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1// SPDX-License-Identifier: GPL-2.0
2//
3// Register cache access API - rbtree caching support
4//
5// Copyright 2011 Wolfson Microelectronics plc
6//
7// Author: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
8
9#include <linux/debugfs.h>
10#include <linux/device.h>
11#include <linux/rbtree.h>
12#include <linux/seq_file.h>
13#include <linux/slab.h>
14
15#include "internal.h"
16
17static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
18 unsigned int value);
19static int regcache_rbtree_exit(struct regmap *map);
20
21struct regcache_rbtree_node {
22 /* block of adjacent registers */
23 void *block;
24 /* Which registers are present */
25 unsigned long *cache_present;
26 /* base register handled by this block */
27 unsigned int base_reg;
28 /* number of registers available in the block */
29 unsigned int blklen;
30 /* the actual rbtree node holding this block */
31 struct rb_node node;
32};
33
34struct regcache_rbtree_ctx {
35 struct rb_root root;
36 struct regcache_rbtree_node *cached_rbnode;
37};
38
39static inline void regcache_rbtree_get_base_top_reg(
40 struct regmap *map,
41 struct regcache_rbtree_node *rbnode,
42 unsigned int *base, unsigned int *top)
43{
44 *base = rbnode->base_reg;
45 *top = rbnode->base_reg + ((rbnode->blklen - 1) * map->reg_stride);
46}
47
48static unsigned int regcache_rbtree_get_register(struct regmap *map,
49 struct regcache_rbtree_node *rbnode, unsigned int idx)
50{
51 return regcache_get_val(map, rbnode->block, idx);
52}
53
54static void regcache_rbtree_set_register(struct regmap *map,
55 struct regcache_rbtree_node *rbnode,
56 unsigned int idx, unsigned int val)
57{
58 set_bit(idx, rbnode->cache_present);
59 regcache_set_val(map, rbnode->block, idx, val);
60}
61
62static struct regcache_rbtree_node *regcache_rbtree_lookup(struct regmap *map,
63 unsigned int reg)
64{
65 struct regcache_rbtree_ctx *rbtree_ctx = map->cache;
66 struct rb_node *node;
67 struct regcache_rbtree_node *rbnode;
68 unsigned int base_reg, top_reg;
69
70 rbnode = rbtree_ctx->cached_rbnode;
71 if (rbnode) {
72 regcache_rbtree_get_base_top_reg(map, rbnode, &base_reg,
73 &top_reg);
74 if (reg >= base_reg && reg <= top_reg)
75 return rbnode;
76 }
77
78 node = rbtree_ctx->root.rb_node;
79 while (node) {
80 rbnode = rb_entry(node, struct regcache_rbtree_node, node);
81 regcache_rbtree_get_base_top_reg(map, rbnode, &base_reg,
82 &top_reg);
83 if (reg >= base_reg && reg <= top_reg) {
84 rbtree_ctx->cached_rbnode = rbnode;
85 return rbnode;
86 } else if (reg > top_reg) {
87 node = node->rb_right;
88 } else if (reg < base_reg) {
89 node = node->rb_left;
90 }
91 }
92
93 return NULL;
94}
95
96static int regcache_rbtree_insert(struct regmap *map, struct rb_root *root,
97 struct regcache_rbtree_node *rbnode)
98{
99 struct rb_node **new, *parent;
100 struct regcache_rbtree_node *rbnode_tmp;
101 unsigned int base_reg_tmp, top_reg_tmp;
102 unsigned int base_reg;
103
104 parent = NULL;
105 new = &root->rb_node;
106 while (*new) {
107 rbnode_tmp = rb_entry(*new, struct regcache_rbtree_node, node);
108 /* base and top registers of the current rbnode */
109 regcache_rbtree_get_base_top_reg(map, rbnode_tmp, &base_reg_tmp,
110 &top_reg_tmp);
111 /* base register of the rbnode to be added */
112 base_reg = rbnode->base_reg;
113 parent = *new;
114 /* if this register has already been inserted, just return */
115 if (base_reg >= base_reg_tmp &&
116 base_reg <= top_reg_tmp)
117 return 0;
118 else if (base_reg > top_reg_tmp)
119 new = &((*new)->rb_right);
120 else if (base_reg < base_reg_tmp)
121 new = &((*new)->rb_left);
122 }
123
124 /* insert the node into the rbtree */
125 rb_link_node(&rbnode->node, parent, new);
126 rb_insert_color(&rbnode->node, root);
127
128 return 1;
129}
130
131#ifdef CONFIG_DEBUG_FS
132static int rbtree_show(struct seq_file *s, void *ignored)
133{
134 struct regmap *map = s->private;
135 struct regcache_rbtree_ctx *rbtree_ctx = map->cache;
136 struct regcache_rbtree_node *n;
137 struct rb_node *node;
138 unsigned int base, top;
139 size_t mem_size;
140 int nodes = 0;
141 int registers = 0;
142 int this_registers, average;
143
144 map->lock(map->lock_arg);
145
146 mem_size = sizeof(*rbtree_ctx);
147
148 for (node = rb_first(&rbtree_ctx->root); node != NULL;
149 node = rb_next(node)) {
150 n = rb_entry(node, struct regcache_rbtree_node, node);
151 mem_size += sizeof(*n);
152 mem_size += (n->blklen * map->cache_word_size);
153 mem_size += BITS_TO_LONGS(n->blklen) * sizeof(long);
154
155 regcache_rbtree_get_base_top_reg(map, n, &base, &top);
156 this_registers = ((top - base) / map->reg_stride) + 1;
157 seq_printf(s, "%x-%x (%d)\n", base, top, this_registers);
158
159 nodes++;
160 registers += this_registers;
161 }
162
163 if (nodes)
164 average = registers / nodes;
165 else
166 average = 0;
167
168 seq_printf(s, "%d nodes, %d registers, average %d registers, used %zu bytes\n",
169 nodes, registers, average, mem_size);
170
171 map->unlock(map->lock_arg);
172
173 return 0;
174}
175
176DEFINE_SHOW_ATTRIBUTE(rbtree);
177
178static void rbtree_debugfs_init(struct regmap *map)
179{
180 debugfs_create_file("rbtree", 0400, map->debugfs, map, &rbtree_fops);
181}
182#endif
183
184static int regcache_rbtree_init(struct regmap *map)
185{
186 struct regcache_rbtree_ctx *rbtree_ctx;
187 int i;
188 int ret;
189
190 map->cache = kmalloc(sizeof *rbtree_ctx, GFP_KERNEL);
191 if (!map->cache)
192 return -ENOMEM;
193
194 rbtree_ctx = map->cache;
195 rbtree_ctx->root = RB_ROOT;
196 rbtree_ctx->cached_rbnode = NULL;
197
198 for (i = 0; i < map->num_reg_defaults; i++) {
199 ret = regcache_rbtree_write(map,
200 map->reg_defaults[i].reg,
201 map->reg_defaults[i].def);
202 if (ret)
203 goto err;
204 }
205
206 return 0;
207
208err:
209 regcache_rbtree_exit(map);
210 return ret;
211}
212
213static int regcache_rbtree_exit(struct regmap *map)
214{
215 struct rb_node *next;
216 struct regcache_rbtree_ctx *rbtree_ctx;
217 struct regcache_rbtree_node *rbtree_node;
218
219 /* if we've already been called then just return */
220 rbtree_ctx = map->cache;
221 if (!rbtree_ctx)
222 return 0;
223
224 /* free up the rbtree */
225 next = rb_first(&rbtree_ctx->root);
226 while (next) {
227 rbtree_node = rb_entry(next, struct regcache_rbtree_node, node);
228 next = rb_next(&rbtree_node->node);
229 rb_erase(&rbtree_node->node, &rbtree_ctx->root);
230 kfree(rbtree_node->cache_present);
231 kfree(rbtree_node->block);
232 kfree(rbtree_node);
233 }
234
235 /* release the resources */
236 kfree(map->cache);
237 map->cache = NULL;
238
239 return 0;
240}
241
242static int regcache_rbtree_read(struct regmap *map,
243 unsigned int reg, unsigned int *value)
244{
245 struct regcache_rbtree_node *rbnode;
246 unsigned int reg_tmp;
247
248 rbnode = regcache_rbtree_lookup(map, reg);
249 if (rbnode) {
250 reg_tmp = (reg - rbnode->base_reg) / map->reg_stride;
251 if (!test_bit(reg_tmp, rbnode->cache_present))
252 return -ENOENT;
253 *value = regcache_rbtree_get_register(map, rbnode, reg_tmp);
254 } else {
255 return -ENOENT;
256 }
257
258 return 0;
259}
260
261
262static int regcache_rbtree_insert_to_block(struct regmap *map,
263 struct regcache_rbtree_node *rbnode,
264 unsigned int base_reg,
265 unsigned int top_reg,
266 unsigned int reg,
267 unsigned int value)
268{
269 unsigned int blklen;
270 unsigned int pos, offset;
271 unsigned long *present;
272 u8 *blk;
273
274 blklen = (top_reg - base_reg) / map->reg_stride + 1;
275 pos = (reg - base_reg) / map->reg_stride;
276 offset = (rbnode->base_reg - base_reg) / map->reg_stride;
277
278 blk = krealloc(rbnode->block,
279 blklen * map->cache_word_size,
280 map->alloc_flags);
281 if (!blk)
282 return -ENOMEM;
283
284 rbnode->block = blk;
285
286 if (BITS_TO_LONGS(blklen) > BITS_TO_LONGS(rbnode->blklen)) {
287 present = krealloc(rbnode->cache_present,
288 BITS_TO_LONGS(blklen) * sizeof(*present),
289 map->alloc_flags);
290 if (!present)
291 return -ENOMEM;
292
293 memset(present + BITS_TO_LONGS(rbnode->blklen), 0,
294 (BITS_TO_LONGS(blklen) - BITS_TO_LONGS(rbnode->blklen))
295 * sizeof(*present));
296 } else {
297 present = rbnode->cache_present;
298 }
299
300 /* insert the register value in the correct place in the rbnode block */
301 if (pos == 0) {
302 memmove(blk + offset * map->cache_word_size,
303 blk, rbnode->blklen * map->cache_word_size);
304 bitmap_shift_left(present, present, offset, blklen);
305 }
306
307 /* update the rbnode block, its size and the base register */
308 rbnode->blklen = blklen;
309 rbnode->base_reg = base_reg;
310 rbnode->cache_present = present;
311
312 regcache_rbtree_set_register(map, rbnode, pos, value);
313 return 0;
314}
315
316static struct regcache_rbtree_node *
317regcache_rbtree_node_alloc(struct regmap *map, unsigned int reg)
318{
319 struct regcache_rbtree_node *rbnode;
320 const struct regmap_range *range;
321 int i;
322
323 rbnode = kzalloc(sizeof(*rbnode), map->alloc_flags);
324 if (!rbnode)
325 return NULL;
326
327 /* If there is a read table then use it to guess at an allocation */
328 if (map->rd_table) {
329 for (i = 0; i < map->rd_table->n_yes_ranges; i++) {
330 if (regmap_reg_in_range(reg,
331 &map->rd_table->yes_ranges[i]))
332 break;
333 }
334
335 if (i != map->rd_table->n_yes_ranges) {
336 range = &map->rd_table->yes_ranges[i];
337 rbnode->blklen = (range->range_max - range->range_min) /
338 map->reg_stride + 1;
339 rbnode->base_reg = range->range_min;
340 }
341 }
342
343 if (!rbnode->blklen) {
344 rbnode->blklen = 1;
345 rbnode->base_reg = reg;
346 }
347
348 rbnode->block = kmalloc_array(rbnode->blklen, map->cache_word_size,
349 map->alloc_flags);
350 if (!rbnode->block)
351 goto err_free;
352
353 rbnode->cache_present = kcalloc(BITS_TO_LONGS(rbnode->blklen),
354 sizeof(*rbnode->cache_present),
355 map->alloc_flags);
356 if (!rbnode->cache_present)
357 goto err_free_block;
358
359 return rbnode;
360
361err_free_block:
362 kfree(rbnode->block);
363err_free:
364 kfree(rbnode);
365 return NULL;
366}
367
368static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
369 unsigned int value)
370{
371 struct regcache_rbtree_ctx *rbtree_ctx;
372 struct regcache_rbtree_node *rbnode, *rbnode_tmp;
373 struct rb_node *node;
374 unsigned int reg_tmp;
375 int ret;
376
377 rbtree_ctx = map->cache;
378
379 /* if we can't locate it in the cached rbnode we'll have
380 * to traverse the rbtree looking for it.
381 */
382 rbnode = regcache_rbtree_lookup(map, reg);
383 if (rbnode) {
384 reg_tmp = (reg - rbnode->base_reg) / map->reg_stride;
385 regcache_rbtree_set_register(map, rbnode, reg_tmp, value);
386 } else {
387 unsigned int base_reg, top_reg;
388 unsigned int new_base_reg, new_top_reg;
389 unsigned int min, max;
390 unsigned int max_dist;
391 unsigned int dist, best_dist = UINT_MAX;
392
393 max_dist = map->reg_stride * sizeof(*rbnode_tmp) /
394 map->cache_word_size;
395 if (reg < max_dist)
396 min = 0;
397 else
398 min = reg - max_dist;
399 max = reg + max_dist;
400
401 /* look for an adjacent register to the one we are about to add */
402 node = rbtree_ctx->root.rb_node;
403 while (node) {
404 rbnode_tmp = rb_entry(node, struct regcache_rbtree_node,
405 node);
406
407 regcache_rbtree_get_base_top_reg(map, rbnode_tmp,
408 &base_reg, &top_reg);
409
410 if (base_reg <= max && top_reg >= min) {
411 if (reg < base_reg)
412 dist = base_reg - reg;
413 else if (reg > top_reg)
414 dist = reg - top_reg;
415 else
416 dist = 0;
417 if (dist < best_dist) {
418 rbnode = rbnode_tmp;
419 best_dist = dist;
420 new_base_reg = min(reg, base_reg);
421 new_top_reg = max(reg, top_reg);
422 }
423 }
424
425 /*
426 * Keep looking, we want to choose the closest block,
427 * otherwise we might end up creating overlapping
428 * blocks, which breaks the rbtree.
429 */
430 if (reg < base_reg)
431 node = node->rb_left;
432 else if (reg > top_reg)
433 node = node->rb_right;
434 else
435 break;
436 }
437
438 if (rbnode) {
439 ret = regcache_rbtree_insert_to_block(map, rbnode,
440 new_base_reg,
441 new_top_reg, reg,
442 value);
443 if (ret)
444 return ret;
445 rbtree_ctx->cached_rbnode = rbnode;
446 return 0;
447 }
448
449 /* We did not manage to find a place to insert it in
450 * an existing block so create a new rbnode.
451 */
452 rbnode = regcache_rbtree_node_alloc(map, reg);
453 if (!rbnode)
454 return -ENOMEM;
455 regcache_rbtree_set_register(map, rbnode,
456 (reg - rbnode->base_reg) / map->reg_stride,
457 value);
458 regcache_rbtree_insert(map, &rbtree_ctx->root, rbnode);
459 rbtree_ctx->cached_rbnode = rbnode;
460 }
461
462 return 0;
463}
464
465static int regcache_rbtree_sync(struct regmap *map, unsigned int min,
466 unsigned int max)
467{
468 struct regcache_rbtree_ctx *rbtree_ctx;
469 struct rb_node *node;
470 struct regcache_rbtree_node *rbnode;
471 unsigned int base_reg, top_reg;
472 unsigned int start, end;
473 int ret;
474
475 map->async = true;
476
477 rbtree_ctx = map->cache;
478 for (node = rb_first(&rbtree_ctx->root); node; node = rb_next(node)) {
479 rbnode = rb_entry(node, struct regcache_rbtree_node, node);
480
481 regcache_rbtree_get_base_top_reg(map, rbnode, &base_reg,
482 &top_reg);
483 if (base_reg > max)
484 break;
485 if (top_reg < min)
486 continue;
487
488 if (min > base_reg)
489 start = (min - base_reg) / map->reg_stride;
490 else
491 start = 0;
492
493 if (max < top_reg)
494 end = (max - base_reg) / map->reg_stride + 1;
495 else
496 end = rbnode->blklen;
497
498 ret = regcache_sync_block(map, rbnode->block,
499 rbnode->cache_present,
500 rbnode->base_reg, start, end);
501 if (ret != 0)
502 return ret;
503 }
504
505 map->async = false;
506
507 return regmap_async_complete(map);
508}
509
510static int regcache_rbtree_drop(struct regmap *map, unsigned int min,
511 unsigned int max)
512{
513 struct regcache_rbtree_ctx *rbtree_ctx;
514 struct regcache_rbtree_node *rbnode;
515 struct rb_node *node;
516 unsigned int base_reg, top_reg;
517 unsigned int start, end;
518
519 rbtree_ctx = map->cache;
520 for (node = rb_first(&rbtree_ctx->root); node; node = rb_next(node)) {
521 rbnode = rb_entry(node, struct regcache_rbtree_node, node);
522
523 regcache_rbtree_get_base_top_reg(map, rbnode, &base_reg,
524 &top_reg);
525 if (base_reg > max)
526 break;
527 if (top_reg < min)
528 continue;
529
530 if (min > base_reg)
531 start = (min - base_reg) / map->reg_stride;
532 else
533 start = 0;
534
535 if (max < top_reg)
536 end = (max - base_reg) / map->reg_stride + 1;
537 else
538 end = rbnode->blklen;
539
540 bitmap_clear(rbnode->cache_present, start, end - start);
541 }
542
543 return 0;
544}
545
546struct regcache_ops regcache_rbtree_ops = {
547 .type = REGCACHE_RBTREE,
548 .name = "rbtree",
549 .init = regcache_rbtree_init,
550 .exit = regcache_rbtree_exit,
551#ifdef CONFIG_DEBUG_FS
552 .debugfs_init = rbtree_debugfs_init,
553#endif
554 .read = regcache_rbtree_read,
555 .write = regcache_rbtree_write,
556 .sync = regcache_rbtree_sync,
557 .drop = regcache_rbtree_drop,
558};
1/*
2 * Register cache access API - rbtree caching support
3 *
4 * Copyright 2011 Wolfson Microelectronics plc
5 *
6 * Author: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#include <linux/slab.h>
14#include <linux/device.h>
15#include <linux/debugfs.h>
16#include <linux/rbtree.h>
17#include <linux/seq_file.h>
18
19#include "internal.h"
20
21static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
22 unsigned int value);
23static int regcache_rbtree_exit(struct regmap *map);
24
25struct regcache_rbtree_node {
26 /* the actual rbtree node holding this block */
27 struct rb_node node;
28 /* base register handled by this block */
29 unsigned int base_reg;
30 /* block of adjacent registers */
31 void *block;
32 /* number of registers available in the block */
33 unsigned int blklen;
34} __attribute__ ((packed));
35
36struct regcache_rbtree_ctx {
37 struct rb_root root;
38 struct regcache_rbtree_node *cached_rbnode;
39};
40
41static inline void regcache_rbtree_get_base_top_reg(
42 struct regmap *map,
43 struct regcache_rbtree_node *rbnode,
44 unsigned int *base, unsigned int *top)
45{
46 *base = rbnode->base_reg;
47 *top = rbnode->base_reg + ((rbnode->blklen - 1) * map->reg_stride);
48}
49
50static unsigned int regcache_rbtree_get_register(
51 struct regcache_rbtree_node *rbnode, unsigned int idx,
52 unsigned int word_size)
53{
54 return regcache_get_val(rbnode->block, idx, word_size);
55}
56
57static void regcache_rbtree_set_register(struct regcache_rbtree_node *rbnode,
58 unsigned int idx, unsigned int val,
59 unsigned int word_size)
60{
61 regcache_set_val(rbnode->block, idx, val, word_size);
62}
63
64static struct regcache_rbtree_node *regcache_rbtree_lookup(struct regmap *map,
65 unsigned int reg)
66{
67 struct regcache_rbtree_ctx *rbtree_ctx = map->cache;
68 struct rb_node *node;
69 struct regcache_rbtree_node *rbnode;
70 unsigned int base_reg, top_reg;
71
72 rbnode = rbtree_ctx->cached_rbnode;
73 if (rbnode) {
74 regcache_rbtree_get_base_top_reg(map, rbnode, &base_reg,
75 &top_reg);
76 if (reg >= base_reg && reg <= top_reg)
77 return rbnode;
78 }
79
80 node = rbtree_ctx->root.rb_node;
81 while (node) {
82 rbnode = container_of(node, struct regcache_rbtree_node, node);
83 regcache_rbtree_get_base_top_reg(map, rbnode, &base_reg,
84 &top_reg);
85 if (reg >= base_reg && reg <= top_reg) {
86 rbtree_ctx->cached_rbnode = rbnode;
87 return rbnode;
88 } else if (reg > top_reg) {
89 node = node->rb_right;
90 } else if (reg < base_reg) {
91 node = node->rb_left;
92 }
93 }
94
95 return NULL;
96}
97
98static int regcache_rbtree_insert(struct regmap *map, struct rb_root *root,
99 struct regcache_rbtree_node *rbnode)
100{
101 struct rb_node **new, *parent;
102 struct regcache_rbtree_node *rbnode_tmp;
103 unsigned int base_reg_tmp, top_reg_tmp;
104 unsigned int base_reg;
105
106 parent = NULL;
107 new = &root->rb_node;
108 while (*new) {
109 rbnode_tmp = container_of(*new, struct regcache_rbtree_node,
110 node);
111 /* base and top registers of the current rbnode */
112 regcache_rbtree_get_base_top_reg(map, rbnode_tmp, &base_reg_tmp,
113 &top_reg_tmp);
114 /* base register of the rbnode to be added */
115 base_reg = rbnode->base_reg;
116 parent = *new;
117 /* if this register has already been inserted, just return */
118 if (base_reg >= base_reg_tmp &&
119 base_reg <= top_reg_tmp)
120 return 0;
121 else if (base_reg > top_reg_tmp)
122 new = &((*new)->rb_right);
123 else if (base_reg < base_reg_tmp)
124 new = &((*new)->rb_left);
125 }
126
127 /* insert the node into the rbtree */
128 rb_link_node(&rbnode->node, parent, new);
129 rb_insert_color(&rbnode->node, root);
130
131 return 1;
132}
133
134#ifdef CONFIG_DEBUG_FS
135static int rbtree_show(struct seq_file *s, void *ignored)
136{
137 struct regmap *map = s->private;
138 struct regcache_rbtree_ctx *rbtree_ctx = map->cache;
139 struct regcache_rbtree_node *n;
140 struct rb_node *node;
141 unsigned int base, top;
142 int nodes = 0;
143 int registers = 0;
144 int this_registers, average;
145
146 map->lock(map);
147
148 for (node = rb_first(&rbtree_ctx->root); node != NULL;
149 node = rb_next(node)) {
150 n = container_of(node, struct regcache_rbtree_node, node);
151
152 regcache_rbtree_get_base_top_reg(map, n, &base, &top);
153 this_registers = ((top - base) / map->reg_stride) + 1;
154 seq_printf(s, "%x-%x (%d)\n", base, top, this_registers);
155
156 nodes++;
157 registers += this_registers;
158 }
159
160 if (nodes)
161 average = registers / nodes;
162 else
163 average = 0;
164
165 seq_printf(s, "%d nodes, %d registers, average %d registers\n",
166 nodes, registers, average);
167
168 map->unlock(map);
169
170 return 0;
171}
172
173static int rbtree_open(struct inode *inode, struct file *file)
174{
175 return single_open(file, rbtree_show, inode->i_private);
176}
177
178static const struct file_operations rbtree_fops = {
179 .open = rbtree_open,
180 .read = seq_read,
181 .llseek = seq_lseek,
182 .release = single_release,
183};
184
185static void rbtree_debugfs_init(struct regmap *map)
186{
187 debugfs_create_file("rbtree", 0400, map->debugfs, map, &rbtree_fops);
188}
189#else
190static void rbtree_debugfs_init(struct regmap *map)
191{
192}
193#endif
194
195static int regcache_rbtree_init(struct regmap *map)
196{
197 struct regcache_rbtree_ctx *rbtree_ctx;
198 int i;
199 int ret;
200
201 map->cache = kmalloc(sizeof *rbtree_ctx, GFP_KERNEL);
202 if (!map->cache)
203 return -ENOMEM;
204
205 rbtree_ctx = map->cache;
206 rbtree_ctx->root = RB_ROOT;
207 rbtree_ctx->cached_rbnode = NULL;
208
209 for (i = 0; i < map->num_reg_defaults; i++) {
210 ret = regcache_rbtree_write(map,
211 map->reg_defaults[i].reg,
212 map->reg_defaults[i].def);
213 if (ret)
214 goto err;
215 }
216
217 rbtree_debugfs_init(map);
218
219 return 0;
220
221err:
222 regcache_rbtree_exit(map);
223 return ret;
224}
225
226static int regcache_rbtree_exit(struct regmap *map)
227{
228 struct rb_node *next;
229 struct regcache_rbtree_ctx *rbtree_ctx;
230 struct regcache_rbtree_node *rbtree_node;
231
232 /* if we've already been called then just return */
233 rbtree_ctx = map->cache;
234 if (!rbtree_ctx)
235 return 0;
236
237 /* free up the rbtree */
238 next = rb_first(&rbtree_ctx->root);
239 while (next) {
240 rbtree_node = rb_entry(next, struct regcache_rbtree_node, node);
241 next = rb_next(&rbtree_node->node);
242 rb_erase(&rbtree_node->node, &rbtree_ctx->root);
243 kfree(rbtree_node->block);
244 kfree(rbtree_node);
245 }
246
247 /* release the resources */
248 kfree(map->cache);
249 map->cache = NULL;
250
251 return 0;
252}
253
254static int regcache_rbtree_read(struct regmap *map,
255 unsigned int reg, unsigned int *value)
256{
257 struct regcache_rbtree_node *rbnode;
258 unsigned int reg_tmp;
259
260 rbnode = regcache_rbtree_lookup(map, reg);
261 if (rbnode) {
262 reg_tmp = (reg - rbnode->base_reg) / map->reg_stride;
263 *value = regcache_rbtree_get_register(rbnode, reg_tmp,
264 map->cache_word_size);
265 } else {
266 return -ENOENT;
267 }
268
269 return 0;
270}
271
272
273static int regcache_rbtree_insert_to_block(struct regcache_rbtree_node *rbnode,
274 unsigned int pos, unsigned int reg,
275 unsigned int value, unsigned int word_size)
276{
277 u8 *blk;
278
279 blk = krealloc(rbnode->block,
280 (rbnode->blklen + 1) * word_size, GFP_KERNEL);
281 if (!blk)
282 return -ENOMEM;
283
284 /* insert the register value in the correct place in the rbnode block */
285 memmove(blk + (pos + 1) * word_size,
286 blk + pos * word_size,
287 (rbnode->blklen - pos) * word_size);
288
289 /* update the rbnode block, its size and the base register */
290 rbnode->block = blk;
291 rbnode->blklen++;
292 if (!pos)
293 rbnode->base_reg = reg;
294
295 regcache_rbtree_set_register(rbnode, pos, value, word_size);
296 return 0;
297}
298
299static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
300 unsigned int value)
301{
302 struct regcache_rbtree_ctx *rbtree_ctx;
303 struct regcache_rbtree_node *rbnode, *rbnode_tmp;
304 struct rb_node *node;
305 unsigned int val;
306 unsigned int reg_tmp;
307 unsigned int pos;
308 int i;
309 int ret;
310
311 rbtree_ctx = map->cache;
312 /* if we can't locate it in the cached rbnode we'll have
313 * to traverse the rbtree looking for it.
314 */
315 rbnode = regcache_rbtree_lookup(map, reg);
316 if (rbnode) {
317 reg_tmp = (reg - rbnode->base_reg) / map->reg_stride;
318 val = regcache_rbtree_get_register(rbnode, reg_tmp,
319 map->cache_word_size);
320 if (val == value)
321 return 0;
322 regcache_rbtree_set_register(rbnode, reg_tmp, value,
323 map->cache_word_size);
324 } else {
325 /* look for an adjacent register to the one we are about to add */
326 for (node = rb_first(&rbtree_ctx->root); node;
327 node = rb_next(node)) {
328 rbnode_tmp = rb_entry(node, struct regcache_rbtree_node,
329 node);
330 for (i = 0; i < rbnode_tmp->blklen; i++) {
331 reg_tmp = rbnode_tmp->base_reg +
332 (i * map->reg_stride);
333 if (abs(reg_tmp - reg) != map->reg_stride)
334 continue;
335 /* decide where in the block to place our register */
336 if (reg_tmp + map->reg_stride == reg)
337 pos = i + 1;
338 else
339 pos = i;
340 ret = regcache_rbtree_insert_to_block(rbnode_tmp, pos,
341 reg, value,
342 map->cache_word_size);
343 if (ret)
344 return ret;
345 rbtree_ctx->cached_rbnode = rbnode_tmp;
346 return 0;
347 }
348 }
349 /* we did not manage to find a place to insert it in an existing
350 * block so create a new rbnode with a single register in its block.
351 * This block will get populated further if any other adjacent
352 * registers get modified in the future.
353 */
354 rbnode = kzalloc(sizeof *rbnode, GFP_KERNEL);
355 if (!rbnode)
356 return -ENOMEM;
357 rbnode->blklen = 1;
358 rbnode->base_reg = reg;
359 rbnode->block = kmalloc(rbnode->blklen * map->cache_word_size,
360 GFP_KERNEL);
361 if (!rbnode->block) {
362 kfree(rbnode);
363 return -ENOMEM;
364 }
365 regcache_rbtree_set_register(rbnode, 0, value, map->cache_word_size);
366 regcache_rbtree_insert(map, &rbtree_ctx->root, rbnode);
367 rbtree_ctx->cached_rbnode = rbnode;
368 }
369
370 return 0;
371}
372
373static int regcache_rbtree_sync(struct regmap *map, unsigned int min,
374 unsigned int max)
375{
376 struct regcache_rbtree_ctx *rbtree_ctx;
377 struct rb_node *node;
378 struct regcache_rbtree_node *rbnode;
379 unsigned int regtmp;
380 unsigned int val;
381 int ret;
382 int i, base, end;
383
384 rbtree_ctx = map->cache;
385 for (node = rb_first(&rbtree_ctx->root); node; node = rb_next(node)) {
386 rbnode = rb_entry(node, struct regcache_rbtree_node, node);
387
388 if (rbnode->base_reg < min)
389 continue;
390 if (rbnode->base_reg > max)
391 break;
392 if (rbnode->base_reg + rbnode->blklen < min)
393 continue;
394
395 if (min > rbnode->base_reg)
396 base = min - rbnode->base_reg;
397 else
398 base = 0;
399
400 if (max < rbnode->base_reg + rbnode->blklen)
401 end = rbnode->base_reg + rbnode->blklen - max;
402 else
403 end = rbnode->blklen;
404
405 for (i = base; i < end; i++) {
406 regtmp = rbnode->base_reg + (i * map->reg_stride);
407 val = regcache_rbtree_get_register(rbnode, i,
408 map->cache_word_size);
409
410 /* Is this the hardware default? If so skip. */
411 ret = regcache_lookup_reg(map, regtmp);
412 if (ret >= 0 && val == map->reg_defaults[ret].def)
413 continue;
414
415 map->cache_bypass = 1;
416 ret = _regmap_write(map, regtmp, val);
417 map->cache_bypass = 0;
418 if (ret)
419 return ret;
420 dev_dbg(map->dev, "Synced register %#x, value %#x\n",
421 regtmp, val);
422 }
423 }
424
425 return 0;
426}
427
428struct regcache_ops regcache_rbtree_ops = {
429 .type = REGCACHE_RBTREE,
430 .name = "rbtree",
431 .init = regcache_rbtree_init,
432 .exit = regcache_rbtree_exit,
433 .read = regcache_rbtree_read,
434 .write = regcache_rbtree_write,
435 .sync = regcache_rbtree_sync
436};