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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 | ||
24 | void | |
25 | ktrace_init(int zentries) | |
26 | { | |
27 | ktrace_zentries = zentries; | |
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 | ||
39 | void | |
40 | ktrace_uninit(void) | |
41 | { | |
42 | kmem_cache_destroy(ktrace_hdr_zone); | |
43 | kmem_cache_destroy(ktrace_ent_zone); | |
44 | } | |
45 | ||
46 | /* | |
47 | * ktrace_alloc() | |
48 | * | |
49 | * Allocate a ktrace header and enough buffering for the given | |
50 | * number of entries. | |
51 | */ | |
52 | ktrace_t * | |
53 | ktrace_alloc(int nentries, int sleep) | |
54 | { | |
55 | ktrace_t *ktp; | |
56 | ktrace_entry_t *ktep; | |
57 | ||
58 | ktp = (ktrace_t*)kmem_zone_alloc(ktrace_hdr_zone, sleep); | |
59 | ||
60 | if (ktp == (ktrace_t*)NULL) { | |
61 | /* | |
62 | * KM_SLEEP callers don't expect failure. | |
63 | */ | |
64 | if (sleep & KM_SLEEP) | |
65 | panic("ktrace_alloc: NULL memory on KM_SLEEP request!"); | |
66 | ||
67 | return NULL; | |
68 | } | |
69 | ||
70 | /* | |
71 | * Special treatment for buffers with the ktrace_zentries entries | |
72 | */ | |
73 | if (nentries == ktrace_zentries) { | |
74 | ktep = (ktrace_entry_t*)kmem_zone_zalloc(ktrace_ent_zone, | |
75 | sleep); | |
76 | } else { | |
77 | ktep = (ktrace_entry_t*)kmem_zalloc((nentries * sizeof(*ktep)), | |
78 | sleep); | |
79 | } | |
80 | ||
81 | if (ktep == NULL) { | |
82 | /* | |
83 | * KM_SLEEP callers don't expect failure. | |
84 | */ | |
85 | if (sleep & KM_SLEEP) | |
86 | panic("ktrace_alloc: NULL memory on KM_SLEEP request!"); | |
87 | ||
88 | kmem_free(ktp, sizeof(*ktp)); | |
89 | ||
90 | return NULL; | |
91 | } | |
92 | ||
93 | spinlock_init(&(ktp->kt_lock), "kt_lock"); | |
94 | ||
95 | ktp->kt_entries = ktep; | |
96 | ktp->kt_nentries = nentries; | |
97 | ktp->kt_index = 0; | |
98 | ktp->kt_rollover = 0; | |
99 | return ktp; | |
100 | } | |
101 | ||
102 | ||
103 | /* | |
104 | * ktrace_free() | |
105 | * | |
106 | * Free up the ktrace header and buffer. It is up to the caller | |
107 | * to ensure that no-one is referencing it. | |
108 | */ | |
109 | void | |
110 | ktrace_free(ktrace_t *ktp) | |
111 | { | |
112 | int entries_size; | |
113 | ||
114 | if (ktp == (ktrace_t *)NULL) | |
115 | return; | |
116 | ||
117 | spinlock_destroy(&ktp->kt_lock); | |
118 | ||
119 | /* | |
120 | * Special treatment for the Vnode trace buffer. | |
121 | */ | |
122 | if (ktp->kt_nentries == ktrace_zentries) { | |
123 | kmem_zone_free(ktrace_ent_zone, ktp->kt_entries); | |
124 | } else { | |
125 | entries_size = (int)(ktp->kt_nentries * sizeof(ktrace_entry_t)); | |
126 | ||
127 | kmem_free(ktp->kt_entries, entries_size); | |
128 | } | |
129 | ||
130 | kmem_zone_free(ktrace_hdr_zone, ktp); | |
131 | } | |
132 | ||
133 | ||
134 | /* | |
135 | * Enter the given values into the "next" entry in the trace buffer. | |
136 | * kt_index is always the index of the next entry to be filled. | |
137 | */ | |
138 | void | |
139 | ktrace_enter( | |
140 | ktrace_t *ktp, | |
141 | void *val0, | |
142 | void *val1, | |
143 | void *val2, | |
144 | void *val3, | |
145 | void *val4, | |
146 | void *val5, | |
147 | void *val6, | |
148 | void *val7, | |
149 | void *val8, | |
150 | void *val9, | |
151 | void *val10, | |
152 | void *val11, | |
153 | void *val12, | |
154 | void *val13, | |
155 | void *val14, | |
156 | void *val15) | |
157 | { | |
a9f6a0dd | 158 | static DEFINE_SPINLOCK(wrap_lock); |
1da177e4 LT |
159 | unsigned long flags; |
160 | int index; | |
161 | ktrace_entry_t *ktep; | |
162 | ||
163 | ASSERT(ktp != NULL); | |
164 | ||
165 | /* | |
166 | * Grab an entry by pushing the index up to the next one. | |
167 | */ | |
168 | spin_lock_irqsave(&wrap_lock, flags); | |
169 | index = ktp->kt_index; | |
170 | if (++ktp->kt_index == ktp->kt_nentries) | |
171 | ktp->kt_index = 0; | |
172 | spin_unlock_irqrestore(&wrap_lock, flags); | |
173 | ||
174 | if (!ktp->kt_rollover && index == ktp->kt_nentries - 1) | |
175 | ktp->kt_rollover = 1; | |
176 | ||
177 | ASSERT((index >= 0) && (index < ktp->kt_nentries)); | |
178 | ||
179 | ktep = &(ktp->kt_entries[index]); | |
180 | ||
181 | ktep->val[0] = val0; | |
182 | ktep->val[1] = val1; | |
183 | ktep->val[2] = val2; | |
184 | ktep->val[3] = val3; | |
185 | ktep->val[4] = val4; | |
186 | ktep->val[5] = val5; | |
187 | ktep->val[6] = val6; | |
188 | ktep->val[7] = val7; | |
189 | ktep->val[8] = val8; | |
190 | ktep->val[9] = val9; | |
191 | ktep->val[10] = val10; | |
192 | ktep->val[11] = val11; | |
193 | ktep->val[12] = val12; | |
194 | ktep->val[13] = val13; | |
195 | ktep->val[14] = val14; | |
196 | ktep->val[15] = val15; | |
197 | } | |
198 | ||
199 | /* | |
200 | * Return the number of entries in the trace buffer. | |
201 | */ | |
202 | int | |
203 | ktrace_nentries( | |
204 | ktrace_t *ktp) | |
205 | { | |
206 | if (ktp == NULL) { | |
207 | return 0; | |
208 | } | |
209 | ||
210 | return (ktp->kt_rollover ? ktp->kt_nentries : ktp->kt_index); | |
211 | } | |
212 | ||
213 | /* | |
214 | * ktrace_first() | |
215 | * | |
216 | * This is used to find the start of the trace buffer. | |
217 | * In conjunction with ktrace_next() it can be used to | |
218 | * iterate through the entire trace buffer. This code does | |
219 | * not do any locking because it is assumed that it is called | |
220 | * from the debugger. | |
221 | * | |
222 | * The caller must pass in a pointer to a ktrace_snap | |
223 | * structure in which we will keep some state used to | |
224 | * iterate through the buffer. This state must not touched | |
225 | * by any code outside of this module. | |
226 | */ | |
227 | ktrace_entry_t * | |
228 | ktrace_first(ktrace_t *ktp, ktrace_snap_t *ktsp) | |
229 | { | |
230 | ktrace_entry_t *ktep; | |
231 | int index; | |
232 | int nentries; | |
233 | ||
234 | if (ktp->kt_rollover) | |
235 | index = ktp->kt_index; | |
236 | else | |
237 | index = 0; | |
238 | ||
239 | ktsp->ks_start = index; | |
240 | ktep = &(ktp->kt_entries[index]); | |
241 | ||
242 | nentries = ktrace_nentries(ktp); | |
243 | index++; | |
244 | if (index < nentries) { | |
245 | ktsp->ks_index = index; | |
246 | } else { | |
247 | ktsp->ks_index = 0; | |
248 | if (index > nentries) | |
249 | ktep = NULL; | |
250 | } | |
251 | return ktep; | |
252 | } | |
253 | ||
254 | /* | |
255 | * ktrace_next() | |
256 | * | |
257 | * This is used to iterate through the entries of the given | |
258 | * trace buffer. The caller must pass in the ktrace_snap_t | |
259 | * structure initialized by ktrace_first(). The return value | |
260 | * will be either a pointer to the next ktrace_entry or NULL | |
261 | * if all of the entries have been traversed. | |
262 | */ | |
263 | ktrace_entry_t * | |
264 | ktrace_next( | |
265 | ktrace_t *ktp, | |
266 | ktrace_snap_t *ktsp) | |
267 | { | |
268 | int index; | |
269 | ktrace_entry_t *ktep; | |
270 | ||
271 | index = ktsp->ks_index; | |
272 | if (index == ktsp->ks_start) { | |
273 | ktep = NULL; | |
274 | } else { | |
275 | ktep = &ktp->kt_entries[index]; | |
276 | } | |
277 | ||
278 | index++; | |
279 | if (index == ktrace_nentries(ktp)) { | |
280 | ktsp->ks_index = 0; | |
281 | } else { | |
282 | ktsp->ks_index = index; | |
283 | } | |
284 | ||
285 | return ktep; | |
286 | } | |
287 | ||
288 | /* | |
289 | * ktrace_skip() | |
290 | * | |
291 | * Skip the next "count" entries and return the entry after that. | |
292 | * Return NULL if this causes us to iterate past the beginning again. | |
293 | */ | |
294 | ktrace_entry_t * | |
295 | ktrace_skip( | |
296 | ktrace_t *ktp, | |
297 | int count, | |
298 | ktrace_snap_t *ktsp) | |
299 | { | |
300 | int index; | |
301 | int new_index; | |
302 | ktrace_entry_t *ktep; | |
303 | int nentries = ktrace_nentries(ktp); | |
304 | ||
305 | index = ktsp->ks_index; | |
306 | new_index = index + count; | |
307 | while (new_index >= nentries) { | |
308 | new_index -= nentries; | |
309 | } | |
310 | if (index == ktsp->ks_start) { | |
311 | /* | |
312 | * We've iterated around to the start, so we're done. | |
313 | */ | |
314 | ktep = NULL; | |
315 | } else if ((new_index < index) && (index < ktsp->ks_index)) { | |
316 | /* | |
317 | * We've skipped past the start again, so we're done. | |
318 | */ | |
319 | ktep = NULL; | |
320 | ktsp->ks_index = ktsp->ks_start; | |
321 | } else { | |
322 | ktep = &(ktp->kt_entries[new_index]); | |
323 | new_index++; | |
324 | if (new_index == nentries) { | |
325 | ktsp->ks_index = 0; | |
326 | } else { | |
327 | ktsp->ks_index = new_index; | |
328 | } | |
329 | } | |
330 | return ktep; | |
331 | } |