| @@ -1,187 +1,189 @@ | | | @@ -1,187 +1,189 @@ |
1 | /* $NetBSD: subr_pserialize.c,v 1.15 2019/12/03 13:30:52 martin Exp $ */ | | 1 | /* $NetBSD: subr_pserialize.c,v 1.16 2019/12/05 03:21:17 riastradh Exp $ */ |
2 | | | 2 | |
3 | /*- | | 3 | /*- |
4 | * Copyright (c) 2010, 2011 The NetBSD Foundation, Inc. | | 4 | * Copyright (c) 2010, 2011 The NetBSD Foundation, Inc. |
5 | * All rights reserved. | | 5 | * All rights reserved. |
6 | * | | 6 | * |
7 | * Redistribution and use in source and binary forms, with or without | | 7 | * Redistribution and use in source and binary forms, with or without |
8 | * modification, are permitted provided that the following conditions | | 8 | * modification, are permitted provided that the following conditions |
9 | * are met: | | 9 | * are met: |
10 | * 1. Redistributions of source code must retain the above copyright | | 10 | * 1. Redistributions of source code must retain the above copyright |
11 | * notice, this list of conditions and the following disclaimer. | | 11 | * notice, this list of conditions and the following disclaimer. |
12 | * 2. Redistributions in binary form must reproduce the above copyright | | 12 | * 2. Redistributions in binary form must reproduce the above copyright |
13 | * notice, this list of conditions and the following disclaimer in the | | 13 | * notice, this list of conditions and the following disclaimer in the |
14 | * documentation and/or other materials provided with the distribution. | | 14 | * documentation and/or other materials provided with the distribution. |
15 | * | | 15 | * |
16 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS | | 16 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
17 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED | | 17 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
18 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR | | 18 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
19 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS | | 19 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
20 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | | 20 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
21 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | | 21 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
22 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | | 22 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
23 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | | 23 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
24 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | | 24 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
25 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | | 25 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
26 | * POSSIBILITY OF SUCH DAMAGE. | | 26 | * POSSIBILITY OF SUCH DAMAGE. |
27 | */ | | 27 | */ |
28 | | | 28 | |
29 | /* | | 29 | /* |
30 | * Passive serialization. | | 30 | * Passive serialization. |
31 | */ | | 31 | */ |
32 | | | 32 | |
33 | #include <sys/cdefs.h> | | 33 | #include <sys/cdefs.h> |
34 | __KERNEL_RCSID(0, "$NetBSD: subr_pserialize.c,v 1.15 2019/12/03 13:30:52 martin Exp $"); | | 34 | __KERNEL_RCSID(0, "$NetBSD: subr_pserialize.c,v 1.16 2019/12/05 03:21:17 riastradh Exp $"); |
35 | | | 35 | |
36 | #include <sys/param.h> | | 36 | #include <sys/param.h> |
37 | #include <sys/atomic.h> | | 37 | #include <sys/atomic.h> |
38 | #include <sys/cpu.h> | | 38 | #include <sys/cpu.h> |
39 | #include <sys/evcnt.h> | | 39 | #include <sys/evcnt.h> |
40 | #include <sys/kmem.h> | | 40 | #include <sys/kmem.h> |
| | | 41 | #include <sys/mutex.h> |
41 | #include <sys/pserialize.h> | | 42 | #include <sys/pserialize.h> |
42 | #include <sys/xcall.h> | | 43 | #include <sys/xcall.h> |
43 | | | 44 | |
44 | struct pserialize { | | 45 | struct pserialize { |
45 | lwp_t * psz_owner; | | 46 | lwp_t * psz_owner; |
46 | }; | | 47 | }; |
47 | | | 48 | |
| | | 49 | static kmutex_t psz_lock __cacheline_aligned; |
48 | static struct evcnt psz_ev_excl __cacheline_aligned; | | 50 | static struct evcnt psz_ev_excl __cacheline_aligned; |
49 | | | 51 | |
50 | /* | | 52 | /* |
51 | * pserialize_init: | | 53 | * pserialize_init: |
52 | * | | 54 | * |
53 | * Initialize passive serialization structures. | | 55 | * Initialize passive serialization structures. |
54 | */ | | 56 | */ |
55 | void | | 57 | void |
56 | pserialize_init(void) | | 58 | pserialize_init(void) |
57 | { | | 59 | { |
58 | | | 60 | |
| | | 61 | mutex_init(&psz_lock, MUTEX_DEFAULT, IPL_NONE); |
59 | evcnt_attach_dynamic(&psz_ev_excl, EVCNT_TYPE_MISC, NULL, | | 62 | evcnt_attach_dynamic(&psz_ev_excl, EVCNT_TYPE_MISC, NULL, |
60 | "pserialize", "exclusive access"); | | 63 | "pserialize", "exclusive access"); |
61 | } | | 64 | } |
62 | | | 65 | |
63 | /* | | 66 | /* |
64 | * pserialize_create: | | 67 | * pserialize_create: |
65 | * | | 68 | * |
66 | * Create and initialize a passive serialization object. | | 69 | * Create and initialize a passive serialization object. |
67 | */ | | 70 | */ |
68 | pserialize_t | | 71 | pserialize_t |
69 | pserialize_create(void) | | 72 | pserialize_create(void) |
70 | { | | 73 | { |
71 | pserialize_t psz; | | 74 | pserialize_t psz; |
72 | | | 75 | |
73 | psz = kmem_zalloc(sizeof(*psz), KM_SLEEP); | | 76 | psz = kmem_zalloc(sizeof(*psz), KM_SLEEP); |
74 | return psz; | | 77 | return psz; |
75 | } | | 78 | } |
76 | | | 79 | |
77 | /* | | 80 | /* |
78 | * pserialize_destroy: | | 81 | * pserialize_destroy: |
79 | * | | 82 | * |
80 | * Destroy a passive serialization object. | | 83 | * Destroy a passive serialization object. |
81 | */ | | 84 | */ |
82 | void | | 85 | void |
83 | pserialize_destroy(pserialize_t psz) | | 86 | pserialize_destroy(pserialize_t psz) |
84 | { | | 87 | { |
85 | | | 88 | |
86 | KASSERT(psz->psz_owner == NULL); | | 89 | KASSERT(psz->psz_owner == NULL); |
87 | kmem_free(psz, sizeof(*psz)); | | 90 | kmem_free(psz, sizeof(*psz)); |
88 | } | | 91 | } |
89 | | | 92 | |
90 | /* | | 93 | /* |
91 | * pserialize_perform: | | 94 | * pserialize_perform: |
92 | * | | 95 | * |
93 | * Perform the write side of passive serialization. This operation | | 96 | * Perform the write side of passive serialization. This operation |
94 | * MUST be serialized at a caller level (e.g. with a mutex or by a | | 97 | * MUST be serialized at a caller level (e.g. with a mutex or by a |
95 | * single-threaded use). | | 98 | * single-threaded use). |
96 | */ | | 99 | */ |
97 | void | | 100 | void |
98 | pserialize_perform(pserialize_t psz) | | 101 | pserialize_perform(pserialize_t psz) |
99 | { | | 102 | { |
100 | | | 103 | |
101 | KASSERT(!cpu_intr_p()); | | 104 | KASSERT(!cpu_intr_p()); |
102 | KASSERT(!cpu_softintr_p()); | | 105 | KASSERT(!cpu_softintr_p()); |
103 | | | 106 | |
104 | if (__predict_false(panicstr != NULL)) { | | 107 | if (__predict_false(panicstr != NULL)) { |
105 | return; | | 108 | return; |
106 | } | | 109 | } |
107 | KASSERT(psz->psz_owner == NULL); | | 110 | KASSERT(psz->psz_owner == NULL); |
108 | | | 111 | |
109 | if (__predict_false(mp_online == false)) { | | 112 | if (__predict_false(mp_online == false)) { |
110 | psz_ev_excl.ev_count++; | | 113 | psz_ev_excl.ev_count++; |
111 | return; | | 114 | return; |
112 | } | | 115 | } |
113 | | | 116 | |
114 | psz->psz_owner = curlwp; | | 117 | psz->psz_owner = curlwp; |
115 | | | 118 | |
116 | /* | | 119 | /* |
117 | * Broadcast a NOP to all CPUs and wait until all of them complete. | | 120 | * Broadcast a NOP to all CPUs and wait until all of them complete. |
118 | */ | | 121 | */ |
119 | xc_barrier(XC_HIGHPRI); | | 122 | xc_barrier(XC_HIGHPRI); |
120 | | | 123 | |
121 | KASSERT(psz->psz_owner == curlwp); | | 124 | KASSERT(psz->psz_owner == curlwp); |
122 | psz->psz_owner = NULL; | | 125 | psz->psz_owner = NULL; |
123 | #ifdef __HAVE_ATOMIC64_LOADSTORE | | 126 | mutex_enter(&psz_lock); |
124 | atomic_store_relaxed(&psz_ev_excl.ev_count, | | 127 | psz_ev_excl.ev_count++; |
125 | 1 + atomic_load_relaxed(&psz_ev_excl.ev_count)); | | 128 | mutex_exit(&psz_lock); |
126 | #endif | | | |
127 | } | | 129 | } |
128 | | | 130 | |
129 | int | | 131 | int |
130 | pserialize_read_enter(void) | | 132 | pserialize_read_enter(void) |
131 | { | | 133 | { |
132 | int s; | | 134 | int s; |
133 | | | 135 | |
134 | s = splsoftserial(); | | 136 | s = splsoftserial(); |
135 | curcpu()->ci_psz_read_depth++; | | 137 | curcpu()->ci_psz_read_depth++; |
136 | __insn_barrier(); | | 138 | __insn_barrier(); |
137 | return s; | | 139 | return s; |
138 | } | | 140 | } |
139 | | | 141 | |
140 | void | | 142 | void |
141 | pserialize_read_exit(int s) | | 143 | pserialize_read_exit(int s) |
142 | { | | 144 | { |
143 | | | 145 | |
144 | KASSERT(kpreempt_disabled()); | | 146 | KASSERT(kpreempt_disabled()); |
145 | | | 147 | |
146 | __insn_barrier(); | | 148 | __insn_barrier(); |
147 | if (__predict_false(curcpu()->ci_psz_read_depth-- == 0)) | | 149 | if (__predict_false(curcpu()->ci_psz_read_depth-- == 0)) |
148 | panic("mismatching pserialize_read_exit()"); | | 150 | panic("mismatching pserialize_read_exit()"); |
149 | splx(s); | | 151 | splx(s); |
150 | } | | 152 | } |
151 | | | 153 | |
152 | /* | | 154 | /* |
153 | * pserialize_in_read_section: | | 155 | * pserialize_in_read_section: |
154 | * | | 156 | * |
155 | * True if the caller is in a pserialize read section. To be used | | 157 | * True if the caller is in a pserialize read section. To be used |
156 | * only for diagnostic assertions where we want to guarantee the | | 158 | * only for diagnostic assertions where we want to guarantee the |
157 | * condition like: | | 159 | * condition like: |
158 | * | | 160 | * |
159 | * KASSERT(pserialize_in_read_section()); | | 161 | * KASSERT(pserialize_in_read_section()); |
160 | */ | | 162 | */ |
161 | bool | | 163 | bool |
162 | pserialize_in_read_section(void) | | 164 | pserialize_in_read_section(void) |
163 | { | | 165 | { |
164 | | | 166 | |
165 | return kpreempt_disabled() && curcpu()->ci_psz_read_depth > 0; | | 167 | return kpreempt_disabled() && curcpu()->ci_psz_read_depth > 0; |
166 | } | | 168 | } |
167 | | | 169 | |
168 | /* | | 170 | /* |
169 | * pserialize_not_in_read_section: | | 171 | * pserialize_not_in_read_section: |
170 | * | | 172 | * |
171 | * True if the caller is not in a pserialize read section. To be | | 173 | * True if the caller is not in a pserialize read section. To be |
172 | * used only for diagnostic assertions where we want to guarantee | | 174 | * used only for diagnostic assertions where we want to guarantee |
173 | * the condition like: | | 175 | * the condition like: |
174 | * | | 176 | * |
175 | * KASSERT(pserialize_not_in_read_section()); | | 177 | * KASSERT(pserialize_not_in_read_section()); |
176 | */ | | 178 | */ |
177 | bool | | 179 | bool |
178 | pserialize_not_in_read_section(void) | | 180 | pserialize_not_in_read_section(void) |
179 | { | | 181 | { |
180 | bool notin; | | 182 | bool notin; |
181 | | | 183 | |
182 | kpreempt_disable(); | | 184 | kpreempt_disable(); |
183 | notin = (curcpu()->ci_psz_read_depth == 0); | | 185 | notin = (curcpu()->ci_psz_read_depth == 0); |
184 | kpreempt_enable(); | | 186 | kpreempt_enable(); |
185 | | | 187 | |
186 | return notin; | | 188 | return notin; |
187 | } | | 189 | } |