Commit | Line | Data |
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82158610 | 1 | /* |
27afafe2 MD |
2 | * mem.spin: Promela code to validate memory barriers with out-of-order memory |
3 | * and out-of-order instruction scheduling. | |
4 | * | |
5 | * Algorithm verified : | |
6 | * | |
7 | * alpha = 0; | |
8 | * beta = 0; | |
9 | * | |
10 | * Process A Process B | |
11 | * alpha = 1; x = beta; | |
12 | * wmb(); rmb(); | |
13 | * beta = 1; y = alpha; | |
14 | * | |
15 | * if x = 1, then y will = 1 when it is read. | |
82158610 MD |
16 | * |
17 | * This program is free software; you can redistribute it and/or modify | |
18 | * it under the terms of the GNU General Public License as published by | |
19 | * the Free Software Foundation; either version 2 of the License, or | |
20 | * (at your option) any later version. | |
21 | * | |
22 | * This program is distributed in the hope that it will be useful, | |
23 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
24 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
25 | * GNU General Public License for more details. | |
26 | * | |
27 | * You should have received a copy of the GNU General Public License | |
28 | * along with this program; if not, write to the Free Software | |
29 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
30 | * | |
31 | * Copyright (c) 2009 Mathieu Desnoyers | |
32 | */ | |
33 | ||
34 | /* Promela validation variables. */ | |
35 | ||
dfa8abef MD |
36 | /* |
37 | * Produced process control and data flow. Updated after each instruction to | |
38 | * show which variables are ready. Using one-hot bit encoding per variable to | |
39 | * save state space. Used as triggers to execute the instructions having those | |
40 | * variables as input. Leaving bits active to inhibit instruction execution. | |
41 | * Scheme used to make instruction disabling and automatic dependency fall-back | |
42 | * automatic. | |
43 | */ | |
44 | ||
45 | #define CONSUME_TOKENS(state, bits, notbits) \ | |
46 | ((!(state & (notbits))) && (state & (bits)) == (bits)) | |
47 | ||
48 | #define PRODUCE_TOKENS(state, bits) \ | |
49 | state = state | (bits); | |
50 | ||
51 | #define CLEAR_TOKENS(state, bits) \ | |
52 | state = state & ~(bits) | |
82158610 MD |
53 | |
54 | #define NR_PROCS 2 | |
55 | ||
56 | #define get_pid() (_pid) | |
57 | ||
58 | /* | |
59 | * Each process have its own data in cache. Caches are randomly updated. | |
60 | * smp_wmb and smp_rmb forces cache updates (write and read), wmb_mb forces | |
61 | * both. | |
62 | */ | |
63 | ||
dfa8abef MD |
64 | #define DECLARE_CACHED_VAR(type, x, v) \ |
65 | type mem_##x = v; \ | |
66 | type cached_##x[NR_PROCS] = v; \ | |
67 | bit cache_dirty_##x[NR_PROCS] = 0; | |
82158610 MD |
68 | |
69 | #define IS_CACHE_DIRTY(x, id) (cache_dirty_##x[id]) | |
70 | ||
dfa8abef MD |
71 | #define READ_CACHED_VAR(x) \ |
72 | (cached_##x[get_pid()]) | |
82158610 | 73 | |
dfa8abef MD |
74 | #define WRITE_CACHED_VAR(x, v) \ |
75 | atomic { \ | |
82158610 MD |
76 | cached_##x[get_pid()] = v; \ |
77 | cache_dirty_##x[get_pid()] = 1; \ | |
78 | } | |
79 | ||
80 | #define CACHE_WRITE_TO_MEM(x, id) \ | |
81 | if \ | |
82 | :: IS_CACHE_DIRTY(x, id) -> \ | |
83 | mem_##x = cached_##x[id]; \ | |
84 | cache_dirty_##x[id] = 0; \ | |
85 | :: else -> \ | |
86 | skip \ | |
87 | fi; | |
88 | ||
dfa8abef MD |
89 | #define CACHE_READ_FROM_MEM(x, id) \ |
90 | if \ | |
91 | :: !IS_CACHE_DIRTY(x, id) -> \ | |
92 | cached_##x[id] = mem_##x; \ | |
93 | :: else -> \ | |
94 | skip \ | |
82158610 MD |
95 | fi; |
96 | ||
97 | /* | |
98 | * May update other caches if cache is dirty, or not. | |
99 | */ | |
dfa8abef MD |
100 | #define RANDOM_CACHE_WRITE_TO_MEM(x, id) \ |
101 | if \ | |
82158610 | 102 | :: 1 -> CACHE_WRITE_TO_MEM(x, id); \ |
dfa8abef | 103 | :: 1 -> skip \ |
82158610 MD |
104 | fi; |
105 | ||
106 | #define RANDOM_CACHE_READ_FROM_MEM(x, id)\ | |
dfa8abef | 107 | if \ |
82158610 | 108 | :: 1 -> CACHE_READ_FROM_MEM(x, id); \ |
dfa8abef | 109 | :: 1 -> skip \ |
82158610 MD |
110 | fi; |
111 | ||
dfa8abef MD |
112 | inline ooo_mem() |
113 | { | |
114 | atomic { | |
115 | RANDOM_CACHE_WRITE_TO_MEM(alpha, get_pid()); | |
116 | RANDOM_CACHE_WRITE_TO_MEM(beta, get_pid()); | |
117 | RANDOM_CACHE_READ_FROM_MEM(alpha, get_pid()); | |
118 | RANDOM_CACHE_READ_FROM_MEM(beta, get_pid()); | |
119 | } | |
120 | } | |
121 | ||
122 | /* must consume all prior read tokens */ | |
82158610 MD |
123 | inline smp_rmb() |
124 | { | |
125 | atomic { | |
dfa8abef | 126 | /* todo : consume all read tokens .. ? */ |
82158610 MD |
127 | CACHE_READ_FROM_MEM(alpha, get_pid()); |
128 | CACHE_READ_FROM_MEM(beta, get_pid()); | |
129 | } | |
130 | } | |
131 | ||
dfa8abef | 132 | /* must consume all prior write tokens */ |
82158610 MD |
133 | inline smp_wmb() |
134 | { | |
135 | atomic { | |
136 | CACHE_WRITE_TO_MEM(alpha, get_pid()); | |
137 | CACHE_WRITE_TO_MEM(beta, get_pid()); | |
138 | } | |
139 | } | |
140 | ||
dfa8abef MD |
141 | /* sync_core() must consume all prior read and write tokens, including rmb/wmb |
142 | * tokens */ | |
143 | ||
144 | /* must consume all prior read and write tokens */ | |
82158610 MD |
145 | inline smp_mb() |
146 | { | |
147 | atomic { | |
148 | smp_wmb(); | |
dfa8abef | 149 | /* sync_core() */ |
82158610 MD |
150 | smp_rmb(); |
151 | } | |
152 | } | |
153 | ||
154 | /* Keep in sync manually with smp_rmb, wmp_wmb and ooo_mem */ | |
155 | DECLARE_CACHED_VAR(byte, alpha, 0); | |
156 | DECLARE_CACHED_VAR(byte, beta, 0); | |
157 | ||
82158610 MD |
158 | /* value 2 is uninitialized */ |
159 | byte read_one = 2; | |
160 | byte read_two = 2; | |
161 | ||
dfa8abef MD |
162 | /* |
163 | * Bit encoding, proc_one_produced : | |
164 | */ | |
165 | ||
166 | #define P1_PROD_NONE (1 << 0) | |
167 | ||
168 | #define P1_READ_ONE (1 << 1) | |
169 | #define P1_RMB (1 << 2) | |
170 | #define P1_READ_TWO (1 << 3) | |
171 | ||
172 | /* Only need a single color. */ | |
173 | byte proc_one_produced; | |
174 | ||
82158610 MD |
175 | active proctype test_proc_one() |
176 | { | |
177 | assert(get_pid() < NR_PROCS); | |
178 | ||
dfa8abef MD |
179 | PRODUCE_TOKENS(proc_one_produced, P1_PROD_NONE); |
180 | #ifdef NO_RMB | |
181 | PRODUCE_TOKENS(proc_one_produced, P1_RMB); | |
82158610 | 182 | #endif |
dfa8abef MD |
183 | |
184 | do | |
185 | :: CONSUME_TOKENS(proc_one_produced, | |
186 | P1_PROD_NONE, P1_READ_ONE) -> | |
187 | ooo_mem(); | |
188 | read_one = READ_CACHED_VAR(beta); | |
189 | ooo_mem(); | |
190 | PRODUCE_TOKENS(proc_one_produced, P1_READ_ONE); | |
191 | :: CONSUME_TOKENS(proc_one_produced, | |
192 | P1_READ_ONE, P1_RMB) -> | |
193 | smp_rmb(); | |
194 | PRODUCE_TOKENS(proc_one_produced, P1_RMB); | |
195 | :: CONSUME_TOKENS(proc_one_produced, | |
196 | P1_RMB, P1_READ_TWO) -> | |
197 | ooo_mem(); | |
198 | read_two = READ_CACHED_VAR(alpha); | |
199 | ooo_mem(); | |
200 | PRODUCE_TOKENS(proc_one_produced, P1_READ_TWO); | |
201 | :: CONSUME_TOKENS(proc_one_produced, | |
202 | P1_PROD_NONE | P1_READ_ONE | P1_RMB | |
203 | | P1_READ_TWO, 0) -> | |
204 | break; | |
205 | od; | |
206 | ||
207 | //CLEAR_TOKENS(proc_one_produced, | |
208 | // P1_PROD_NONE | P1_READ_ONE | P1_RMB | P1_READ_TWO); | |
209 | ||
210 | // test : [] (read_one == 1 -> read_two == 1) | |
211 | assert(read_one != 1 || read_two == 1); | |
82158610 MD |
212 | } |
213 | ||
dfa8abef MD |
214 | |
215 | /* | |
216 | * Bit encoding, proc_two_produced : | |
217 | */ | |
218 | ||
219 | #define P2_PROD_NONE (1 << 0) | |
220 | ||
221 | #define P2_WRITE_ONE (1 << 1) | |
222 | #define P2_WMB (1 << 2) | |
223 | #define P2_WRITE_TWO (1 << 3) | |
224 | ||
225 | /* Only need a single color. */ | |
226 | byte proc_two_produced; | |
227 | ||
82158610 MD |
228 | active proctype test_proc_two() |
229 | { | |
230 | assert(get_pid() < NR_PROCS); | |
231 | ||
dfa8abef MD |
232 | PRODUCE_TOKENS(proc_two_produced, P2_PROD_NONE); |
233 | #ifdef NO_WMB | |
234 | PRODUCE_TOKENS(proc_two_produced, P2_WMB); | |
82158610 | 235 | #endif |
dfa8abef MD |
236 | |
237 | do | |
238 | :: CONSUME_TOKENS(proc_two_produced, | |
239 | P2_PROD_NONE, P2_WRITE_ONE) -> | |
240 | ooo_mem(); | |
241 | WRITE_CACHED_VAR(alpha, 1); | |
242 | ooo_mem(); | |
243 | PRODUCE_TOKENS(proc_two_produced, P2_WRITE_ONE); | |
244 | :: CONSUME_TOKENS(proc_two_produced, | |
245 | P2_WRITE_ONE, P2_WMB) -> | |
246 | smp_wmb(); | |
247 | PRODUCE_TOKENS(proc_two_produced, P2_WMB); | |
248 | :: CONSUME_TOKENS(proc_two_produced, | |
249 | P2_WMB, P2_WRITE_TWO) -> | |
250 | ooo_mem(); | |
251 | WRITE_CACHED_VAR(beta, 1); | |
252 | ooo_mem(); | |
253 | PRODUCE_TOKENS(proc_two_produced, P2_WRITE_TWO); | |
254 | :: CONSUME_TOKENS(proc_two_produced, | |
255 | P2_PROD_NONE | P2_WRITE_ONE | |
256 | | P2_WMB | P2_WRITE_TWO, 0) -> | |
257 | break; | |
258 | od; | |
259 | ||
260 | //CLEAR_TOKENS(proc_two_produced, | |
261 | // P2_PROD_NONE | P2_WRITE_ONE | P2_WMB | P2_WRITE_TWO); | |
82158610 | 262 | } |