03b8c7b623
If an architecture has futex_atomic_cmpxchg_inatomic() implemented and there is no runtime check necessary, allow to skip the test within futex_init(). This allows to get rid of some code which would always give the same result, and also allows the compiler to optimize a couple of if statements away. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Finn Thain <fthain@telegraphics.com.au> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Link: http://lkml.kernel.org/r/20140302120947.GA3641@osiris Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
71 lines
1.8 KiB
C
71 lines
1.8 KiB
C
#ifndef _LINUX_FUTEX_H
|
|
#define _LINUX_FUTEX_H
|
|
|
|
#include <uapi/linux/futex.h>
|
|
|
|
struct inode;
|
|
struct mm_struct;
|
|
struct task_struct;
|
|
union ktime;
|
|
|
|
long do_futex(u32 __user *uaddr, int op, u32 val, union ktime *timeout,
|
|
u32 __user *uaddr2, u32 val2, u32 val3);
|
|
|
|
extern int
|
|
handle_futex_death(u32 __user *uaddr, struct task_struct *curr, int pi);
|
|
|
|
/*
|
|
* Futexes are matched on equal values of this key.
|
|
* The key type depends on whether it's a shared or private mapping.
|
|
* Don't rearrange members without looking at hash_futex().
|
|
*
|
|
* offset is aligned to a multiple of sizeof(u32) (== 4) by definition.
|
|
* We use the two low order bits of offset to tell what is the kind of key :
|
|
* 00 : Private process futex (PTHREAD_PROCESS_PRIVATE)
|
|
* (no reference on an inode or mm)
|
|
* 01 : Shared futex (PTHREAD_PROCESS_SHARED)
|
|
* mapped on a file (reference on the underlying inode)
|
|
* 10 : Shared futex (PTHREAD_PROCESS_SHARED)
|
|
* (but private mapping on an mm, and reference taken on it)
|
|
*/
|
|
|
|
#define FUT_OFF_INODE 1 /* We set bit 0 if key has a reference on inode */
|
|
#define FUT_OFF_MMSHARED 2 /* We set bit 1 if key has a reference on mm */
|
|
|
|
union futex_key {
|
|
struct {
|
|
unsigned long pgoff;
|
|
struct inode *inode;
|
|
int offset;
|
|
} shared;
|
|
struct {
|
|
unsigned long address;
|
|
struct mm_struct *mm;
|
|
int offset;
|
|
} private;
|
|
struct {
|
|
unsigned long word;
|
|
void *ptr;
|
|
int offset;
|
|
} both;
|
|
};
|
|
|
|
#define FUTEX_KEY_INIT (union futex_key) { .both = { .ptr = NULL } }
|
|
|
|
#ifdef CONFIG_FUTEX
|
|
extern void exit_robust_list(struct task_struct *curr);
|
|
extern void exit_pi_state_list(struct task_struct *curr);
|
|
#ifdef CONFIG_HAVE_FUTEX_CMPXCHG
|
|
#define futex_cmpxchg_enabled 1
|
|
#else
|
|
extern int futex_cmpxchg_enabled;
|
|
#endif
|
|
#else
|
|
static inline void exit_robust_list(struct task_struct *curr)
|
|
{
|
|
}
|
|
static inline void exit_pi_state_list(struct task_struct *curr)
|
|
{
|
|
}
|
|
#endif
|
|
#endif
|