1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2020 Linaro Limited, All rights reserved.
4 * Author: Mike Leach <mike.leach@linaro.org>
5 */
6
7 #include <linux/configfs.h>
8
9 #include "coresight-config.h"
10 #include "coresight-syscfg-configfs.h"
11
12 /* create a default ci_type. */
cscfg_create_ci_type(void)13 static inline struct config_item_type *cscfg_create_ci_type(void)
14 {
15 struct config_item_type *ci_type;
16
17 ci_type = devm_kzalloc(cscfg_device(), sizeof(*ci_type), GFP_KERNEL);
18 if (ci_type)
19 ci_type->ct_owner = THIS_MODULE;
20
21 return ci_type;
22 }
23
24 /* configurations sub-group */
25
26 /* attributes for the config view group */
cscfg_cfg_description_show(struct config_item * item,char * page)27 static ssize_t cscfg_cfg_description_show(struct config_item *item, char *page)
28 {
29 struct cscfg_fs_config *fs_config = container_of(to_config_group(item),
30 struct cscfg_fs_config, group);
31
32 return scnprintf(page, PAGE_SIZE, "%s", fs_config->config_desc->description);
33 }
34 CONFIGFS_ATTR_RO(cscfg_cfg_, description);
35
cscfg_cfg_feature_refs_show(struct config_item * item,char * page)36 static ssize_t cscfg_cfg_feature_refs_show(struct config_item *item, char *page)
37 {
38 struct cscfg_fs_config *fs_config = container_of(to_config_group(item),
39 struct cscfg_fs_config, group);
40 const struct cscfg_config_desc *config_desc = fs_config->config_desc;
41 ssize_t ch_used = 0;
42 int i;
43
44 for (i = 0; i < config_desc->nr_feat_refs; i++)
45 ch_used += scnprintf(page + ch_used, PAGE_SIZE - ch_used,
46 "%s\n", config_desc->feat_ref_names[i]);
47 return ch_used;
48 }
49 CONFIGFS_ATTR_RO(cscfg_cfg_, feature_refs);
50
51 /* list preset values in order of features and params */
cscfg_cfg_values_show(struct config_item * item,char * page)52 static ssize_t cscfg_cfg_values_show(struct config_item *item, char *page)
53 {
54 const struct cscfg_feature_desc *feat_desc;
55 const struct cscfg_config_desc *config_desc;
56 struct cscfg_fs_preset *fs_preset;
57 int i, j, val_idx, preset_idx;
58 ssize_t used = 0;
59
60 fs_preset = container_of(to_config_group(item), struct cscfg_fs_preset, group);
61 config_desc = fs_preset->config_desc;
62
63 if (!config_desc->nr_presets)
64 return 0;
65
66 preset_idx = fs_preset->preset_num - 1;
67
68 /* start index on the correct array line */
69 val_idx = config_desc->nr_total_params * preset_idx;
70
71 /*
72 * A set of presets is the sum of all params in used features,
73 * in order of declaration of features and params in the features
74 */
75 for (i = 0; i < config_desc->nr_feat_refs; i++) {
76 feat_desc = cscfg_get_named_feat_desc(config_desc->feat_ref_names[i]);
77 for (j = 0; j < feat_desc->nr_params; j++) {
78 used += scnprintf(page + used, PAGE_SIZE - used,
79 "%s.%s = 0x%llx ",
80 feat_desc->name,
81 feat_desc->params_desc[j].name,
82 config_desc->presets[val_idx++]);
83 }
84 }
85 used += scnprintf(page + used, PAGE_SIZE - used, "\n");
86
87 return used;
88 }
89 CONFIGFS_ATTR_RO(cscfg_cfg_, values);
90
cscfg_cfg_enable_show(struct config_item * item,char * page)91 static ssize_t cscfg_cfg_enable_show(struct config_item *item, char *page)
92 {
93 struct cscfg_fs_config *fs_config = container_of(to_config_group(item),
94 struct cscfg_fs_config, group);
95
96 return scnprintf(page, PAGE_SIZE, "%d\n", fs_config->active);
97 }
98
cscfg_cfg_enable_store(struct config_item * item,const char * page,size_t count)99 static ssize_t cscfg_cfg_enable_store(struct config_item *item,
100 const char *page, size_t count)
101 {
102 struct cscfg_fs_config *fs_config = container_of(to_config_group(item),
103 struct cscfg_fs_config, group);
104 int err;
105 bool val;
106
107 err = kstrtobool(page, &val);
108 if (!err)
109 err = cscfg_config_sysfs_activate(fs_config->config_desc, val);
110 if (!err) {
111 fs_config->active = val;
112 if (val)
113 cscfg_config_sysfs_set_preset(fs_config->preset);
114 }
115 return err ? err : count;
116 }
117 CONFIGFS_ATTR(cscfg_cfg_, enable);
118
cscfg_cfg_preset_show(struct config_item * item,char * page)119 static ssize_t cscfg_cfg_preset_show(struct config_item *item, char *page)
120 {
121 struct cscfg_fs_config *fs_config = container_of(to_config_group(item),
122 struct cscfg_fs_config, group);
123
124 return scnprintf(page, PAGE_SIZE, "%d\n", fs_config->preset);
125 }
126
cscfg_cfg_preset_store(struct config_item * item,const char * page,size_t count)127 static ssize_t cscfg_cfg_preset_store(struct config_item *item,
128 const char *page, size_t count)
129 {
130 struct cscfg_fs_config *fs_config = container_of(to_config_group(item),
131 struct cscfg_fs_config, group);
132 int preset, err;
133
134 err = kstrtoint(page, 0, &preset);
135 if (!err) {
136 /*
137 * presets start at 1, and go up to max (15),
138 * but the config may provide fewer.
139 */
140 if ((preset < 1) || (preset > fs_config->config_desc->nr_presets))
141 err = -EINVAL;
142 }
143
144 if (!err) {
145 /* set new value */
146 fs_config->preset = preset;
147 /* set on system if active */
148 if (fs_config->active)
149 cscfg_config_sysfs_set_preset(fs_config->preset);
150 }
151 return err ? err : count;
152 }
153 CONFIGFS_ATTR(cscfg_cfg_, preset);
154
155 static struct configfs_attribute *cscfg_config_view_attrs[] = {
156 &cscfg_cfg_attr_description,
157 &cscfg_cfg_attr_feature_refs,
158 &cscfg_cfg_attr_enable,
159 &cscfg_cfg_attr_preset,
160 NULL,
161 };
162
163 static struct config_item_type cscfg_config_view_type = {
164 .ct_owner = THIS_MODULE,
165 .ct_attrs = cscfg_config_view_attrs,
166 };
167
168 static struct configfs_attribute *cscfg_config_preset_attrs[] = {
169 &cscfg_cfg_attr_values,
170 NULL,
171 };
172
173 static struct config_item_type cscfg_config_preset_type = {
174 .ct_owner = THIS_MODULE,
175 .ct_attrs = cscfg_config_preset_attrs,
176 };
177
cscfg_add_preset_groups(struct cscfg_fs_config * cfg_view)178 static int cscfg_add_preset_groups(struct cscfg_fs_config *cfg_view)
179 {
180 int preset_num;
181 struct cscfg_fs_preset *cfg_fs_preset;
182 struct cscfg_config_desc *config_desc = cfg_view->config_desc;
183 char name[CONFIGFS_ITEM_NAME_LEN];
184
185 if (!config_desc->nr_presets)
186 return 0;
187
188 for (preset_num = 1; preset_num <= config_desc->nr_presets; preset_num++) {
189 cfg_fs_preset = devm_kzalloc(cscfg_device(),
190 sizeof(struct cscfg_fs_preset), GFP_KERNEL);
191
192 if (!cfg_fs_preset)
193 return -ENOMEM;
194
195 snprintf(name, CONFIGFS_ITEM_NAME_LEN, "preset%d", preset_num);
196 cfg_fs_preset->preset_num = preset_num;
197 cfg_fs_preset->config_desc = cfg_view->config_desc;
198 config_group_init_type_name(&cfg_fs_preset->group, name,
199 &cscfg_config_preset_type);
200 configfs_add_default_group(&cfg_fs_preset->group, &cfg_view->group);
201 }
202 return 0;
203 }
204
cscfg_create_config_group(struct cscfg_config_desc * config_desc)205 static struct config_group *cscfg_create_config_group(struct cscfg_config_desc *config_desc)
206 {
207 struct cscfg_fs_config *cfg_view;
208 struct device *dev = cscfg_device();
209 int err;
210
211 if (!dev)
212 return ERR_PTR(-EINVAL);
213
214 cfg_view = devm_kzalloc(dev, sizeof(struct cscfg_fs_config), GFP_KERNEL);
215 if (!cfg_view)
216 return ERR_PTR(-ENOMEM);
217
218 cfg_view->config_desc = config_desc;
219 config_group_init_type_name(&cfg_view->group, config_desc->name, &cscfg_config_view_type);
220
221 /* add in a preset<n> dir for each preset */
222 err = cscfg_add_preset_groups(cfg_view);
223 if (err)
224 return ERR_PTR(err);
225
226 return &cfg_view->group;
227 }
228
229 /* attributes for features view */
230
cscfg_feat_description_show(struct config_item * item,char * page)231 static ssize_t cscfg_feat_description_show(struct config_item *item, char *page)
232 {
233 struct cscfg_fs_feature *fs_feat = container_of(to_config_group(item),
234 struct cscfg_fs_feature, group);
235
236 return scnprintf(page, PAGE_SIZE, "%s", fs_feat->feat_desc->description);
237 }
238 CONFIGFS_ATTR_RO(cscfg_feat_, description);
239
cscfg_feat_matches_show(struct config_item * item,char * page)240 static ssize_t cscfg_feat_matches_show(struct config_item *item, char *page)
241 {
242 struct cscfg_fs_feature *fs_feat = container_of(to_config_group(item),
243 struct cscfg_fs_feature, group);
244 u32 match_flags = fs_feat->feat_desc->match_flags;
245 int used = 0;
246
247 if (match_flags & CS_CFG_MATCH_CLASS_SRC_ALL)
248 used = scnprintf(page, PAGE_SIZE, "SRC_ALL ");
249
250 if (match_flags & CS_CFG_MATCH_CLASS_SRC_ETM4)
251 used += scnprintf(page + used, PAGE_SIZE - used, "SRC_ETMV4 ");
252
253 used += scnprintf(page + used, PAGE_SIZE - used, "\n");
254 return used;
255 }
256 CONFIGFS_ATTR_RO(cscfg_feat_, matches);
257
cscfg_feat_nr_params_show(struct config_item * item,char * page)258 static ssize_t cscfg_feat_nr_params_show(struct config_item *item, char *page)
259 {
260 struct cscfg_fs_feature *fs_feat = container_of(to_config_group(item),
261 struct cscfg_fs_feature, group);
262
263 return scnprintf(page, PAGE_SIZE, "%d\n", fs_feat->feat_desc->nr_params);
264 }
265 CONFIGFS_ATTR_RO(cscfg_feat_, nr_params);
266
267 /* base feature desc attrib structures */
268 static struct configfs_attribute *cscfg_feature_view_attrs[] = {
269 &cscfg_feat_attr_description,
270 &cscfg_feat_attr_matches,
271 &cscfg_feat_attr_nr_params,
272 NULL,
273 };
274
275 static struct config_item_type cscfg_feature_view_type = {
276 .ct_owner = THIS_MODULE,
277 .ct_attrs = cscfg_feature_view_attrs,
278 };
279
cscfg_param_value_show(struct config_item * item,char * page)280 static ssize_t cscfg_param_value_show(struct config_item *item, char *page)
281 {
282 struct cscfg_fs_param *param_item = container_of(to_config_group(item),
283 struct cscfg_fs_param, group);
284 u64 value = param_item->feat_desc->params_desc[param_item->param_idx].value;
285
286 return scnprintf(page, PAGE_SIZE, "0x%llx\n", value);
287 }
288
cscfg_param_value_store(struct config_item * item,const char * page,size_t size)289 static ssize_t cscfg_param_value_store(struct config_item *item,
290 const char *page, size_t size)
291 {
292 struct cscfg_fs_param *param_item = container_of(to_config_group(item),
293 struct cscfg_fs_param, group);
294 struct cscfg_feature_desc *feat_desc = param_item->feat_desc;
295 int param_idx = param_item->param_idx;
296 u64 value;
297 int err;
298
299 err = kstrtoull(page, 0, &value);
300 if (!err)
301 err = cscfg_update_feat_param_val(feat_desc, param_idx, value);
302
303 return err ? err : size;
304 }
305 CONFIGFS_ATTR(cscfg_param_, value);
306
307 static struct configfs_attribute *cscfg_param_view_attrs[] = {
308 &cscfg_param_attr_value,
309 NULL,
310 };
311
312 static struct config_item_type cscfg_param_view_type = {
313 .ct_owner = THIS_MODULE,
314 .ct_attrs = cscfg_param_view_attrs,
315 };
316
317 /*
318 * configfs has far less functionality provided to add attributes dynamically than sysfs,
319 * and the show and store fns pass the enclosing config_item so the actual attribute cannot
320 * be determined. Therefore we add each item as a group directory, with a value attribute.
321 */
cscfg_create_params_group_items(struct cscfg_feature_desc * feat_desc,struct config_group * params_group)322 static int cscfg_create_params_group_items(struct cscfg_feature_desc *feat_desc,
323 struct config_group *params_group)
324 {
325 struct device *dev = cscfg_device();
326 struct cscfg_fs_param *param_item;
327 int i;
328
329 /* parameter items - as groups with default_value attribute */
330 for (i = 0; i < feat_desc->nr_params; i++) {
331 param_item = devm_kzalloc(dev, sizeof(struct cscfg_fs_param), GFP_KERNEL);
332 if (!param_item)
333 return -ENOMEM;
334 param_item->feat_desc = feat_desc;
335 param_item->param_idx = i;
336 config_group_init_type_name(¶m_item->group,
337 feat_desc->params_desc[i].name,
338 &cscfg_param_view_type);
339 configfs_add_default_group(¶m_item->group, params_group);
340 }
341 return 0;
342 }
343
cscfg_create_feature_group(struct cscfg_feature_desc * feat_desc)344 static struct config_group *cscfg_create_feature_group(struct cscfg_feature_desc *feat_desc)
345 {
346 struct cscfg_fs_feature *feat_view;
347 struct config_item_type *params_group_type;
348 struct config_group *params_group = NULL;
349 struct device *dev = cscfg_device();
350 int item_err;
351
352 if (!dev)
353 return ERR_PTR(-EINVAL);
354
355 feat_view = devm_kzalloc(dev, sizeof(struct cscfg_fs_feature), GFP_KERNEL);
356 if (!feat_view)
357 return ERR_PTR(-ENOMEM);
358
359 if (feat_desc->nr_params) {
360 params_group = devm_kzalloc(dev, sizeof(struct config_group), GFP_KERNEL);
361 if (!params_group)
362 return ERR_PTR(-ENOMEM);
363
364 params_group_type = cscfg_create_ci_type();
365 if (!params_group_type)
366 return ERR_PTR(-ENOMEM);
367 }
368
369 feat_view->feat_desc = feat_desc;
370 config_group_init_type_name(&feat_view->group,
371 feat_desc->name,
372 &cscfg_feature_view_type);
373 if (params_group) {
374 config_group_init_type_name(params_group, "params", params_group_type);
375 configfs_add_default_group(params_group, &feat_view->group);
376 item_err = cscfg_create_params_group_items(feat_desc, params_group);
377 if (item_err)
378 return ERR_PTR(item_err);
379 }
380 return &feat_view->group;
381 }
382
383 static struct config_item_type cscfg_configs_type = {
384 .ct_owner = THIS_MODULE,
385 };
386
387 static struct config_group cscfg_configs_grp = {
388 .cg_item = {
389 .ci_namebuf = "configurations",
390 .ci_type = &cscfg_configs_type,
391 },
392 };
393
394 /* add configuration to configurations group */
cscfg_configfs_add_config(struct cscfg_config_desc * config_desc)395 int cscfg_configfs_add_config(struct cscfg_config_desc *config_desc)
396 {
397 struct config_group *new_group;
398 int err;
399
400 new_group = cscfg_create_config_group(config_desc);
401 if (IS_ERR(new_group))
402 return PTR_ERR(new_group);
403 err = configfs_register_group(&cscfg_configs_grp, new_group);
404 if (!err)
405 config_desc->fs_group = new_group;
406 return err;
407 }
408
cscfg_configfs_del_config(struct cscfg_config_desc * config_desc)409 void cscfg_configfs_del_config(struct cscfg_config_desc *config_desc)
410 {
411 if (config_desc->fs_group) {
412 configfs_unregister_group(config_desc->fs_group);
413 config_desc->fs_group = NULL;
414 }
415 }
416
417 static struct config_item_type cscfg_features_type = {
418 .ct_owner = THIS_MODULE,
419 };
420
421 static struct config_group cscfg_features_grp = {
422 .cg_item = {
423 .ci_namebuf = "features",
424 .ci_type = &cscfg_features_type,
425 },
426 };
427
428 /* add feature to features group */
cscfg_configfs_add_feature(struct cscfg_feature_desc * feat_desc)429 int cscfg_configfs_add_feature(struct cscfg_feature_desc *feat_desc)
430 {
431 struct config_group *new_group;
432 int err;
433
434 new_group = cscfg_create_feature_group(feat_desc);
435 if (IS_ERR(new_group))
436 return PTR_ERR(new_group);
437 err = configfs_register_group(&cscfg_features_grp, new_group);
438 if (!err)
439 feat_desc->fs_group = new_group;
440 return err;
441 }
442
cscfg_configfs_del_feature(struct cscfg_feature_desc * feat_desc)443 void cscfg_configfs_del_feature(struct cscfg_feature_desc *feat_desc)
444 {
445 if (feat_desc->fs_group) {
446 configfs_unregister_group(feat_desc->fs_group);
447 feat_desc->fs_group = NULL;
448 }
449 }
450
cscfg_configfs_init(struct cscfg_manager * cscfg_mgr)451 int cscfg_configfs_init(struct cscfg_manager *cscfg_mgr)
452 {
453 struct configfs_subsystem *subsys;
454 struct config_item_type *ci_type;
455
456 if (!cscfg_mgr)
457 return -EINVAL;
458
459 ci_type = cscfg_create_ci_type();
460 if (!ci_type)
461 return -ENOMEM;
462
463 subsys = &cscfg_mgr->cfgfs_subsys;
464 config_item_set_name(&subsys->su_group.cg_item, CSCFG_FS_SUBSYS_NAME);
465 subsys->su_group.cg_item.ci_type = ci_type;
466
467 config_group_init(&subsys->su_group);
468 mutex_init(&subsys->su_mutex);
469
470 /* Add default groups to subsystem */
471 config_group_init(&cscfg_configs_grp);
472 configfs_add_default_group(&cscfg_configs_grp, &subsys->su_group);
473
474 config_group_init(&cscfg_features_grp);
475 configfs_add_default_group(&cscfg_features_grp, &subsys->su_group);
476
477 return configfs_register_subsystem(subsys);
478 }
479
cscfg_configfs_release(struct cscfg_manager * cscfg_mgr)480 void cscfg_configfs_release(struct cscfg_manager *cscfg_mgr)
481 {
482 configfs_unregister_subsystem(&cscfg_mgr->cfgfs_subsys);
483 }
484