hc
2024-05-10 37f49e37ab4cb5d0bc4c60eb5c6d4dd57db767bb
kernel/include/linux/rcu_sync.h
....@@ -1,19 +1,6 @@
1
+/* SPDX-License-Identifier: GPL-2.0+ */
12 /*
23 * RCU-based infrastructure for lightweight reader-writer locking
3
- *
4
- * This program is free software; you can redistribute it and/or modify
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- * it under the terms of the GNU General Public License as published by
6
- * the Free Software Foundation; either version 2 of the License, or
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- * (at your option) any later version.
8
- *
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- * This program is distributed in the hope that it will be useful,
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- * but WITHOUT ANY WARRANTY; without even the implied warranty of
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- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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- * GNU General Public License for more details.
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- *
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- * You should have received a copy of the GNU General Public License
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- * along with this program; if not, you can access it online at
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- * http://www.gnu.org/licenses/gpl-2.0.html.
174 *
185 * Copyright (c) 2015, Red Hat, Inc.
196 *
....@@ -26,62 +13,42 @@
2613 #include <linux/wait.h>
2714 #include <linux/rcupdate.h>
2815
29
-enum rcu_sync_type { RCU_SYNC, RCU_SCHED_SYNC, RCU_BH_SYNC };
30
-
3116 /* Structure to mediate between updaters and fastpath-using readers. */
3217 struct rcu_sync {
3318 int gp_state;
3419 int gp_count;
3520 wait_queue_head_t gp_wait;
3621
37
- int cb_state;
3822 struct rcu_head cb_head;
39
-
40
- enum rcu_sync_type gp_type;
4123 };
42
-
43
-extern void rcu_sync_lockdep_assert(struct rcu_sync *);
4424
4525 /**
4626 * rcu_sync_is_idle() - Are readers permitted to use their fastpaths?
4727 * @rsp: Pointer to rcu_sync structure to use for synchronization
4828 *
49
- * Returns true if readers are permitted to use their fastpaths.
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- * Must be invoked within an RCU read-side critical section whose
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- * flavor matches that of the rcu_sync struture.
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+ * Returns true if readers are permitted to use their fastpaths. Must be
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+ * invoked within some flavor of RCU read-side critical section.
5231 */
5332 static inline bool rcu_sync_is_idle(struct rcu_sync *rsp)
5433 {
55
-#ifdef CONFIG_PROVE_RCU
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- rcu_sync_lockdep_assert(rsp);
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-#endif
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- return !rsp->gp_state; /* GP_IDLE */
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+ RCU_LOCKDEP_WARN(!rcu_read_lock_any_held(),
35
+ "suspicious rcu_sync_is_idle() usage");
36
+ return !READ_ONCE(rsp->gp_state); /* GP_IDLE */
5937 }
6038
61
-extern void rcu_sync_init(struct rcu_sync *, enum rcu_sync_type);
39
+extern void rcu_sync_init(struct rcu_sync *);
6240 extern void rcu_sync_enter_start(struct rcu_sync *);
6341 extern void rcu_sync_enter(struct rcu_sync *);
6442 extern void rcu_sync_exit(struct rcu_sync *);
6543 extern void rcu_sync_dtor(struct rcu_sync *);
6644
67
-#define __RCU_SYNC_INITIALIZER(name, type) { \
45
+#define __RCU_SYNC_INITIALIZER(name) { \
6846 .gp_state = 0, \
6947 .gp_count = 0, \
7048 .gp_wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.gp_wait), \
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- .cb_state = 0, \
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- .gp_type = type, \
7349 }
7450
75
-#define __DEFINE_RCU_SYNC(name, type) \
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- struct rcu_sync_struct name = __RCU_SYNC_INITIALIZER(name, type)
77
-
78
-#define DEFINE_RCU_SYNC(name) \
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- __DEFINE_RCU_SYNC(name, RCU_SYNC)
80
-
81
-#define DEFINE_RCU_SCHED_SYNC(name) \
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- __DEFINE_RCU_SYNC(name, RCU_SCHED_SYNC)
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-
84
-#define DEFINE_RCU_BH_SYNC(name) \
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- __DEFINE_RCU_SYNC(name, RCU_BH_SYNC)
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+#define DEFINE_RCU_SYNC(name) \
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+ struct rcu_sync name = __RCU_SYNC_INITIALIZER(name)
8653
8754 #endif /* _LINUX_RCU_SYNC_H_ */