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 static int __sched
__ww_rt_mutex_lock(struct ww_mutex * lock,struct ww_acquire_ctx * ww_ctx,unsigned int state,unsigned long ip)13 __ww_rt_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ww_ctx,
14 unsigned int state, unsigned long ip)
15 {
16 struct lockdep_map __maybe_unused *nest_lock = NULL;
17 struct rt_mutex *rtm = &lock->base;
18 int ret;
19
20 might_sleep();
21
22 if (ww_ctx) {
23 if (unlikely(ww_ctx == READ_ONCE(lock->ctx)))
24 return -EALREADY;
25
26 /*
27 * Reset the wounded flag after a kill. No other process can
28 * race and wound us here, since they can't have a valid owner
29 * pointer if we don't have any locks held.
30 */
31 if (ww_ctx->acquired == 0)
32 ww_ctx->wounded = 0;
33
34 #ifdef CONFIG_DEBUG_LOCK_ALLOC
35 nest_lock = &ww_ctx->dep_map;
36 #endif
37 }
38 mutex_acquire_nest(&rtm->dep_map, 0, 0, nest_lock, ip);
39
40 if (likely(rt_mutex_cmpxchg_acquire(&rtm->rtmutex, NULL, current))) {
41 if (ww_ctx)
42 ww_mutex_set_context_fastpath(lock, ww_ctx);
43 return 0;
44 }
45
46 ret = rt_mutex_slowlock(&rtm->rtmutex, ww_ctx, state);
47
48 if (ret)
49 mutex_release(&rtm->dep_map, ip);
50 return ret;
51 }
52
53 int __sched
ww_mutex_lock(struct ww_mutex * lock,struct ww_acquire_ctx * ctx)54 ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
55 {
56 return __ww_rt_mutex_lock(lock, ctx, TASK_UNINTERRUPTIBLE, _RET_IP_);
57 }
58 EXPORT_SYMBOL(ww_mutex_lock);
59
60 int __sched
ww_mutex_lock_interruptible(struct ww_mutex * lock,struct ww_acquire_ctx * ctx)61 ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
62 {
63 return __ww_rt_mutex_lock(lock, ctx, TASK_INTERRUPTIBLE, _RET_IP_);
64 }
65 EXPORT_SYMBOL(ww_mutex_lock_interruptible);
66
ww_mutex_unlock(struct ww_mutex * lock)67 void __sched ww_mutex_unlock(struct ww_mutex *lock)
68 {
69 struct rt_mutex *rtm = &lock->base;
70
71 __ww_mutex_unlock(lock);
72
73 mutex_release(&rtm->dep_map, _RET_IP_);
74 __rt_mutex_unlock(&rtm->rtmutex);
75 }
76 EXPORT_SYMBOL(ww_mutex_unlock);
77
