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/* fdso.h - file descriptor attached shared objects
*
* (c) 2007 B. Brandenburg, LITMUS^RT project
*/
#ifndef _LINUX_FDSO_H_
#define _LINUX_FDSO_H_
#include <linux/list.h>
#include <asm/atomic.h>
#include <linux/fs.h>
#define MAX_OBJECT_DESCRIPTORS 32
typedef enum {
MIN_OBJ_TYPE = 0,
FMLP_SEM = 0,
SRP_SEM = 1,
MAX_OBJ_TYPE = 1
} obj_type_t;
struct inode_obj_id {
struct list_head list;
atomic_t count;
struct inode* inode;
obj_type_t type;
void* obj;
unsigned int id;
};
struct od_table_entry {
unsigned int used;
struct inode_obj_id* obj;
void* extra;
};
struct fdso_ops {
void* (*create) (void);
void (*destroy)(void*);
int (*open) (struct od_table_entry*, void* __user);
int (*close) (struct od_table_entry*);
};
/* translate a userspace supplied od into the raw table entry
* returns NULL if od is invalid
*/
struct od_table_entry* __od_lookup(int od);
/* translate a userspace supplied od into the associated object
* returns NULL if od is invalid
*/
static inline void* od_lookup(int od, obj_type_t type)
{
struct od_table_entry* e = __od_lookup(od);
return e && e->obj->type == type ? e->obj->obj : NULL;
}
#define lookup_fmlp_sem(od)((struct pi_semaphore*) od_lookup(od, FMLP_SEM))
#define lookup_srp_sem(od) ((struct srp_semaphore*) od_lookup(od, SRP_SEM))
#define lookup_ics(od) ((struct ics*) od_lookup(od, ICS_ID))
#endif
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