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 #include <linux/kernel.h>
14 #include <linux/kref.h>
15 #include <linux/notifier.h>
16 #include <linux/proc_fs.h>
17 #include <linux/spinlock.h>
18 #include <linux/cpu.h>
19 #include <linux/slab.h>
20 #include "offline_states.h"
21 
22 #include <asm/prom.h>
23 #include <asm/machdep.h>
24 #include <asm/uaccess.h>
25 #include <asm/rtas.h>
26 #include <asm/pSeries_reconfig.h>
27 
28 struct cc_workarea {
29 	u32	drc_index;
30 	u32	zero;
31 	u32	name_offset;
32 	u32	prop_length;
33 	u32	prop_offset;
34 };
35 
36 void dlpar_free_cc_property(struct property *prop)
37 {
38 	kfree(prop->name);
39 	kfree(prop->value);
40 	kfree(prop);
41 }
42 
43 static struct property *dlpar_parse_cc_property(struct cc_workarea *ccwa)
44 {
45 	struct property *prop;
46 	char *name;
47 	char *value;
48 
49 	prop = kzalloc(sizeof(*prop), GFP_KERNEL);
50 	if (!prop)
51 		return NULL;
52 
53 	name = (char *)ccwa + ccwa->name_offset;
54 	prop->name = kstrdup(name, GFP_KERNEL);
55 
56 	prop->length = ccwa->prop_length;
57 	value = (char *)ccwa + ccwa->prop_offset;
58 	prop->value = kmemdup(value, prop->length, GFP_KERNEL);
59 	if (!prop->value) {
60 		dlpar_free_cc_property(prop);
61 		return NULL;
62 	}
63 
64 	return prop;
65 }
66 
67 static struct device_node *dlpar_parse_cc_node(struct cc_workarea *ccwa)
68 {
69 	struct device_node *dn;
70 	char *name;
71 
72 	dn = kzalloc(sizeof(*dn), GFP_KERNEL);
73 	if (!dn)
74 		return NULL;
75 
76 	/* The configure connector reported name does not contain a
77 	 * preceding '/', so we allocate a buffer large enough to
78 	 * prepend this to the full_name.
79 	 */
80 	name = (char *)ccwa + ccwa->name_offset;
81 	dn->full_name = kasprintf(GFP_KERNEL, "/%s", name);
82 	if (!dn->full_name) {
83 		kfree(dn);
84 		return NULL;
85 	}
86 
87 	return dn;
88 }
89 
90 static void dlpar_free_one_cc_node(struct device_node *dn)
91 {
92 	struct property *prop;
93 
94 	while (dn->properties) {
95 		prop = dn->properties;
96 		dn->properties = prop->next;
97 		dlpar_free_cc_property(prop);
98 	}
99 
100 	kfree(dn->full_name);
101 	kfree(dn);
102 }
103 
104 void dlpar_free_cc_nodes(struct device_node *dn)
105 {
106 	if (dn->child)
107 		dlpar_free_cc_nodes(dn->child);
108 
109 	if (dn->sibling)
110 		dlpar_free_cc_nodes(dn->sibling);
111 
112 	dlpar_free_one_cc_node(dn);
113 }
114 
115 #define COMPLETE	0
116 #define NEXT_SIBLING    1
117 #define NEXT_CHILD      2
118 #define NEXT_PROPERTY   3
119 #define PREV_PARENT     4
120 #define MORE_MEMORY     5
121 #define CALL_AGAIN	-2
122 #define ERR_CFG_USE     -9003
123 
124 struct device_node *dlpar_configure_connector(u32 drc_index)
125 {
126 	struct device_node *dn;
127 	struct device_node *first_dn = NULL;
128 	struct device_node *last_dn = NULL;
129 	struct property *property;
130 	struct property *last_property = NULL;
131 	struct cc_workarea *ccwa;
132 	char *data_buf;
133 	int cc_token;
134 	int rc = -1;
135 
136 	cc_token = rtas_token("ibm,configure-connector");
137 	if (cc_token == RTAS_UNKNOWN_SERVICE)
138 		return NULL;
139 
140 	data_buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
141 	if (!data_buf)
142 		return NULL;
143 
144 	ccwa = (struct cc_workarea *)&data_buf[0];
145 	ccwa->drc_index = drc_index;
146 	ccwa->zero = 0;
147 
148 	do {
149 		/* Since we release the rtas_data_buf lock between configure
150 		 * connector calls we want to re-populate the rtas_data_buffer
151 		 * with the contents of the previous call.
152 		 */
153 		spin_lock(&rtas_data_buf_lock);
154 
155 		memcpy(rtas_data_buf, data_buf, RTAS_DATA_BUF_SIZE);
156 		rc = rtas_call(cc_token, 2, 1, NULL, rtas_data_buf, NULL);
157 		memcpy(data_buf, rtas_data_buf, RTAS_DATA_BUF_SIZE);
158 
159 		spin_unlock(&rtas_data_buf_lock);
160 
161 		switch (rc) {
162 		case COMPLETE:
163 			break;
164 
165 		case NEXT_SIBLING:
166 			dn = dlpar_parse_cc_node(ccwa);
167 			if (!dn)
168 				goto cc_error;
169 
170 			dn->parent = last_dn->parent;
171 			last_dn->sibling = dn;
172 			last_dn = dn;
173 			break;
174 
175 		case NEXT_CHILD:
176 			dn = dlpar_parse_cc_node(ccwa);
177 			if (!dn)
178 				goto cc_error;
179 
180 			if (!first_dn)
181 				first_dn = dn;
182 			else {
183 				dn->parent = last_dn;
184 				if (last_dn)
185 					last_dn->child = dn;
186 			}
187 
188 			last_dn = dn;
189 			break;
190 
191 		case NEXT_PROPERTY:
192 			property = dlpar_parse_cc_property(ccwa);
193 			if (!property)
194 				goto cc_error;
195 
196 			if (!last_dn->properties)
197 				last_dn->properties = property;
198 			else
199 				last_property->next = property;
200 
201 			last_property = property;
202 			break;
203 
204 		case PREV_PARENT:
205 			last_dn = last_dn->parent;
206 			break;
207 
208 		case CALL_AGAIN:
209 			break;
210 
211 		case MORE_MEMORY:
212 		case ERR_CFG_USE:
213 		default:
214 			printk(KERN_ERR "Unexpected Error (%d) "
215 			       "returned from configure-connector\n", rc);
216 			goto cc_error;
217 		}
218 	} while (rc);
219 
220 cc_error:
221 	kfree(data_buf);
222 
223 	if (rc) {
224 		if (first_dn)
225 			dlpar_free_cc_nodes(first_dn);
226 
227 		return NULL;
228 	}
229 
230 	return first_dn;
231 }
232 
233 static struct device_node *derive_parent(const char *path)
234 {
235 	struct device_node *parent;
236 	char *last_slash;
237 
238 	last_slash = strrchr(path, '/');
239 	if (last_slash == path) {
240 		parent = of_find_node_by_path("/");
241 	} else {
242 		char *parent_path;
243 		int parent_path_len = last_slash - path + 1;
244 		parent_path = kmalloc(parent_path_len, GFP_KERNEL);
245 		if (!parent_path)
246 			return NULL;
247 
248 		strlcpy(parent_path, path, parent_path_len);
249 		parent = of_find_node_by_path(parent_path);
250 		kfree(parent_path);
251 	}
252 
253 	return parent;
254 }
255 
256 int dlpar_attach_node(struct device_node *dn)
257 {
258 #ifdef CONFIG_PROC_DEVICETREE
259 	struct proc_dir_entry *ent;
260 #endif
261 	int rc;
262 
263 	of_node_set_flag(dn, OF_DYNAMIC);
264 	kref_init(&dn->kref);
265 	dn->parent = derive_parent(dn->full_name);
266 	if (!dn->parent)
267 		return -ENOMEM;
268 
269 	rc = pSeries_reconfig_notify(PSERIES_RECONFIG_ADD, dn);
270 	if (rc) {
271 		printk(KERN_ERR "Failed to add device node %s\n",
272 		       dn->full_name);
273 		return rc;
274 	}
275 
276 	of_attach_node(dn);
277 
278 #ifdef CONFIG_PROC_DEVICETREE
279 	ent = proc_mkdir(strrchr(dn->full_name, '/') + 1, dn->parent->pde);
280 	if (ent)
281 		proc_device_tree_add_node(dn, ent);
282 #endif
283 
284 	of_node_put(dn->parent);
285 	return 0;
286 }
287 
288 int dlpar_detach_node(struct device_node *dn)
289 {
290 #ifdef CONFIG_PROC_DEVICETREE
291 	struct device_node *parent = dn->parent;
292 	struct property *prop = dn->properties;
293 
294 	while (prop) {
295 		remove_proc_entry(prop->name, dn->pde);
296 		prop = prop->next;
297 	}
298 
299 	if (dn->pde)
300 		remove_proc_entry(dn->pde->name, parent->pde);
301 #endif
302 
303 	pSeries_reconfig_notify(PSERIES_RECONFIG_REMOVE, dn);
304 	of_detach_node(dn);
305 	of_node_put(dn); /* Must decrement the refcount */
306 
307 	return 0;
308 }
309 
310 #define DR_ENTITY_SENSE		9003
311 #define DR_ENTITY_PRESENT	1
312 #define DR_ENTITY_UNUSABLE	2
313 #define ALLOCATION_STATE	9003
314 #define ALLOC_UNUSABLE		0
315 #define ALLOC_USABLE		1
316 #define ISOLATION_STATE		9001
317 #define ISOLATE			0
318 #define UNISOLATE		1
319 
320 int dlpar_acquire_drc(u32 drc_index)
321 {
322 	int dr_status, rc;
323 
324 	rc = rtas_call(rtas_token("get-sensor-state"), 2, 2, &dr_status,
325 		       DR_ENTITY_SENSE, drc_index);
326 	if (rc || dr_status != DR_ENTITY_UNUSABLE)
327 		return -1;
328 
329 	rc = rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_USABLE);
330 	if (rc)
331 		return rc;
332 
333 	rc = rtas_set_indicator(ISOLATION_STATE, drc_index, UNISOLATE);
334 	if (rc) {
335 		rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_UNUSABLE);
336 		return rc;
337 	}
338 
339 	return 0;
340 }
341 
342 int dlpar_release_drc(u32 drc_index)
343 {
344 	int dr_status, rc;
345 
346 	rc = rtas_call(rtas_token("get-sensor-state"), 2, 2, &dr_status,
347 		       DR_ENTITY_SENSE, drc_index);
348 	if (rc || dr_status != DR_ENTITY_PRESENT)
349 		return -1;
350 
351 	rc = rtas_set_indicator(ISOLATION_STATE, drc_index, ISOLATE);
352 	if (rc)
353 		return rc;
354 
355 	rc = rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_UNUSABLE);
356 	if (rc) {
357 		rtas_set_indicator(ISOLATION_STATE, drc_index, UNISOLATE);
358 		return rc;
359 	}
360 
361 	return 0;
362 }
363 
364 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
365 
366 static int dlpar_online_cpu(struct device_node *dn)
367 {
368 	int rc = 0;
369 	unsigned int cpu;
370 	int len, nthreads, i;
371 	const u32 *intserv;
372 
373 	intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
374 	if (!intserv)
375 		return -EINVAL;
376 
377 	nthreads = len / sizeof(u32);
378 
379 	cpu_maps_update_begin();
380 	for (i = 0; i < nthreads; i++) {
381 		for_each_present_cpu(cpu) {
382 			if (get_hard_smp_processor_id(cpu) != intserv[i])
383 				continue;
384 			BUG_ON(get_cpu_current_state(cpu)
385 					!= CPU_STATE_OFFLINE);
386 			cpu_maps_update_done();
387 			rc = cpu_up(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", intserv[i]);
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;
408 	unsigned long drc_index;
409 	char *cpu_name;
410 	int rc;
411 
412 	cpu_hotplug_driver_lock();
413 	rc = strict_strtoul(buf, 0, &drc_index);
414 	if (rc) {
415 		rc = -EINVAL;
416 		goto out;
417 	}
418 
419 	dn = dlpar_configure_connector(drc_index);
420 	if (!dn) {
421 		rc = -EINVAL;
422 		goto out;
423 	}
424 
425 	/* configure-connector reports cpus as living in the base
426 	 * directory of the device tree.  CPUs actually live in the
427 	 * cpus directory so we need to fixup the full_name.
428 	 */
429 	cpu_name = kasprintf(GFP_KERNEL, "/cpus%s", dn->full_name);
430 	if (!cpu_name) {
431 		dlpar_free_cc_nodes(dn);
432 		rc = -ENOMEM;
433 		goto out;
434 	}
435 
436 	kfree(dn->full_name);
437 	dn->full_name = cpu_name;
438 
439 	rc = dlpar_acquire_drc(drc_index);
440 	if (rc) {
441 		dlpar_free_cc_nodes(dn);
442 		rc = -EINVAL;
443 		goto out;
444 	}
445 
446 	rc = dlpar_attach_node(dn);
447 	if (rc) {
448 		dlpar_release_drc(drc_index);
449 		dlpar_free_cc_nodes(dn);
450 		goto out;
451 	}
452 
453 	rc = dlpar_online_cpu(dn);
454 out:
455 	cpu_hotplug_driver_unlock();
456 
457 	return rc ? rc : count;
458 }
459 
460 static int dlpar_offline_cpu(struct device_node *dn)
461 {
462 	int rc = 0;
463 	unsigned int cpu;
464 	int len, nthreads, i;
465 	const u32 *intserv;
466 
467 	intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
468 	if (!intserv)
469 		return -EINVAL;
470 
471 	nthreads = len / sizeof(u32);
472 
473 	cpu_maps_update_begin();
474 	for (i = 0; i < nthreads; i++) {
475 		for_each_present_cpu(cpu) {
476 			if (get_hard_smp_processor_id(cpu) != intserv[i])
477 				continue;
478 
479 			if (get_cpu_current_state(cpu) == CPU_STATE_OFFLINE)
480 				break;
481 
482 			if (get_cpu_current_state(cpu) == CPU_STATE_ONLINE) {
483 				set_preferred_offline_state(cpu, CPU_STATE_OFFLINE);
484 				cpu_maps_update_done();
485 				rc = cpu_down(cpu);
486 				if (rc)
487 					goto out;
488 				cpu_maps_update_begin();
489 				break;
490 
491 			}
492 
493 			/*
494 			 * The cpu is in CPU_STATE_INACTIVE.
495 			 * Upgrade it's state to CPU_STATE_OFFLINE.
496 			 */
497 			set_preferred_offline_state(cpu, CPU_STATE_OFFLINE);
498 			BUG_ON(plpar_hcall_norets(H_PROD, intserv[i])
499 								!= H_SUCCESS);
500 			__cpu_die(cpu);
501 			break;
502 		}
503 		if (cpu == num_possible_cpus())
504 			printk(KERN_WARNING "Could not find cpu to offline "
505 			       "with physical id 0x%x\n", intserv[i]);
506 	}
507 	cpu_maps_update_done();
508 
509 out:
510 	return rc;
511 
512 }
513 
514 static ssize_t dlpar_cpu_release(const char *buf, size_t count)
515 {
516 	struct device_node *dn;
517 	const u32 *drc_index;
518 	int rc;
519 
520 	dn = of_find_node_by_path(buf);
521 	if (!dn)
522 		return -EINVAL;
523 
524 	drc_index = of_get_property(dn, "ibm,my-drc-index", NULL);
525 	if (!drc_index) {
526 		of_node_put(dn);
527 		return -EINVAL;
528 	}
529 
530 	cpu_hotplug_driver_lock();
531 	rc = dlpar_offline_cpu(dn);
532 	if (rc) {
533 		of_node_put(dn);
534 		rc = -EINVAL;
535 		goto out;
536 	}
537 
538 	rc = dlpar_release_drc(*drc_index);
539 	if (rc) {
540 		of_node_put(dn);
541 		goto out;
542 	}
543 
544 	rc = dlpar_detach_node(dn);
545 	if (rc) {
546 		dlpar_acquire_drc(*drc_index);
547 		goto out;
548 	}
549 
550 	of_node_put(dn);
551 out:
552 	cpu_hotplug_driver_unlock();
553 	return rc ? rc : count;
554 }
555 
556 static int __init pseries_dlpar_init(void)
557 {
558 	ppc_md.cpu_probe = dlpar_cpu_probe;
559 	ppc_md.cpu_release = dlpar_cpu_release;
560 
561 	return 0;
562 }
563 machine_device_initcall(pseries, pseries_dlpar_init);
564 
565 #endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
566