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| 1 | +/* SPDX-License-Identifier: GPL-2.0+ */ |
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1 | 2 | /* |
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2 | 3 | * RCU-based infrastructure for lightweight reader-writer locking |
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3 | | - * |
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4 | | - * This program is free software; you can redistribute it and/or modify |
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5 | | - * it under the terms of the GNU General Public License as published by |
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6 | | - * the Free Software Foundation; either version 2 of the License, or |
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7 | | - * (at your option) any later version. |
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8 | | - * |
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9 | | - * This program is distributed in the hope that it will be useful, |
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10 | | - * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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11 | | - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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12 | | - * GNU General Public License for more details. |
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13 | | - * |
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14 | | - * You should have received a copy of the GNU General Public License |
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15 | | - * along with this program; if not, you can access it online at |
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16 | | - * http://www.gnu.org/licenses/gpl-2.0.html. |
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17 | 4 | * |
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18 | 5 | * Copyright (c) 2015, Red Hat, Inc. |
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19 | 6 | * |
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.. | .. |
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26 | 13 | #include <linux/wait.h> |
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27 | 14 | #include <linux/rcupdate.h> |
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28 | 15 | |
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29 | | -enum rcu_sync_type { RCU_SYNC, RCU_SCHED_SYNC, RCU_BH_SYNC }; |
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30 | | - |
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31 | 16 | /* Structure to mediate between updaters and fastpath-using readers. */ |
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32 | 17 | struct rcu_sync { |
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33 | 18 | int gp_state; |
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34 | 19 | int gp_count; |
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35 | 20 | wait_queue_head_t gp_wait; |
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36 | 21 | |
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37 | | - int cb_state; |
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38 | 22 | struct rcu_head cb_head; |
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39 | | - |
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40 | | - enum rcu_sync_type gp_type; |
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41 | 23 | }; |
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42 | | - |
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43 | | -extern void rcu_sync_lockdep_assert(struct rcu_sync *); |
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44 | 24 | |
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45 | 25 | /** |
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46 | 26 | * rcu_sync_is_idle() - Are readers permitted to use their fastpaths? |
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47 | 27 | * @rsp: Pointer to rcu_sync structure to use for synchronization |
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48 | 28 | * |
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49 | | - * Returns true if readers are permitted to use their fastpaths. |
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50 | | - * Must be invoked within an RCU read-side critical section whose |
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51 | | - * flavor matches that of the rcu_sync struture. |
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| 29 | + * Returns true if readers are permitted to use their fastpaths. Must be |
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| 30 | + * invoked within some flavor of RCU read-side critical section. |
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52 | 31 | */ |
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53 | 32 | static inline bool rcu_sync_is_idle(struct rcu_sync *rsp) |
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54 | 33 | { |
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55 | | -#ifdef CONFIG_PROVE_RCU |
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56 | | - rcu_sync_lockdep_assert(rsp); |
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57 | | -#endif |
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58 | | - return !rsp->gp_state; /* GP_IDLE */ |
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| 34 | + RCU_LOCKDEP_WARN(!rcu_read_lock_any_held(), |
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| 35 | + "suspicious rcu_sync_is_idle() usage"); |
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| 36 | + return !READ_ONCE(rsp->gp_state); /* GP_IDLE */ |
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59 | 37 | } |
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60 | 38 | |
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61 | | -extern void rcu_sync_init(struct rcu_sync *, enum rcu_sync_type); |
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| 39 | +extern void rcu_sync_init(struct rcu_sync *); |
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62 | 40 | extern void rcu_sync_enter_start(struct rcu_sync *); |
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63 | 41 | extern void rcu_sync_enter(struct rcu_sync *); |
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64 | 42 | extern void rcu_sync_exit(struct rcu_sync *); |
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65 | 43 | extern void rcu_sync_dtor(struct rcu_sync *); |
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66 | 44 | |
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67 | | -#define __RCU_SYNC_INITIALIZER(name, type) { \ |
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| 45 | +#define __RCU_SYNC_INITIALIZER(name) { \ |
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68 | 46 | .gp_state = 0, \ |
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69 | 47 | .gp_count = 0, \ |
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70 | 48 | .gp_wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.gp_wait), \ |
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71 | | - .cb_state = 0, \ |
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72 | | - .gp_type = type, \ |
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73 | 49 | } |
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74 | 50 | |
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75 | | -#define __DEFINE_RCU_SYNC(name, type) \ |
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76 | | - struct rcu_sync_struct name = __RCU_SYNC_INITIALIZER(name, type) |
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77 | | - |
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78 | | -#define DEFINE_RCU_SYNC(name) \ |
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79 | | - __DEFINE_RCU_SYNC(name, RCU_SYNC) |
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80 | | - |
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81 | | -#define DEFINE_RCU_SCHED_SYNC(name) \ |
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82 | | - __DEFINE_RCU_SYNC(name, RCU_SCHED_SYNC) |
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83 | | - |
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84 | | -#define DEFINE_RCU_BH_SYNC(name) \ |
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85 | | - __DEFINE_RCU_SYNC(name, RCU_BH_SYNC) |
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| 51 | +#define DEFINE_RCU_SYNC(name) \ |
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| 52 | + struct rcu_sync name = __RCU_SYNC_INITIALIZER(name) |
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86 | 53 | |
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87 | 54 | #endif /* _LINUX_RCU_SYNC_H_ */ |
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