Commit | Line | Data |
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1da177e4 | 1 | /* |
7b718769 NS |
2 | * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc. |
3 | * All Rights Reserved. | |
1da177e4 | 4 | * |
7b718769 NS |
5 | * This program is free software; you can redistribute it and/or |
6 | * modify it under the terms of the GNU General Public License as | |
1da177e4 LT |
7 | * published by the Free Software Foundation. |
8 | * | |
7b718769 NS |
9 | * This program is distributed in the hope that it would be useful, |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
1da177e4 | 13 | * |
7b718769 NS |
14 | * You should have received a copy of the GNU General Public License |
15 | * along with this program; if not, write the Free Software Foundation, | |
16 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
1da177e4 | 17 | */ |
1da177e4 LT |
18 | #include <xfs.h> |
19 | ||
20 | static kmem_zone_t *ktrace_hdr_zone; | |
21 | static kmem_zone_t *ktrace_ent_zone; | |
22 | static int ktrace_zentries; | |
23 | ||
de2eeea6 | 24 | void __init |
1da177e4 LT |
25 | ktrace_init(int zentries) |
26 | { | |
d2341541 | 27 | ktrace_zentries = roundup_pow_of_two(zentries); |
1da177e4 LT |
28 | |
29 | ktrace_hdr_zone = kmem_zone_init(sizeof(ktrace_t), | |
30 | "ktrace_hdr"); | |
31 | ASSERT(ktrace_hdr_zone); | |
32 | ||
33 | ktrace_ent_zone = kmem_zone_init(ktrace_zentries | |
34 | * sizeof(ktrace_entry_t), | |
35 | "ktrace_ent"); | |
36 | ASSERT(ktrace_ent_zone); | |
37 | } | |
38 | ||
de2eeea6 | 39 | void __exit |
1da177e4 LT |
40 | ktrace_uninit(void) |
41 | { | |
3758dee9 NS |
42 | kmem_zone_destroy(ktrace_hdr_zone); |
43 | kmem_zone_destroy(ktrace_ent_zone); | |
1da177e4 LT |
44 | } |
45 | ||
46 | /* | |
47 | * ktrace_alloc() | |
48 | * | |
49 | * Allocate a ktrace header and enough buffering for the given | |
d2341541 DC |
50 | * number of entries. Round the number of entries up to a |
51 | * power of 2 so we can do fast masking to get the index from | |
52 | * the atomic index counter. | |
1da177e4 LT |
53 | */ |
54 | ktrace_t * | |
4750ddb0 | 55 | ktrace_alloc(int nentries, unsigned int __nocast sleep) |
1da177e4 LT |
56 | { |
57 | ktrace_t *ktp; | |
58 | ktrace_entry_t *ktep; | |
d2341541 | 59 | int entries; |
1da177e4 LT |
60 | |
61 | ktp = (ktrace_t*)kmem_zone_alloc(ktrace_hdr_zone, sleep); | |
62 | ||
63 | if (ktp == (ktrace_t*)NULL) { | |
64 | /* | |
65 | * KM_SLEEP callers don't expect failure. | |
66 | */ | |
67 | if (sleep & KM_SLEEP) | |
68 | panic("ktrace_alloc: NULL memory on KM_SLEEP request!"); | |
69 | ||
70 | return NULL; | |
71 | } | |
72 | ||
73 | /* | |
74 | * Special treatment for buffers with the ktrace_zentries entries | |
75 | */ | |
d2341541 DC |
76 | entries = roundup_pow_of_two(nentries); |
77 | if (entries == ktrace_zentries) { | |
1da177e4 LT |
78 | ktep = (ktrace_entry_t*)kmem_zone_zalloc(ktrace_ent_zone, |
79 | sleep); | |
80 | } else { | |
d2341541 | 81 | ktep = (ktrace_entry_t*)kmem_zalloc((entries * sizeof(*ktep)), |
efb8ad7e | 82 | sleep | KM_LARGE); |
1da177e4 LT |
83 | } |
84 | ||
85 | if (ktep == NULL) { | |
86 | /* | |
87 | * KM_SLEEP callers don't expect failure. | |
88 | */ | |
89 | if (sleep & KM_SLEEP) | |
90 | panic("ktrace_alloc: NULL memory on KM_SLEEP request!"); | |
91 | ||
f0e2d93c | 92 | kmem_free(ktp); |
1da177e4 LT |
93 | |
94 | return NULL; | |
95 | } | |
96 | ||
1da177e4 | 97 | ktp->kt_entries = ktep; |
d2341541 DC |
98 | ktp->kt_nentries = entries; |
99 | ASSERT(is_power_of_2(entries)); | |
100 | ktp->kt_index_mask = entries - 1; | |
6ee4752f | 101 | atomic_set(&ktp->kt_index, 0); |
1da177e4 LT |
102 | ktp->kt_rollover = 0; |
103 | return ktp; | |
104 | } | |
105 | ||
106 | ||
107 | /* | |
108 | * ktrace_free() | |
109 | * | |
110 | * Free up the ktrace header and buffer. It is up to the caller | |
111 | * to ensure that no-one is referencing it. | |
112 | */ | |
113 | void | |
114 | ktrace_free(ktrace_t *ktp) | |
115 | { | |
1da177e4 LT |
116 | if (ktp == (ktrace_t *)NULL) |
117 | return; | |
118 | ||
1da177e4 LT |
119 | /* |
120 | * Special treatment for the Vnode trace buffer. | |
121 | */ | |
a5b429d4 | 122 | if (ktp->kt_nentries == ktrace_zentries) |
1da177e4 | 123 | kmem_zone_free(ktrace_ent_zone, ktp->kt_entries); |
a5b429d4 | 124 | else |
f0e2d93c | 125 | kmem_free(ktp->kt_entries); |
1da177e4 LT |
126 | |
127 | kmem_zone_free(ktrace_hdr_zone, ktp); | |
128 | } | |
129 | ||
130 | ||
131 | /* | |
132 | * Enter the given values into the "next" entry in the trace buffer. | |
133 | * kt_index is always the index of the next entry to be filled. | |
134 | */ | |
135 | void | |
136 | ktrace_enter( | |
137 | ktrace_t *ktp, | |
138 | void *val0, | |
139 | void *val1, | |
140 | void *val2, | |
141 | void *val3, | |
142 | void *val4, | |
143 | void *val5, | |
144 | void *val6, | |
145 | void *val7, | |
146 | void *val8, | |
147 | void *val9, | |
148 | void *val10, | |
149 | void *val11, | |
150 | void *val12, | |
151 | void *val13, | |
152 | void *val14, | |
153 | void *val15) | |
154 | { | |
1da177e4 LT |
155 | int index; |
156 | ktrace_entry_t *ktep; | |
157 | ||
158 | ASSERT(ktp != NULL); | |
159 | ||
160 | /* | |
161 | * Grab an entry by pushing the index up to the next one. | |
162 | */ | |
6ee4752f | 163 | index = atomic_add_return(1, &ktp->kt_index); |
d2341541 | 164 | index = (index - 1) & ktp->kt_index_mask; |
1da177e4 LT |
165 | if (!ktp->kt_rollover && index == ktp->kt_nentries - 1) |
166 | ktp->kt_rollover = 1; | |
167 | ||
168 | ASSERT((index >= 0) && (index < ktp->kt_nentries)); | |
169 | ||
170 | ktep = &(ktp->kt_entries[index]); | |
171 | ||
172 | ktep->val[0] = val0; | |
173 | ktep->val[1] = val1; | |
174 | ktep->val[2] = val2; | |
175 | ktep->val[3] = val3; | |
176 | ktep->val[4] = val4; | |
177 | ktep->val[5] = val5; | |
178 | ktep->val[6] = val6; | |
179 | ktep->val[7] = val7; | |
180 | ktep->val[8] = val8; | |
181 | ktep->val[9] = val9; | |
182 | ktep->val[10] = val10; | |
183 | ktep->val[11] = val11; | |
184 | ktep->val[12] = val12; | |
185 | ktep->val[13] = val13; | |
186 | ktep->val[14] = val14; | |
187 | ktep->val[15] = val15; | |
188 | } | |
189 | ||
190 | /* | |
191 | * Return the number of entries in the trace buffer. | |
192 | */ | |
193 | int | |
194 | ktrace_nentries( | |
195 | ktrace_t *ktp) | |
196 | { | |
6ee4752f DC |
197 | int index; |
198 | if (ktp == NULL) | |
1da177e4 | 199 | return 0; |
1da177e4 | 200 | |
d2341541 | 201 | index = atomic_read(&ktp->kt_index) & ktp->kt_index_mask; |
6ee4752f | 202 | return (ktp->kt_rollover ? ktp->kt_nentries : index); |
1da177e4 LT |
203 | } |
204 | ||
205 | /* | |
206 | * ktrace_first() | |
207 | * | |
208 | * This is used to find the start of the trace buffer. | |
209 | * In conjunction with ktrace_next() it can be used to | |
210 | * iterate through the entire trace buffer. This code does | |
211 | * not do any locking because it is assumed that it is called | |
212 | * from the debugger. | |
213 | * | |
214 | * The caller must pass in a pointer to a ktrace_snap | |
215 | * structure in which we will keep some state used to | |
216 | * iterate through the buffer. This state must not touched | |
217 | * by any code outside of this module. | |
218 | */ | |
219 | ktrace_entry_t * | |
220 | ktrace_first(ktrace_t *ktp, ktrace_snap_t *ktsp) | |
221 | { | |
222 | ktrace_entry_t *ktep; | |
223 | int index; | |
224 | int nentries; | |
225 | ||
226 | if (ktp->kt_rollover) | |
d2341541 | 227 | index = atomic_read(&ktp->kt_index) & ktp->kt_index_mask; |
1da177e4 LT |
228 | else |
229 | index = 0; | |
230 | ||
231 | ktsp->ks_start = index; | |
232 | ktep = &(ktp->kt_entries[index]); | |
233 | ||
234 | nentries = ktrace_nentries(ktp); | |
235 | index++; | |
236 | if (index < nentries) { | |
237 | ktsp->ks_index = index; | |
238 | } else { | |
239 | ktsp->ks_index = 0; | |
240 | if (index > nentries) | |
241 | ktep = NULL; | |
242 | } | |
243 | return ktep; | |
244 | } | |
245 | ||
246 | /* | |
247 | * ktrace_next() | |
248 | * | |
249 | * This is used to iterate through the entries of the given | |
250 | * trace buffer. The caller must pass in the ktrace_snap_t | |
251 | * structure initialized by ktrace_first(). The return value | |
252 | * will be either a pointer to the next ktrace_entry or NULL | |
253 | * if all of the entries have been traversed. | |
254 | */ | |
255 | ktrace_entry_t * | |
256 | ktrace_next( | |
257 | ktrace_t *ktp, | |
258 | ktrace_snap_t *ktsp) | |
259 | { | |
260 | int index; | |
261 | ktrace_entry_t *ktep; | |
262 | ||
263 | index = ktsp->ks_index; | |
264 | if (index == ktsp->ks_start) { | |
265 | ktep = NULL; | |
266 | } else { | |
267 | ktep = &ktp->kt_entries[index]; | |
268 | } | |
269 | ||
270 | index++; | |
271 | if (index == ktrace_nentries(ktp)) { | |
272 | ktsp->ks_index = 0; | |
273 | } else { | |
274 | ktsp->ks_index = index; | |
275 | } | |
276 | ||
277 | return ktep; | |
278 | } | |
279 | ||
280 | /* | |
281 | * ktrace_skip() | |
282 | * | |
283 | * Skip the next "count" entries and return the entry after that. | |
284 | * Return NULL if this causes us to iterate past the beginning again. | |
285 | */ | |
286 | ktrace_entry_t * | |
287 | ktrace_skip( | |
288 | ktrace_t *ktp, | |
289 | int count, | |
290 | ktrace_snap_t *ktsp) | |
291 | { | |
292 | int index; | |
293 | int new_index; | |
294 | ktrace_entry_t *ktep; | |
295 | int nentries = ktrace_nentries(ktp); | |
296 | ||
297 | index = ktsp->ks_index; | |
298 | new_index = index + count; | |
299 | while (new_index >= nentries) { | |
300 | new_index -= nentries; | |
301 | } | |
302 | if (index == ktsp->ks_start) { | |
303 | /* | |
304 | * We've iterated around to the start, so we're done. | |
305 | */ | |
306 | ktep = NULL; | |
307 | } else if ((new_index < index) && (index < ktsp->ks_index)) { | |
308 | /* | |
309 | * We've skipped past the start again, so we're done. | |
310 | */ | |
311 | ktep = NULL; | |
312 | ktsp->ks_index = ktsp->ks_start; | |
313 | } else { | |
314 | ktep = &(ktp->kt_entries[new_index]); | |
315 | new_index++; | |
316 | if (new_index == nentries) { | |
317 | ktsp->ks_index = 0; | |
318 | } else { | |
319 | ktsp->ks_index = new_index; | |
320 | } | |
321 | } | |
322 | return ktep; | |
323 | } |