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Linux/arch/ia64/kernel/salinfo.c

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  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 
 53 MODULE_AUTHOR("Jesse Barnes <jbarnes@sgi.com>");
 54 MODULE_DESCRIPTION("/proc interface to IA-64 SAL features");
 55 MODULE_LICENSE("GPL");
 56 
 57 static const struct file_operations proc_salinfo_fops;
 58 
 59 typedef 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  */
 69 static 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 
 78 static char *salinfo_log_name[] = {
 79         "mca",
 80         "init",
 81         "cmc",
 82         "cpe",
 83 };
 84 
 85 static 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  */
 94 struct 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  */
136 enum salinfo_state {
137         STATE_NO_DATA,
138         STATE_LOG_RECORD,
139         STATE_OEMDATA,
140 };
141 
142 struct 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 
158 static struct salinfo_data salinfo_data[ARRAY_SIZE(salinfo_log_name)];
159 
160 static DEFINE_SPINLOCK(data_lock);
161 static 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  */
176 int (*salinfo_platform_oemdata)(const u8 *sect_header, u8 **oemdata, u64 *oemdata_size);
177 
178 struct 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  */
193 static void
194 salinfo_work_to_do(struct salinfo_data *data)
195 {
196         (void)(down_trylock(&data->mutex) ?: 0);
197         up(&data->mutex);
198 }
199 
200 static void
201 salinfo_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 
207 static void
208 shift1_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  */
227 void
228 salinfo_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)
268 static struct timer_list salinfo_timer;
269 extern void ia64_mlogbuf_dump(void);
270 
271 static void
272 salinfo_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 
284 static void
285 salinfo_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 
294 static int
295 salinfo_event_open(struct inode *inode, struct file *file)
296 {
297         if (!capable(CAP_SYS_ADMIN))
298                 return -EPERM;
299         return 0;
300 }
301 
302 static ssize_t
303 salinfo_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 
310 retry:
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 
353 static const struct file_operations salinfo_event_fops = {
354         .open  = salinfo_event_open,
355         .read  = salinfo_event_read,
356         .llseek = noop_llseek,
357 };
358 
359 static int
360 salinfo_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 
384 static int
385 salinfo_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 
401 static void
402 call_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 
410 static void
411 salinfo_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 
422 static void
423 salinfo_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);
432 retry:
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 
460 static ssize_t
461 salinfo_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 
480 static void
481 salinfo_log_clear_cpu(void *context)
482 {
483         struct salinfo_data *data = context;
484         ia64_sal_clear_state_info(data->type);
485 }
486 
487 static int
488 salinfo_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 
519 static ssize_t
520 salinfo_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 
563 static 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 
571 static int
572 salinfo_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 
612 static struct notifier_block salinfo_cpu_notifier =
613 {
614         .notifier_call = salinfo_cpu_callback,
615         .priority = 0,
616 };
617 
618 static int __init
619 salinfo_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  */
685 static 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" : "\n");
689         return 0;
690 }
691 
692 static int proc_salinfo_open(struct inode *inode, struct file *file)
693 {
694         return single_open(file, proc_salinfo_show, PDE_DATA(inode));
695 }
696 
697 static 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 
704 module_init(salinfo_init);
705 

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