1/*
2 * salinfo.c
3 *
4 * Creates entries in /proc/sal for various system features.
5 *
6 * Copyright (c) 2003, 2006 Silicon Graphics, Inc.  All rights reserved.
7 * Copyright (c) 2003 Hewlett-Packard Co
8 *	Bjorn Helgaas <bjorn.helgaas@hp.com>
9 *
10 * 10/30/2001	jbarnes@sgi.com		copied much of Stephane's palinfo
11 *					code to create this file
12 * Oct 23 2003	kaos@sgi.com
13 *   Replace IPI with set_cpus_allowed() to read a record from the required cpu.
14 *   Redesign salinfo log processing to separate interrupt and user space
15 *   contexts.
16 *   Cache the record across multi-block reads from user space.
17 *   Support > 64 cpus.
18 *   Delete module_exit and MOD_INC/DEC_COUNT, salinfo cannot be a module.
19 *
20 * Jan 28 2004	kaos@sgi.com
21 *   Periodically check for outstanding MCA or INIT records.
22 *
23 * Dec  5 2004	kaos@sgi.com
24 *   Standardize which records are cleared automatically.
25 *
26 * Aug 18 2005	kaos@sgi.com
27 *   mca.c may not pass a buffer, a NULL buffer just indicates that a new
28 *   record is available in SAL.
29 *   Replace some NR_CPUS by cpus_online, for hotplug cpu.
30 *
31 * Jan  5 2006        kaos@sgi.com
32 *   Handle hotplug cpus coming online.
33 *   Handle hotplug cpus going offline while they still have outstanding records.
34 *   Use the cpu_* macros consistently.
35 *   Replace the counting semaphore with a mutex and a test if the cpumask is non-empty.
36 *   Modify the locking to make the test for "work to do" an atomic operation.
37 */
38
39#include <linux/capability.h>
40#include <linux/cpu.h>
41#include <linux/types.h>
42#include <linux/proc_fs.h>
43#include <linux/seq_file.h>
44#include <linux/module.h>
45#include <linux/smp.h>
46#include <linux/timer.h>
47#include <linux/vmalloc.h>
48#include <linux/semaphore.h>
49
50#include <asm/sal.h>
51#include <asm/uaccess.h>
52
53MODULE_AUTHOR("Jesse Barnes <jbarnes@sgi.com>");
54MODULE_DESCRIPTION("/proc interface to IA-64 SAL features");
55MODULE_LICENSE("GPL");
56
57static const struct file_operations proc_salinfo_fops;
58
59typedef struct {
60	const char		*name;		/* name of the proc entry */
61	unsigned long           feature;        /* feature bit */
62	struct proc_dir_entry	*entry;		/* registered entry (removal) */
63} salinfo_entry_t;
64
65/*
66 * List {name,feature} pairs for every entry in /proc/sal/<feature>
67 * that this module exports
68 */
69static const salinfo_entry_t salinfo_entries[]={
70	{ "bus_lock",           IA64_SAL_PLATFORM_FEATURE_BUS_LOCK, },
71	{ "irq_redirection",	IA64_SAL_PLATFORM_FEATURE_IRQ_REDIR_HINT, },
72	{ "ipi_redirection",	IA64_SAL_PLATFORM_FEATURE_IPI_REDIR_HINT, },
73	{ "itc_drift",		IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT, },
74};
75
76#define NR_SALINFO_ENTRIES ARRAY_SIZE(salinfo_entries)
77
78static char *salinfo_log_name[] = {
79	"mca",
80	"init",
81	"cmc",
82	"cpe",
83};
84
85static struct proc_dir_entry *salinfo_proc_entries[
86	ARRAY_SIZE(salinfo_entries) +			/* /proc/sal/bus_lock */
87	ARRAY_SIZE(salinfo_log_name) +			/* /proc/sal/{mca,...} */
88	(2 * ARRAY_SIZE(salinfo_log_name)) +		/* /proc/sal/mca/{event,data} */
89	1];						/* /proc/sal */
90
91/* Some records we get ourselves, some are accessed as saved data in buffers
92 * that are owned by mca.c.
93 */
94struct salinfo_data_saved {
95	u8*			buffer;
96	u64			size;
97	u64			id;
98	int			cpu;
99};
100
101/* State transitions.  Actions are :-
102 *   Write "read <cpunum>" to the data file.
103 *   Write "clear <cpunum>" to the data file.
104 *   Write "oemdata <cpunum> <offset> to the data file.
105 *   Read from the data file.
106 *   Close the data file.
107 *
108 * Start state is NO_DATA.
109 *
110 * NO_DATA
111 *    write "read <cpunum>" -> NO_DATA or LOG_RECORD.
112 *    write "clear <cpunum>" -> NO_DATA or LOG_RECORD.
113 *    write "oemdata <cpunum> <offset> -> return -EINVAL.
114 *    read data -> return EOF.
115 *    close -> unchanged.  Free record areas.
116 *
117 * LOG_RECORD
118 *    write "read <cpunum>" -> NO_DATA or LOG_RECORD.
119 *    write "clear <cpunum>" -> NO_DATA or LOG_RECORD.
120 *    write "oemdata <cpunum> <offset> -> format the oem data, goto OEMDATA.
121 *    read data -> return the INIT/MCA/CMC/CPE record.
122 *    close -> unchanged.  Keep record areas.
123 *
124 * OEMDATA
125 *    write "read <cpunum>" -> NO_DATA or LOG_RECORD.
126 *    write "clear <cpunum>" -> NO_DATA or LOG_RECORD.
127 *    write "oemdata <cpunum> <offset> -> format the oem data, goto OEMDATA.
128 *    read data -> return the formatted oemdata.
129 *    close -> unchanged.  Keep record areas.
130 *
131 * Closing the data file does not change the state.  This allows shell scripts
132 * to manipulate salinfo data, each shell redirection opens the file, does one
133 * action then closes it again.  The record areas are only freed at close when
134 * the state is NO_DATA.
135 */
136enum salinfo_state {
137	STATE_NO_DATA,
138	STATE_LOG_RECORD,
139	STATE_OEMDATA,
140};
141
142struct salinfo_data {
143	cpumask_t		cpu_event;	/* which cpus have outstanding events */
144	struct semaphore	mutex;
145	u8			*log_buffer;
146	u64			log_size;
147	u8			*oemdata;	/* decoded oem data */
148	u64			oemdata_size;
149	int			open;		/* single-open to prevent races */
150	u8			type;
151	u8			saved_num;	/* using a saved record? */
152	enum salinfo_state	state :8;	/* processing state */
153	u8			padding;
154	int			cpu_check;	/* next CPU to check */
155	struct salinfo_data_saved data_saved[5];/* save last 5 records from mca.c, must be < 255 */
156};
157
158static struct salinfo_data salinfo_data[ARRAY_SIZE(salinfo_log_name)];
159
160static DEFINE_SPINLOCK(data_lock);
161static DEFINE_SPINLOCK(data_saved_lock);
162
163/** salinfo_platform_oemdata - optional callback to decode oemdata from an error
164 * record.
165 * @sect_header: pointer to the start of the section to decode.
166 * @oemdata: returns vmalloc area containing the decoded output.
167 * @oemdata_size: returns length of decoded output (strlen).
168 *
169 * Description: If user space asks for oem data to be decoded by the kernel
170 * and/or prom and the platform has set salinfo_platform_oemdata to the address
171 * of a platform specific routine then call that routine.  salinfo_platform_oemdata
172 * vmalloc's and formats its output area, returning the address of the text
173 * and its strlen.  Returns 0 for success, -ve for error.  The callback is
174 * invoked on the cpu that generated the error record.
175 */
176int (*salinfo_platform_oemdata)(const u8 *sect_header, u8 **oemdata, u64 *oemdata_size);
177
178struct salinfo_platform_oemdata_parms {
179	const u8 *efi_guid;
180	u8 **oemdata;
181	u64 *oemdata_size;
182	int ret;
183};
184
185/* Kick the mutex that tells user space that there is work to do.  Instead of
186 * trying to track the state of the mutex across multiple cpus, in user
187 * context, interrupt context, non-maskable interrupt context and hotplug cpu,
188 * it is far easier just to grab the mutex if it is free then release it.
189 *
190 * This routine must be called with data_saved_lock held, to make the down/up
191 * operation atomic.
192 */
193static void
194salinfo_work_to_do(struct salinfo_data *data)
195{
196	(void)(down_trylock(&data->mutex) ?: 0);
197	up(&data->mutex);
198}
199
200static void
201salinfo_platform_oemdata_cpu(void *context)
202{
203	struct salinfo_platform_oemdata_parms *parms = context;
204	parms->ret = salinfo_platform_oemdata(parms->efi_guid, parms->oemdata, parms->oemdata_size);
205}
206
207static void
208shift1_data_saved (struct salinfo_data *data, int shift)
209{
210	memcpy(data->data_saved+shift, data->data_saved+shift+1,
211	       (ARRAY_SIZE(data->data_saved) - (shift+1)) * sizeof(data->data_saved[0]));
212	memset(data->data_saved + ARRAY_SIZE(data->data_saved) - 1, 0,
213	       sizeof(data->data_saved[0]));
214}
215
216/* This routine is invoked in interrupt context.  Note: mca.c enables
217 * interrupts before calling this code for CMC/CPE.  MCA and INIT events are
218 * not irq safe, do not call any routines that use spinlocks, they may deadlock.
219 * MCA and INIT records are recorded, a timer event will look for any
220 * outstanding events and wake up the user space code.
221 *
222 * The buffer passed from mca.c points to the output from ia64_log_get. This is
223 * a persistent buffer but its contents can change between the interrupt and
224 * when user space processes the record.  Save the record id to identify
225 * changes.  If the buffer is NULL then just update the bitmap.
226 */
227void
228salinfo_log_wakeup(int type, u8 *buffer, u64 size, int irqsafe)
229{
230	struct salinfo_data *data = salinfo_data + type;
231	struct salinfo_data_saved *data_saved;
232	unsigned long flags = 0;
233	int i;
234	int saved_size = ARRAY_SIZE(data->data_saved);
235
236	BUG_ON(type >= ARRAY_SIZE(salinfo_log_name));
237
238	if (irqsafe)
239		spin_lock_irqsave(&data_saved_lock, flags);
240	if (buffer) {
241		for (i = 0, data_saved = data->data_saved; i < saved_size; ++i, ++data_saved) {
242			if (!data_saved->buffer)
243				break;
244		}
245		if (i == saved_size) {
246			if (!data->saved_num) {
247				shift1_data_saved(data, 0);
248				data_saved = data->data_saved + saved_size - 1;
249			} else
250				data_saved = NULL;
251		}
252		if (data_saved) {
253			data_saved->cpu = smp_processor_id();
254			data_saved->id = ((sal_log_record_header_t *)buffer)->id;
255			data_saved->size = size;
256			data_saved->buffer = buffer;
257		}
258	}
259	cpumask_set_cpu(smp_processor_id(), &data->cpu_event);
260	if (irqsafe) {
261		salinfo_work_to_do(data);
262		spin_unlock_irqrestore(&data_saved_lock, flags);
263	}
264}
265
266/* Check for outstanding MCA/INIT records every minute (arbitrary) */
267#define SALINFO_TIMER_DELAY (60*HZ)
268static struct timer_list salinfo_timer;
269extern void ia64_mlogbuf_dump(void);
270
271static void
272salinfo_timeout_check(struct salinfo_data *data)
273{
274	unsigned long flags;
275	if (!data->open)
276		return;
277	if (!cpumask_empty(&data->cpu_event)) {
278		spin_lock_irqsave(&data_saved_lock, flags);
279		salinfo_work_to_do(data);
280		spin_unlock_irqrestore(&data_saved_lock, flags);
281	}
282}
283
284static void
285salinfo_timeout (unsigned long arg)
286{
287	ia64_mlogbuf_dump();
288	salinfo_timeout_check(salinfo_data + SAL_INFO_TYPE_MCA);
289	salinfo_timeout_check(salinfo_data + SAL_INFO_TYPE_INIT);
290	salinfo_timer.expires = jiffies + SALINFO_TIMER_DELAY;
291	add_timer(&salinfo_timer);
292}
293
294static int
295salinfo_event_open(struct inode *inode, struct file *file)
296{
297	if (!capable(CAP_SYS_ADMIN))
298		return -EPERM;
299	return 0;
300}
301
302static ssize_t
303salinfo_event_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
304{
305	struct salinfo_data *data = PDE_DATA(file_inode(file));
306	char cmd[32];
307	size_t size;
308	int i, n, cpu = -1;
309
310retry:
311	if (cpumask_empty(&data->cpu_event) && down_trylock(&data->mutex)) {
312		if (file->f_flags & O_NONBLOCK)
313			return -EAGAIN;
314		if (down_interruptible(&data->mutex))
315			return -EINTR;
316	}
317
318	n = data->cpu_check;
319	for (i = 0; i < nr_cpu_ids; i++) {
320		if (cpumask_test_cpu(n, &data->cpu_event)) {
321			if (!cpu_online(n)) {
322				cpumask_clear_cpu(n, &data->cpu_event);
323				continue;
324			}
325			cpu = n;
326			break;
327		}
328		if (++n == nr_cpu_ids)
329			n = 0;
330	}
331
332	if (cpu == -1)
333		goto retry;
334
335	ia64_mlogbuf_dump();
336
337	/* for next read, start checking at next CPU */
338	data->cpu_check = cpu;
339	if (++data->cpu_check == nr_cpu_ids)
340		data->cpu_check = 0;
341
342	snprintf(cmd, sizeof(cmd), "read %d\n", cpu);
343
344	size = strlen(cmd);
345	if (size > count)
346		size = count;
347	if (copy_to_user(buffer, cmd, size))
348		return -EFAULT;
349
350	return size;
351}
352
353static const struct file_operations salinfo_event_fops = {
354	.open  = salinfo_event_open,
355	.read  = salinfo_event_read,
356	.llseek = noop_llseek,
357};
358
359static int
360salinfo_log_open(struct inode *inode, struct file *file)
361{
362	struct salinfo_data *data = PDE_DATA(inode);
363
364	if (!capable(CAP_SYS_ADMIN))
365		return -EPERM;
366
367	spin_lock(&data_lock);
368	if (data->open) {
369		spin_unlock(&data_lock);
370		return -EBUSY;
371	}
372	data->open = 1;
373	spin_unlock(&data_lock);
374
375	if (data->state == STATE_NO_DATA &&
376	    !(data->log_buffer = vmalloc(ia64_sal_get_state_info_size(data->type)))) {
377		data->open = 0;
378		return -ENOMEM;
379	}
380
381	return 0;
382}
383
384static int
385salinfo_log_release(struct inode *inode, struct file *file)
386{
387	struct salinfo_data *data = PDE_DATA(inode);
388
389	if (data->state == STATE_NO_DATA) {
390		vfree(data->log_buffer);
391		vfree(data->oemdata);
392		data->log_buffer = NULL;
393		data->oemdata = NULL;
394	}
395	spin_lock(&data_lock);
396	data->open = 0;
397	spin_unlock(&data_lock);
398	return 0;
399}
400
401static void
402call_on_cpu(int cpu, void (*fn)(void *), void *arg)
403{
404	cpumask_t save_cpus_allowed = current->cpus_allowed;
405	set_cpus_allowed_ptr(current, cpumask_of(cpu));
406	(*fn)(arg);
407	set_cpus_allowed_ptr(current, &save_cpus_allowed);
408}
409
410static void
411salinfo_log_read_cpu(void *context)
412{
413	struct salinfo_data *data = context;
414	sal_log_record_header_t *rh;
415	data->log_size = ia64_sal_get_state_info(data->type, (u64 *) data->log_buffer);
416	rh = (sal_log_record_header_t *)(data->log_buffer);
417	/* Clear corrected errors as they are read from SAL */
418	if (rh->severity == sal_log_severity_corrected)
419		ia64_sal_clear_state_info(data->type);
420}
421
422static void
423salinfo_log_new_read(int cpu, struct salinfo_data *data)
424{
425	struct salinfo_data_saved *data_saved;
426	unsigned long flags;
427	int i;
428	int saved_size = ARRAY_SIZE(data->data_saved);
429
430	data->saved_num = 0;
431	spin_lock_irqsave(&data_saved_lock, flags);
432retry:
433	for (i = 0, data_saved = data->data_saved; i < saved_size; ++i, ++data_saved) {
434		if (data_saved->buffer && data_saved->cpu == cpu) {
435			sal_log_record_header_t *rh = (sal_log_record_header_t *)(data_saved->buffer);
436			data->log_size = data_saved->size;
437			memcpy(data->log_buffer, rh, data->log_size);
438			barrier();	/* id check must not be moved */
439			if (rh->id == data_saved->id) {
440				data->saved_num = i+1;
441				break;
442			}
443			/* saved record changed by mca.c since interrupt, discard it */
444			shift1_data_saved(data, i);
445			goto retry;
446		}
447	}
448	spin_unlock_irqrestore(&data_saved_lock, flags);
449
450	if (!data->saved_num)
451		call_on_cpu(cpu, salinfo_log_read_cpu, data);
452	if (!data->log_size) {
453		data->state = STATE_NO_DATA;
454		cpumask_clear_cpu(cpu, &data->cpu_event);
455	} else {
456		data->state = STATE_LOG_RECORD;
457	}
458}
459
460static ssize_t
461salinfo_log_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
462{
463	struct salinfo_data *data = PDE_DATA(file_inode(file));
464	u8 *buf;
465	u64 bufsize;
466
467	if (data->state == STATE_LOG_RECORD) {
468		buf = data->log_buffer;
469		bufsize = data->log_size;
470	} else if (data->state == STATE_OEMDATA) {
471		buf = data->oemdata;
472		bufsize = data->oemdata_size;
473	} else {
474		buf = NULL;
475		bufsize = 0;
476	}
477	return simple_read_from_buffer(buffer, count, ppos, buf, bufsize);
478}
479
480static void
481salinfo_log_clear_cpu(void *context)
482{
483	struct salinfo_data *data = context;
484	ia64_sal_clear_state_info(data->type);
485}
486
487static int
488salinfo_log_clear(struct salinfo_data *data, int cpu)
489{
490	sal_log_record_header_t *rh;
491	unsigned long flags;
492	spin_lock_irqsave(&data_saved_lock, flags);
493	data->state = STATE_NO_DATA;
494	if (!cpumask_test_cpu(cpu, &data->cpu_event)) {
495		spin_unlock_irqrestore(&data_saved_lock, flags);
496		return 0;
497	}
498	cpumask_clear_cpu(cpu, &data->cpu_event);
499	if (data->saved_num) {
500		shift1_data_saved(data, data->saved_num - 1);
501		data->saved_num = 0;
502	}
503	spin_unlock_irqrestore(&data_saved_lock, flags);
504	rh = (sal_log_record_header_t *)(data->log_buffer);
505	/* Corrected errors have already been cleared from SAL */
506	if (rh->severity != sal_log_severity_corrected)
507		call_on_cpu(cpu, salinfo_log_clear_cpu, data);
508	/* clearing a record may make a new record visible */
509	salinfo_log_new_read(cpu, data);
510	if (data->state == STATE_LOG_RECORD) {
511		spin_lock_irqsave(&data_saved_lock, flags);
512		cpumask_set_cpu(cpu, &data->cpu_event);
513		salinfo_work_to_do(data);
514		spin_unlock_irqrestore(&data_saved_lock, flags);
515	}
516	return 0;
517}
518
519static ssize_t
520salinfo_log_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
521{
522	struct salinfo_data *data = PDE_DATA(file_inode(file));
523	char cmd[32];
524	size_t size;
525	u32 offset;
526	int cpu;
527
528	size = sizeof(cmd);
529	if (count < size)
530		size = count;
531	if (copy_from_user(cmd, buffer, size))
532		return -EFAULT;
533
534	if (sscanf(cmd, "read %d", &cpu) == 1) {
535		salinfo_log_new_read(cpu, data);
536	} else if (sscanf(cmd, "clear %d", &cpu) == 1) {
537		int ret;
538		if ((ret = salinfo_log_clear(data, cpu)))
539			count = ret;
540	} else if (sscanf(cmd, "oemdata %d %d", &cpu, &offset) == 2) {
541		if (data->state != STATE_LOG_RECORD && data->state != STATE_OEMDATA)
542			return -EINVAL;
543		if (offset > data->log_size - sizeof(efi_guid_t))
544			return -EINVAL;
545		data->state = STATE_OEMDATA;
546		if (salinfo_platform_oemdata) {
547			struct salinfo_platform_oemdata_parms parms = {
548				.efi_guid = data->log_buffer + offset,
549				.oemdata = &data->oemdata,
550				.oemdata_size = &data->oemdata_size
551			};
552			call_on_cpu(cpu, salinfo_platform_oemdata_cpu, &parms);
553			if (parms.ret)
554				count = parms.ret;
555		} else
556			data->oemdata_size = 0;
557	} else
558		return -EINVAL;
559
560	return count;
561}
562
563static const struct file_operations salinfo_data_fops = {
564	.open    = salinfo_log_open,
565	.release = salinfo_log_release,
566	.read    = salinfo_log_read,
567	.write   = salinfo_log_write,
568	.llseek  = default_llseek,
569};
570
571static int
572salinfo_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
573{
574	unsigned int i, cpu = (unsigned long)hcpu;
575	unsigned long flags;
576	struct salinfo_data *data;
577	switch (action) {
578	case CPU_ONLINE:
579	case CPU_ONLINE_FROZEN:
580		spin_lock_irqsave(&data_saved_lock, flags);
581		for (i = 0, data = salinfo_data;
582		     i < ARRAY_SIZE(salinfo_data);
583		     ++i, ++data) {
584			cpumask_set_cpu(cpu, &data->cpu_event);
585			salinfo_work_to_do(data);
586		}
587		spin_unlock_irqrestore(&data_saved_lock, flags);
588		break;
589	case CPU_DEAD:
590	case CPU_DEAD_FROZEN:
591		spin_lock_irqsave(&data_saved_lock, flags);
592		for (i = 0, data = salinfo_data;
593		     i < ARRAY_SIZE(salinfo_data);
594		     ++i, ++data) {
595			struct salinfo_data_saved *data_saved;
596			int j;
597			for (j = ARRAY_SIZE(data->data_saved) - 1, data_saved = data->data_saved + j;
598			     j >= 0;
599			     --j, --data_saved) {
600				if (data_saved->buffer && data_saved->cpu == cpu) {
601					shift1_data_saved(data, j);
602				}
603			}
604			cpumask_clear_cpu(cpu, &data->cpu_event);
605		}
606		spin_unlock_irqrestore(&data_saved_lock, flags);
607		break;
608	}
609	return NOTIFY_OK;
610}
611
612static struct notifier_block salinfo_cpu_notifier =
613{
614	.notifier_call = salinfo_cpu_callback,
615	.priority = 0,
616};
617
618static int __init
619salinfo_init(void)
620{
621	struct proc_dir_entry *salinfo_dir; /* /proc/sal dir entry */
622	struct proc_dir_entry **sdir = salinfo_proc_entries; /* keeps track of every entry */
623	struct proc_dir_entry *dir, *entry;
624	struct salinfo_data *data;
625	int i, j;
626
627	salinfo_dir = proc_mkdir("sal", NULL);
628	if (!salinfo_dir)
629		return 0;
630
631	for (i=0; i < NR_SALINFO_ENTRIES; i++) {
632		/* pass the feature bit in question as misc data */
633		*sdir++ = proc_create_data(salinfo_entries[i].name, 0, salinfo_dir,
634					   &proc_salinfo_fops,
635					   (void *)salinfo_entries[i].feature);
636	}
637
638	cpu_notifier_register_begin();
639
640	for (i = 0; i < ARRAY_SIZE(salinfo_log_name); i++) {
641		data = salinfo_data + i;
642		data->type = i;
643		sema_init(&data->mutex, 1);
644		dir = proc_mkdir(salinfo_log_name[i], salinfo_dir);
645		if (!dir)
646			continue;
647
648		entry = proc_create_data("event", S_IRUSR, dir,
649					 &salinfo_event_fops, data);
650		if (!entry)
651			continue;
652		*sdir++ = entry;
653
654		entry = proc_create_data("data", S_IRUSR | S_IWUSR, dir,
655					 &salinfo_data_fops, data);
656		if (!entry)
657			continue;
658		*sdir++ = entry;
659
660		/* we missed any events before now */
661		for_each_online_cpu(j)
662			cpumask_set_cpu(j, &data->cpu_event);
663
664		*sdir++ = dir;
665	}
666
667	*sdir++ = salinfo_dir;
668
669	init_timer(&salinfo_timer);
670	salinfo_timer.expires = jiffies + SALINFO_TIMER_DELAY;
671	salinfo_timer.function = &salinfo_timeout;
672	add_timer(&salinfo_timer);
673
674	__register_hotcpu_notifier(&salinfo_cpu_notifier);
675
676	cpu_notifier_register_done();
677
678	return 0;
679}
680
681/*
682 * 'data' contains an integer that corresponds to the feature we're
683 * testing
684 */
685static int proc_salinfo_show(struct seq_file *m, void *v)
686{
687	unsigned long data = (unsigned long)v;
688	seq_puts(m, (sal_platform_features & data) ? "1\n" : "0\n");
689	return 0;
690}
691
692static int proc_salinfo_open(struct inode *inode, struct file *file)
693{
694	return single_open(file, proc_salinfo_show, PDE_DATA(inode));
695}
696
697static const struct file_operations proc_salinfo_fops = {
698	.open		= proc_salinfo_open,
699	.read		= seq_read,
700	.llseek		= seq_lseek,
701	.release	= single_release,
702};
703
704module_init(salinfo_init);
705