Commit | Line | Data |
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61009379 MD |
1 | /* |
2 | * rcuja/rcuja.c | |
3 | * | |
4 | * Userspace RCU library - RCU Judy Array | |
5 | * | |
6 | * Copyright 2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
7 | * | |
8 | * This library is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU Lesser General Public | |
10 | * License as published by the Free Software Foundation; either | |
11 | * version 2.1 of the License, or (at your option) any later version. | |
12 | * | |
13 | * This library is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | * Lesser General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU Lesser General Public | |
19 | * License along with this library; if not, write to the Free Software | |
20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
21 | */ | |
22 | ||
195e72d3 | 23 | #define _LGPL_SOURCE |
e5227865 | 24 | #include <stdint.h> |
8e519e3c | 25 | #include <errno.h> |
d68c6810 | 26 | #include <limits.h> |
61009379 | 27 | #include <urcu/rcuja.h> |
d68c6810 MD |
28 | #include <urcu/compiler.h> |
29 | #include <urcu/arch.h> | |
30 | #include <assert.h> | |
8e519e3c MD |
31 | #include <urcu-pointer.h> |
32 | ||
61009379 | 33 | #include "rcuja-internal.h" |
d68c6810 | 34 | #include "bitfield.h" |
61009379 | 35 | |
d68c6810 | 36 | enum rcu_ja_type_class { |
e5227865 | 37 | RCU_JA_LINEAR = 0, /* Type A */ |
fd800776 MD |
38 | /* 32-bit: 1 to 25 children, 8 to 128 bytes */ |
39 | /* 64-bit: 1 to 28 children, 16 to 256 bytes */ | |
40 | RCU_JA_POOL = 1, /* Type B */ | |
41 | /* 32-bit: 26 to 100 children, 256 to 512 bytes */ | |
42 | /* 64-bit: 29 to 112 children, 512 to 1024 bytes */ | |
e5227865 | 43 | RCU_JA_PIGEON = 2, /* Type C */ |
fd800776 MD |
44 | /* 32-bit: 101 to 256 children, 1024 bytes */ |
45 | /* 64-bit: 113 to 256 children, 2048 bytes */ | |
e5227865 | 46 | /* Leaf nodes are implicit from their height in the tree */ |
1db4943c | 47 | RCU_JA_NR_TYPES, |
e1db2db5 MD |
48 | |
49 | RCU_JA_NULL, /* not an encoded type, but keeps code regular */ | |
e5227865 MD |
50 | }; |
51 | ||
d68c6810 MD |
52 | struct rcu_ja_type { |
53 | enum rcu_ja_type_class type_class; | |
8e519e3c MD |
54 | uint16_t min_child; /* minimum number of children: 1 to 256 */ |
55 | uint16_t max_child; /* maximum number of children: 1 to 256 */ | |
56 | uint16_t max_linear_child; /* per-pool max nr. children: 1 to 256 */ | |
57 | uint16_t order; /* node size is (1 << order), in bytes */ | |
fd800776 MD |
58 | uint16_t nr_pool_order; /* number of pools */ |
59 | uint16_t pool_size_order; /* pool size */ | |
e5227865 MD |
60 | }; |
61 | ||
d68c6810 MD |
62 | /* |
63 | * Number of least significant pointer bits reserved to represent the | |
64 | * child type. | |
65 | */ | |
66 | #define JA_TYPE_BITS 3 | |
67 | #define JA_TYPE_MAX_NR (1U << JA_TYPE_BITS) | |
68 | #define JA_TYPE_MASK (JA_TYPE_MAX_NR - 1) | |
69 | #define JA_PTR_MASK (~JA_TYPE_MASK) | |
70 | ||
71 | #define JA_ENTRY_PER_NODE 256UL | |
72 | ||
e1db2db5 MD |
73 | /* |
74 | * Entry for NULL node is at index 8 of the table. It is never encoded | |
75 | * in flags. | |
76 | */ | |
77 | #define NODE_INDEX_NULL 8 | |
78 | ||
e5227865 MD |
79 | /* |
80 | * Iteration on the array to find the right node size for the number of | |
d68c6810 | 81 | * children stops when it reaches .max_child == 256 (this is the largest |
e5227865 | 82 | * possible node size, which contains 256 children). |
d68c6810 MD |
83 | * The min_child overlaps with the previous max_child to provide an |
84 | * hysteresis loop to reallocation for patterns of cyclic add/removal | |
85 | * within the same node. | |
86 | * The node the index within the following arrays is represented on 3 | |
87 | * bits. It identifies the node type, min/max number of children, and | |
88 | * the size order. | |
3d45251f MD |
89 | * The max_child values for the RCU_JA_POOL below result from |
90 | * statistical approximation: over million populations, the max_child | |
91 | * covers between 97% and 99% of the populations generated. Therefore, a | |
92 | * fallback should exist to cover the rare extreme population unbalance | |
93 | * cases, but it will not have a major impact on speed nor space | |
94 | * consumption, since those are rare cases. | |
e5227865 | 95 | */ |
e5227865 | 96 | |
d68c6810 MD |
97 | #if (CAA_BITS_PER_LONG < 64) |
98 | /* 32-bit pointers */ | |
1db4943c MD |
99 | enum { |
100 | ja_type_0_max_child = 1, | |
101 | ja_type_1_max_child = 3, | |
102 | ja_type_2_max_child = 6, | |
103 | ja_type_3_max_child = 12, | |
104 | ja_type_4_max_child = 25, | |
105 | ja_type_5_max_child = 48, | |
106 | ja_type_6_max_child = 92, | |
107 | ja_type_7_max_child = 256, | |
e1db2db5 | 108 | ja_type_8_max_child = 0, /* NULL */ |
1db4943c MD |
109 | }; |
110 | ||
8e519e3c MD |
111 | enum { |
112 | ja_type_0_max_linear_child = 1, | |
113 | ja_type_1_max_linear_child = 3, | |
114 | ja_type_2_max_linear_child = 6, | |
115 | ja_type_3_max_linear_child = 12, | |
116 | ja_type_4_max_linear_child = 25, | |
117 | ja_type_5_max_linear_child = 24, | |
118 | ja_type_6_max_linear_child = 23, | |
119 | }; | |
120 | ||
1db4943c MD |
121 | enum { |
122 | ja_type_5_nr_pool_order = 1, | |
123 | ja_type_6_nr_pool_order = 2, | |
124 | }; | |
125 | ||
d68c6810 | 126 | const struct rcu_ja_type ja_types[] = { |
8e519e3c MD |
127 | { .type_class = RCU_JA_LINEAR, .min_child = 1, .max_child = ja_type_0_max_child, .max_linear_child = ja_type_0_max_linear_child, .order = 3, }, |
128 | { .type_class = RCU_JA_LINEAR, .min_child = 1, .max_child = ja_type_1_max_child, .max_linear_child = ja_type_1_max_linear_child, .order = 4, }, | |
129 | { .type_class = RCU_JA_LINEAR, .min_child = 3, .max_child = ja_type_2_max_child, .max_linear_child = ja_type_2_max_linear_child, .order = 5, }, | |
130 | { .type_class = RCU_JA_LINEAR, .min_child = 4, .max_child = ja_type_3_max_child, .max_linear_child = ja_type_3_max_linear_child, .order = 6, }, | |
131 | { .type_class = RCU_JA_LINEAR, .min_child = 10, .max_child = ja_type_4_max_child, .max_linear_child = ja_type_4_max_linear_child, .order = 7, }, | |
e5227865 | 132 | |
fd800776 | 133 | /* Pools may fill sooner than max_child */ |
8e519e3c MD |
134 | { .type_class = RCU_JA_POOL, .min_child = 20, .max_child = ja_type_5_max_child, .max_linear_child = ja_type_5_max_linear_child, .order = 8, .nr_pool_order = ja_type_5_nr_pool_order, .pool_size_order = 7, }, |
135 | { .type_class = RCU_JA_POOL, .min_child = 45, .max_child = ja_type_6_max_child, .max_linear_child = ja_type_6_max_linear_child, .order = 9, .nr_pool_order = ja_type_6_nr_pool_order, .pool_size_order = 7, }, | |
3d45251f MD |
136 | |
137 | /* | |
138 | * TODO: Upon node removal below min_child, if child pool is | |
139 | * filled beyond capacity, we need to roll back to pigeon. | |
140 | */ | |
1db4943c | 141 | { .type_class = RCU_JA_PIGEON, .min_child = 89, .max_child = ja_type_7_max_child, .order = 10, }, |
e1db2db5 MD |
142 | |
143 | { .type_class = RCU_JA_NULL, .min_child = 0, .max_child = ja_type_8_max_child, }, | |
d68c6810 | 144 | }; |
d68c6810 MD |
145 | #else /* !(CAA_BITS_PER_LONG < 64) */ |
146 | /* 64-bit pointers */ | |
1db4943c MD |
147 | enum { |
148 | ja_type_0_max_child = 1, | |
149 | ja_type_1_max_child = 3, | |
150 | ja_type_2_max_child = 7, | |
151 | ja_type_3_max_child = 14, | |
152 | ja_type_4_max_child = 28, | |
153 | ja_type_5_max_child = 54, | |
154 | ja_type_6_max_child = 104, | |
155 | ja_type_7_max_child = 256, | |
e1db2db5 | 156 | ja_type_8_max_child = 256, |
1db4943c MD |
157 | }; |
158 | ||
8e519e3c MD |
159 | enum { |
160 | ja_type_0_max_linear_child = 1, | |
161 | ja_type_1_max_linear_child = 3, | |
162 | ja_type_2_max_linear_child = 7, | |
163 | ja_type_3_max_linear_child = 14, | |
164 | ja_type_4_max_linear_child = 28, | |
165 | ja_type_5_max_linear_child = 27, | |
166 | ja_type_6_max_linear_child = 26, | |
167 | }; | |
168 | ||
1db4943c MD |
169 | enum { |
170 | ja_type_5_nr_pool_order = 1, | |
171 | ja_type_6_nr_pool_order = 2, | |
172 | }; | |
173 | ||
d68c6810 | 174 | const struct rcu_ja_type ja_types[] = { |
8e519e3c MD |
175 | { .type_class = RCU_JA_LINEAR, .min_child = 1, .max_child = ja_type_0_max_child, .max_linear_child = ja_type_0_max_linear_child, .order = 4, }, |
176 | { .type_class = RCU_JA_LINEAR, .min_child = 1, .max_child = ja_type_1_max_child, .max_linear_child = ja_type_1_max_linear_child, .order = 5, }, | |
177 | { .type_class = RCU_JA_LINEAR, .min_child = 3, .max_child = ja_type_2_max_child, .max_linear_child = ja_type_2_max_linear_child, .order = 6, }, | |
178 | { .type_class = RCU_JA_LINEAR, .min_child = 5, .max_child = ja_type_3_max_child, .max_linear_child = ja_type_3_max_linear_child, .order = 7, }, | |
179 | { .type_class = RCU_JA_LINEAR, .min_child = 10, .max_child = ja_type_4_max_child, .max_linear_child = ja_type_4_max_linear_child, .order = 8, }, | |
e5227865 | 180 | |
3d45251f | 181 | /* Pools may fill sooner than max_child. */ |
8e519e3c MD |
182 | { .type_class = RCU_JA_POOL, .min_child = 22, .max_child = ja_type_5_max_child, .max_linear_child = ja_type_5_max_linear_child, .order = 9, .nr_pool_order = ja_type_5_nr_pool_order, .pool_size_order = 8, }, |
183 | { .type_class = RCU_JA_POOL, .min_child = 51, .max_child = ja_type_6_max_child, .max_linear_child = ja_type_6_max_linear_child, .order = 10, .nr_pool_order = ja_type_6_nr_pool_order, .pool_size_order = 8, }, | |
e5227865 | 184 | |
3d45251f MD |
185 | /* |
186 | * TODO: Upon node removal below min_child, if child pool is | |
187 | * filled beyond capacity, we need to roll back to pigeon. | |
188 | */ | |
1db4943c | 189 | { .type_class = RCU_JA_PIGEON, .min_child = 101, .max_child = ja_type_7_max_child, .order = 11, }, |
e1db2db5 MD |
190 | |
191 | { .type_class = RCU_JA_NULL, .min_child = 0, .max_child = ja_type_8_max_child, }, | |
e5227865 | 192 | }; |
d68c6810 | 193 | #endif /* !(BITS_PER_LONG < 64) */ |
e5227865 | 194 | |
1db4943c MD |
195 | static inline __attribute__((unused)) |
196 | void static_array_size_check(void) | |
197 | { | |
e1db2db5 | 198 | CAA_BUILD_BUG_ON(CAA_ARRAY_SIZE(ja_types) < JA_TYPE_MAX_NR); |
1db4943c MD |
199 | } |
200 | ||
e5227865 | 201 | /* |
1db4943c MD |
202 | * The rcu_ja_node contains the compressed node data needed for |
203 | * read-side. For linear and pool node configurations, it starts with a | |
204 | * byte counting the number of children in the node. Then, the | |
205 | * node-specific data is placed. | |
206 | * The node mutex, if any is needed, protecting concurrent updated of | |
207 | * each node is placed in a separate hash table indexed by node address. | |
208 | * For the pigeon configuration, the number of children is also kept in | |
209 | * a separate hash table, indexed by node address, because it is only | |
210 | * required for updates. | |
e5227865 | 211 | */ |
1db4943c | 212 | |
ff38c745 MD |
213 | #define DECLARE_LINEAR_NODE(index) \ |
214 | struct { \ | |
215 | uint8_t nr_child; \ | |
216 | uint8_t child_value[ja_type_## index ##_max_linear_child]; \ | |
217 | struct rcu_ja_node_flag *child_ptr[ja_type_## index ##_max_linear_child]; \ | |
218 | } | |
219 | ||
220 | #define DECLARE_POOL_NODE(index) \ | |
221 | struct { \ | |
222 | struct { \ | |
223 | uint8_t nr_child; \ | |
224 | uint8_t child_value[ja_type_## index ##_max_linear_child]; \ | |
225 | struct rcu_ja_node_flag *child_ptr[ja_type_## index ##_max_linear_child]; \ | |
226 | } linear[1U << ja_type_## index ##_nr_pool_order]; \ | |
227 | } | |
1db4943c | 228 | |
e5227865 | 229 | struct rcu_ja_node { |
1db4943c MD |
230 | union { |
231 | /* Linear configuration */ | |
232 | DECLARE_LINEAR_NODE(0) conf_0; | |
233 | DECLARE_LINEAR_NODE(1) conf_1; | |
234 | DECLARE_LINEAR_NODE(2) conf_2; | |
235 | DECLARE_LINEAR_NODE(3) conf_3; | |
236 | DECLARE_LINEAR_NODE(4) conf_4; | |
237 | ||
238 | /* Pool configuration */ | |
239 | DECLARE_POOL_NODE(5) conf_5; | |
240 | DECLARE_POOL_NODE(6) conf_6; | |
241 | ||
242 | /* Pigeon configuration */ | |
243 | struct { | |
244 | struct rcu_ja_node_flag *child[ja_type_7_max_child]; | |
245 | } conf_7; | |
246 | /* data aliasing nodes for computed accesses */ | |
247 | uint8_t data[sizeof(struct rcu_ja_node_flag *) * ja_type_7_max_child]; | |
248 | } u; | |
e5227865 MD |
249 | }; |
250 | ||
d68c6810 | 251 | static |
8e519e3c MD |
252 | struct rcu_ja_node_flag *ja_node_flag(struct rcu_ja_node *node, |
253 | unsigned int type) | |
d68c6810 | 254 | { |
1db4943c | 255 | assert(type < RCU_JA_NR_TYPES); |
d68c6810 MD |
256 | return (struct rcu_ja_node_flag *) (((unsigned long) node) | type); |
257 | } | |
258 | ||
e1db2db5 MD |
259 | static |
260 | struct rcu_ja_node *ja_node_ptr(struct rcu_ja_node_flag *node) | |
261 | { | |
262 | return (struct rcu_ja_node *) (((unsigned long) node) | JA_PTR_MASK); | |
263 | } | |
264 | ||
d68c6810 MD |
265 | static |
266 | unsigned int ja_node_type(struct rcu_ja_node_flag *node) | |
267 | { | |
268 | unsigned int type; | |
269 | ||
e1db2db5 MD |
270 | if (ja_node_ptr(node) == NULL) { |
271 | return NODE_INDEX_NULL; | |
272 | } | |
d68c6810 | 273 | type = (unsigned int) ((unsigned long) node & JA_TYPE_MASK); |
1db4943c | 274 | assert(type < RCU_JA_NR_TYPES); |
d68c6810 MD |
275 | return type; |
276 | } | |
277 | ||
7a0b2331 | 278 | struct rcu_ja_node *alloc_rcu_ja_node(const struct rcu_ja_type *ja_type) |
e5227865 | 279 | { |
1db4943c | 280 | return calloc(1U << ja_type->order, sizeof(char)); |
e5227865 MD |
281 | } |
282 | ||
283 | void free_rcu_ja_node(struct rcu_ja_node *node) | |
284 | { | |
285 | free(node); | |
286 | } | |
287 | ||
d68c6810 MD |
288 | #define __JA_ALIGN_MASK(v, mask) (((v) + (mask)) & ~(mask)) |
289 | #define JA_ALIGN(v, align) __JA_ALIGN_MASK(v, (typeof(v)) (align) - 1) | |
290 | #define __JA_FLOOR_MASK(v, mask) ((v) & ~(mask)) | |
291 | #define JA_FLOOR(v, align) __JA_FLOOR_MASK(v, (typeof(v)) (align) - 1) | |
292 | ||
293 | static | |
1db4943c | 294 | uint8_t *align_ptr_size(uint8_t *ptr) |
d68c6810 | 295 | { |
1db4943c | 296 | return (uint8_t *) JA_ALIGN((unsigned long) ptr, sizeof(void *)); |
d68c6810 MD |
297 | } |
298 | ||
13a7f5a6 MD |
299 | /* |
300 | * The order in which values and pointers are does does not matter: if | |
301 | * a value is missing, we return NULL. If a value is there, but its | |
302 | * associated pointers is still NULL, we return NULL too. | |
303 | */ | |
d68c6810 MD |
304 | static |
305 | struct rcu_ja_node_flag *ja_linear_node_get_nth(const struct rcu_ja_type *type, | |
8e519e3c MD |
306 | struct rcu_ja_node *node, |
307 | uint8_t n) | |
d68c6810 MD |
308 | { |
309 | uint8_t nr_child; | |
310 | uint8_t *values; | |
1db4943c | 311 | struct rcu_ja_node_flag **pointers; |
d68c6810 MD |
312 | struct rcu_ja_node_flag *ptr; |
313 | unsigned int i; | |
314 | ||
8e519e3c | 315 | assert(type->type_class == RCU_JA_LINEAR || type->type_class == RCU_JA_POOL); |
d68c6810 | 316 | |
13a7f5a6 MD |
317 | nr_child = CMM_LOAD_SHARED(node->u.data[0]); |
318 | cmm_smp_rmb(); /* read nr_child before values and pointers */ | |
8e519e3c MD |
319 | assert(nr_child <= type->max_linear_child); |
320 | assert(type->type_class != RCU_JA_LINEAR || nr_child >= type->min_child); | |
d68c6810 | 321 | |
1db4943c | 322 | values = &node->u.data[1]; |
d68c6810 | 323 | for (i = 0; i < nr_child; i++) { |
13a7f5a6 | 324 | if (CMM_LOAD_SHARED(values[i]) == n) |
d68c6810 MD |
325 | break; |
326 | } | |
327 | if (i >= nr_child) | |
328 | return NULL; | |
8e519e3c | 329 | pointers = (struct rcu_ja_node_flag **) align_ptr_size(&values[type->max_linear_child]); |
13a7f5a6 | 330 | ptr = rcu_dereference(pointers[i]); |
d68c6810 MD |
331 | assert(ja_node_ptr(ptr) != NULL); |
332 | return ptr; | |
333 | } | |
334 | ||
d68c6810 | 335 | static |
fd800776 | 336 | struct rcu_ja_node_flag *ja_pool_node_get_nth(const struct rcu_ja_type *type, |
8e519e3c MD |
337 | struct rcu_ja_node *node, |
338 | uint8_t n) | |
d68c6810 | 339 | { |
fd800776 | 340 | struct rcu_ja_node *linear; |
d68c6810 | 341 | |
fd800776 | 342 | assert(type->type_class == RCU_JA_POOL); |
e1db2db5 MD |
343 | /* |
344 | * TODO: currently, we select the pool by highest bits. We | |
345 | * should support various encodings. | |
346 | */ | |
fd800776 | 347 | linear = (struct rcu_ja_node *) |
1db4943c | 348 | &node->u.data[((unsigned long) n >> (CHAR_BIT - type->nr_pool_order)) << type->pool_size_order]; |
8e519e3c | 349 | return ja_linear_node_get_nth(type, linear, n); |
d68c6810 MD |
350 | } |
351 | ||
352 | static | |
353 | struct rcu_ja_node_flag *ja_pigeon_node_get_nth(const struct rcu_ja_type *type, | |
8e519e3c MD |
354 | struct rcu_ja_node *node, |
355 | uint8_t n) | |
d68c6810 MD |
356 | { |
357 | assert(type->type_class == RCU_JA_PIGEON); | |
13a7f5a6 | 358 | return rcu_dereference(((struct rcu_ja_node_flag **) node->u.data)[n]); |
d68c6810 MD |
359 | } |
360 | ||
13a7f5a6 MD |
361 | /* |
362 | * ja_node_get_nth: get nth item from a node. | |
363 | * node_flag is already rcu_dereference'd. | |
364 | */ | |
d68c6810 MD |
365 | static |
366 | struct rcu_ja_node_flag *ja_node_get_nth(struct rcu_ja_node_flag *node_flag, | |
8e519e3c | 367 | uint8_t n) |
d68c6810 MD |
368 | { |
369 | unsigned int type_index; | |
370 | struct rcu_ja_node *node; | |
371 | const struct rcu_ja_type *type; | |
372 | ||
d68c6810 MD |
373 | node = ja_node_ptr(node_flag); |
374 | assert(node != NULL); | |
375 | type_index = ja_node_type(node_flag); | |
376 | type = &ja_types[type_index]; | |
377 | ||
378 | switch (type->type_class) { | |
379 | case RCU_JA_LINEAR: | |
380 | return ja_linear_node_get_nth(type, node, n); | |
fd800776 MD |
381 | case RCU_JA_POOL: |
382 | return ja_pool_node_get_nth(type, node, n); | |
d68c6810 MD |
383 | case RCU_JA_PIGEON: |
384 | return ja_pigeon_node_get_nth(type, node, n); | |
385 | default: | |
386 | assert(0); | |
387 | return (void *) -1UL; | |
388 | } | |
389 | } | |
390 | ||
e1db2db5 MD |
391 | static |
392 | unsigned int ja_get_nr_child(struct rcu_ja_shadow_node *shadow_node) | |
393 | { | |
394 | return shadow_node->nr_child; | |
395 | } | |
396 | ||
8e519e3c MD |
397 | static |
398 | int ja_linear_node_set_nth(const struct rcu_ja_type *type, | |
399 | struct rcu_ja_node *node, | |
e1db2db5 | 400 | struct rcu_ja_shadow_node *shadow_node, |
8e519e3c MD |
401 | uint8_t n, |
402 | struct rcu_ja_node_flag *child_node_flag) | |
403 | { | |
404 | uint8_t nr_child; | |
405 | uint8_t *values, *nr_child_ptr; | |
406 | struct rcu_ja_node_flag **pointers; | |
407 | unsigned int i; | |
408 | ||
409 | assert(type->type_class == RCU_JA_LINEAR || type->type_class == RCU_JA_POOL); | |
410 | ||
411 | nr_child_ptr = &node->u.data[0]; | |
412 | nr_child = *nr_child_ptr; | |
413 | assert(nr_child <= type->max_linear_child); | |
414 | assert(type->type_class != RCU_JA_LINEAR || nr_child >= type->min_child); | |
415 | ||
416 | values = &node->u.data[1]; | |
417 | for (i = 0; i < nr_child; i++) { | |
418 | if (values[i] == n) | |
419 | return -EEXIST; | |
420 | } | |
421 | if (nr_child >= type->max_linear_child) { | |
422 | /* No space left in this node type */ | |
423 | return -ENOSPC; | |
424 | } | |
425 | pointers = (struct rcu_ja_node_flag **) align_ptr_size(&values[type->max_linear_child]); | |
13a7f5a6 MD |
426 | assert(pointers[nr_child] == NULL); |
427 | rcu_assign_pointer(pointers[nr_child], child_node_flag); | |
428 | CMM_STORE_SHARED(values[nr_child], n); | |
429 | cmm_smp_wmb(); /* write value and pointer before nr_child */ | |
430 | CMM_STORE_SHARED(*nr_child_ptr, nr_child + 1); | |
e1db2db5 | 431 | shadow_node->nr_child++; |
8e519e3c MD |
432 | return 0; |
433 | } | |
434 | ||
435 | static | |
436 | int ja_pool_node_set_nth(const struct rcu_ja_type *type, | |
437 | struct rcu_ja_node *node, | |
e1db2db5 | 438 | struct rcu_ja_shadow_node *shadow_node, |
8e519e3c MD |
439 | uint8_t n, |
440 | struct rcu_ja_node_flag *child_node_flag) | |
441 | { | |
442 | struct rcu_ja_node *linear; | |
443 | ||
444 | assert(type->type_class == RCU_JA_POOL); | |
445 | linear = (struct rcu_ja_node *) | |
446 | &node->u.data[((unsigned long) n >> (CHAR_BIT - type->nr_pool_order)) << type->pool_size_order]; | |
e1db2db5 MD |
447 | return ja_linear_node_set_nth(type, linear, shadow_node, |
448 | n, child_node_flag); | |
8e519e3c MD |
449 | } |
450 | ||
451 | static | |
452 | int ja_pigeon_node_set_nth(const struct rcu_ja_type *type, | |
453 | struct rcu_ja_node *node, | |
e1db2db5 | 454 | struct rcu_ja_shadow_node *shadow_node, |
8e519e3c MD |
455 | uint8_t n, |
456 | struct rcu_ja_node_flag *child_node_flag) | |
457 | { | |
458 | struct rcu_ja_node_flag **ptr; | |
459 | ||
460 | assert(type->type_class == RCU_JA_PIGEON); | |
461 | ptr = &((struct rcu_ja_node_flag **) node->u.data)[n]; | |
462 | if (*ptr != NULL) | |
463 | return -EEXIST; | |
464 | rcu_assign_pointer(*ptr, child_node_flag); | |
e1db2db5 | 465 | shadow_node->nr_child++; |
8e519e3c MD |
466 | return 0; |
467 | } | |
468 | ||
d68c6810 | 469 | /* |
7a0b2331 | 470 | * _ja_node_set_nth: set nth item within a node. Return an error |
8e519e3c MD |
471 | * (negative error value) if it is already there. |
472 | * TODO: exclusive access on node. | |
d68c6810 | 473 | */ |
8e519e3c | 474 | static |
e1db2db5 MD |
475 | int _ja_node_set_nth(const struct rcu_ja_type *type, |
476 | struct rcu_ja_node *node, | |
477 | struct rcu_ja_shadow_node *shadow_node, | |
478 | uint8_t n, | |
8e519e3c MD |
479 | struct rcu_ja_node_flag *child_node_flag) |
480 | { | |
8e519e3c MD |
481 | switch (type->type_class) { |
482 | case RCU_JA_LINEAR: | |
e1db2db5 | 483 | return ja_linear_node_set_nth(type, node, shadow_node, n, |
8e519e3c MD |
484 | child_node_flag); |
485 | case RCU_JA_POOL: | |
e1db2db5 | 486 | return ja_pool_node_set_nth(type, node, shadow_node, n, |
8e519e3c MD |
487 | child_node_flag); |
488 | case RCU_JA_PIGEON: | |
e1db2db5 | 489 | return ja_pigeon_node_set_nth(type, node, shadow_node, n, |
8e519e3c | 490 | child_node_flag); |
e1db2db5 MD |
491 | case RCU_JA_NULL: |
492 | return -ENOSPC; | |
8e519e3c MD |
493 | default: |
494 | assert(0); | |
495 | return -EINVAL; | |
496 | } | |
497 | ||
498 | return 0; | |
499 | } | |
7a0b2331 MD |
500 | |
501 | /* | |
502 | * ja_node_recompact_add: recompact a node, adding a new child. | |
e1db2db5 | 503 | * TODO: for pool type, take selection bit(s) into account. |
7a0b2331 MD |
504 | */ |
505 | static | |
e1db2db5 MD |
506 | int ja_node_recompact_add(struct rcu_ja *ja, |
507 | unsigned int old_type_index, | |
508 | const struct rcu_ja_type *old_type, | |
509 | struct rcu_ja_node *old_node, | |
510 | struct rcu_ja_shadow_node **shadow_node, | |
511 | struct rcu_ja_node_flag **old_node_flag, uint8_t n, | |
7a0b2331 | 512 | struct rcu_ja_node_flag *child_node_flag) |
7a0b2331 | 513 | { |
e1db2db5 MD |
514 | unsigned int new_type_index; |
515 | struct rcu_ja_node *new_node; | |
516 | const struct rcu_ja_type *new_type; | |
7a0b2331 MD |
517 | struct rcu_ja_node_flag *new_node_flag; |
518 | unsigned int i; | |
519 | int ret; | |
520 | ||
e1db2db5 | 521 | if (*shadow_node == NULL) { |
7a0b2331 MD |
522 | new_type_index = 0; |
523 | } else { | |
7a0b2331 MD |
524 | new_type_index = old_type_index + 1; |
525 | } | |
526 | new_type = &ja_types[new_type_index]; | |
527 | new_node = alloc_rcu_ja_node(new_type); | |
528 | if (!new_node) | |
529 | return -ENOMEM; | |
530 | new_node_flag = ja_node_flag(new_node, new_type_index); | |
531 | ||
e1db2db5 MD |
532 | ret = rcuja_shadow_set(ja->ht, new_node, *shadow_node); |
533 | if (ret) | |
534 | return ret; | |
535 | ||
536 | if (*shadow_node == NULL) { | |
537 | *shadow_node = rcuja_shadow_lookup_lock(ja->ht, new_node); | |
538 | assert(*shadow_node); | |
539 | } | |
540 | ||
541 | (*shadow_node)->nr_child = 0; | |
7a0b2331 MD |
542 | for (i = 0; i < old_type->max_child; i++) { |
543 | struct rcu_ja_node_flag *iter; | |
544 | ||
545 | iter = ja_node_get_nth(*old_node_flag, i); | |
546 | if (!iter) | |
547 | continue; | |
e1db2db5 MD |
548 | ret = _ja_node_set_nth(new_type, new_node, *shadow_node, |
549 | i, iter); | |
7a0b2331 MD |
550 | assert(!ret); |
551 | } | |
552 | /* add node */ | |
e1db2db5 MD |
553 | ret = _ja_node_set_nth(new_type, new_node, *shadow_node, |
554 | n, child_node_flag); | |
7a0b2331 | 555 | assert(!ret); |
8eba1a4b MD |
556 | /* Replace the old node with the new recompacted one */ |
557 | rcu_assign_pointer(*old_node_flag, new_node_flag); | |
e1db2db5 MD |
558 | ret = rcuja_shadow_clear(ja->ht, old_node, |
559 | RCUJA_SHADOW_CLEAR_FREE_NODE); | |
560 | assert(!ret); | |
7a0b2331 MD |
561 | return 0; |
562 | } | |
563 | ||
564 | static | |
e1db2db5 MD |
565 | int ja_node_set_nth(struct rcu_ja *ja, |
566 | struct rcu_ja_node_flag **node_flag, uint8_t n, | |
7a0b2331 MD |
567 | struct rcu_ja_node_flag *child_node_flag) |
568 | { | |
569 | int ret; | |
e1db2db5 MD |
570 | unsigned int type_index; |
571 | const struct rcu_ja_type *type; | |
572 | struct rcu_ja_node *node; | |
573 | struct rcu_ja_shadow_node *shadow_node = NULL; | |
7a0b2331 | 574 | |
e1db2db5 MD |
575 | node = ja_node_ptr(*node_flag); |
576 | type_index = ja_node_type(*node_flag); | |
577 | type = &ja_types[type_index]; | |
578 | if (node != NULL) { | |
579 | shadow_node = rcuja_shadow_lookup_lock(ja->ht, node); | |
580 | assert(shadow_node); | |
581 | } | |
582 | ret = _ja_node_set_nth(type, node, shadow_node, | |
583 | n, child_node_flag); | |
7a0b2331 | 584 | if (ret == -ENOSPC) { |
e1db2db5 MD |
585 | /* Not enough space in node, need to recompact. */ |
586 | ret = ja_node_recompact_add(ja, type_index, type, node, | |
587 | &shadow_node, node_flag, n, child_node_flag); | |
588 | /* recompact always leave shadow_node locked */ | |
7a0b2331 | 589 | } |
e1db2db5 | 590 | rcuja_shadow_unlock(shadow_node); |
7a0b2331 MD |
591 | return ret; |
592 | } |