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 	 * preceeding '/', 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 NEXT_SIBLING    1
116 #define NEXT_CHILD      2
117 #define NEXT_PROPERTY   3
118 #define PREV_PARENT     4
119 #define MORE_MEMORY     5
120 #define CALL_AGAIN	-2
121 #define ERR_CFG_USE     -9003
122 
123 struct device_node *dlpar_configure_connector(u32 drc_index)
124 {
125 	struct device_node *dn;
126 	struct device_node *first_dn = NULL;
127 	struct device_node *last_dn = NULL;
128 	struct property *property;
129 	struct property *last_property = NULL;
130 	struct cc_workarea *ccwa;
131 	char *data_buf;
132 	int cc_token;
133 	int rc = -1;
134 
135 	cc_token = rtas_token("ibm,configure-connector");
136 	if (cc_token == RTAS_UNKNOWN_SERVICE)
137 		return NULL;
138 
139 	data_buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
140 	if (!data_buf)
141 		return NULL;
142 
143 	ccwa = (struct cc_workarea *)&data_buf[0];
144 	ccwa->drc_index = drc_index;
145 	ccwa->zero = 0;
146 
147 	do {
148 		/* Since we release the rtas_data_buf lock between configure
149 		 * connector calls we want to re-populate the rtas_data_buffer
150 		 * with the contents of the previous call.
151 		 */
152 		spin_lock(&rtas_data_buf_lock);
153 
154 		memcpy(rtas_data_buf, data_buf, RTAS_DATA_BUF_SIZE);
155 		rc = rtas_call(cc_token, 2, 1, NULL, rtas_data_buf, NULL);
156 		memcpy(data_buf, rtas_data_buf, RTAS_DATA_BUF_SIZE);
157 
158 		spin_unlock(&rtas_data_buf_lock);
159 
160 		switch (rc) {
161 		case NEXT_SIBLING:
162 			dn = dlpar_parse_cc_node(ccwa);
163 			if (!dn)
164 				goto cc_error;
165 
166 			dn->parent = last_dn->parent;
167 			last_dn->sibling = dn;
168 			last_dn = dn;
169 			break;
170 
171 		case NEXT_CHILD:
172 			dn = dlpar_parse_cc_node(ccwa);
173 			if (!dn)
174 				goto cc_error;
175 
176 			if (!first_dn)
177 				first_dn = dn;
178 			else {
179 				dn->parent = last_dn;
180 				if (last_dn)
181 					last_dn->child = dn;
182 			}
183 
184 			last_dn = dn;
185 			break;
186 
187 		case NEXT_PROPERTY:
188 			property = dlpar_parse_cc_property(ccwa);
189 			if (!property)
190 				goto cc_error;
191 
192 			if (!last_dn->properties)
193 				last_dn->properties = property;
194 			else
195 				last_property->next = property;
196 
197 			last_property = property;
198 			break;
199 
200 		case PREV_PARENT:
201 			last_dn = last_dn->parent;
202 			break;
203 
204 		case CALL_AGAIN:
205 			break;
206 
207 		case MORE_MEMORY:
208 		case ERR_CFG_USE:
209 		default:
210 			printk(KERN_ERR "Unexpected Error (%d) "
211 			       "returned from configure-connector\n", rc);
212 			goto cc_error;
213 		}
214 	} while (rc);
215 
216 cc_error:
217 	kfree(data_buf);
218 
219 	if (rc) {
220 		if (first_dn)
221 			dlpar_free_cc_nodes(first_dn);
222 
223 		return NULL;
224 	}
225 
226 	return first_dn;
227 }
228 
229 static struct device_node *derive_parent(const char *path)
230 {
231 	struct device_node *parent;
232 	char *last_slash;
233 
234 	last_slash = strrchr(path, '/');
235 	if (last_slash == path) {
236 		parent = of_find_node_by_path("/");
237 	} else {
238 		char *parent_path;
239 		int parent_path_len = last_slash - path + 1;
240 		parent_path = kmalloc(parent_path_len, GFP_KERNEL);
241 		if (!parent_path)
242 			return NULL;
243 
244 		strlcpy(parent_path, path, parent_path_len);
245 		parent = of_find_node_by_path(parent_path);
246 		kfree(parent_path);
247 	}
248 
249 	return parent;
250 }
251 
252 int dlpar_attach_node(struct device_node *dn)
253 {
254 #ifdef CONFIG_PROC_DEVICETREE
255 	struct proc_dir_entry *ent;
256 #endif
257 	int rc;
258 
259 	of_node_set_flag(dn, OF_DYNAMIC);
260 	kref_init(&dn->kref);
261 	dn->parent = derive_parent(dn->full_name);
262 	if (!dn->parent)
263 		return -ENOMEM;
264 
265 	rc = blocking_notifier_call_chain(&pSeries_reconfig_chain,
266 					  PSERIES_RECONFIG_ADD, dn);
267 	if (rc == NOTIFY_BAD) {
268 		printk(KERN_ERR "Failed to add device node %s\n",
269 		       dn->full_name);
270 		return -ENOMEM; /* For now, safe to assume kmalloc failure */
271 	}
272 
273 	of_attach_node(dn);
274 
275 #ifdef CONFIG_PROC_DEVICETREE
276 	ent = proc_mkdir(strrchr(dn->full_name, '/') + 1, dn->parent->pde);
277 	if (ent)
278 		proc_device_tree_add_node(dn, ent);
279 #endif
280 
281 	of_node_put(dn->parent);
282 	return 0;
283 }
284 
285 int dlpar_detach_node(struct device_node *dn)
286 {
287 #ifdef CONFIG_PROC_DEVICETREE
288 	struct device_node *parent = dn->parent;
289 	struct property *prop = dn->properties;
290 
291 	while (prop) {
292 		remove_proc_entry(prop->name, dn->pde);
293 		prop = prop->next;
294 	}
295 
296 	if (dn->pde)
297 		remove_proc_entry(dn->pde->name, parent->pde);
298 #endif
299 
300 	blocking_notifier_call_chain(&pSeries_reconfig_chain,
301 			    PSERIES_RECONFIG_REMOVE, dn);
302 	of_detach_node(dn);
303 	of_node_put(dn); /* Must decrement the refcount */
304 
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 u32 *intserv;
370 
371 	intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
372 	if (!intserv)
373 		return -EINVAL;
374 
375 	nthreads = len / sizeof(u32);
376 
377 	cpu_maps_update_begin();
378 	for (i = 0; i < nthreads; i++) {
379 		for_each_present_cpu(cpu) {
380 			if (get_hard_smp_processor_id(cpu) != intserv[i])
381 				continue;
382 			BUG_ON(get_cpu_current_state(cpu)
383 					!= CPU_STATE_OFFLINE);
384 			cpu_maps_update_done();
385 			rc = cpu_up(cpu);
386 			if (rc)
387 				goto out;
388 			cpu_maps_update_begin();
389 
390 			break;
391 		}
392 		if (cpu == num_possible_cpus())
393 			printk(KERN_WARNING "Could not find cpu to online "
394 			       "with physical id 0x%x\n", intserv[i]);
395 	}
396 	cpu_maps_update_done();
397 
398 out:
399 	return rc;
400 
401 }
402 
403 static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
404 {
405 	struct device_node *dn;
406 	unsigned long drc_index;
407 	char *cpu_name;
408 	int rc;
409 
410 	cpu_hotplug_driver_lock();
411 	rc = strict_strtoul(buf, 0, &drc_index);
412 	if (rc) {
413 		rc = -EINVAL;
414 		goto out;
415 	}
416 
417 	dn = dlpar_configure_connector(drc_index);
418 	if (!dn) {
419 		rc = -EINVAL;
420 		goto out;
421 	}
422 
423 	/* configure-connector reports cpus as living in the base
424 	 * directory of the device tree.  CPUs actually live in the
425 	 * cpus directory so we need to fixup the full_name.
426 	 */
427 	cpu_name = kasprintf(GFP_KERNEL, "/cpus%s", dn->full_name);
428 	if (!cpu_name) {
429 		dlpar_free_cc_nodes(dn);
430 		rc = -ENOMEM;
431 		goto out;
432 	}
433 
434 	kfree(dn->full_name);
435 	dn->full_name = cpu_name;
436 
437 	rc = dlpar_acquire_drc(drc_index);
438 	if (rc) {
439 		dlpar_free_cc_nodes(dn);
440 		rc = -EINVAL;
441 		goto out;
442 	}
443 
444 	rc = dlpar_attach_node(dn);
445 	if (rc) {
446 		dlpar_release_drc(drc_index);
447 		dlpar_free_cc_nodes(dn);
448 		goto out;
449 	}
450 
451 	rc = dlpar_online_cpu(dn);
452 out:
453 	cpu_hotplug_driver_unlock();
454 
455 	return rc ? rc : count;
456 }
457 
458 static int dlpar_offline_cpu(struct device_node *dn)
459 {
460 	int rc = 0;
461 	unsigned int cpu;
462 	int len, nthreads, i;
463 	const u32 *intserv;
464 
465 	intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
466 	if (!intserv)
467 		return -EINVAL;
468 
469 	nthreads = len / sizeof(u32);
470 
471 	cpu_maps_update_begin();
472 	for (i = 0; i < nthreads; i++) {
473 		for_each_present_cpu(cpu) {
474 			if (get_hard_smp_processor_id(cpu) != intserv[i])
475 				continue;
476 
477 			if (get_cpu_current_state(cpu) == CPU_STATE_OFFLINE)
478 				break;
479 
480 			if (get_cpu_current_state(cpu) == CPU_STATE_ONLINE) {
481 				set_preferred_offline_state(cpu, CPU_STATE_OFFLINE);
482 				cpu_maps_update_done();
483 				rc = cpu_down(cpu);
484 				if (rc)
485 					goto out;
486 				cpu_maps_update_begin();
487 				break;
488 
489 			}
490 
491 			/*
492 			 * The cpu is in CPU_STATE_INACTIVE.
493 			 * Upgrade it's state to CPU_STATE_OFFLINE.
494 			 */
495 			set_preferred_offline_state(cpu, CPU_STATE_OFFLINE);
496 			BUG_ON(plpar_hcall_norets(H_PROD, intserv[i])
497 								!= H_SUCCESS);
498 			__cpu_die(cpu);
499 			break;
500 		}
501 		if (cpu == num_possible_cpus())
502 			printk(KERN_WARNING "Could not find cpu to offline "
503 			       "with physical id 0x%x\n", intserv[i]);
504 	}
505 	cpu_maps_update_done();
506 
507 out:
508 	return rc;
509 
510 }
511 
512 static ssize_t dlpar_cpu_release(const char *buf, size_t count)
513 {
514 	struct device_node *dn;
515 	const u32 *drc_index;
516 	int rc;
517 
518 	dn = of_find_node_by_path(buf);
519 	if (!dn)
520 		return -EINVAL;
521 
522 	drc_index = of_get_property(dn, "ibm,my-drc-index", NULL);
523 	if (!drc_index) {
524 		of_node_put(dn);
525 		return -EINVAL;
526 	}
527 
528 	cpu_hotplug_driver_lock();
529 	rc = dlpar_offline_cpu(dn);
530 	if (rc) {
531 		of_node_put(dn);
532 		rc = -EINVAL;
533 		goto out;
534 	}
535 
536 	rc = dlpar_release_drc(*drc_index);
537 	if (rc) {
538 		of_node_put(dn);
539 		goto out;
540 	}
541 
542 	rc = dlpar_detach_node(dn);
543 	if (rc) {
544 		dlpar_acquire_drc(*drc_index);
545 		goto out;
546 	}
547 
548 	of_node_put(dn);
549 out:
550 	cpu_hotplug_driver_unlock();
551 	return rc ? rc : count;
552 }
553 
554 static int __init pseries_dlpar_init(void)
555 {
556 	ppc_md.cpu_probe = dlpar_cpu_probe;
557 	ppc_md.cpu_release = dlpar_cpu_release;
558 
559 	return 0;
560 }
561 machine_device_initcall(pseries, pseries_dlpar_init);
562 
563 #endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
564