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 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 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 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 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