1 /*
2 * Copyright (c) 2016 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28 #include <stddef.h>
29 #include <kern/debug.h>
30 #include <kern/locks.h>
31 #include <kern/thread.h>
32 #include <kern/thread_call.h>
33 #include <net/nwk_wq.h>
34 #include <sys/proc_internal.h>
35 #include <sys/systm.h>
36 #include <sys/mcache.h>
37
38 static TAILQ_HEAD(, nwk_wq_entry) nwk_wq_head =
39 TAILQ_HEAD_INITIALIZER(nwk_wq_head);
40 static LCK_GRP_DECLARE(nwk_wq_lock_group, "Network work queue lock");
41 static LCK_MTX_DECLARE(nwk_wq_lock, &nwk_wq_lock_group);
42
43 /* Wait channel for Network work queue */
44 static void *nwk_wq_waitch = NULL;
45 static void nwk_wq_thread_func(void *, wait_result_t);
46
47 static int nwk_wq_thread_cont(int err);
48 static void nwk_wq_thread_func(void *v, wait_result_t w);
49
50 void
nwk_wq_init(void)51 nwk_wq_init(void)
52 {
53 thread_t nwk_wq_thread __single = THREAD_NULL;
54
55 if (kernel_thread_start(nwk_wq_thread_func,
56 NULL, &nwk_wq_thread) != KERN_SUCCESS) {
57 panic_plain("%s: couldn't create network work queue thread", __func__);
58 /* NOTREACHED */
59 }
60 thread_deallocate(nwk_wq_thread);
61 }
62
63 static int
nwk_wq_thread_cont(int err)64 nwk_wq_thread_cont(int err)
65 {
66 TAILQ_HEAD(, nwk_wq_entry) temp_nwk_wq_head;
67 struct nwk_wq_entry *nwk_item __single;
68 struct nwk_wq_entry *nwk_item_next __single;
69
70 #pragma unused(err)
71 for (;;) {
72 nwk_item = NULL;
73 nwk_item_next = NULL;
74 TAILQ_INIT(&temp_nwk_wq_head);
75
76 LCK_MTX_ASSERT(&nwk_wq_lock, LCK_MTX_ASSERT_OWNED);
77 while (TAILQ_FIRST(&nwk_wq_head) == NULL) {
78 (void) msleep0(&nwk_wq_waitch, &nwk_wq_lock,
79 (PZERO - 1), "nwk_wq_thread_cont", 0,
80 nwk_wq_thread_cont);
81 /* NOTREACHED */
82 }
83
84 TAILQ_SWAP(&temp_nwk_wq_head, &nwk_wq_head, nwk_wq_entry, nwk_wq_link);
85 VERIFY(TAILQ_EMPTY(&nwk_wq_head));
86 lck_mtx_unlock(&nwk_wq_lock);
87
88 VERIFY(TAILQ_FIRST(&temp_nwk_wq_head) != NULL);
89 TAILQ_FOREACH_SAFE(nwk_item, &temp_nwk_wq_head, nwk_wq_link, nwk_item_next) {
90 nwk_item->func(nwk_item);
91 /* nwk_item has been freed by the callback */
92 }
93 lck_mtx_lock(&nwk_wq_lock);
94 }
95 }
96
97 __dead2
98 static void
nwk_wq_thread_func(void * v,wait_result_t w)99 nwk_wq_thread_func(void *v, wait_result_t w)
100 {
101 #pragma unused(v, w)
102 lck_mtx_lock(&nwk_wq_lock);
103 (void) msleep0(&nwk_wq_waitch, &nwk_wq_lock,
104 (PZERO - 1), "nwk_wq_thread_func", 0, nwk_wq_thread_cont);
105 /*
106 * msleep0() shouldn't have returned as PCATCH was not set;
107 * therefore assert in this case.
108 */
109 lck_mtx_unlock(&nwk_wq_lock);
110 VERIFY(0);
111 }
112
113 void
nwk_wq_enqueue(struct nwk_wq_entry * nwk_item)114 nwk_wq_enqueue(struct nwk_wq_entry *nwk_item)
115 {
116 lck_mtx_lock(&nwk_wq_lock);
117 TAILQ_INSERT_TAIL(&nwk_wq_head, nwk_item, nwk_wq_link);
118 lck_mtx_unlock(&nwk_wq_lock);
119 wakeup((caddr_t)&nwk_wq_waitch);
120 }
121