/* SPDX-License-Identifier: GPL-2.0 */

  #ifndef __LINUX_SMP_H
  #define __LINUX_SMP_H
  
  /*
   *	Generic SMP support
   *		Alan Cox. <alan@redhat.com>
   */

  #include <linux/errno.h>

  #include <linux/types.h>

  #include <linux/list.h>

  #include <linux/cpumask.h>

  #include <linux/init.h>

  #include <linux/llist.h>

  typedef void (*smp_call_func_t)(void *info);

  struct __call_single_data {

  	struct llist_node llist;

  	smp_call_func_t func;

  	void *info;

  	unsigned int flags;

  };

  /* Use __aligned() to avoid to use 2 cache lines for 1 csd */
  typedef struct __call_single_data call_single_data_t
  	__aligned(sizeof(struct __call_single_data));

  /* total number of cpus in this system (may exceed NR_CPUS) */
  extern unsigned int total_cpus;

  int smp_call_function_single(int cpuid, smp_call_func_t func, void *info,
  			     int wait);

  /*

   * Call a function on all processors
   */

  void on_each_cpu(smp_call_func_t func, void *info, int wait);

  
  /*

   * Call a function on processors specified by mask, which might include
   * the local one.
   */
  void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
  		void *info, bool wait);
  
  /*
   * Call a function on each processor for which the supplied function
   * cond_func returns a positive value. This may include the local
   * processor.
   */
  void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
  		smp_call_func_t func, void *info, bool wait,
  		gfp_t gfp_flags);

  void on_each_cpu_cond_mask(bool (*cond_func)(int cpu, void *info),
  		smp_call_func_t func, void *info, bool wait,
  		gfp_t gfp_flags, const struct cpumask *mask);

  int smp_call_function_single_async(int cpu, call_single_data_t *csd);

  #ifdef CONFIG_SMP
  
  #include <linux/preempt.h>
  #include <linux/kernel.h>
  #include <linux/compiler.h>
  #include <linux/thread_info.h>
  #include <asm/smp.h>

  
  /*
   * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
   * (defined in asm header):

   */

  
  /*
   * stops all CPUs but the current one:
   */
  extern void smp_send_stop(void);
  
  /*
   * sends a 'reschedule' event to another CPU:
   */
  extern void smp_send_reschedule(int cpu);
  
  
  /*
   * Prepare machine for booting other CPUs.
   */
  extern void smp_prepare_cpus(unsigned int max_cpus);
  
  /*
   * Bring a CPU up
   */

  extern int __cpu_up(unsigned int cpunum, struct task_struct *tidle);

  
  /*
   * Final polishing of CPUs
   */
  extern void smp_cpus_done(unsigned int max_cpus);
  
  /*
   * Call a function on all other processors
   */

  void smp_call_function(smp_call_func_t func, void *info, int wait);

  void smp_call_function_many(const struct cpumask *mask,

  			    smp_call_func_t func, void *info, bool wait);

  int smp_call_function_any(const struct cpumask *mask,

  			  smp_call_func_t func, void *info, int wait);

  void kick_all_cpus_sync(void);

  void wake_up_all_idle_cpus(void);

  /*
   * Generic and arch helpers
   */

  void __init call_function_init(void);

  void generic_smp_call_function_single_interrupt(void);

  #define generic_smp_call_function_interrupt \
  	generic_smp_call_function_single_interrupt

  /*

   * Mark the boot cpu "online" so that it can call console drivers in
   * printk() and can access its per-cpu storage.
   */
  void smp_prepare_boot_cpu(void);

  extern unsigned int setup_max_cpus;

  extern void __init setup_nr_cpu_ids(void);
  extern void __init smp_init(void);

  extern int __boot_cpu_id;
  
  static inline int get_boot_cpu_id(void)
  {
  	return __boot_cpu_id;
  }

  #else /* !SMP */

  static inline void smp_send_stop(void) { }

  /*
   *	These macros fold the SMP functionality into a single CPU system
   */

  #define raw_smp_processor_id()			0

  static inline void up_smp_call_function(smp_call_func_t func, void *info)

  {

  }

  #define smp_call_function(func, info, wait) \

  			(up_smp_call_function(func, info))

  static inline void smp_send_reschedule(int cpu) { }

  #define smp_prepare_boot_cpu()			do {} while (0)

  #define smp_call_function_many(mask, func, info, wait) \
  			(up_smp_call_function(func, info))

  static inline void call_function_init(void) { }

  
  static inline int

  smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,

  		      void *info, int wait)

  {

  	return smp_call_function_single(0, func, info, wait);

  }

  static inline void kick_all_cpus_sync(void) {  }

  static inline void wake_up_all_idle_cpus(void) {  }

  #ifdef CONFIG_UP_LATE_INIT
  extern void __init up_late_init(void);
  static inline void smp_init(void) { up_late_init(); }
  #else
  static inline void smp_init(void) { }
  #endif

  static inline int get_boot_cpu_id(void)
  {
  	return 0;
  }

  #endif /* !SMP */

  /**
   * raw_processor_id() - get the current (unstable) CPU id
   *
   * For then you know what you are doing and need an unstable
   * CPU id.
   */
  
  /**
   * smp_processor_id() - get the current (stable) CPU id
   *
   * This is the normal accessor to the CPU id and should be used
   * whenever possible.
   *
   * The CPU id is stable when:

   *

   *  - IRQs are disabled;
   *  - preemption is disabled;
   *  - the task is CPU affine.

   *

   * When CONFIG_DEBUG_PREEMPT; we verify these assumption and WARN
   * when smp_processor_id() is used when the CPU id is not stable.

   */

  
  /*
   * Allow the architecture to differentiate between a stable and unstable read.
   * For example, x86 uses an IRQ-safe asm-volatile read for the unstable but a
   * regular asm read for the stable.
   */
  #ifndef __smp_processor_id
  #define __smp_processor_id(x) raw_smp_processor_id(x)
  #endif

  #ifdef CONFIG_DEBUG_PREEMPT
    extern unsigned int debug_smp_processor_id(void);
  # define smp_processor_id() debug_smp_processor_id()

  #else

  # define smp_processor_id() __smp_processor_id()

  #endif

  #define get_cpu()		({ preempt_disable(); __smp_processor_id(); })

  #define put_cpu()		preempt_enable()

  /*
   * Callback to arch code if there's nosmp or maxcpus=0 on the
   * boot command line:
   */
  extern void arch_disable_smp_support(void);

  extern void arch_enable_nonboot_cpus_begin(void);
  extern void arch_enable_nonboot_cpus_end(void);

  void smp_setup_processor_id(void);

  int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par,
  		    bool phys);

  /* SMP core functions */
  int smpcfd_prepare_cpu(unsigned int cpu);
  int smpcfd_dead_cpu(unsigned int cpu);
  int smpcfd_dying_cpu(unsigned int cpu);

  #endif /* __LINUX_SMP_H */