1 /*
2  * Support for dynamic reconfiguration for PCI, Memory, and CPU
3  * Hotplug and Dynamic Logical Partitioning on RPA platforms.
4  *
5  * Copyright (C) 2009 Nathan Fontenot
6  * Copyright (C) 2009 IBM Corporation
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License version
10  * 2 as published by the Free Software Foundation.
11  */
12 
13 #define pr_fmt(fmt)	"dlpar: " fmt
14 
15 #include <linux/kernel.h>
16 #include <linux/notifier.h>
17 #include <linux/spinlock.h>
18 #include <linux/cpu.h>
19 #include <linux/slab.h>
20 #include <linux/of.h>
21 
22 #include "of_helpers.h"
23 #include "pseries.h"
24 
25 #include <asm/prom.h>
26 #include <asm/machdep.h>
27 #include <linux/uaccess.h>
28 #include <asm/rtas.h>
29 
30 static struct workqueue_struct *pseries_hp_wq;
31 
32 struct pseries_hp_work {
33 	struct work_struct work;
34 	struct pseries_hp_errorlog *errlog;
35 	struct completion *hp_completion;
36 	int *rc;
37 };
38 
39 struct cc_workarea {
40 	__be32	drc_index;
41 	__be32	zero;
42 	__be32	name_offset;
43 	__be32	prop_length;
44 	__be32	prop_offset;
45 };
46 
47 void dlpar_free_cc_property(struct property *prop)
48 {
49 	kfree(prop->name);
50 	kfree(prop->value);
51 	kfree(prop);
52 }
53 
54 static struct property *dlpar_parse_cc_property(struct cc_workarea *ccwa)
55 {
56 	struct property *prop;
57 	char *name;
58 	char *value;
59 
60 	prop = kzalloc(sizeof(*prop), GFP_KERNEL);
61 	if (!prop)
62 		return NULL;
63 
64 	name = (char *)ccwa + be32_to_cpu(ccwa->name_offset);
65 	prop->name = kstrdup(name, GFP_KERNEL);
66 
67 	prop->length = be32_to_cpu(ccwa->prop_length);
68 	value = (char *)ccwa + be32_to_cpu(ccwa->prop_offset);
69 	prop->value = kmemdup(value, prop->length, GFP_KERNEL);
70 	if (!prop->value) {
71 		dlpar_free_cc_property(prop);
72 		return NULL;
73 	}
74 
75 	return prop;
76 }
77 
78 static struct device_node *dlpar_parse_cc_node(struct cc_workarea *ccwa,
79 					       const char *path)
80 {
81 	struct device_node *dn;
82 	char *name;
83 
84 	/* If parent node path is "/" advance path to NULL terminator to
85 	 * prevent double leading slashs in full_name.
86 	 */
87 	if (!path[1])
88 		path++;
89 
90 	dn = kzalloc(sizeof(*dn), GFP_KERNEL);
91 	if (!dn)
92 		return NULL;
93 
94 	name = (char *)ccwa + be32_to_cpu(ccwa->name_offset);
95 	dn->full_name = kasprintf(GFP_KERNEL, "%s/%s", path, name);
96 	if (!dn->full_name) {
97 		kfree(dn);
98 		return NULL;
99 	}
100 
101 	of_node_set_flag(dn, OF_DYNAMIC);
102 	of_node_init(dn);
103 
104 	return dn;
105 }
106 
107 static void dlpar_free_one_cc_node(struct device_node *dn)
108 {
109 	struct property *prop;
110 
111 	while (dn->properties) {
112 		prop = dn->properties;
113 		dn->properties = prop->next;
114 		dlpar_free_cc_property(prop);
115 	}
116 
117 	kfree(dn->full_name);
118 	kfree(dn);
119 }
120 
121 void dlpar_free_cc_nodes(struct device_node *dn)
122 {
123 	if (dn->child)
124 		dlpar_free_cc_nodes(dn->child);
125 
126 	if (dn->sibling)
127 		dlpar_free_cc_nodes(dn->sibling);
128 
129 	dlpar_free_one_cc_node(dn);
130 }
131 
132 #define COMPLETE	0
133 #define NEXT_SIBLING    1
134 #define NEXT_CHILD      2
135 #define NEXT_PROPERTY   3
136 #define PREV_PARENT     4
137 #define MORE_MEMORY     5
138 #define CALL_AGAIN	-2
139 #define ERR_CFG_USE     -9003
140 
141 struct device_node *dlpar_configure_connector(__be32 drc_index,
142 					      struct device_node *parent)
143 {
144 	struct device_node *dn;
145 	struct device_node *first_dn = NULL;
146 	struct device_node *last_dn = NULL;
147 	struct property *property;
148 	struct property *last_property = NULL;
149 	struct cc_workarea *ccwa;
150 	char *data_buf;
151 	const char *parent_path = parent->full_name;
152 	int cc_token;
153 	int rc = -1;
154 
155 	cc_token = rtas_token("ibm,configure-connector");
156 	if (cc_token == RTAS_UNKNOWN_SERVICE)
157 		return NULL;
158 
159 	data_buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
160 	if (!data_buf)
161 		return NULL;
162 
163 	ccwa = (struct cc_workarea *)&data_buf[0];
164 	ccwa->drc_index = drc_index;
165 	ccwa->zero = 0;
166 
167 	do {
168 		/* Since we release the rtas_data_buf lock between configure
169 		 * connector calls we want to re-populate the rtas_data_buffer
170 		 * with the contents of the previous call.
171 		 */
172 		spin_lock(&rtas_data_buf_lock);
173 
174 		memcpy(rtas_data_buf, data_buf, RTAS_DATA_BUF_SIZE);
175 		rc = rtas_call(cc_token, 2, 1, NULL, rtas_data_buf, NULL);
176 		memcpy(data_buf, rtas_data_buf, RTAS_DATA_BUF_SIZE);
177 
178 		spin_unlock(&rtas_data_buf_lock);
179 
180 		switch (rc) {
181 		case COMPLETE:
182 			break;
183 
184 		case NEXT_SIBLING:
185 			dn = dlpar_parse_cc_node(ccwa, parent_path);
186 			if (!dn)
187 				goto cc_error;
188 
189 			dn->parent = last_dn->parent;
190 			last_dn->sibling = dn;
191 			last_dn = dn;
192 			break;
193 
194 		case NEXT_CHILD:
195 			if (first_dn)
196 				parent_path = last_dn->full_name;
197 
198 			dn = dlpar_parse_cc_node(ccwa, parent_path);
199 			if (!dn)
200 				goto cc_error;
201 
202 			if (!first_dn) {
203 				dn->parent = parent;
204 				first_dn = dn;
205 			} else {
206 				dn->parent = last_dn;
207 				if (last_dn)
208 					last_dn->child = dn;
209 			}
210 
211 			last_dn = dn;
212 			break;
213 
214 		case NEXT_PROPERTY:
215 			property = dlpar_parse_cc_property(ccwa);
216 			if (!property)
217 				goto cc_error;
218 
219 			if (!last_dn->properties)
220 				last_dn->properties = property;
221 			else
222 				last_property->next = property;
223 
224 			last_property = property;
225 			break;
226 
227 		case PREV_PARENT:
228 			last_dn = last_dn->parent;
229 			parent_path = last_dn->parent->full_name;
230 			break;
231 
232 		case CALL_AGAIN:
233 			break;
234 
235 		case MORE_MEMORY:
236 		case ERR_CFG_USE:
237 		default:
238 			printk(KERN_ERR "Unexpected Error (%d) "
239 			       "returned from configure-connector\n", rc);
240 			goto cc_error;
241 		}
242 	} while (rc);
243 
244 cc_error:
245 	kfree(data_buf);
246 
247 	if (rc) {
248 		if (first_dn)
249 			dlpar_free_cc_nodes(first_dn);
250 
251 		return NULL;
252 	}
253 
254 	return first_dn;
255 }
256 
257 int dlpar_attach_node(struct device_node *dn, struct device_node *parent)
258 {
259 	int rc;
260 
261 	dn->parent = parent;
262 
263 	rc = of_attach_node(dn);
264 	if (rc) {
265 		printk(KERN_ERR "Failed to add device node %pOF\n", dn);
266 		return rc;
267 	}
268 
269 	of_node_put(dn->parent);
270 	return 0;
271 }
272 
273 int dlpar_detach_node(struct device_node *dn)
274 {
275 	struct device_node *child;
276 	int rc;
277 
278 	child = of_get_next_child(dn, NULL);
279 	while (child) {
280 		dlpar_detach_node(child);
281 		child = of_get_next_child(dn, child);
282 	}
283 
284 	rc = of_detach_node(dn);
285 	if (rc)
286 		return rc;
287 
288 	return 0;
289 }
290 
291 #define DR_ENTITY_SENSE		9003
292 #define DR_ENTITY_PRESENT	1
293 #define DR_ENTITY_UNUSABLE	2
294 #define ALLOCATION_STATE	9003
295 #define ALLOC_UNUSABLE		0
296 #define ALLOC_USABLE		1
297 #define ISOLATION_STATE		9001
298 #define ISOLATE			0
299 #define UNISOLATE		1
300 
301 int dlpar_acquire_drc(u32 drc_index)
302 {
303 	int dr_status, rc;
304 
305 	rc = rtas_call(rtas_token("get-sensor-state"), 2, 2, &dr_status,
306 		       DR_ENTITY_SENSE, drc_index);
307 	if (rc || dr_status != DR_ENTITY_UNUSABLE)
308 		return -1;
309 
310 	rc = rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_USABLE);
311 	if (rc)
312 		return rc;
313 
314 	rc = rtas_set_indicator(ISOLATION_STATE, drc_index, UNISOLATE);
315 	if (rc) {
316 		rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_UNUSABLE);
317 		return rc;
318 	}
319 
320 	return 0;
321 }
322 
323 int dlpar_release_drc(u32 drc_index)
324 {
325 	int dr_status, rc;
326 
327 	rc = rtas_call(rtas_token("get-sensor-state"), 2, 2, &dr_status,
328 		       DR_ENTITY_SENSE, drc_index);
329 	if (rc || dr_status != DR_ENTITY_PRESENT)
330 		return -1;
331 
332 	rc = rtas_set_indicator(ISOLATION_STATE, drc_index, ISOLATE);
333 	if (rc)
334 		return rc;
335 
336 	rc = rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_UNUSABLE);
337 	if (rc) {
338 		rtas_set_indicator(ISOLATION_STATE, drc_index, UNISOLATE);
339 		return rc;
340 	}
341 
342 	return 0;
343 }
344 
345 static int handle_dlpar_errorlog(struct pseries_hp_errorlog *hp_elog)
346 {
347 	int rc;
348 
349 	/* pseries error logs are in BE format, convert to cpu type */
350 	switch (hp_elog->id_type) {
351 	case PSERIES_HP_ELOG_ID_DRC_COUNT:
352 		hp_elog->_drc_u.drc_count =
353 				be32_to_cpu(hp_elog->_drc_u.drc_count);
354 		break;
355 	case PSERIES_HP_ELOG_ID_DRC_INDEX:
356 		hp_elog->_drc_u.drc_index =
357 				be32_to_cpu(hp_elog->_drc_u.drc_index);
358 		break;
359 	case PSERIES_HP_ELOG_ID_DRC_IC:
360 		hp_elog->_drc_u.ic.count =
361 				be32_to_cpu(hp_elog->_drc_u.ic.count);
362 		hp_elog->_drc_u.ic.index =
363 				be32_to_cpu(hp_elog->_drc_u.ic.index);
364 	}
365 
366 	switch (hp_elog->resource) {
367 	case PSERIES_HP_ELOG_RESOURCE_MEM:
368 		rc = dlpar_memory(hp_elog);
369 		break;
370 	case PSERIES_HP_ELOG_RESOURCE_CPU:
371 		rc = dlpar_cpu(hp_elog);
372 		break;
373 	default:
374 		pr_warn_ratelimited("Invalid resource (%d) specified\n",
375 				    hp_elog->resource);
376 		rc = -EINVAL;
377 	}
378 
379 	return rc;
380 }
381 
382 static void pseries_hp_work_fn(struct work_struct *work)
383 {
384 	struct pseries_hp_work *hp_work =
385 			container_of(work, struct pseries_hp_work, work);
386 
387 	if (hp_work->rc)
388 		*(hp_work->rc) = handle_dlpar_errorlog(hp_work->errlog);
389 	else
390 		handle_dlpar_errorlog(hp_work->errlog);
391 
392 	if (hp_work->hp_completion)
393 		complete(hp_work->hp_completion);
394 
395 	kfree(hp_work->errlog);
396 	kfree((void *)work);
397 }
398 
399 void queue_hotplug_event(struct pseries_hp_errorlog *hp_errlog,
400 			 struct completion *hotplug_done, int *rc)
401 {
402 	struct pseries_hp_work *work;
403 	struct pseries_hp_errorlog *hp_errlog_copy;
404 
405 	hp_errlog_copy = kmalloc(sizeof(struct pseries_hp_errorlog),
406 				 GFP_KERNEL);
407 	memcpy(hp_errlog_copy, hp_errlog, sizeof(struct pseries_hp_errorlog));
408 
409 	work = kmalloc(sizeof(struct pseries_hp_work), GFP_KERNEL);
410 	if (work) {
411 		INIT_WORK((struct work_struct *)work, pseries_hp_work_fn);
412 		work->errlog = hp_errlog_copy;
413 		work->hp_completion = hotplug_done;
414 		work->rc = rc;
415 		queue_work(pseries_hp_wq, (struct work_struct *)work);
416 	} else {
417 		*rc = -ENOMEM;
418 		kfree(hp_errlog_copy);
419 		complete(hotplug_done);
420 	}
421 }
422 
423 static int dlpar_parse_resource(char **cmd, struct pseries_hp_errorlog *hp_elog)
424 {
425 	char *arg;
426 
427 	arg = strsep(cmd, " ");
428 	if (!arg)
429 		return -EINVAL;
430 
431 	if (sysfs_streq(arg, "memory")) {
432 		hp_elog->resource = PSERIES_HP_ELOG_RESOURCE_MEM;
433 	} else if (sysfs_streq(arg, "cpu")) {
434 		hp_elog->resource = PSERIES_HP_ELOG_RESOURCE_CPU;
435 	} else {
436 		pr_err("Invalid resource specified.\n");
437 		return -EINVAL;
438 	}
439 
440 	return 0;
441 }
442 
443 static int dlpar_parse_action(char **cmd, struct pseries_hp_errorlog *hp_elog)
444 {
445 	char *arg;
446 
447 	arg = strsep(cmd, " ");
448 	if (!arg)
449 		return -EINVAL;
450 
451 	if (sysfs_streq(arg, "add")) {
452 		hp_elog->action = PSERIES_HP_ELOG_ACTION_ADD;
453 	} else if (sysfs_streq(arg, "remove")) {
454 		hp_elog->action = PSERIES_HP_ELOG_ACTION_REMOVE;
455 	} else {
456 		pr_err("Invalid action specified.\n");
457 		return -EINVAL;
458 	}
459 
460 	return 0;
461 }
462 
463 static int dlpar_parse_id_type(char **cmd, struct pseries_hp_errorlog *hp_elog)
464 {
465 	char *arg;
466 	u32 count, index;
467 
468 	arg = strsep(cmd, " ");
469 	if (!arg)
470 		return -EINVAL;
471 
472 	if (sysfs_streq(arg, "indexed-count")) {
473 		hp_elog->id_type = PSERIES_HP_ELOG_ID_DRC_IC;
474 		arg = strsep(cmd, " ");
475 		if (!arg) {
476 			pr_err("No DRC count specified.\n");
477 			return -EINVAL;
478 		}
479 
480 		if (kstrtou32(arg, 0, &count)) {
481 			pr_err("Invalid DRC count specified.\n");
482 			return -EINVAL;
483 		}
484 
485 		arg = strsep(cmd, " ");
486 		if (!arg) {
487 			pr_err("No DRC Index specified.\n");
488 			return -EINVAL;
489 		}
490 
491 		if (kstrtou32(arg, 0, &index)) {
492 			pr_err("Invalid DRC Index specified.\n");
493 			return -EINVAL;
494 		}
495 
496 		hp_elog->_drc_u.ic.count = cpu_to_be32(count);
497 		hp_elog->_drc_u.ic.index = cpu_to_be32(index);
498 	} else if (sysfs_streq(arg, "index")) {
499 		hp_elog->id_type = PSERIES_HP_ELOG_ID_DRC_INDEX;
500 		arg = strsep(cmd, " ");
501 		if (!arg) {
502 			pr_err("No DRC Index specified.\n");
503 			return -EINVAL;
504 		}
505 
506 		if (kstrtou32(arg, 0, &index)) {
507 			pr_err("Invalid DRC Index specified.\n");
508 			return -EINVAL;
509 		}
510 
511 		hp_elog->_drc_u.drc_index = cpu_to_be32(index);
512 	} else if (sysfs_streq(arg, "count")) {
513 		hp_elog->id_type = PSERIES_HP_ELOG_ID_DRC_COUNT;
514 		arg = strsep(cmd, " ");
515 		if (!arg) {
516 			pr_err("No DRC count specified.\n");
517 			return -EINVAL;
518 		}
519 
520 		if (kstrtou32(arg, 0, &count)) {
521 			pr_err("Invalid DRC count specified.\n");
522 			return -EINVAL;
523 		}
524 
525 		hp_elog->_drc_u.drc_count = cpu_to_be32(count);
526 	} else {
527 		pr_err("Invalid id_type specified.\n");
528 		return -EINVAL;
529 	}
530 
531 	return 0;
532 }
533 
534 static ssize_t dlpar_store(struct class *class, struct class_attribute *attr,
535 			   const char *buf, size_t count)
536 {
537 	struct pseries_hp_errorlog *hp_elog;
538 	struct completion hotplug_done;
539 	char *argbuf;
540 	char *args;
541 	int rc;
542 
543 	args = argbuf = kstrdup(buf, GFP_KERNEL);
544 	hp_elog = kzalloc(sizeof(*hp_elog), GFP_KERNEL);
545 	if (!hp_elog || !argbuf) {
546 		pr_info("Could not allocate resources for DLPAR operation\n");
547 		kfree(argbuf);
548 		kfree(hp_elog);
549 		return -ENOMEM;
550 	}
551 
552 	/*
553 	 * Parse out the request from the user, this will be in the form:
554 	 * <resource> <action> <id_type> <id>
555 	 */
556 	rc = dlpar_parse_resource(&args, hp_elog);
557 	if (rc)
558 		goto dlpar_store_out;
559 
560 	rc = dlpar_parse_action(&args, hp_elog);
561 	if (rc)
562 		goto dlpar_store_out;
563 
564 	rc = dlpar_parse_id_type(&args, hp_elog);
565 	if (rc)
566 		goto dlpar_store_out;
567 
568 	init_completion(&hotplug_done);
569 	queue_hotplug_event(hp_elog, &hotplug_done, &rc);
570 	wait_for_completion(&hotplug_done);
571 
572 dlpar_store_out:
573 	kfree(argbuf);
574 	kfree(hp_elog);
575 
576 	if (rc)
577 		pr_err("Could not handle DLPAR request \"%s\"\n", buf);
578 
579 	return rc ? rc : count;
580 }
581 
582 static ssize_t dlpar_show(struct class *class, struct class_attribute *attr,
583 			  char *buf)
584 {
585 	return sprintf(buf, "%s\n", "memory,cpu");
586 }
587 
588 static CLASS_ATTR_RW(dlpar);
589 
590 static int __init pseries_dlpar_init(void)
591 {
592 	pseries_hp_wq = alloc_workqueue("pseries hotplug workqueue",
593 					WQ_UNBOUND, 1);
594 	return sysfs_create_file(kernel_kobj, &class_attr_dlpar.attr);
595 }
596 machine_device_initcall(pseries, pseries_dlpar_init);
597 
598