| 1 | /* $NetBSD: ww_mutex.h,v 1.11 2015/05/21 21:55:55 riastradh Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c) 2014 The NetBSD Foundation, Inc. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * This code is derived from software contributed to The NetBSD Foundation |
| 8 | * by Taylor R. Campbell. |
| 9 | * |
| 10 | * Redistribution and use in source and binary forms, with or without |
| 11 | * modification, are permitted provided that the following conditions |
| 12 | * are met: |
| 13 | * 1. Redistributions of source code must retain the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer. |
| 15 | * 2. Redistributions in binary form must reproduce the above copyright |
| 16 | * notice, this list of conditions and the following disclaimer in the |
| 17 | * documentation and/or other materials provided with the distribution. |
| 18 | * |
| 19 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
| 20 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| 21 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 22 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
| 23 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 29 | * POSSIBILITY OF SUCH DAMAGE. |
| 30 | */ |
| 31 | |
| 32 | #ifndef _ASM_WW_MUTEX_H_ |
| 33 | #define _ASM_WW_MUTEX_H_ |
| 34 | |
| 35 | #include <sys/types.h> |
| 36 | #include <sys/condvar.h> |
| 37 | #include <sys/mutex.h> |
| 38 | #include <sys/rbtree.h> |
| 39 | |
| 40 | struct ww_class { |
| 41 | volatile uint64_t wwc_ticket; |
| 42 | }; |
| 43 | |
| 44 | #define DEFINE_WW_CLASS(CLASS) \ |
| 45 | struct ww_class CLASS = { \ |
| 46 | .wwc_ticket = 0, \ |
| 47 | } |
| 48 | |
| 49 | struct ww_acquire_ctx { |
| 50 | struct ww_class *wwx_class __diagused; |
| 51 | struct lwp *wwx_owner __diagused; |
| 52 | uint64_t wwx_ticket; |
| 53 | unsigned wwx_acquired; |
| 54 | bool wwx_acquire_done; |
| 55 | struct rb_node wwx_rb_node; |
| 56 | }; |
| 57 | |
| 58 | struct ww_mutex { |
| 59 | enum ww_mutex_state { |
| 60 | WW_UNLOCKED, /* nobody owns it */ |
| 61 | WW_OWNED, /* owned by a lwp without a context */ |
| 62 | WW_CTX, /* owned by a context */ |
| 63 | WW_WANTOWN, /* owned by ctx, waiters w/o ctx waiting */ |
| 64 | } wwm_state; |
| 65 | union { |
| 66 | struct lwp *owner; |
| 67 | struct ww_acquire_ctx *ctx; |
| 68 | } wwm_u; |
| 69 | /* |
| 70 | * XXX wwm_lock must *not* be first, so that the ww_mutex has a |
| 71 | * different address from the kmutex for LOCKDEBUG purposes. |
| 72 | */ |
| 73 | kmutex_t wwm_lock; |
| 74 | struct ww_class *wwm_class; |
| 75 | struct rb_tree wwm_waiters; |
| 76 | kcondvar_t wwm_cv; |
| 77 | #ifdef LOCKDEBUG |
| 78 | bool wwm_debug; |
| 79 | #endif |
| 80 | }; |
| 81 | |
| 82 | /* XXX Make the nm output a little more greppable... */ |
| 83 | #define ww_acquire_done linux_ww_acquire_done |
| 84 | #define ww_acquire_fini linux_ww_acquire_fini |
| 85 | #define ww_acquire_init linux_ww_acquire_init |
| 86 | #define ww_mutex_destroy linux_ww_mutex_destroy |
| 87 | #define ww_mutex_init linux_ww_mutex_init |
| 88 | #define ww_mutex_is_locked linux_ww_mutex_is_locked |
| 89 | #define ww_mutex_lock linux_ww_mutex_lock |
| 90 | #define ww_mutex_lock_interruptible linux_ww_mutex_lock_interruptible |
| 91 | #define ww_mutex_lock_slow linux_ww_mutex_lock_slow |
| 92 | #define ww_mutex_lock_slow_interruptible linux_ww_mutex_lock_slow_interruptible |
| 93 | #define ww_mutex_trylock linux_ww_mutex_trylock |
| 94 | #define ww_mutex_unlock linux_ww_mutex_unlock |
| 95 | |
| 96 | void ww_acquire_init(struct ww_acquire_ctx *, struct ww_class *); |
| 97 | void ww_acquire_done(struct ww_acquire_ctx *); |
| 98 | void ww_acquire_fini(struct ww_acquire_ctx *); |
| 99 | |
| 100 | void ww_mutex_init(struct ww_mutex *, struct ww_class *); |
| 101 | void ww_mutex_destroy(struct ww_mutex *); |
| 102 | |
| 103 | /* |
| 104 | * WARNING: ww_mutex_is_locked returns true if it is locked by ANYONE. |
| 105 | * Does NOT mean `Do I hold this lock?' (answering which really |
| 106 | * requires an acquire context). |
| 107 | */ |
| 108 | bool ww_mutex_is_locked(struct ww_mutex *); |
| 109 | |
| 110 | int ww_mutex_lock(struct ww_mutex *, struct ww_acquire_ctx *); |
| 111 | int ww_mutex_lock_interruptible(struct ww_mutex *, |
| 112 | struct ww_acquire_ctx *); |
| 113 | void ww_mutex_lock_slow(struct ww_mutex *, struct ww_acquire_ctx *); |
| 114 | int ww_mutex_lock_slow_interruptible(struct ww_mutex *, |
| 115 | struct ww_acquire_ctx *); |
| 116 | int ww_mutex_trylock(struct ww_mutex *); |
| 117 | void ww_mutex_unlock(struct ww_mutex *); |
| 118 | |
| 119 | #endif /* _ASM_WW_MUTEX_H_ */ |
| 120 | |