1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Support for Partition Mobility/Migration
4 *
5 * Copyright (C) 2010 Nathan Fontenot
6 * Copyright (C) 2010 IBM Corporation
7 */
8
9
10#define pr_fmt(fmt) "mobility: " fmt
11
12#include <linux/cpu.h>
13#include <linux/kernel.h>
14#include <linux/kobject.h>
15#include <linux/nmi.h>
16#include <linux/sched.h>
17#include <linux/smp.h>
18#include <linux/stat.h>
19#include <linux/stop_machine.h>
20#include <linux/completion.h>
21#include <linux/device.h>
22#include <linux/delay.h>
23#include <linux/slab.h>
24#include <linux/stringify.h>
25
26#include <asm/machdep.h>
27#include <asm/nmi.h>
28#include <asm/rtas.h>
29#include "pseries.h"
30#include "vas.h"	/* vas_migration_handler() */
31#include "../../kernel/cacheinfo.h"
32
33static struct kobject *mobility_kobj;
34
35struct update_props_workarea {
36	__be32 phandle;
37	__be32 state;
38	__be64 reserved;
39	__be32 nprops;
40} __packed;
41
42#define NODE_ACTION_MASK	0xff000000
43#define NODE_COUNT_MASK		0x00ffffff
44
45#define DELETE_DT_NODE	0x01000000
46#define UPDATE_DT_NODE	0x02000000
47#define ADD_DT_NODE	0x03000000
48
49#define MIGRATION_SCOPE	(1)
50#define PRRN_SCOPE -2
51
52#ifdef CONFIG_PPC_WATCHDOG
53static unsigned int nmi_wd_lpm_factor = 200;
54
55#ifdef CONFIG_SYSCTL
56static struct ctl_table nmi_wd_lpm_factor_ctl_table[] = {
57	{
58		.procname	= "nmi_wd_lpm_factor",
59		.data		= &nmi_wd_lpm_factor,
60		.maxlen		= sizeof(int),
61		.mode		= 0644,
62		.proc_handler	= proc_douintvec_minmax,
63	},
64};
65
66static int __init register_nmi_wd_lpm_factor_sysctl(void)
67{
68	register_sysctl("kernel", nmi_wd_lpm_factor_ctl_table);
69
70	return 0;
71}
72device_initcall(register_nmi_wd_lpm_factor_sysctl);
73#endif /* CONFIG_SYSCTL */
74#endif /* CONFIG_PPC_WATCHDOG */
75
76static int mobility_rtas_call(int token, char *buf, s32 scope)
77{
78	int rc;
79
80	spin_lock(&rtas_data_buf_lock);
81
82	memcpy(rtas_data_buf, buf, RTAS_DATA_BUF_SIZE);
83	rc = rtas_call(token, 2, 1, NULL, rtas_data_buf, scope);
84	memcpy(buf, rtas_data_buf, RTAS_DATA_BUF_SIZE);
85
86	spin_unlock(&rtas_data_buf_lock);
87	return rc;
88}
89
90static int delete_dt_node(struct device_node *dn)
91{
92	struct device_node *pdn;
93	bool is_platfac;
94
95	pdn = of_get_parent(dn);
96	is_platfac = of_node_is_type(dn, "ibm,platform-facilities") ||
97		     of_node_is_type(pdn, "ibm,platform-facilities");
98	of_node_put(pdn);
99
100	/*
101	 * The drivers that bind to nodes in the platform-facilities
102	 * hierarchy don't support node removal, and the removal directive
103	 * from firmware is always followed by an add of an equivalent
104	 * node. The capability (e.g. RNG, encryption, compression)
105	 * represented by the node is never interrupted by the migration.
106	 * So ignore changes to this part of the tree.
107	 */
108	if (is_platfac) {
109		pr_notice("ignoring remove operation for %pOFfp\n", dn);
110		return 0;
111	}
112
113	pr_debug("removing node %pOFfp\n", dn);
114	dlpar_detach_node(dn);
115	return 0;
116}
117
118static int update_dt_property(struct device_node *dn, struct property **prop,
119			      const char *name, u32 vd, char *value)
120{
121	struct property *new_prop = *prop;
122	int more = 0;
123
124	/* A negative 'vd' value indicates that only part of the new property
125	 * value is contained in the buffer and we need to call
126	 * ibm,update-properties again to get the rest of the value.
127	 *
128	 * A negative value is also the two's compliment of the actual value.
129	 */
130	if (vd & 0x80000000) {
131		vd = ~vd + 1;
132		more = 1;
133	}
134
135	if (new_prop) {
136		/* partial property fixup */
137		char *new_data = kzalloc(new_prop->length + vd, GFP_KERNEL);
138		if (!new_data)
139			return -ENOMEM;
140
141		memcpy(new_data, new_prop->value, new_prop->length);
142		memcpy(new_data + new_prop->length, value, vd);
143
144		kfree(new_prop->value);
145		new_prop->value = new_data;
146		new_prop->length += vd;
147	} else {
148		new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
149		if (!new_prop)
150			return -ENOMEM;
151
152		new_prop->name = kstrdup(name, GFP_KERNEL);
153		if (!new_prop->name) {
154			kfree(new_prop);
155			return -ENOMEM;
156		}
157
158		new_prop->length = vd;
159		new_prop->value = kzalloc(new_prop->length, GFP_KERNEL);
160		if (!new_prop->value) {
161			kfree(new_prop->name);
162			kfree(new_prop);
163			return -ENOMEM;
164		}
165
166		memcpy(new_prop->value, value, vd);
167		*prop = new_prop;
168	}
169
170	if (!more) {
171		pr_debug("updating node %pOF property %s\n", dn, name);
172		of_update_property(dn, new_prop);
173		*prop = NULL;
174	}
175
176	return 0;
177}
178
179static int update_dt_node(struct device_node *dn, s32 scope)
180{
181	struct update_props_workarea *upwa;
182	struct property *prop = NULL;
183	int i, rc, rtas_rc;
184	char *prop_data;
185	char *rtas_buf;
186	int update_properties_token;
187	u32 nprops;
188	u32 vd;
189
190	update_properties_token = rtas_function_token(RTAS_FN_IBM_UPDATE_PROPERTIES);
191	if (update_properties_token == RTAS_UNKNOWN_SERVICE)
192		return -EINVAL;
193
194	rtas_buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
195	if (!rtas_buf)
196		return -ENOMEM;
197
198	upwa = (struct update_props_workarea *)&rtas_buf[0];
199	upwa->phandle = cpu_to_be32(dn->phandle);
200
201	do {
202		rtas_rc = mobility_rtas_call(update_properties_token, rtas_buf,
203					scope);
204		if (rtas_rc < 0)
205			break;
206
207		prop_data = rtas_buf + sizeof(*upwa);
208		nprops = be32_to_cpu(upwa->nprops);
209
210		/* On the first call to ibm,update-properties for a node the
211		 * first property value descriptor contains an empty
212		 * property name, the property value length encoded as u32,
213		 * and the property value is the node path being updated.
214		 */
215		if (*prop_data == 0) {
216			prop_data++;
217			vd = be32_to_cpu(*(__be32 *)prop_data);
218			prop_data += vd + sizeof(vd);
219			nprops--;
220		}
221
222		for (i = 0; i < nprops; i++) {
223			char *prop_name;
224
225			prop_name = prop_data;
226			prop_data += strlen(prop_name) + 1;
227			vd = be32_to_cpu(*(__be32 *)prop_data);
228			prop_data += sizeof(vd);
229
230			switch (vd) {
231			case 0x00000000:
232				/* name only property, nothing to do */
233				break;
234
235			case 0x80000000:
236				of_remove_property(dn, of_find_property(dn,
237							prop_name, NULL));
238				prop = NULL;
239				break;
240
241			default:
242				rc = update_dt_property(dn, &prop, prop_name,
243							vd, prop_data);
244				if (rc) {
245					pr_err("updating %s property failed: %d\n",
246					       prop_name, rc);
247				}
248
249				prop_data += vd;
250				break;
251			}
252
253			cond_resched();
254		}
255
256		cond_resched();
257	} while (rtas_rc == 1);
258
259	kfree(rtas_buf);
260	return 0;
261}
262
263static int add_dt_node(struct device_node *parent_dn, __be32 drc_index)
264{
265	struct device_node *dn;
266	int rc;
267
268	dn = dlpar_configure_connector(drc_index, parent_dn);
269	if (!dn)
270		return -ENOENT;
271
272	/*
273	 * Since delete_dt_node() ignores this node type, this is the
274	 * necessary counterpart. We also know that a platform-facilities
275	 * node returned from dlpar_configure_connector() has children
276	 * attached, and dlpar_attach_node() only adds the parent, leaking
277	 * the children. So ignore these on the add side for now.
278	 */
279	if (of_node_is_type(dn, "ibm,platform-facilities")) {
280		pr_notice("ignoring add operation for %pOF\n", dn);
281		dlpar_free_cc_nodes(dn);
282		return 0;
283	}
284
285	rc = dlpar_attach_node(dn, parent_dn);
286	if (rc)
287		dlpar_free_cc_nodes(dn);
288
289	pr_debug("added node %pOFfp\n", dn);
290
291	return rc;
292}
293
294static int pseries_devicetree_update(s32 scope)
295{
296	char *rtas_buf;
297	__be32 *data;
298	int update_nodes_token;
299	int rc;
300
301	update_nodes_token = rtas_function_token(RTAS_FN_IBM_UPDATE_NODES);
302	if (update_nodes_token == RTAS_UNKNOWN_SERVICE)
303		return 0;
304
305	rtas_buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
306	if (!rtas_buf)
307		return -ENOMEM;
308
309	do {
310		rc = mobility_rtas_call(update_nodes_token, rtas_buf, scope);
311		if (rc && rc != 1)
312			break;
313
314		data = (__be32 *)rtas_buf + 4;
315		while (be32_to_cpu(*data) & NODE_ACTION_MASK) {
316			int i;
317			u32 action = be32_to_cpu(*data) & NODE_ACTION_MASK;
318			u32 node_count = be32_to_cpu(*data) & NODE_COUNT_MASK;
319
320			data++;
321
322			for (i = 0; i < node_count; i++) {
323				struct device_node *np;
324				__be32 phandle = *data++;
325				__be32 drc_index;
326
327				np = of_find_node_by_phandle(be32_to_cpu(phandle));
328				if (!np) {
329					pr_warn("Failed lookup: phandle 0x%x for action 0x%x\n",
330						be32_to_cpu(phandle), action);
331					continue;
332				}
333
334				switch (action) {
335				case DELETE_DT_NODE:
336					delete_dt_node(np);
337					break;
338				case UPDATE_DT_NODE:
339					update_dt_node(np, scope);
340					break;
341				case ADD_DT_NODE:
342					drc_index = *data++;
343					add_dt_node(np, drc_index);
344					break;
345				}
346
347				of_node_put(np);
348				cond_resched();
349			}
350		}
351
352		cond_resched();
353	} while (rc == 1);
354
355	kfree(rtas_buf);
356	return rc;
357}
358
359void post_mobility_fixup(void)
360{
361	int rc;
362
363	rtas_activate_firmware();
364
365	/*
366	 * We don't want CPUs to go online/offline while the device
367	 * tree is being updated.
368	 */
369	cpus_read_lock();
370
371	/*
372	 * It's common for the destination firmware to replace cache
373	 * nodes.  Release all of the cacheinfo hierarchy's references
374	 * before updating the device tree.
375	 */
376	cacheinfo_teardown();
377
378	rc = pseries_devicetree_update(MIGRATION_SCOPE);
379	if (rc)
380		pr_err("device tree update failed: %d\n", rc);
381
382	cacheinfo_rebuild();
383
384	cpus_read_unlock();
385
386	/* Possibly switch to a new L1 flush type */
387	pseries_setup_security_mitigations();
388
389	/* Reinitialise system information for hv-24x7 */
390	read_24x7_sys_info();
391
392	return;
393}
394
395static int poll_vasi_state(u64 handle, unsigned long *res)
396{
397	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
398	long hvrc;
399	int ret;
400
401	hvrc = plpar_hcall(H_VASI_STATE, retbuf, handle);
402	switch (hvrc) {
403	case H_SUCCESS:
404		ret = 0;
405		*res = retbuf[0];
406		break;
407	case H_PARAMETER:
408		ret = -EINVAL;
409		break;
410	case H_FUNCTION:
411		ret = -EOPNOTSUPP;
412		break;
413	case H_HARDWARE:
414	default:
415		pr_err("unexpected H_VASI_STATE result %ld\n", hvrc);
416		ret = -EIO;
417		break;
418	}
419	return ret;
420}
421
422static int wait_for_vasi_session_suspending(u64 handle)
423{
424	unsigned long state;
425	int ret;
426
427	/*
428	 * Wait for transition from H_VASI_ENABLED to
429	 * H_VASI_SUSPENDING. Treat anything else as an error.
430	 */
431	while (true) {
432		ret = poll_vasi_state(handle, &state);
433
434		if (ret != 0 || state == H_VASI_SUSPENDING) {
435			break;
436		} else if (state == H_VASI_ENABLED) {
437			ssleep(1);
438		} else {
439			pr_err("unexpected H_VASI_STATE result %lu\n", state);
440			ret = -EIO;
441			break;
442		}
443	}
444
445	/*
446	 * Proceed even if H_VASI_STATE is unavailable. If H_JOIN or
447	 * ibm,suspend-me are also unimplemented, we'll recover then.
448	 */
449	if (ret == -EOPNOTSUPP)
450		ret = 0;
451
452	return ret;
453}
454
455static void wait_for_vasi_session_completed(u64 handle)
456{
457	unsigned long state = 0;
458	int ret;
459
460	pr_info("waiting for memory transfer to complete...\n");
461
462	/*
463	 * Wait for transition from H_VASI_RESUMED to H_VASI_COMPLETED.
464	 */
465	while (true) {
466		ret = poll_vasi_state(handle, &state);
467
468		/*
469		 * If the memory transfer is already complete and the migration
470		 * has been cleaned up by the hypervisor, H_PARAMETER is return,
471		 * which is translate in EINVAL by poll_vasi_state().
472		 */
473		if (ret == -EINVAL || (!ret && state == H_VASI_COMPLETED)) {
474			pr_info("memory transfer completed.\n");
475			break;
476		}
477
478		if (ret) {
479			pr_err("H_VASI_STATE return error (%d)\n", ret);
480			break;
481		}
482
483		if (state != H_VASI_RESUMED) {
484			pr_err("unexpected H_VASI_STATE result %lu\n", state);
485			break;
486		}
487
488		msleep(500);
489	}
490}
491
492static void prod_single(unsigned int target_cpu)
493{
494	long hvrc;
495	int hwid;
496
497	hwid = get_hard_smp_processor_id(target_cpu);
498	hvrc = plpar_hcall_norets(H_PROD, hwid);
499	if (hvrc == H_SUCCESS)
500		return;
501	pr_err_ratelimited("H_PROD of CPU %u (hwid %d) error: %ld\n",
502			   target_cpu, hwid, hvrc);
503}
504
505static void prod_others(void)
506{
507	unsigned int cpu;
508
509	for_each_online_cpu(cpu) {
510		if (cpu != smp_processor_id())
511			prod_single(cpu);
512	}
513}
514
515static u16 clamp_slb_size(void)
516{
517#ifdef CONFIG_PPC_64S_HASH_MMU
518	u16 prev = mmu_slb_size;
519
520	slb_set_size(SLB_MIN_SIZE);
521
522	return prev;
523#else
524	return 0;
525#endif
526}
527
528static int do_suspend(void)
529{
530	u16 saved_slb_size;
531	int status;
532	int ret;
533
534	pr_info("calling ibm,suspend-me on CPU %i\n", smp_processor_id());
535
536	/*
537	 * The destination processor model may have fewer SLB entries
538	 * than the source. We reduce mmu_slb_size to a safe minimum
539	 * before suspending in order to minimize the possibility of
540	 * programming non-existent entries on the destination. If
541	 * suspend fails, we restore it before returning. On success
542	 * the OF reconfig path will update it from the new device
543	 * tree after resuming on the destination.
544	 */
545	saved_slb_size = clamp_slb_size();
546
547	ret = rtas_ibm_suspend_me(&status);
548	if (ret != 0) {
549		pr_err("ibm,suspend-me error: %d\n", status);
550		slb_set_size(saved_slb_size);
551	}
552
553	return ret;
554}
555
556/**
557 * struct pseries_suspend_info - State shared between CPUs for join/suspend.
558 * @counter: Threads are to increment this upon resuming from suspend
559 *           or if an error is received from H_JOIN. The thread which performs
560 *           the first increment (i.e. sets it to 1) is responsible for
561 *           waking the other threads.
562 * @done: False if join/suspend is in progress. True if the operation is
563 *        complete (successful or not).
564 */
565struct pseries_suspend_info {
566	atomic_t counter;
567	bool done;
568};
569
570static int do_join(void *arg)
571{
572	struct pseries_suspend_info *info = arg;
573	atomic_t *counter = &info->counter;
574	long hvrc;
575	int ret;
576
577retry:
578	/* Must ensure MSR.EE off for H_JOIN. */
579	hard_irq_disable();
580	hvrc = plpar_hcall_norets(H_JOIN);
581
582	switch (hvrc) {
583	case H_CONTINUE:
584		/*
585		 * All other CPUs are offline or in H_JOIN. This CPU
586		 * attempts the suspend.
587		 */
588		ret = do_suspend();
589		break;
590	case H_SUCCESS:
591		/*
592		 * The suspend is complete and this cpu has received a
593		 * prod, or we've received a stray prod from unrelated
594		 * code (e.g. paravirt spinlocks) and we need to join
595		 * again.
596		 *
597		 * This barrier orders the return from H_JOIN above vs
598		 * the load of info->done. It pairs with the barrier
599		 * in the wakeup/prod path below.
600		 */
601		smp_mb();
602		if (READ_ONCE(info->done) == false) {
603			pr_info_ratelimited("premature return from H_JOIN on CPU %i, retrying",
604					    smp_processor_id());
605			goto retry;
606		}
607		ret = 0;
608		break;
609	case H_BAD_MODE:
610	case H_HARDWARE:
611	default:
612		ret = -EIO;
613		pr_err_ratelimited("H_JOIN error %ld on CPU %i\n",
614				   hvrc, smp_processor_id());
615		break;
616	}
617
618	if (atomic_inc_return(counter) == 1) {
619		pr_info("CPU %u waking all threads\n", smp_processor_id());
620		WRITE_ONCE(info->done, true);
621		/*
622		 * This barrier orders the store to info->done vs subsequent
623		 * H_PRODs to wake the other CPUs. It pairs with the barrier
624		 * in the H_SUCCESS case above.
625		 */
626		smp_mb();
627		prod_others();
628	}
629	/*
630	 * Execution may have been suspended for several seconds, so reset
631	 * the watchdogs. touch_nmi_watchdog() also touches the soft lockup
632	 * watchdog.
633	 */
634	rcu_cpu_stall_reset();
635	touch_nmi_watchdog();
636
637	return ret;
638}
639
640/*
641 * Abort reason code byte 0. We use only the 'Migrating partition' value.
642 */
643enum vasi_aborting_entity {
644	ORCHESTRATOR        = 1,
645	VSP_SOURCE          = 2,
646	PARTITION_FIRMWARE  = 3,
647	PLATFORM_FIRMWARE   = 4,
648	VSP_TARGET          = 5,
649	MIGRATING_PARTITION = 6,
650};
651
652static void pseries_cancel_migration(u64 handle, int err)
653{
654	u32 reason_code;
655	u32 detail;
656	u8 entity;
657	long hvrc;
658
659	entity = MIGRATING_PARTITION;
660	detail = abs(err) & 0xffffff;
661	reason_code = (entity << 24) | detail;
662
663	hvrc = plpar_hcall_norets(H_VASI_SIGNAL, handle,
664				  H_VASI_SIGNAL_CANCEL, reason_code);
665	if (hvrc)
666		pr_err("H_VASI_SIGNAL error: %ld\n", hvrc);
667}
668
669static int pseries_suspend(u64 handle)
670{
671	const unsigned int max_attempts = 5;
672	unsigned int retry_interval_ms = 1;
673	unsigned int attempt = 1;
674	int ret;
675
676	while (true) {
677		struct pseries_suspend_info info;
678		unsigned long vasi_state;
679		int vasi_err;
680
681		info = (struct pseries_suspend_info) {
682			.counter = ATOMIC_INIT(0),
683			.done = false,
684		};
685
686		ret = stop_machine(do_join, &info, cpu_online_mask);
687		if (ret == 0)
688			break;
689		/*
690		 * Encountered an error. If the VASI stream is still
691		 * in Suspending state, it's likely a transient
692		 * condition related to some device in the partition
693		 * and we can retry in the hope that the cause has
694		 * cleared after some delay.
695		 *
696		 * A better design would allow drivers etc to prepare
697		 * for the suspend and avoid conditions which prevent
698		 * the suspend from succeeding. For now, we have this
699		 * mitigation.
700		 */
701		pr_notice("Partition suspend attempt %u of %u error: %d\n",
702			  attempt, max_attempts, ret);
703
704		if (attempt == max_attempts)
705			break;
706
707		vasi_err = poll_vasi_state(handle, &vasi_state);
708		if (vasi_err == 0) {
709			if (vasi_state != H_VASI_SUSPENDING) {
710				pr_notice("VASI state %lu after failed suspend\n",
711					  vasi_state);
712				break;
713			}
714		} else if (vasi_err != -EOPNOTSUPP) {
715			pr_err("VASI state poll error: %d", vasi_err);
716			break;
717		}
718
719		pr_notice("Will retry partition suspend after %u ms\n",
720			  retry_interval_ms);
721
722		msleep(retry_interval_ms);
723		retry_interval_ms *= 10;
724		attempt++;
725	}
726
727	return ret;
728}
729
730static int pseries_migrate_partition(u64 handle)
731{
732	int ret;
733	unsigned int factor = 0;
734
735#ifdef CONFIG_PPC_WATCHDOG
736	factor = nmi_wd_lpm_factor;
737#endif
738	/*
739	 * When the migration is initiated, the hypervisor changes VAS
740	 * mappings to prepare before OS gets the notification and
741	 * closes all VAS windows. NX generates continuous faults during
742	 * this time and the user space can not differentiate these
743	 * faults from the migration event. So reduce this time window
744	 * by closing VAS windows at the beginning of this function.
745	 */
746	vas_migration_handler(VAS_SUSPEND);
747
748	ret = wait_for_vasi_session_suspending(handle);
749	if (ret)
750		goto out;
751
752	if (factor)
753		watchdog_hardlockup_set_timeout_pct(factor);
754
755	ret = pseries_suspend(handle);
756	if (ret == 0) {
757		post_mobility_fixup();
758		/*
759		 * Wait until the memory transfer is complete, so that the user
760		 * space process returns from the syscall after the transfer is
761		 * complete. This allows the user hooks to be executed at the
762		 * right time.
763		 */
764		wait_for_vasi_session_completed(handle);
765	} else
766		pseries_cancel_migration(handle, ret);
767
768	if (factor)
769		watchdog_hardlockup_set_timeout_pct(0);
770
771out:
772	vas_migration_handler(VAS_RESUME);
773
774	return ret;
775}
776
777int rtas_syscall_dispatch_ibm_suspend_me(u64 handle)
778{
779	return pseries_migrate_partition(handle);
780}
781
782static ssize_t migration_store(const struct class *class,
783			       const struct class_attribute *attr, const char *buf,
784			       size_t count)
785{
786	u64 streamid;
787	int rc;
788
789	rc = kstrtou64(buf, 0, &streamid);
790	if (rc)
791		return rc;
792
793	rc = pseries_migrate_partition(streamid);
794	if (rc)
795		return rc;
796
797	return count;
798}
799
800/*
801 * Used by drmgr to determine the kernel behavior of the migration interface.
802 *
803 * Version 1: Performs all PAPR requirements for migration including
804 *	firmware activation and device tree update.
805 */
806#define MIGRATION_API_VERSION	1
807
808static CLASS_ATTR_WO(migration);
809static CLASS_ATTR_STRING(api_version, 0444, __stringify(MIGRATION_API_VERSION));
810
811static int __init mobility_sysfs_init(void)
812{
813	int rc;
814
815	mobility_kobj = kobject_create_and_add("mobility", kernel_kobj);
816	if (!mobility_kobj)
817		return -ENOMEM;
818
819	rc = sysfs_create_file(mobility_kobj, &class_attr_migration.attr);
820	if (rc)
821		pr_err("unable to create migration sysfs file (%d)\n", rc);
822
823	rc = sysfs_create_file(mobility_kobj, &class_attr_api_version.attr.attr);
824	if (rc)
825		pr_err("unable to create api_version sysfs file (%d)\n", rc);
826
827	return 0;
828}
829machine_device_initcall(pseries, mobility_sysfs_init);
830