)
     99 
    100 #endif /* !SMP */
    101 
    102 /*
    103  * smp_processor_id(): get the current CPU ID.
    104  *
    105  * if DEBUG_PREEMPT is enabled the we check whether it is
    106  * used in a preemption-safe way. (smp_processor_id() is safe
    107  * if it's used in a preemption-off critical section, or in
    108  * a thread that is bound to the current CPU.)
    109  *
    110  * NOTE: raw_smp_processor_id() is for internal use only
    111  * (smp_processor_id() is the preferred variant), but in rare
    112  * instances it might also be used to turn off false positives
    113  * (i.e. smp_processor_id() use that the debugging code reports but
    114  * which use for some reason is legal). Don't use this to hack around
    115  * the warning message, as your code might not work under PREEMPT.
    116  */
    117 #ifdef CONFIG_DEBUG_PREEMPT
    118   extern unsigned int debug_smp_processor_id(void);
    119 # define smp_processor_id() debug_smp_processor_id()
    120 #else
    121 # define smp_processor_id() raw_smp_processor_id()
    122 #endif
    123 
    124 #define get_cpu()		({ preempt_disable(); smp_processor_id(); })
    125 #define put_cpu()		preempt_enable()
    126 #define put_cpu_no_resched()	preempt_enable_no_resched()
    127 
    128 void smp_setup_processor_id(void);
    129 
    130 #endif /* __LINUX_SMP_H */
    131