1 /* MECHANICALLY GENERATED, DO NOT EDIT!!! */
6 * common.h: Common Linux kernel-isms.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; but version 2 of the License only due
11 * to code included from the Linux kernel.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
22 * Copyright (c) 2006 Paul E. McKenney, IBM.
24 * Much code taken from the Linux kernel. For such code, the option
25 * to redistribute under later versions of GPL might not be available.
28 #ifndef __always_inline
29 #define __always_inline inline
32 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
33 #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
36 # define stringify_in_c(...) __VA_ARGS__
37 # define ASM_CONST(x) x
39 /* This version of stringify will deal with commas... */
40 # define __stringify_in_c(...) #__VA_ARGS__
41 # define stringify_in_c(...) __stringify_in_c(__VA_ARGS__) " "
42 # define __ASM_CONST(x) x##UL
43 # define ASM_CONST(x) __ASM_CONST(x)
48 * arch-i386.h: Expose x86 atomic instructions. 80486 and better only.
50 * This program is free software; you can redistribute it and/or modify
51 * it under the terms of the GNU General Public License as published by
52 * the Free Software Foundation, but version 2 only due to inclusion
53 * of Linux-kernel code.
55 * This program is distributed in the hope that it will be useful,
56 * but WITHOUT ANY WARRANTY; without even the implied warranty of
57 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
58 * GNU General Public License for more details.
60 * You should have received a copy of the GNU General Public License
61 * along with this program; if not, write to the Free Software
62 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
64 * Copyright (c) 2006 Paul E. McKenney, IBM.
66 * Much code taken from the Linux kernel. For such code, the option
67 * to redistribute under later versions of GPL might not be available.
74 #define CACHE_LINE_SIZE 64
75 #define ____cacheline_internodealigned_in_smp \
76 __attribute__((__aligned__(1 << 6)))
78 #define LOCK_PREFIX "lock ; "
81 * Atomic data structure, initialization, and access.
84 typedef struct { volatile int counter
; } atomic_t
;
86 #define ATOMIC_INIT(i) { (i) }
88 #define atomic_read(v) ((v)->counter)
89 #define atomic_set(v, i) (((v)->counter) = (i))
96 * atomic_add - add integer to atomic variable
97 * @i: integer value to add
98 * @v: pointer of type atomic_t
100 * Atomically adds @i to @v.
102 static __inline__
void atomic_add(int i
, atomic_t
*v
)
104 __asm__
__volatile__(
105 LOCK_PREFIX
"addl %1,%0"
111 * atomic_sub - subtract the atomic variable
112 * @i: integer value to subtract
113 * @v: pointer of type atomic_t
115 * Atomically subtracts @i from @v.
117 static __inline__
void atomic_sub(int i
, atomic_t
*v
)
119 __asm__
__volatile__(
120 LOCK_PREFIX
"subl %1,%0"
126 * atomic_sub_and_test - subtract value from variable and test result
127 * @i: integer value to subtract
128 * @v: pointer of type atomic_t
130 * Atomically subtracts @i from @v and returns
131 * true if the result is zero, or false for all
134 static __inline__
int atomic_sub_and_test(int i
, atomic_t
*v
)
138 __asm__
__volatile__(
139 LOCK_PREFIX
"subl %2,%0; sete %1"
140 :"+m" (v
->counter
), "=qm" (c
)
141 :"ir" (i
) : "memory");
146 * atomic_inc - increment atomic variable
147 * @v: pointer of type atomic_t
149 * Atomically increments @v by 1.
151 static __inline__
void atomic_inc(atomic_t
*v
)
153 __asm__
__volatile__(
154 LOCK_PREFIX
"incl %0"
159 * atomic_dec - decrement atomic variable
160 * @v: pointer of type atomic_t
162 * Atomically decrements @v by 1.
164 static __inline__
void atomic_dec(atomic_t
*v
)
166 __asm__
__volatile__(
167 LOCK_PREFIX
"decl %0"
172 * atomic_dec_and_test - decrement and test
173 * @v: pointer of type atomic_t
175 * Atomically decrements @v by 1 and
176 * returns true if the result is 0, or false for all other
179 static __inline__
int atomic_dec_and_test(atomic_t
*v
)
183 __asm__
__volatile__(
184 LOCK_PREFIX
"decl %0; sete %1"
185 :"+m" (v
->counter
), "=qm" (c
)
191 * atomic_inc_and_test - increment and test
192 * @v: pointer of type atomic_t
194 * Atomically increments @v by 1
195 * and returns true if the result is zero, or false for all
198 static __inline__
int atomic_inc_and_test(atomic_t
*v
)
202 __asm__
__volatile__(
203 LOCK_PREFIX
"incl %0; sete %1"
204 :"+m" (v
->counter
), "=qm" (c
)
210 * atomic_add_negative - add and test if negative
211 * @v: pointer of type atomic_t
212 * @i: integer value to add
214 * Atomically adds @i to @v and returns true
215 * if the result is negative, or false when
216 * result is greater than or equal to zero.
218 static __inline__
int atomic_add_negative(int i
, atomic_t
*v
)
222 __asm__
__volatile__(
223 LOCK_PREFIX
"addl %2,%0; sets %1"
224 :"+m" (v
->counter
), "=qm" (c
)
225 :"ir" (i
) : "memory");
230 * atomic_add_return - add and return
231 * @v: pointer of type atomic_t
232 * @i: integer value to add
234 * Atomically adds @i to @v and returns @i + @v
236 static __inline__
int atomic_add_return(int i
, atomic_t
*v
)
241 __asm__
__volatile__(
242 LOCK_PREFIX
"xaddl %0, %1;"
244 :"m"(v
->counter
), "0"(i
));
248 static __inline__
int atomic_sub_return(int i
, atomic_t
*v
)
250 return atomic_add_return(-i
,v
);
253 static inline unsigned int
254 cmpxchg(volatile long *ptr
, long oldval
, long newval
)
256 unsigned long retval
;
259 "lock; cmpxchgl %4,(%2)\n"
260 "# end atomic_cmpxchg4"
261 : "=a" (retval
), "=m" (*ptr
)
262 : "r" (ptr
), "0" (oldval
), "r" (newval
), "m" (*ptr
)
267 #define atomic_cmpxchg(v, old, new) ((int)cmpxchg(&((v)->counter), old, new))
268 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
271 * atomic_add_unless - add unless the number is a given value
272 * @v: pointer of type atomic_t
273 * @a: the amount to add to v...
274 * @u: ...unless v is equal to u.
276 * Atomically adds @a to @v, so long as it was not @u.
277 * Returns non-zero if @v was not @u, and zero otherwise.
279 #define atomic_add_unless(v, a, u) \
282 c = atomic_read(v); \
284 if (unlikely(c == (u))) \
286 old = atomic_cmpxchg((v), c, c + (a)); \
287 if (likely(old == c)) \
293 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
295 #define atomic_inc_return(v) (atomic_add_return(1,v))
296 #define atomic_dec_return(v) (atomic_sub_return(1,v))
298 /* These are x86-specific, used by some header files */
299 #define atomic_clear_mask(mask, addr) \
300 __asm__ __volatile__(LOCK_PREFIX "andl %0,%1" \
301 : : "r" (~(mask)),"m" (*addr) : "memory")
303 #define atomic_set_mask(mask, addr) \
304 __asm__ __volatile__(LOCK_PREFIX "orl %0,%1" \
305 : : "r" (mask),"m" (*(addr)) : "memory")
307 /* Atomic operations are already serializing on x86 */
308 #define smp_mb__before_atomic_dec() barrier()
309 #define smp_mb__after_atomic_dec() barrier()
310 #define smp_mb__before_atomic_inc() barrier()
311 #define smp_mb__after_atomic_inc() barrier()
314 * api_pthreads.h: API mapping to pthreads environment.
316 * This program is free software; you can redistribute it and/or modify
317 * it under the terms of the GNU General Public License as published by
318 * the Free Software Foundation; either version 2 of the License, or
319 * (at your option) any later version. However, please note that much
320 * of the code in this file derives from the Linux kernel, and that such
321 * code may not be available except under GPLv2.
323 * This program is distributed in the hope that it will be useful,
324 * but WITHOUT ANY WARRANTY; without even the implied warranty of
325 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
326 * GNU General Public License for more details.
328 * You should have received a copy of the GNU General Public License
329 * along with this program; if not, write to the Free Software
330 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
332 * Copyright (c) 2006 Paul E. McKenney, IBM.
339 #include <sys/types.h>
343 #include <sys/param.h>
344 /* #include "atomic.h" */
349 #define container_of(ptr, type, member) ({ \
350 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
351 (type *)( (char *)__mptr - offsetof(type,member) );})
354 * Default machine parameters.
357 #ifndef CACHE_LINE_SIZE
358 #define CACHE_LINE_SIZE 128
359 #endif /* #ifndef CACHE_LINE_SIZE */
362 * Exclusive locking primitives.
365 typedef pthread_mutex_t spinlock_t
;
367 #define DEFINE_SPINLOCK(lock) spinlock_t lock = PTHREAD_MUTEX_INITIALIZER;
368 #define __SPIN_LOCK_UNLOCKED(lockp) PTHREAD_MUTEX_INITIALIZER
370 static void spin_lock_init(spinlock_t
*sp
)
372 if (pthread_mutex_init(sp
, NULL
) != 0) {
373 perror("spin_lock_init:pthread_mutex_init");
378 static void spin_lock(spinlock_t
*sp
)
380 if (pthread_mutex_lock(sp
) != 0) {
381 perror("spin_lock:pthread_mutex_lock");
386 static void spin_unlock(spinlock_t
*sp
)
388 if (pthread_mutex_unlock(sp
) != 0) {
389 perror("spin_unlock:pthread_mutex_unlock");
394 #define spin_lock_irqsave(l, f) do { f = 1; spin_lock(l); } while (0)
395 #define spin_unlock_irqrestore(l, f) do { f = 0; spin_unlock(l); } while (0)
398 * Thread creation/destruction primitives.
401 typedef pthread_t thread_id_t
;
403 #define NR_THREADS 128
405 #define __THREAD_ID_MAP_EMPTY 0
406 #define __THREAD_ID_MAP_WAITING 1
407 thread_id_t __thread_id_map
[NR_THREADS
];
408 spinlock_t __thread_id_map_mutex
;
410 #define for_each_thread(t) \
411 for (t = 0; t < NR_THREADS; t++)
413 #define for_each_running_thread(t) \
414 for (t = 0; t < NR_THREADS; t++) \
415 if ((__thread_id_map[t] != __THREAD_ID_MAP_EMPTY) && \
416 (__thread_id_map[t] != __THREAD_ID_MAP_WAITING))
418 pthread_key_t thread_id_key
;
420 static int __smp_thread_id(void)
423 thread_id_t tid
= pthread_self();
425 for (i
= 0; i
< NR_THREADS
; i
++) {
426 if (__thread_id_map
[i
] == tid
) {
427 long v
= i
+ 1; /* must be non-NULL. */
429 if (pthread_setspecific(thread_id_key
, (void *)v
) != 0) {
430 perror("pthread_setspecific");
436 spin_lock(&__thread_id_map_mutex
);
437 for (i
= 0; i
< NR_THREADS
; i
++) {
438 if (__thread_id_map
[i
] == tid
)
439 spin_unlock(&__thread_id_map_mutex
);
442 spin_unlock(&__thread_id_map_mutex
);
443 fprintf(stderr
, "smp_thread_id: Rogue thread, id: %d(%#x)\n",
448 static int smp_thread_id(void)
452 id
= pthread_getspecific(thread_id_key
);
454 return __smp_thread_id();
455 return (long)(id
- 1);
458 static thread_id_t
create_thread(void *(*func
)(void *), void *arg
)
463 spin_lock(&__thread_id_map_mutex
);
464 for (i
= 0; i
< NR_THREADS
; i
++) {
465 if (__thread_id_map
[i
] == __THREAD_ID_MAP_EMPTY
)
468 if (i
>= NR_THREADS
) {
469 spin_unlock(&__thread_id_map_mutex
);
470 fprintf(stderr
, "Thread limit of %d exceeded!\n", NR_THREADS
);
473 __thread_id_map
[i
] = __THREAD_ID_MAP_WAITING
;
474 spin_unlock(&__thread_id_map_mutex
);
475 if (pthread_create(&tid
, NULL
, func
, arg
) != 0) {
476 perror("create_thread:pthread_create");
479 __thread_id_map
[i
] = tid
;
483 static void *wait_thread(thread_id_t tid
)
488 for (i
= 0; i
< NR_THREADS
; i
++) {
489 if (__thread_id_map
[i
] == tid
)
492 if (i
>= NR_THREADS
){
493 fprintf(stderr
, "wait_thread: bad tid = %d(%#x)\n",
497 if (pthread_join(tid
, &vp
) != 0) {
498 perror("wait_thread:pthread_join");
501 __thread_id_map
[i
] = __THREAD_ID_MAP_EMPTY
;
505 static void wait_all_threads(void)
510 for (i
= 1; i
< NR_THREADS
; i
++) {
511 tid
= __thread_id_map
[i
];
512 if (tid
!= __THREAD_ID_MAP_EMPTY
&&
513 tid
!= __THREAD_ID_MAP_WAITING
)
514 (void)wait_thread(tid
);
518 static void run_on(int cpu
)
524 sched_setaffinity(0, sizeof(mask
), &mask
);
528 * timekeeping -- very crude -- should use MONOTONIC...
531 long long get_microseconds(void)
535 if (gettimeofday(&tv
, NULL
) != 0)
537 return ((long long)tv
.tv_sec
) * 1000000LL + (long long)tv
.tv_usec
;
541 * Per-thread variables.
544 #define DEFINE_PER_THREAD(type, name) \
547 __attribute__((__aligned__(CACHE_LINE_SIZE))); \
548 } __per_thread_##name[NR_THREADS];
549 #define DECLARE_PER_THREAD(type, name) extern DEFINE_PER_THREAD(type, name)
551 #define per_thread(name, thread) __per_thread_##name[thread].v
552 #define __get_thread_var(name) per_thread(name, smp_thread_id())
554 #define init_per_thread(name, v) \
557 for (__i_p_t_i = 0; __i_p_t_i < NR_THREADS; __i_p_t_i++) \
558 per_thread(name, __i_p_t_i) = v; \
562 * CPU traversal primitives.
567 #endif /* #ifndef NR_CPUS */
569 #define for_each_possible_cpu(cpu) \
570 for (cpu = 0; cpu < NR_CPUS; cpu++)
571 #define for_each_online_cpu(cpu) \
572 for (cpu = 0; cpu < NR_CPUS; cpu++)
578 #define DEFINE_PER_CPU(type, name) \
581 __attribute__((__aligned__(CACHE_LINE_SIZE))); \
582 } __per_cpu_##name[NR_CPUS]
583 #define DECLARE_PER_CPU(type, name) extern DEFINE_PER_CPU(type, name)
585 DEFINE_PER_THREAD(int, smp_processor_id
);
587 #define per_cpu(name, thread) __per_cpu_##name[thread].v
588 #define __get_cpu_var(name) per_cpu(name, smp_processor_id())
590 #define init_per_cpu(name, v) \
593 for (__i_p_c_i = 0; __i_p_c_i < NR_CPUS; __i_p_c_i++) \
594 per_cpu(name, __i_p_c_i) = v; \
598 * CPU state checking (crowbarred).
601 #define idle_cpu(cpu) 0
602 #define in_softirq() 1
603 #define hardirq_count() 0
604 #define PREEMPT_SHIFT 0
605 #define SOFTIRQ_SHIFT (PREEMPT_SHIFT + PREEMPT_BITS)
606 #define HARDIRQ_SHIFT (SOFTIRQ_SHIFT + SOFTIRQ_BITS)
607 #define PREEMPT_BITS 8
608 #define SOFTIRQ_BITS 8
614 struct notifier_block
{
615 int (*notifier_call
)(struct notifier_block
*, unsigned long, void *);
616 struct notifier_block
*next
;
620 #define CPU_ONLINE 0x0002 /* CPU (unsigned)v is up */
621 #define CPU_UP_PREPARE 0x0003 /* CPU (unsigned)v coming up */
622 #define CPU_UP_CANCELED 0x0004 /* CPU (unsigned)v NOT coming up */
623 #define CPU_DOWN_PREPARE 0x0005 /* CPU (unsigned)v going down */
624 #define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */
625 #define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */
626 #define CPU_DYING 0x0008 /* CPU (unsigned)v not running any task,
627 * not handling interrupts, soon dead */
628 #define CPU_POST_DEAD 0x0009 /* CPU (unsigned)v dead, cpu_hotplug
631 /* Used for CPU hotplug events occuring while tasks are frozen due to a suspend
632 * operation in progress
634 #define CPU_TASKS_FROZEN 0x0010
636 #define CPU_ONLINE_FROZEN (CPU_ONLINE | CPU_TASKS_FROZEN)
637 #define CPU_UP_PREPARE_FROZEN (CPU_UP_PREPARE | CPU_TASKS_FROZEN)
638 #define CPU_UP_CANCELED_FROZEN (CPU_UP_CANCELED | CPU_TASKS_FROZEN)
639 #define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
640 #define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
641 #define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN)
642 #define CPU_DYING_FROZEN (CPU_DYING | CPU_TASKS_FROZEN)
644 /* Hibernation and suspend events */
645 #define PM_HIBERNATION_PREPARE 0x0001 /* Going to hibernate */
646 #define PM_POST_HIBERNATION 0x0002 /* Hibernation finished */
647 #define PM_SUSPEND_PREPARE 0x0003 /* Going to suspend the system */
648 #define PM_POST_SUSPEND 0x0004 /* Suspend finished */
649 #define PM_RESTORE_PREPARE 0x0005 /* Going to restore a saved image */
650 #define PM_POST_RESTORE 0x0006 /* Restore failed */
652 #define NOTIFY_DONE 0x0000 /* Don't care */
653 #define NOTIFY_OK 0x0001 /* Suits me */
654 #define NOTIFY_STOP_MASK 0x8000 /* Don't call further */
655 #define NOTIFY_BAD (NOTIFY_STOP_MASK|0x0002)
656 /* Bad/Veto action */
658 * Clean way to return from the notifier and stop further calls.
660 #define NOTIFY_STOP (NOTIFY_OK|NOTIFY_STOP_MASK)
666 #define BUG_ON(c) do { if (!(c)) abort(); } while (0)
669 * Initialization -- Must be called before calling any primitives.
672 static void smp_init(void)
676 spin_lock_init(&__thread_id_map_mutex
);
677 __thread_id_map
[0] = pthread_self();
678 for (i
= 1; i
< NR_THREADS
; i
++)
679 __thread_id_map
[i
] = __THREAD_ID_MAP_EMPTY
;
680 init_per_thread(smp_processor_id
, 0);
681 if (pthread_key_create(&thread_id_key
, NULL
) != 0) {
682 perror("pthread_key_create");
687 /* Taken from the Linux kernel source tree, so GPLv2-only!!! */
689 #ifndef _LINUX_LIST_H
690 #define _LINUX_LIST_H
692 #define LIST_POISON1 ((void *) 0x00100100)
693 #define LIST_POISON2 ((void *) 0x00200200)
695 #define container_of(ptr, type, member) ({ \
696 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
697 (type *)( (char *)__mptr - offsetof(type,member) );})
700 * Simple doubly linked list implementation.
702 * Some of the internal functions ("__xxx") are useful when
703 * manipulating whole lists rather than single entries, as
704 * sometimes we already know the next/prev entries and we can
705 * generate better code by using them directly rather than
706 * using the generic single-entry routines.
710 struct list_head
*next
, *prev
;
713 #define LIST_HEAD_INIT(name) { &(name), &(name) }
715 #define LIST_HEAD(name) \
716 struct list_head name = LIST_HEAD_INIT(name)
718 static inline void INIT_LIST_HEAD(struct list_head
*list
)
725 * Insert a new entry between two known consecutive entries.
727 * This is only for internal list manipulation where we know
728 * the prev/next entries already!
730 #ifndef CONFIG_DEBUG_LIST
731 static inline void __list_add(struct list_head
*new,
732 struct list_head
*prev
,
733 struct list_head
*next
)
741 extern void __list_add(struct list_head
*new,
742 struct list_head
*prev
,
743 struct list_head
*next
);
747 * list_add - add a new entry
748 * @new: new entry to be added
749 * @head: list head to add it after
751 * Insert a new entry after the specified head.
752 * This is good for implementing stacks.
754 static inline void list_add(struct list_head
*new, struct list_head
*head
)
756 __list_add(new, head
, head
->next
);
761 * list_add_tail - add a new entry
762 * @new: new entry to be added
763 * @head: list head to add it before
765 * Insert a new entry before the specified head.
766 * This is useful for implementing queues.
768 static inline void list_add_tail(struct list_head
*new, struct list_head
*head
)
770 __list_add(new, head
->prev
, head
);
774 * Delete a list entry by making the prev/next entries
775 * point to each other.
777 * This is only for internal list manipulation where we know
778 * the prev/next entries already!
780 static inline void __list_del(struct list_head
* prev
, struct list_head
* next
)
787 * list_del - deletes entry from list.
788 * @entry: the element to delete from the list.
789 * Note: list_empty() on entry does not return true after this, the entry is
790 * in an undefined state.
792 #ifndef CONFIG_DEBUG_LIST
793 static inline void list_del(struct list_head
*entry
)
795 __list_del(entry
->prev
, entry
->next
);
796 entry
->next
= LIST_POISON1
;
797 entry
->prev
= LIST_POISON2
;
800 extern void list_del(struct list_head
*entry
);
804 * list_replace - replace old entry by new one
805 * @old : the element to be replaced
806 * @new : the new element to insert
808 * If @old was empty, it will be overwritten.
810 static inline void list_replace(struct list_head
*old
,
811 struct list_head
*new)
813 new->next
= old
->next
;
814 new->next
->prev
= new;
815 new->prev
= old
->prev
;
816 new->prev
->next
= new;
819 static inline void list_replace_init(struct list_head
*old
,
820 struct list_head
*new)
822 list_replace(old
, new);
827 * list_del_init - deletes entry from list and reinitialize it.
828 * @entry: the element to delete from the list.
830 static inline void list_del_init(struct list_head
*entry
)
832 __list_del(entry
->prev
, entry
->next
);
833 INIT_LIST_HEAD(entry
);
837 * list_move - delete from one list and add as another's head
838 * @list: the entry to move
839 * @head: the head that will precede our entry
841 static inline void list_move(struct list_head
*list
, struct list_head
*head
)
843 __list_del(list
->prev
, list
->next
);
844 list_add(list
, head
);
848 * list_move_tail - delete from one list and add as another's tail
849 * @list: the entry to move
850 * @head: the head that will follow our entry
852 static inline void list_move_tail(struct list_head
*list
,
853 struct list_head
*head
)
855 __list_del(list
->prev
, list
->next
);
856 list_add_tail(list
, head
);
860 * list_is_last - tests whether @list is the last entry in list @head
861 * @list: the entry to test
862 * @head: the head of the list
864 static inline int list_is_last(const struct list_head
*list
,
865 const struct list_head
*head
)
867 return list
->next
== head
;
871 * list_empty - tests whether a list is empty
872 * @head: the list to test.
874 static inline int list_empty(const struct list_head
*head
)
876 return head
->next
== head
;
880 * list_empty_careful - tests whether a list is empty and not being modified
881 * @head: the list to test
884 * tests whether a list is empty _and_ checks that no other CPU might be
885 * in the process of modifying either member (next or prev)
887 * NOTE: using list_empty_careful() without synchronization
888 * can only be safe if the only activity that can happen
889 * to the list entry is list_del_init(). Eg. it cannot be used
890 * if another CPU could re-list_add() it.
892 static inline int list_empty_careful(const struct list_head
*head
)
894 struct list_head
*next
= head
->next
;
895 return (next
== head
) && (next
== head
->prev
);
899 * list_is_singular - tests whether a list has just one entry.
900 * @head: the list to test.
902 static inline int list_is_singular(const struct list_head
*head
)
904 return !list_empty(head
) && (head
->next
== head
->prev
);
907 static inline void __list_cut_position(struct list_head
*list
,
908 struct list_head
*head
, struct list_head
*entry
)
910 struct list_head
*new_first
= entry
->next
;
911 list
->next
= head
->next
;
912 list
->next
->prev
= list
;
915 head
->next
= new_first
;
916 new_first
->prev
= head
;
920 * list_cut_position - cut a list into two
921 * @list: a new list to add all removed entries
922 * @head: a list with entries
923 * @entry: an entry within head, could be the head itself
924 * and if so we won't cut the list
926 * This helper moves the initial part of @head, up to and
927 * including @entry, from @head to @list. You should
928 * pass on @entry an element you know is on @head. @list
929 * should be an empty list or a list you do not care about
933 static inline void list_cut_position(struct list_head
*list
,
934 struct list_head
*head
, struct list_head
*entry
)
936 if (list_empty(head
))
938 if (list_is_singular(head
) &&
939 (head
->next
!= entry
&& head
!= entry
))
942 INIT_LIST_HEAD(list
);
944 __list_cut_position(list
, head
, entry
);
947 static inline void __list_splice(const struct list_head
*list
,
948 struct list_head
*prev
,
949 struct list_head
*next
)
951 struct list_head
*first
= list
->next
;
952 struct list_head
*last
= list
->prev
;
962 * list_splice - join two lists, this is designed for stacks
963 * @list: the new list to add.
964 * @head: the place to add it in the first list.
966 static inline void list_splice(const struct list_head
*list
,
967 struct list_head
*head
)
969 if (!list_empty(list
))
970 __list_splice(list
, head
, head
->next
);
974 * list_splice_tail - join two lists, each list being a queue
975 * @list: the new list to add.
976 * @head: the place to add it in the first list.
978 static inline void list_splice_tail(struct list_head
*list
,
979 struct list_head
*head
)
981 if (!list_empty(list
))
982 __list_splice(list
, head
->prev
, head
);
986 * list_splice_init - join two lists and reinitialise the emptied list.
987 * @list: the new list to add.
988 * @head: the place to add it in the first list.
990 * The list at @list is reinitialised
992 static inline void list_splice_init(struct list_head
*list
,
993 struct list_head
*head
)
995 if (!list_empty(list
)) {
996 __list_splice(list
, head
, head
->next
);
997 INIT_LIST_HEAD(list
);
1002 * list_splice_tail_init - join two lists and reinitialise the emptied list
1003 * @list: the new list to add.
1004 * @head: the place to add it in the first list.
1006 * Each of the lists is a queue.
1007 * The list at @list is reinitialised
1009 static inline void list_splice_tail_init(struct list_head
*list
,
1010 struct list_head
*head
)
1012 if (!list_empty(list
)) {
1013 __list_splice(list
, head
->prev
, head
);
1014 INIT_LIST_HEAD(list
);
1019 * list_entry - get the struct for this entry
1020 * @ptr: the &struct list_head pointer.
1021 * @type: the type of the struct this is embedded in.
1022 * @member: the name of the list_struct within the struct.
1024 #define list_entry(ptr, type, member) \
1025 container_of(ptr, type, member)
1028 * list_first_entry - get the first element from a list
1029 * @ptr: the list head to take the element from.
1030 * @type: the type of the struct this is embedded in.
1031 * @member: the name of the list_struct within the struct.
1033 * Note, that list is expected to be not empty.
1035 #define list_first_entry(ptr, type, member) \
1036 list_entry((ptr)->next, type, member)
1039 * list_for_each - iterate over a list
1040 * @pos: the &struct list_head to use as a loop cursor.
1041 * @head: the head for your list.
1043 #define list_for_each(pos, head) \
1044 for (pos = (head)->next; prefetch(pos->next), pos != (head); \
1048 * __list_for_each - iterate over a list
1049 * @pos: the &struct list_head to use as a loop cursor.
1050 * @head: the head for your list.
1052 * This variant differs from list_for_each() in that it's the
1053 * simplest possible list iteration code, no prefetching is done.
1054 * Use this for code that knows the list to be very short (empty
1055 * or 1 entry) most of the time.
1057 #define __list_for_each(pos, head) \
1058 for (pos = (head)->next; pos != (head); pos = pos->next)
1061 * list_for_each_prev - iterate over a list backwards
1062 * @pos: the &struct list_head to use as a loop cursor.
1063 * @head: the head for your list.
1065 #define list_for_each_prev(pos, head) \
1066 for (pos = (head)->prev; prefetch(pos->prev), pos != (head); \
1070 * list_for_each_safe - iterate over a list safe against removal of list entry
1071 * @pos: the &struct list_head to use as a loop cursor.
1072 * @n: another &struct list_head to use as temporary storage
1073 * @head: the head for your list.
1075 #define list_for_each_safe(pos, n, head) \
1076 for (pos = (head)->next, n = pos->next; pos != (head); \
1077 pos = n, n = pos->next)
1080 * list_for_each_prev_safe - iterate over a list backwards safe against removal of list entry
1081 * @pos: the &struct list_head to use as a loop cursor.
1082 * @n: another &struct list_head to use as temporary storage
1083 * @head: the head for your list.
1085 #define list_for_each_prev_safe(pos, n, head) \
1086 for (pos = (head)->prev, n = pos->prev; \
1087 prefetch(pos->prev), pos != (head); \
1088 pos = n, n = pos->prev)
1091 * list_for_each_entry - iterate over list of given type
1092 * @pos: the type * to use as a loop cursor.
1093 * @head: the head for your list.
1094 * @member: the name of the list_struct within the struct.
1096 #define list_for_each_entry(pos, head, member) \
1097 for (pos = list_entry((head)->next, typeof(*pos), member); \
1098 prefetch(pos->member.next), &pos->member != (head); \
1099 pos = list_entry(pos->member.next, typeof(*pos), member))
1102 * list_for_each_entry_reverse - iterate backwards over list of given type.
1103 * @pos: the type * to use as a loop cursor.
1104 * @head: the head for your list.
1105 * @member: the name of the list_struct within the struct.
1107 #define list_for_each_entry_reverse(pos, head, member) \
1108 for (pos = list_entry((head)->prev, typeof(*pos), member); \
1109 prefetch(pos->member.prev), &pos->member != (head); \
1110 pos = list_entry(pos->member.prev, typeof(*pos), member))
1113 * list_prepare_entry - prepare a pos entry for use in list_for_each_entry_continue()
1114 * @pos: the type * to use as a start point
1115 * @head: the head of the list
1116 * @member: the name of the list_struct within the struct.
1118 * Prepares a pos entry for use as a start point in list_for_each_entry_continue().
1120 #define list_prepare_entry(pos, head, member) \
1121 ((pos) ? : list_entry(head, typeof(*pos), member))
1124 * list_for_each_entry_continue - continue iteration over list of given type
1125 * @pos: the type * to use as a loop cursor.
1126 * @head: the head for your list.
1127 * @member: the name of the list_struct within the struct.
1129 * Continue to iterate over list of given type, continuing after
1130 * the current position.
1132 #define list_for_each_entry_continue(pos, head, member) \
1133 for (pos = list_entry(pos->member.next, typeof(*pos), member); \
1134 prefetch(pos->member.next), &pos->member != (head); \
1135 pos = list_entry(pos->member.next, typeof(*pos), member))
1138 * list_for_each_entry_continue_reverse - iterate backwards from the given point
1139 * @pos: the type * to use as a loop cursor.
1140 * @head: the head for your list.
1141 * @member: the name of the list_struct within the struct.
1143 * Start to iterate over list of given type backwards, continuing after
1144 * the current position.
1146 #define list_for_each_entry_continue_reverse(pos, head, member) \
1147 for (pos = list_entry(pos->member.prev, typeof(*pos), member); \
1148 prefetch(pos->member.prev), &pos->member != (head); \
1149 pos = list_entry(pos->member.prev, typeof(*pos), member))
1152 * list_for_each_entry_from - iterate over list of given type from the current point
1153 * @pos: the type * to use as a loop cursor.
1154 * @head: the head for your list.
1155 * @member: the name of the list_struct within the struct.
1157 * Iterate over list of given type, continuing from current position.
1159 #define list_for_each_entry_from(pos, head, member) \
1160 for (; prefetch(pos->member.next), &pos->member != (head); \
1161 pos = list_entry(pos->member.next, typeof(*pos), member))
1164 * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
1165 * @pos: the type * to use as a loop cursor.
1166 * @n: another type * to use as temporary storage
1167 * @head: the head for your list.
1168 * @member: the name of the list_struct within the struct.
1170 #define list_for_each_entry_safe(pos, n, head, member) \
1171 for (pos = list_entry((head)->next, typeof(*pos), member), \
1172 n = list_entry(pos->member.next, typeof(*pos), member); \
1173 &pos->member != (head); \
1174 pos = n, n = list_entry(n->member.next, typeof(*n), member))
1177 * list_for_each_entry_safe_continue
1178 * @pos: the type * to use as a loop cursor.
1179 * @n: another type * to use as temporary storage
1180 * @head: the head for your list.
1181 * @member: the name of the list_struct within the struct.
1183 * Iterate over list of given type, continuing after current point,
1184 * safe against removal of list entry.
1186 #define list_for_each_entry_safe_continue(pos, n, head, member) \
1187 for (pos = list_entry(pos->member.next, typeof(*pos), member), \
1188 n = list_entry(pos->member.next, typeof(*pos), member); \
1189 &pos->member != (head); \
1190 pos = n, n = list_entry(n->member.next, typeof(*n), member))
1193 * list_for_each_entry_safe_from
1194 * @pos: the type * to use as a loop cursor.
1195 * @n: another type * to use as temporary storage
1196 * @head: the head for your list.
1197 * @member: the name of the list_struct within the struct.
1199 * Iterate over list of given type from current point, safe against
1200 * removal of list entry.
1202 #define list_for_each_entry_safe_from(pos, n, head, member) \
1203 for (n = list_entry(pos->member.next, typeof(*pos), member); \
1204 &pos->member != (head); \
1205 pos = n, n = list_entry(n->member.next, typeof(*n), member))
1208 * list_for_each_entry_safe_reverse
1209 * @pos: the type * to use as a loop cursor.
1210 * @n: another type * to use as temporary storage
1211 * @head: the head for your list.
1212 * @member: the name of the list_struct within the struct.
1214 * Iterate backwards over list of given type, safe against removal
1217 #define list_for_each_entry_safe_reverse(pos, n, head, member) \
1218 for (pos = list_entry((head)->prev, typeof(*pos), member), \
1219 n = list_entry(pos->member.prev, typeof(*pos), member); \
1220 &pos->member != (head); \
1221 pos = n, n = list_entry(n->member.prev, typeof(*n), member))
1224 * Double linked lists with a single pointer list head.
1225 * Mostly useful for hash tables where the two pointer list head is
1227 * You lose the ability to access the tail in O(1).
1231 struct hlist_node
*first
;
1235 struct hlist_node
*next
, **pprev
;
1238 #define HLIST_HEAD_INIT { .first = NULL }
1239 #define HLIST_HEAD(name) struct hlist_head name = { .first = NULL }
1240 #define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)
1241 static inline void INIT_HLIST_NODE(struct hlist_node
*h
)
1247 static inline int hlist_unhashed(const struct hlist_node
*h
)
1252 static inline int hlist_empty(const struct hlist_head
*h
)
1257 static inline void __hlist_del(struct hlist_node
*n
)
1259 struct hlist_node
*next
= n
->next
;
1260 struct hlist_node
**pprev
= n
->pprev
;
1263 next
->pprev
= pprev
;
1266 static inline void hlist_del(struct hlist_node
*n
)
1269 n
->next
= LIST_POISON1
;
1270 n
->pprev
= LIST_POISON2
;
1273 static inline void hlist_del_init(struct hlist_node
*n
)
1275 if (!hlist_unhashed(n
)) {
1281 static inline void hlist_add_head(struct hlist_node
*n
, struct hlist_head
*h
)
1283 struct hlist_node
*first
= h
->first
;
1286 first
->pprev
= &n
->next
;
1288 n
->pprev
= &h
->first
;
1291 /* next must be != NULL */
1292 static inline void hlist_add_before(struct hlist_node
*n
,
1293 struct hlist_node
*next
)
1295 n
->pprev
= next
->pprev
;
1297 next
->pprev
= &n
->next
;
1301 static inline void hlist_add_after(struct hlist_node
*n
,
1302 struct hlist_node
*next
)
1304 next
->next
= n
->next
;
1306 next
->pprev
= &n
->next
;
1309 next
->next
->pprev
= &next
->next
;
1313 * Move a list from one list head to another. Fixup the pprev
1314 * reference of the first entry if it exists.
1316 static inline void hlist_move_list(struct hlist_head
*old
,
1317 struct hlist_head
*new)
1319 new->first
= old
->first
;
1321 new->first
->pprev
= &new->first
;
1325 #define hlist_entry(ptr, type, member) container_of(ptr,type,member)
1327 #define hlist_for_each(pos, head) \
1328 for (pos = (head)->first; pos && ({ prefetch(pos->next); 1; }); \
1331 #define hlist_for_each_safe(pos, n, head) \
1332 for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \
1336 * hlist_for_each_entry - iterate over list of given type
1337 * @tpos: the type * to use as a loop cursor.
1338 * @pos: the &struct hlist_node to use as a loop cursor.
1339 * @head: the head for your list.
1340 * @member: the name of the hlist_node within the struct.
1342 #define hlist_for_each_entry(tpos, pos, head, member) \
1343 for (pos = (head)->first; \
1344 pos && ({ prefetch(pos->next); 1;}) && \
1345 ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
1349 * hlist_for_each_entry_continue - iterate over a hlist continuing after current point
1350 * @tpos: the type * to use as a loop cursor.
1351 * @pos: the &struct hlist_node to use as a loop cursor.
1352 * @member: the name of the hlist_node within the struct.
1354 #define hlist_for_each_entry_continue(tpos, pos, member) \
1355 for (pos = (pos)->next; \
1356 pos && ({ prefetch(pos->next); 1;}) && \
1357 ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
1361 * hlist_for_each_entry_from - iterate over a hlist continuing from current point
1362 * @tpos: the type * to use as a loop cursor.
1363 * @pos: the &struct hlist_node to use as a loop cursor.
1364 * @member: the name of the hlist_node within the struct.
1366 #define hlist_for_each_entry_from(tpos, pos, member) \
1367 for (; pos && ({ prefetch(pos->next); 1;}) && \
1368 ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
1372 * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry
1373 * @tpos: the type * to use as a loop cursor.
1374 * @pos: the &struct hlist_node to use as a loop cursor.
1375 * @n: another &struct hlist_node to use as temporary storage
1376 * @head: the head for your list.
1377 * @member: the name of the hlist_node within the struct.
1379 #define hlist_for_each_entry_safe(tpos, pos, n, head, member) \
1380 for (pos = (head)->first; \
1381 pos && ({ n = pos->next; 1; }) && \
1382 ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \