1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * rtmutex API |
4 | */ |
5 | #include <linux/spinlock.h> |
6 | #include <linux/export.h> |
7 | |
8 | #define RT_MUTEX_BUILD_MUTEX |
9 | #define WW_RT |
10 | #include "rtmutex.c" |
11 | |
12 | int ww_mutex_trylock(struct ww_mutex *lock, struct ww_acquire_ctx *ww_ctx) |
13 | { |
14 | struct rt_mutex *rtm = &lock->base; |
15 | |
16 | if (!ww_ctx) |
17 | return rt_mutex_trylock(lock: rtm); |
18 | |
19 | /* |
20 | * Reset the wounded flag after a kill. No other process can |
21 | * race and wound us here, since they can't have a valid owner |
22 | * pointer if we don't have any locks held. |
23 | */ |
24 | if (ww_ctx->acquired == 0) |
25 | ww_ctx->wounded = 0; |
26 | |
27 | if (__rt_mutex_trylock(lock: &rtm->rtmutex)) { |
28 | ww_mutex_set_context_fastpath(lock, ctx: ww_ctx); |
29 | mutex_acquire_nest(&rtm->dep_map, 0, 1, &ww_ctx->dep_map, _RET_IP_); |
30 | return 1; |
31 | } |
32 | |
33 | return 0; |
34 | } |
35 | EXPORT_SYMBOL(ww_mutex_trylock); |
36 | |
37 | static int __sched |
38 | __ww_rt_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ww_ctx, |
39 | unsigned int state, unsigned long ip) |
40 | { |
41 | struct lockdep_map __maybe_unused *nest_lock = NULL; |
42 | struct rt_mutex *rtm = &lock->base; |
43 | int ret; |
44 | |
45 | might_sleep(); |
46 | |
47 | if (ww_ctx) { |
48 | if (unlikely(ww_ctx == READ_ONCE(lock->ctx))) |
49 | return -EALREADY; |
50 | |
51 | /* |
52 | * Reset the wounded flag after a kill. No other process can |
53 | * race and wound us here, since they can't have a valid owner |
54 | * pointer if we don't have any locks held. |
55 | */ |
56 | if (ww_ctx->acquired == 0) |
57 | ww_ctx->wounded = 0; |
58 | |
59 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
60 | nest_lock = &ww_ctx->dep_map; |
61 | #endif |
62 | } |
63 | mutex_acquire_nest(&rtm->dep_map, 0, 0, nest_lock, ip); |
64 | |
65 | if (likely(rt_mutex_try_acquire(&rtm->rtmutex))) { |
66 | if (ww_ctx) |
67 | ww_mutex_set_context_fastpath(lock, ctx: ww_ctx); |
68 | return 0; |
69 | } |
70 | |
71 | ret = rt_mutex_slowlock(lock: &rtm->rtmutex, ww_ctx, state); |
72 | |
73 | if (ret) |
74 | mutex_release(&rtm->dep_map, ip); |
75 | return ret; |
76 | } |
77 | |
78 | int __sched |
79 | ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) |
80 | { |
81 | return __ww_rt_mutex_lock(lock, ww_ctx: ctx, TASK_UNINTERRUPTIBLE, _RET_IP_); |
82 | } |
83 | EXPORT_SYMBOL(ww_mutex_lock); |
84 | |
85 | int __sched |
86 | ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) |
87 | { |
88 | return __ww_rt_mutex_lock(lock, ww_ctx: ctx, TASK_INTERRUPTIBLE, _RET_IP_); |
89 | } |
90 | EXPORT_SYMBOL(ww_mutex_lock_interruptible); |
91 | |
92 | void __sched ww_mutex_unlock(struct ww_mutex *lock) |
93 | { |
94 | struct rt_mutex *rtm = &lock->base; |
95 | |
96 | __ww_mutex_unlock(lock); |
97 | |
98 | mutex_release(&rtm->dep_map, _RET_IP_); |
99 | __rt_mutex_unlock(lock: &rtm->rtmutex); |
100 | } |
101 | EXPORT_SYMBOL(ww_mutex_unlock); |
102 | |