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-rw-r--r--net/tipc/ref.c91
-rw-r--r--net/tipc/ref.h89
2 files changed, 91 insertions, 89 deletions
diff --git a/net/tipc/ref.c b/net/tipc/ref.c
index c38744c96ed1..d0b240e86ccd 100644
--- a/net/tipc/ref.c
+++ b/net/tipc/ref.c
@@ -2,7 +2,7 @@
2 * net/tipc/ref.c: TIPC object registry code 2 * net/tipc/ref.c: TIPC object registry code
3 * 3 *
4 * Copyright (c) 1991-2006, Ericsson AB 4 * Copyright (c) 1991-2006, Ericsson AB
5 * Copyright (c) 2004-2005, Wind River Systems 5 * Copyright (c) 2004-2007, Wind River Systems
6 * All rights reserved. 6 * All rights reserved.
7 * 7 *
8 * Redistribution and use in source and binary forms, with or without 8 * Redistribution and use in source and binary forms, with or without
@@ -46,6 +46,37 @@
46#include "node.h" 46#include "node.h"
47#include "bcast.h" 47#include "bcast.h"
48 48
49/**
50 * struct reference - TIPC object reference entry
51 * @object: pointer to object associated with reference entry
52 * @lock: spinlock controlling access to object
53 * @data: reference value associated with object (or link to next unused entry)
54 */
55
56struct reference {
57 void *object;
58 spinlock_t lock;
59 union {
60 u32 next_plus_upper;
61 u32 reference;
62 } data;
63};
64
65/**
66 * struct tipc_ref_table - table of TIPC object reference entries
67 * @entries: pointer to array of reference entries
68 * @index_mask: bitmask for array index portion of reference values
69 * @first_free: array index of first unused object reference entry
70 * @last_free: array index of last unused object reference entry
71 */
72
73struct ref_table {
74 struct reference *entries;
75 u32 index_mask;
76 u32 first_free;
77 u32 last_free;
78};
79
49/* 80/*
50 * Object reference table consists of 2**N entries. 81 * Object reference table consists of 2**N entries.
51 * 82 *
@@ -61,7 +92,7 @@
61 * because entry 0's reference field has the form XXXX|1--1. 92 * because entry 0's reference field has the form XXXX|1--1.
62 */ 93 */
63 94
64struct ref_table tipc_ref_table = { NULL }; 95static struct ref_table tipc_ref_table = { NULL };
65 96
66static DEFINE_RWLOCK(ref_table_lock); 97static DEFINE_RWLOCK(ref_table_lock);
67 98
@@ -198,8 +229,8 @@ void tipc_ref_discard(u32 ref)
198 tipc_ref_table.first_free = index; 229 tipc_ref_table.first_free = index;
199 else 230 else
200 /* next_plus_upper is always XXXX|0--0 for last free entry */ 231 /* next_plus_upper is always XXXX|0--0 for last free entry */
201 tipc_ref_table.entries[tipc_ref_table.last_free].data.next_plus_upper 232 tipc_ref_table.entries[tipc_ref_table.last_free].
202 |= index; 233 data.next_plus_upper |= index;
203 tipc_ref_table.last_free = index; 234 tipc_ref_table.last_free = index;
204 235
205 /* increment upper bits of entry to invalidate subsequent references */ 236 /* increment upper bits of entry to invalidate subsequent references */
@@ -208,3 +239,55 @@ exit:
208 write_unlock_bh(&ref_table_lock); 239 write_unlock_bh(&ref_table_lock);
209} 240}
210 241
242/**
243 * tipc_ref_lock - lock referenced object and return pointer to it
244 */
245
246void *tipc_ref_lock(u32 ref)
247{
248 if (likely(tipc_ref_table.entries)) {
249 struct reference *r;
250
251 r = &tipc_ref_table.entries[ref & tipc_ref_table.index_mask];
252 spin_lock_bh(&r->lock);
253 if (likely(r->data.reference == ref))
254 return r->object;
255 spin_unlock_bh(&r->lock);
256 }
257 return NULL;
258}
259
260/**
261 * tipc_ref_unlock - unlock referenced object
262 */
263
264void tipc_ref_unlock(u32 ref)
265{
266 if (likely(tipc_ref_table.entries)) {
267 struct reference *r;
268
269 r = &tipc_ref_table.entries[ref & tipc_ref_table.index_mask];
270 if (likely(r->data.reference == ref))
271 spin_unlock_bh(&r->lock);
272 else
273 err("tipc_ref_unlock() invoked using "
274 "obsolete reference\n");
275 }
276}
277
278/**
279 * tipc_ref_deref - return pointer referenced object (without locking it)
280 */
281
282void *tipc_ref_deref(u32 ref)
283{
284 if (likely(tipc_ref_table.entries)) {
285 struct reference *r;
286
287 r = &tipc_ref_table.entries[ref & tipc_ref_table.index_mask];
288 if (likely(r->data.reference == ref))
289 return r->object;
290 }
291 return NULL;
292}
293
diff --git a/net/tipc/ref.h b/net/tipc/ref.h
index 38f3a7f4a78d..7e3798ea93b9 100644
--- a/net/tipc/ref.h
+++ b/net/tipc/ref.h
@@ -2,7 +2,7 @@
2 * net/tipc/ref.h: Include file for TIPC object registry code 2 * net/tipc/ref.h: Include file for TIPC object registry code
3 * 3 *
4 * Copyright (c) 1991-2006, Ericsson AB 4 * Copyright (c) 1991-2006, Ericsson AB
5 * Copyright (c) 2005, Wind River Systems 5 * Copyright (c) 2005-2006, Wind River Systems
6 * All rights reserved. 6 * All rights reserved.
7 * 7 *
8 * Redistribution and use in source and binary forms, with or without 8 * Redistribution and use in source and binary forms, with or without
@@ -37,95 +37,14 @@
37#ifndef _TIPC_REF_H 37#ifndef _TIPC_REF_H
38#define _TIPC_REF_H 38#define _TIPC_REF_H
39 39
40/**
41 * struct reference - TIPC object reference entry
42 * @object: pointer to object associated with reference entry
43 * @lock: spinlock controlling access to object
44 * @data: reference value associated with object (or link to next unused entry)
45 */
46
47struct reference {
48 void *object;
49 spinlock_t lock;
50 union {
51 u32 next_plus_upper;
52 u32 reference;
53 } data;
54};
55
56/**
57 * struct tipc_ref_table - table of TIPC object reference entries
58 * @entries: pointer to array of reference entries
59 * @index_mask: bitmask for array index portion of reference values
60 * @first_free: array index of first unused object reference entry
61 * @last_free: array index of last unused object reference entry
62 */
63
64struct ref_table {
65 struct reference *entries;
66 u32 index_mask;
67 u32 first_free;
68 u32 last_free;
69};
70
71extern struct ref_table tipc_ref_table;
72
73int tipc_ref_table_init(u32 requested_size, u32 start); 40int tipc_ref_table_init(u32 requested_size, u32 start);
74void tipc_ref_table_stop(void); 41void tipc_ref_table_stop(void);
75 42
76u32 tipc_ref_acquire(void *object, spinlock_t **lock); 43u32 tipc_ref_acquire(void *object, spinlock_t **lock);
77void tipc_ref_discard(u32 ref); 44void tipc_ref_discard(u32 ref);
78 45
79 46void *tipc_ref_lock(u32 ref);
80/** 47void tipc_ref_unlock(u32 ref);
81 * tipc_ref_lock - lock referenced object and return pointer to it 48void *tipc_ref_deref(u32 ref);
82 */
83
84static inline void *tipc_ref_lock(u32 ref)
85{
86 if (likely(tipc_ref_table.entries)) {
87 struct reference *r =
88 &tipc_ref_table.entries[ref & tipc_ref_table.index_mask];
89
90 spin_lock_bh(&r->lock);
91 if (likely(r->data.reference == ref))
92 return r->object;
93 spin_unlock_bh(&r->lock);
94 }
95 return NULL;
96}
97
98/**
99 * tipc_ref_unlock - unlock referenced object
100 */
101
102static inline void tipc_ref_unlock(u32 ref)
103{
104 if (likely(tipc_ref_table.entries)) {
105 struct reference *r =
106 &tipc_ref_table.entries[ref & tipc_ref_table.index_mask];
107
108 if (likely(r->data.reference == ref))
109 spin_unlock_bh(&r->lock);
110 else
111 err("tipc_ref_unlock() invoked using obsolete reference\n");
112 }
113}
114
115/**
116 * tipc_ref_deref - return pointer referenced object (without locking it)
117 */
118
119static inline void *tipc_ref_deref(u32 ref)
120{
121 if (likely(tipc_ref_table.entries)) {
122 struct reference *r =
123 &tipc_ref_table.entries[ref & tipc_ref_table.index_mask];
124
125 if (likely(r->data.reference == ref))
126 return r->object;
127 }
128 return NULL;
129}
130 49
131#endif 50#endif