linux_dsm_epyc7002/include/linux/smp.h
Frederic Weisbecker c46fff2a3b smp: Rename __smp_call_function_single() to smp_call_function_single_async()
The name __smp_call_function_single() doesn't tell much about the
properties of this function, especially when compared to
smp_call_function_single().

The comments above the implementation are also misleading. The main
point of this function is actually not to be able to embed the csd
in an object. This is actually a requirement that result from the
purpose of this function which is to raise an IPI asynchronously.

As such it can be called with interrupts disabled. And this feature
comes at the cost of the caller who then needs to serialize the
IPIs on this csd.

Lets rename the function and enhance the comments so that they reflect
these properties.

Suggested-by: Christoph Hellwig <hch@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@fb.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-02-24 14:47:15 -08:00

193 lines
4.9 KiB
C

#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>
extern void cpu_idle(void);
typedef void (*smp_call_func_t)(void *info);
struct call_single_data {
struct llist_node llist;
smp_call_func_t func;
void *info;
u16 flags;
};
/* 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
*/
int 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);
int smp_call_function_single_async(int cpu, struct call_single_data *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
*/
int 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);
/*
* 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);
#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 int up_smp_call_function(smp_call_func_t func, void *info)
{
return 0;
}
#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) { }
#endif /* !SMP */
/*
* smp_processor_id(): get the current CPU ID.
*
* if DEBUG_PREEMPT is enabled then we check whether it is
* used in a preemption-safe way. (smp_processor_id() is safe
* if it's used in a preemption-off critical section, or in
* a thread that is bound to the current CPU.)
*
* NOTE: raw_smp_processor_id() is for internal use only
* (smp_processor_id() is the preferred variant), but in rare
* instances it might also be used to turn off false positives
* (i.e. smp_processor_id() use that the debugging code reports but
* which use for some reason is legal). Don't use this to hack around
* the warning message, as your code might not work under PREEMPT.
*/
#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() raw_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);
#endif /* __LINUX_SMP_H */