xref: /aosp_15_r20/external/kernel-headers/original/uapi/asm-generic/sembuf.h (revision f80ad8b4341604f5951dab671d41019a6d7087ce)
1*f80ad8b4SAndroid Build Coastguard Worker /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2*f80ad8b4SAndroid Build Coastguard Worker #ifndef __ASM_GENERIC_SEMBUF_H
3*f80ad8b4SAndroid Build Coastguard Worker #define __ASM_GENERIC_SEMBUF_H
4*f80ad8b4SAndroid Build Coastguard Worker 
5*f80ad8b4SAndroid Build Coastguard Worker #include <asm/bitsperlong.h>
6*f80ad8b4SAndroid Build Coastguard Worker #include <asm/ipcbuf.h>
7*f80ad8b4SAndroid Build Coastguard Worker 
8*f80ad8b4SAndroid Build Coastguard Worker /*
9*f80ad8b4SAndroid Build Coastguard Worker  * The semid64_ds structure for most architectures (though it came from x86_32
10*f80ad8b4SAndroid Build Coastguard Worker  * originally). Note extra padding because this structure is passed back and
11*f80ad8b4SAndroid Build Coastguard Worker  * forth between kernel and user space.
12*f80ad8b4SAndroid Build Coastguard Worker  *
13*f80ad8b4SAndroid Build Coastguard Worker  * semid64_ds was originally meant to be architecture specific, but
14*f80ad8b4SAndroid Build Coastguard Worker  * everyone just ended up making identical copies without specific
15*f80ad8b4SAndroid Build Coastguard Worker  * optimizations, so we may just as well all use the same one.
16*f80ad8b4SAndroid Build Coastguard Worker  *
17*f80ad8b4SAndroid Build Coastguard Worker  * 64 bit architectures use a 64-bit long time field here, while
18*f80ad8b4SAndroid Build Coastguard Worker  * 32 bit architectures have a pair of unsigned long values.
19*f80ad8b4SAndroid Build Coastguard Worker  *
20*f80ad8b4SAndroid Build Coastguard Worker  * On big-endian systems, the padding is in the wrong place for
21*f80ad8b4SAndroid Build Coastguard Worker  * historic reasons, so user space has to reconstruct a time_t
22*f80ad8b4SAndroid Build Coastguard Worker  * value using
23*f80ad8b4SAndroid Build Coastguard Worker  *
24*f80ad8b4SAndroid Build Coastguard Worker  * user_semid_ds.sem_otime = kernel_semid64_ds.sem_otime +
25*f80ad8b4SAndroid Build Coastguard Worker  *		((long long)kernel_semid64_ds.sem_otime_high << 32)
26*f80ad8b4SAndroid Build Coastguard Worker  *
27*f80ad8b4SAndroid Build Coastguard Worker  * Pad space is left for 2 miscellaneous 32-bit values
28*f80ad8b4SAndroid Build Coastguard Worker  */
29*f80ad8b4SAndroid Build Coastguard Worker struct semid64_ds {
30*f80ad8b4SAndroid Build Coastguard Worker 	struct ipc64_perm sem_perm;	/* permissions .. see ipc.h */
31*f80ad8b4SAndroid Build Coastguard Worker #if __BITS_PER_LONG == 64
32*f80ad8b4SAndroid Build Coastguard Worker 	long		sem_otime;	/* last semop time */
33*f80ad8b4SAndroid Build Coastguard Worker 	long		sem_ctime;	/* last change time */
34*f80ad8b4SAndroid Build Coastguard Worker #else
35*f80ad8b4SAndroid Build Coastguard Worker 	unsigned long	sem_otime;	/* last semop time */
36*f80ad8b4SAndroid Build Coastguard Worker 	unsigned long	sem_otime_high;
37*f80ad8b4SAndroid Build Coastguard Worker 	unsigned long	sem_ctime;	/* last change time */
38*f80ad8b4SAndroid Build Coastguard Worker 	unsigned long	sem_ctime_high;
39*f80ad8b4SAndroid Build Coastguard Worker #endif
40*f80ad8b4SAndroid Build Coastguard Worker 	unsigned long	sem_nsems;	/* no. of semaphores in array */
41*f80ad8b4SAndroid Build Coastguard Worker 	unsigned long	__unused3;
42*f80ad8b4SAndroid Build Coastguard Worker 	unsigned long	__unused4;
43*f80ad8b4SAndroid Build Coastguard Worker };
44*f80ad8b4SAndroid Build Coastguard Worker 
45*f80ad8b4SAndroid Build Coastguard Worker #endif /* __ASM_GENERIC_SEMBUF_H */
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