include/sys/rwlock.h

   1 #ifndef _SPL_RWLOCK_H
   2 #define _SPL_RWLOCK_H
   3
   4 #include <linux/module.h>
   5 #include <linux/slab.h>
   6 #include <linux/rwsem.h>
   7 #include <asm/current.h>
   8 #include <sys/types.h>
   9 #include <sys/kmem.h>
  10
  11 #ifdef __cplusplus
  12 extern "C" {
  13 #endif
  14
  15 typedef enum {
  16         RW_DRIVER  = 2,         /* driver (DDI) rwlock */
  17         RW_DEFAULT = 4          /* kernel default rwlock */
  18 } krw_type_t;
  19
  20 typedef enum {
  21         RW_WRITER,
  22         RW_READER
  23 } krw_t;
  24
  25
  26 #define RW_MAGIC  0x3423645a
  27 #define RW_POISON 0xa6
  28
  29 typedef struct {
  30         int32_t rw_magic;
  31         int32_t rw_name_size;
  32         char *rw_name;
  33         struct rw_semaphore rw_sem;
  34         struct task_struct *rw_owner;   /* holder of the write lock */
  35 } krwlock_t;
  36
  37 extern void __rw_init(krwlock_t *rwlp, char *name, krw_type_t type, void *arg);
  38 extern void __rw_destroy(krwlock_t *rwlp);
  39 extern int __rw_tryenter(krwlock_t *rwlp, krw_t rw);
  40 extern void __rw_enter(krwlock_t *rwlp, krw_t rw);
  41 extern void __rw_exit(krwlock_t *rwlp);
  42 extern void __rw_downgrade(krwlock_t *rwlp);
  43 extern int __rw_tryupgrade(krwlock_t *rwlp);
  44 extern kthread_t *__rw_owner(krwlock_t *rwlp);
  45 extern int __rw_read_held(krwlock_t *rwlp);
  46 extern int __rw_write_held(krwlock_t *rwlp);
  47 extern int __rw_lock_held(krwlock_t *rwlp);
  48
  49 #define rw_init(rwlp, name, type, arg)                                  \
  50 ({                                                                      \
  51         if ((name) == NULL)                                             \
  52                 __rw_init(rwlp, #rwlp, type, arg);                      \
  53         else                                                            \
  54                 __rw_init(rwlp, name, type, arg);                       \
  55 })
  56 #define rw_destroy(rwlp)        __rw_destroy(rwlp)
  57 #define rw_tryenter(rwlp, rw)   __rw_tryenter(rwlp, rw)
  58 #define rw_enter(rwlp, rw)      __rw_enter(rwlp, rw)
  59 #define rw_exit(rwlp)           __rw_exit(rwlp)
  60 #define rw_downgrade(rwlp)      __rw_downgrade(rwlp)
  61 #define rw_tryupgrade(rwlp)     __rw_tryupgrade(rwlp)
  62 #define rw_owner(rwlp)          __rw_owner(rwlp)
  63 #define RW_READ_HELD(rwlp)      __rw_read_held(rwlp)
  64 #define RW_WRITE_HELD(rwlp)     __rw_write_held(rwlp)
  65 #define RW_LOCK_HELD(rwlp)      __rw_lock_held(rwlp)
  66
  67 #ifdef __cplusplus
  68 }
  69 #endif
  70
  71 #endif /* _SPL_RWLOCK_H */