android_kernel_xiaomi_sm7250/include/linux/smp.h
Rusty Russell 2d3854a37e cpumask: introduce new API, without changing anything
Impact: introduce new APIs

We want to deprecate cpumasks on the stack, as we are headed for
gynormous numbers of CPUs.  Eventually, we want to head towards an
undefined 'struct cpumask' so they can never be declared on stack.

1) New cpumask functions which take pointers instead of copies.
   (cpus_* -> cpumask_*)

2) Several new helpers to reduce requirements for temporary cpumasks
   (cpumask_first_and, cpumask_next_and, cpumask_any_and)

3) Helpers for declaring cpumasks on or offstack for large NR_CPUS
   (cpumask_var_t, alloc_cpumask_var and free_cpumask_var)

4) 'struct cpumask' for explicitness and to mark new-style code.

5) Make iterator functions stop at nr_cpu_ids (a runtime constant),
   not NR_CPUS for time efficiency and for smaller dynamic allocations
   in future.

6) cpumask_copy() so we can allocate less than a full cpumask eventually
   (for alloc_cpumask_var), and so we can eliminate the 'struct cpumask'
   definition eventually.

7) work_on_cpu() helper for doing task on a CPU, rather than saving old
   cpumask for current thread and manipulating it.

8) smp_call_function_many() which is smp_call_function_mask() except
   taking a cpumask pointer.

Note that this patch simply introduces the new functions and leaves
the obsolescent ones in place.  This is to simplify the transition
patches.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-06 09:05:33 +01:00

183 lines
4.6 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>
extern void cpu_idle(void);
struct call_single_data {
struct list_head list;
void (*func) (void *info);
void *info;
u16 flags;
u16 priv;
};
#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);
/*
* Final polishing of CPUs
*/
extern void smp_cpus_done(unsigned int max_cpus);
/*
* Call a function on all other processors
*/
int smp_call_function(void(*func)(void *info), void *info, int wait);
/* Deprecated: use smp_call_function_many() which uses a cpumask ptr. */
int smp_call_function_mask(cpumask_t mask, void(*func)(void *info), void *info,
int wait);
static inline void smp_call_function_many(const struct cpumask *mask,
void (*func)(void *info), void *info,
int wait)
{
smp_call_function_mask(*mask, func, info, wait);
}
int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
int wait);
void __smp_call_function_single(int cpuid, struct call_single_data *data);
/*
* Generic and arch helpers
*/
#ifdef CONFIG_USE_GENERIC_SMP_HELPERS
void generic_smp_call_function_single_interrupt(void);
void generic_smp_call_function_interrupt(void);
void ipi_call_lock(void);
void ipi_call_unlock(void);
void ipi_call_lock_irq(void);
void ipi_call_unlock_irq(void);
#endif
/*
* Call a function on all processors
*/
int on_each_cpu(void (*func) (void *info), void *info, int wait);
#define MSG_ALL_BUT_SELF 0x8000 /* Assume <32768 CPU's */
#define MSG_ALL 0x8001
#define MSG_INVALIDATE_TLB 0x0001 /* Remote processor TLB invalidate */
#define MSG_STOP_CPU 0x0002 /* Sent to shut down slave CPU's
* when rebooting
*/
#define MSG_RESCHEDULE 0x0003 /* Reschedule request from master CPU*/
#define MSG_CALL_FUNCTION 0x0004 /* Call function on all other CPUs */
/*
* 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;
#else /* !SMP */
/*
* These macros fold the SMP functionality into a single CPU system
*/
#define raw_smp_processor_id() 0
static inline int up_smp_call_function(void (*func)(void *), void *info)
{
return 0;
}
#define smp_call_function(func, info, wait) \
(up_smp_call_function(func, info))
#define on_each_cpu(func,info,wait) \
({ \
local_irq_disable(); \
func(info); \
local_irq_enable(); \
0; \
})
static inline void smp_send_reschedule(int cpu) { }
#define num_booting_cpus() 1
#define smp_prepare_boot_cpu() do {} while (0)
#define smp_call_function_single(cpuid, func, info, wait) \
({ \
WARN_ON(cpuid != 0); \
local_irq_disable(); \
(func)(info); \
local_irq_enable(); \
0; \
})
#define smp_call_function_mask(mask, func, info, wait) \
(up_smp_call_function(func, info))
static inline void init_call_single_data(void)
{
}
#endif /* !SMP */
/*
* smp_processor_id(): get the current CPU ID.
*
* if DEBUG_PREEMPT is enabled the 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()
#define put_cpu_no_resched() preempt_enable_no_resched()
void smp_setup_processor_id(void);
#endif /* __LINUX_SMP_H */