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102 lines · 2.3 KiB

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
12int 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(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(&rtm->rtmutex)) {
28 ww_mutex_set_context_fastpath(lock, 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}
35EXPORT_SYMBOL(ww_mutex_trylock);
36
37static 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, ww_ctx);
68 return 0;
69 }
70
71 ret = rt_mutex_slowlock(&rtm->rtmutex, ww_ctx, state);
72
73 if (ret)
74 mutex_release(&rtm->dep_map, ip);
75 return ret;
76}
77
78int __sched
79ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
80{
81 return __ww_rt_mutex_lock(lock, ctx, TASK_UNINTERRUPTIBLE, _RET_IP_);
82}
83EXPORT_SYMBOL(ww_mutex_lock);
84
85int __sched
86ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
87{
88 return __ww_rt_mutex_lock(lock, ctx, TASK_INTERRUPTIBLE, _RET_IP_);
89}
90EXPORT_SYMBOL(ww_mutex_lock_interruptible);
91
92void __sched ww_mutex_unlock(struct ww_mutex *lock)
93 __no_context_analysis
94{
95 struct rt_mutex *rtm = &lock->base;
96
97 __ww_mutex_unlock(lock);
98
99 mutex_release(&rtm->dep_map, _RET_IP_);
100 __rt_mutex_unlock(&rtm->rtmutex);
101}
102EXPORT_SYMBOL(ww_mutex_unlock);