forked from rubenslte/android_kernel_samsung_msm8226
Francescodario Cuzzocrea
85baa390bf
* Samsung Package Version: G800HXXU1CRJ1
* CAF Tag: LA.BF.1.1.3-00110-8x26.0
57 lines
1.8 KiB
C
57 lines
1.8 KiB
C
/* rwsem-spinlock.h: fallback C implementation
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*
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* Copyright (c) 2001 David Howells (dhowells@redhat.com).
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* - Derived partially from ideas by Andrea Arcangeli <andrea@suse.de>
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* - Derived also from comments by Linus
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*/
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#ifndef _LINUX_RWSEM_SPINLOCK_H
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#define _LINUX_RWSEM_SPINLOCK_H
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#ifndef _LINUX_RWSEM_H
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#error "please don't include linux/rwsem-spinlock.h directly, use linux/rwsem.h instead"
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#endif
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#ifdef __KERNEL__
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/*
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* the rw-semaphore definition
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* - if activity is 0 then there are no active readers or writers
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* - if activity is +ve then that is the number of active readers
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* - if activity is -1 then there is one active writer
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* - if wait_list is not empty, then there are processes waiting for the semaphore
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*/
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struct rw_semaphore {
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__s32 activity;
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raw_spinlock_t wait_lock;
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struct list_head wait_list;
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#ifdef CONFIG_DEBUG_LOCK_ALLOC
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struct lockdep_map dep_map;
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#endif
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#ifdef CONFIG_SEC_FORKHANG_DEBUG
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/* FIX - ME This is just for the temporery debug never add this to final version
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* If activity == -1 owner is who posses the lock
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* If activity == 0 owner is who lastly released the lock
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*/
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struct task_struct *owner;
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pid_t owner_pid;
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char owner_comm[16];
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void *caller;
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#endif
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};
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#define RWSEM_UNLOCKED_VALUE 0x00000000
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extern void __down_read(struct rw_semaphore *sem);
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extern int __down_read_trylock(struct rw_semaphore *sem);
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extern void __down_write(struct rw_semaphore *sem);
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extern void __down_write_nested(struct rw_semaphore *sem, int subclass);
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extern int __down_write_trylock(struct rw_semaphore *sem);
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extern void __up_read(struct rw_semaphore *sem);
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extern void __up_write(struct rw_semaphore *sem);
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extern void __downgrade_write(struct rw_semaphore *sem);
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extern int rwsem_is_locked(struct rw_semaphore *sem);
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#endif /* __KERNEL__ */
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#endif /* _LINUX_RWSEM_SPINLOCK_H */
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