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 #include "offline_states.h"
22 #include "pseries.h"
23 
24 #include <asm/prom.h>
25 #include <asm/machdep.h>
26 #include <asm/uaccess.h>
27 #include <asm/rtas.h>
28 
29 struct cc_workarea {
30 	__be32	drc_index;
31 	__be32	zero;
32 	__be32	name_offset;
33 	__be32	prop_length;
34 	__be32	prop_offset;
35 };
36 
37 void dlpar_free_cc_property(struct property *prop)
38 {
39 	kfree(prop->name);
40 	kfree(prop->value);
41 	kfree(prop);
42 }
43 
44 static struct property *dlpar_parse_cc_property(struct cc_workarea *ccwa)
45 {
46 	struct property *prop;
47 	char *name;
48 	char *value;
49 
50 	prop = kzalloc(sizeof(*prop), GFP_KERNEL);
51 	if (!prop)
52 		return NULL;
53 
54 	name = (char *)ccwa + be32_to_cpu(ccwa->name_offset);
55 	prop->name = kstrdup(name, GFP_KERNEL);
56 
57 	prop->length = be32_to_cpu(ccwa->prop_length);
58 	value = (char *)ccwa + be32_to_cpu(ccwa->prop_offset);
59 	prop->value = kmemdup(value, prop->length, GFP_KERNEL);
60 	if (!prop->value) {
61 		dlpar_free_cc_property(prop);
62 		return NULL;
63 	}
64 
65 	return prop;
66 }
67 
68 static struct device_node *dlpar_parse_cc_node(struct cc_workarea *ccwa,
69 					       const char *path)
70 {
71 	struct device_node *dn;
72 	char *name;
73 
74 	/* If parent node path is "/" advance path to NULL terminator to
75 	 * prevent double leading slashs in full_name.
76 	 */
77 	if (!path[1])
78 		path++;
79 
80 	dn = kzalloc(sizeof(*dn), GFP_KERNEL);
81 	if (!dn)
82 		return NULL;
83 
84 	name = (char *)ccwa + be32_to_cpu(ccwa->name_offset);
85 	dn->full_name = kasprintf(GFP_KERNEL, "%s/%s", path, name);
86 	if (!dn->full_name) {
87 		kfree(dn);
88 		return NULL;
89 	}
90 
91 	of_node_set_flag(dn, OF_DYNAMIC);
92 	of_node_init(dn);
93 
94 	return dn;
95 }
96 
97 static void dlpar_free_one_cc_node(struct device_node *dn)
98 {
99 	struct property *prop;
100 
101 	while (dn->properties) {
102 		prop = dn->properties;
103 		dn->properties = prop->next;
104 		dlpar_free_cc_property(prop);
105 	}
106 
107 	kfree(dn->full_name);
108 	kfree(dn);
109 }
110 
111 void dlpar_free_cc_nodes(struct device_node *dn)
112 {
113 	if (dn->child)
114 		dlpar_free_cc_nodes(dn->child);
115 
116 	if (dn->sibling)
117 		dlpar_free_cc_nodes(dn->sibling);
118 
119 	dlpar_free_one_cc_node(dn);
120 }
121 
122 #define COMPLETE	0
123 #define NEXT_SIBLING    1
124 #define NEXT_CHILD      2
125 #define NEXT_PROPERTY   3
126 #define PREV_PARENT     4
127 #define MORE_MEMORY     5
128 #define CALL_AGAIN	-2
129 #define ERR_CFG_USE     -9003
130 
131 struct device_node *dlpar_configure_connector(__be32 drc_index,
132 					      struct device_node *parent)
133 {
134 	struct device_node *dn;
135 	struct device_node *first_dn = NULL;
136 	struct device_node *last_dn = NULL;
137 	struct property *property;
138 	struct property *last_property = NULL;
139 	struct cc_workarea *ccwa;
140 	char *data_buf;
141 	const char *parent_path = parent->full_name;
142 	int cc_token;
143 	int rc = -1;
144 
145 	cc_token = rtas_token("ibm,configure-connector");
146 	if (cc_token == RTAS_UNKNOWN_SERVICE)
147 		return NULL;
148 
149 	data_buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
150 	if (!data_buf)
151 		return NULL;
152 
153 	ccwa = (struct cc_workarea *)&data_buf[0];
154 	ccwa->drc_index = drc_index;
155 	ccwa->zero = 0;
156 
157 	do {
158 		/* Since we release the rtas_data_buf lock between configure
159 		 * connector calls we want to re-populate the rtas_data_buffer
160 		 * with the contents of the previous call.
161 		 */
162 		spin_lock(&rtas_data_buf_lock);
163 
164 		memcpy(rtas_data_buf, data_buf, RTAS_DATA_BUF_SIZE);
165 		rc = rtas_call(cc_token, 2, 1, NULL, rtas_data_buf, NULL);
166 		memcpy(data_buf, rtas_data_buf, RTAS_DATA_BUF_SIZE);
167 
168 		spin_unlock(&rtas_data_buf_lock);
169 
170 		switch (rc) {
171 		case COMPLETE:
172 			break;
173 
174 		case NEXT_SIBLING:
175 			dn = dlpar_parse_cc_node(ccwa, parent_path);
176 			if (!dn)
177 				goto cc_error;
178 
179 			dn->parent = last_dn->parent;
180 			last_dn->sibling = dn;
181 			last_dn = dn;
182 			break;
183 
184 		case NEXT_CHILD:
185 			if (first_dn)
186 				parent_path = last_dn->full_name;
187 
188 			dn = dlpar_parse_cc_node(ccwa, parent_path);
189 			if (!dn)
190 				goto cc_error;
191 
192 			if (!first_dn) {
193 				dn->parent = parent;
194 				first_dn = dn;
195 			} else {
196 				dn->parent = last_dn;
197 				if (last_dn)
198 					last_dn->child = dn;
199 			}
200 
201 			last_dn = dn;
202 			break;
203 
204 		case NEXT_PROPERTY:
205 			property = dlpar_parse_cc_property(ccwa);
206 			if (!property)
207 				goto cc_error;
208 
209 			if (!last_dn->properties)
210 				last_dn->properties = property;
211 			else
212 				last_property->next = property;
213 
214 			last_property = property;
215 			break;
216 
217 		case PREV_PARENT:
218 			last_dn = last_dn->parent;
219 			parent_path = last_dn->parent->full_name;
220 			break;
221 
222 		case CALL_AGAIN:
223 			break;
224 
225 		case MORE_MEMORY:
226 		case ERR_CFG_USE:
227 		default:
228 			printk(KERN_ERR "Unexpected Error (%d) "
229 			       "returned from configure-connector\n", rc);
230 			goto cc_error;
231 		}
232 	} while (rc);
233 
234 cc_error:
235 	kfree(data_buf);
236 
237 	if (rc) {
238 		if (first_dn)
239 			dlpar_free_cc_nodes(first_dn);
240 
241 		return NULL;
242 	}
243 
244 	return first_dn;
245 }
246 
247 static struct device_node *derive_parent(const char *path)
248 {
249 	struct device_node *parent;
250 	char *last_slash;
251 
252 	last_slash = strrchr(path, '/');
253 	if (last_slash == path) {
254 		parent = of_find_node_by_path("/");
255 	} else {
256 		char *parent_path;
257 		int parent_path_len = last_slash - path + 1;
258 		parent_path = kmalloc(parent_path_len, GFP_KERNEL);
259 		if (!parent_path)
260 			return NULL;
261 
262 		strlcpy(parent_path, path, parent_path_len);
263 		parent = of_find_node_by_path(parent_path);
264 		kfree(parent_path);
265 	}
266 
267 	return parent;
268 }
269 
270 int dlpar_attach_node(struct device_node *dn)
271 {
272 	int rc;
273 
274 	dn->parent = derive_parent(dn->full_name);
275 	if (!dn->parent)
276 		return -ENOMEM;
277 
278 	rc = of_attach_node(dn);
279 	if (rc) {
280 		printk(KERN_ERR "Failed to add device node %s\n",
281 		       dn->full_name);
282 		return rc;
283 	}
284 
285 	of_node_put(dn->parent);
286 	return 0;
287 }
288 
289 int dlpar_detach_node(struct device_node *dn)
290 {
291 	struct device_node *child;
292 	int rc;
293 
294 	child = of_get_next_child(dn, NULL);
295 	while (child) {
296 		dlpar_detach_node(child);
297 		child = of_get_next_child(dn, child);
298 	}
299 
300 	rc = of_detach_node(dn);
301 	if (rc)
302 		return rc;
303 
304 	of_node_put(dn); /* Must decrement the refcount */
305 	return 0;
306 }
307 
308 #define DR_ENTITY_SENSE		9003
309 #define DR_ENTITY_PRESENT	1
310 #define DR_ENTITY_UNUSABLE	2
311 #define ALLOCATION_STATE	9003
312 #define ALLOC_UNUSABLE		0
313 #define ALLOC_USABLE		1
314 #define ISOLATION_STATE		9001
315 #define ISOLATE			0
316 #define UNISOLATE		1
317 
318 int dlpar_acquire_drc(u32 drc_index)
319 {
320 	int dr_status, rc;
321 
322 	rc = rtas_call(rtas_token("get-sensor-state"), 2, 2, &dr_status,
323 		       DR_ENTITY_SENSE, drc_index);
324 	if (rc || dr_status != DR_ENTITY_UNUSABLE)
325 		return -1;
326 
327 	rc = rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_USABLE);
328 	if (rc)
329 		return rc;
330 
331 	rc = rtas_set_indicator(ISOLATION_STATE, drc_index, UNISOLATE);
332 	if (rc) {
333 		rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_UNUSABLE);
334 		return rc;
335 	}
336 
337 	return 0;
338 }
339 
340 int dlpar_release_drc(u32 drc_index)
341 {
342 	int dr_status, rc;
343 
344 	rc = rtas_call(rtas_token("get-sensor-state"), 2, 2, &dr_status,
345 		       DR_ENTITY_SENSE, drc_index);
346 	if (rc || dr_status != DR_ENTITY_PRESENT)
347 		return -1;
348 
349 	rc = rtas_set_indicator(ISOLATION_STATE, drc_index, ISOLATE);
350 	if (rc)
351 		return rc;
352 
353 	rc = rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_UNUSABLE);
354 	if (rc) {
355 		rtas_set_indicator(ISOLATION_STATE, drc_index, UNISOLATE);
356 		return rc;
357 	}
358 
359 	return 0;
360 }
361 
362 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
363 
364 static int dlpar_online_cpu(struct device_node *dn)
365 {
366 	int rc = 0;
367 	unsigned int cpu;
368 	int len, nthreads, i;
369 	const __be32 *intserv;
370 	u32 thread;
371 
372 	intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
373 	if (!intserv)
374 		return -EINVAL;
375 
376 	nthreads = len / sizeof(u32);
377 
378 	cpu_maps_update_begin();
379 	for (i = 0; i < nthreads; i++) {
380 		thread = be32_to_cpu(intserv[i]);
381 		for_each_present_cpu(cpu) {
382 			if (get_hard_smp_processor_id(cpu) != thread)
383 				continue;
384 			BUG_ON(get_cpu_current_state(cpu)
385 					!= CPU_STATE_OFFLINE);
386 			cpu_maps_update_done();
387 			rc = device_online(get_cpu_device(cpu));
388 			if (rc)
389 				goto out;
390 			cpu_maps_update_begin();
391 
392 			break;
393 		}
394 		if (cpu == num_possible_cpus())
395 			printk(KERN_WARNING "Could not find cpu to online "
396 			       "with physical id 0x%x\n", thread);
397 	}
398 	cpu_maps_update_done();
399 
400 out:
401 	return rc;
402 
403 }
404 
405 static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
406 {
407 	struct device_node *dn, *parent;
408 	u32 drc_index;
409 	int rc;
410 
411 	rc = kstrtou32(buf, 0, &drc_index);
412 	if (rc)
413 		return -EINVAL;
414 
415 	rc = dlpar_acquire_drc(drc_index);
416 	if (rc)
417 		return -EINVAL;
418 
419 	parent = of_find_node_by_path("/cpus");
420 	if (!parent)
421 		return -ENODEV;
422 
423 	dn = dlpar_configure_connector(cpu_to_be32(drc_index), parent);
424 	of_node_put(parent);
425 	if (!dn)
426 		return -EINVAL;
427 
428 	rc = dlpar_attach_node(dn);
429 	if (rc) {
430 		dlpar_release_drc(drc_index);
431 		dlpar_free_cc_nodes(dn);
432 		return rc;
433 	}
434 
435 	rc = dlpar_online_cpu(dn);
436 	if (rc)
437 		return rc;
438 
439 	return count;
440 }
441 
442 static int dlpar_offline_cpu(struct device_node *dn)
443 {
444 	int rc = 0;
445 	unsigned int cpu;
446 	int len, nthreads, i;
447 	const __be32 *intserv;
448 	u32 thread;
449 
450 	intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
451 	if (!intserv)
452 		return -EINVAL;
453 
454 	nthreads = len / sizeof(u32);
455 
456 	cpu_maps_update_begin();
457 	for (i = 0; i < nthreads; i++) {
458 		thread = be32_to_cpu(intserv[i]);
459 		for_each_present_cpu(cpu) {
460 			if (get_hard_smp_processor_id(cpu) != thread)
461 				continue;
462 
463 			if (get_cpu_current_state(cpu) == CPU_STATE_OFFLINE)
464 				break;
465 
466 			if (get_cpu_current_state(cpu) == CPU_STATE_ONLINE) {
467 				set_preferred_offline_state(cpu, CPU_STATE_OFFLINE);
468 				cpu_maps_update_done();
469 				rc = device_offline(get_cpu_device(cpu));
470 				if (rc)
471 					goto out;
472 				cpu_maps_update_begin();
473 				break;
474 
475 			}
476 
477 			/*
478 			 * The cpu is in CPU_STATE_INACTIVE.
479 			 * Upgrade it's state to CPU_STATE_OFFLINE.
480 			 */
481 			set_preferred_offline_state(cpu, CPU_STATE_OFFLINE);
482 			BUG_ON(plpar_hcall_norets(H_PROD, thread)
483 								!= H_SUCCESS);
484 			__cpu_die(cpu);
485 			break;
486 		}
487 		if (cpu == num_possible_cpus())
488 			printk(KERN_WARNING "Could not find cpu to offline "
489 			       "with physical id 0x%x\n", thread);
490 	}
491 	cpu_maps_update_done();
492 
493 out:
494 	return rc;
495 
496 }
497 
498 static ssize_t dlpar_cpu_release(const char *buf, size_t count)
499 {
500 	struct device_node *dn;
501 	u32 drc_index;
502 	int rc;
503 
504 	dn = of_find_node_by_path(buf);
505 	if (!dn)
506 		return -EINVAL;
507 
508 	rc = of_property_read_u32(dn, "ibm,my-drc-index", &drc_index);
509 	if (rc) {
510 		of_node_put(dn);
511 		return -EINVAL;
512 	}
513 
514 	rc = dlpar_offline_cpu(dn);
515 	if (rc) {
516 		of_node_put(dn);
517 		return -EINVAL;
518 	}
519 
520 	rc = dlpar_release_drc(drc_index);
521 	if (rc) {
522 		of_node_put(dn);
523 		return rc;
524 	}
525 
526 	rc = dlpar_detach_node(dn);
527 	if (rc) {
528 		dlpar_acquire_drc(drc_index);
529 		return rc;
530 	}
531 
532 	of_node_put(dn);
533 
534 	return count;
535 }
536 
537 #endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
538 
539 static int handle_dlpar_errorlog(struct pseries_hp_errorlog *hp_elog)
540 {
541 	int rc;
542 
543 	/* pseries error logs are in BE format, convert to cpu type */
544 	switch (hp_elog->id_type) {
545 	case PSERIES_HP_ELOG_ID_DRC_COUNT:
546 		hp_elog->_drc_u.drc_count =
547 					be32_to_cpu(hp_elog->_drc_u.drc_count);
548 		break;
549 	case PSERIES_HP_ELOG_ID_DRC_INDEX:
550 		hp_elog->_drc_u.drc_index =
551 					be32_to_cpu(hp_elog->_drc_u.drc_index);
552 	}
553 
554 	switch (hp_elog->resource) {
555 	case PSERIES_HP_ELOG_RESOURCE_MEM:
556 		rc = dlpar_memory(hp_elog);
557 		break;
558 	default:
559 		pr_warn_ratelimited("Invalid resource (%d) specified\n",
560 				    hp_elog->resource);
561 		rc = -EINVAL;
562 	}
563 
564 	return rc;
565 }
566 
567 static ssize_t dlpar_store(struct class *class, struct class_attribute *attr,
568 			   const char *buf, size_t count)
569 {
570 	struct pseries_hp_errorlog *hp_elog;
571 	const char *arg;
572 	int rc;
573 
574 	hp_elog = kzalloc(sizeof(*hp_elog), GFP_KERNEL);
575 	if (!hp_elog) {
576 		rc = -ENOMEM;
577 		goto dlpar_store_out;
578 	}
579 
580 	/* Parse out the request from the user, this will be in the form
581 	 * <resource> <action> <id_type> <id>
582 	 */
583 	arg = buf;
584 	if (!strncmp(arg, "memory", 6)) {
585 		hp_elog->resource = PSERIES_HP_ELOG_RESOURCE_MEM;
586 		arg += strlen("memory ");
587 	} else {
588 		pr_err("Invalid resource specified: \"%s\"\n", buf);
589 		rc = -EINVAL;
590 		goto dlpar_store_out;
591 	}
592 
593 	if (!strncmp(arg, "add", 3)) {
594 		hp_elog->action = PSERIES_HP_ELOG_ACTION_ADD;
595 		arg += strlen("add ");
596 	} else if (!strncmp(arg, "remove", 6)) {
597 		hp_elog->action = PSERIES_HP_ELOG_ACTION_REMOVE;
598 		arg += strlen("remove ");
599 	} else {
600 		pr_err("Invalid action specified: \"%s\"\n", buf);
601 		rc = -EINVAL;
602 		goto dlpar_store_out;
603 	}
604 
605 	if (!strncmp(arg, "index", 5)) {
606 		u32 index;
607 
608 		hp_elog->id_type = PSERIES_HP_ELOG_ID_DRC_INDEX;
609 		arg += strlen("index ");
610 		if (kstrtou32(arg, 0, &index)) {
611 			rc = -EINVAL;
612 			pr_err("Invalid drc_index specified: \"%s\"\n", buf);
613 			goto dlpar_store_out;
614 		}
615 
616 		hp_elog->_drc_u.drc_index = cpu_to_be32(index);
617 	} else if (!strncmp(arg, "count", 5)) {
618 		u32 count;
619 
620 		hp_elog->id_type = PSERIES_HP_ELOG_ID_DRC_COUNT;
621 		arg += strlen("count ");
622 		if (kstrtou32(arg, 0, &count)) {
623 			rc = -EINVAL;
624 			pr_err("Invalid count specified: \"%s\"\n", buf);
625 			goto dlpar_store_out;
626 		}
627 
628 		hp_elog->_drc_u.drc_count = cpu_to_be32(count);
629 	} else {
630 		pr_err("Invalid id_type specified: \"%s\"\n", buf);
631 		rc = -EINVAL;
632 		goto dlpar_store_out;
633 	}
634 
635 	rc = handle_dlpar_errorlog(hp_elog);
636 
637 dlpar_store_out:
638 	kfree(hp_elog);
639 	return rc ? rc : count;
640 }
641 
642 static CLASS_ATTR(dlpar, S_IWUSR, NULL, dlpar_store);
643 
644 static int __init pseries_dlpar_init(void)
645 {
646 	int rc;
647 
648 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
649 	ppc_md.cpu_probe = dlpar_cpu_probe;
650 	ppc_md.cpu_release = dlpar_cpu_release;
651 #endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
652 
653 	rc = sysfs_create_file(kernel_kobj, &class_attr_dlpar.attr);
654 
655 	return rc;
656 }
657 machine_device_initcall(pseries, pseries_dlpar_init);
658 
659