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1/*
2 * Interfaces to retrieve and set PDC Stable options (firmware)
3 *
4 * Copyright (C) 2005-2006 Thibaut VARENE <varenet@parisc-linux.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License, version 2, as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 *
19 *
20 * DEV NOTE: the PDC Procedures reference states that:
21 * "A minimum of 96 bytes of Stable Storage is required. Providing more than
22 * 96 bytes of Stable Storage is optional [...]. Failure to provide the
23 * optional locations from 96 to 192 results in the loss of certain
24 * functionality during boot."
25 *
26 * Since locations between 96 and 192 are the various paths, most (if not
27 * all) PA-RISC machines should have them. Anyway, for safety reasons, the
28 * following code can deal with just 96 bytes of Stable Storage, and all
29 * sizes between 96 and 192 bytes (provided they are multiple of struct
30 * device_path size, eg: 128, 160 and 192) to provide full information.
31 * One last word: there's one path we can always count on: the primary path.
32 * Anything above 224 bytes is used for 'osdep2' OS-dependent storage area.
33 *
34 * The first OS-dependent area should always be available. Obviously, this is
35 * not true for the other one. Also bear in mind that reading/writing from/to
36 * osdep2 is much more expensive than from/to osdep1.
37 * NOTE: We do not handle the 2 bytes OS-dep area at 0x5D, nor the first
38 * 2 bytes of storage available right after OSID. That's a total of 4 bytes
39 * sacrificed: -ETOOLAZY :P
40 *
41 * The current policy wrt file permissions is:
42 * - write: root only
43 * - read: (reading triggers PDC calls) ? root only : everyone
44 * The rationale is that PDC calls could hog (DoS) the machine.
45 *
46 * TODO:
47 * - timer/fastsize write calls
48 */
49
50#undef PDCS_DEBUG
51#ifdef PDCS_DEBUG
52#define DPRINTK(fmt, args...) printk(KERN_DEBUG fmt, ## args)
53#else
54#define DPRINTK(fmt, args...)
55#endif
56
57#include <linux/module.h>
58#include <linux/init.h>
59#include <linux/kernel.h>
60#include <linux/string.h>
61#include <linux/capability.h>
62#include <linux/ctype.h>
63#include <linux/sysfs.h>
64#include <linux/kobject.h>
65#include <linux/device.h>
66#include <linux/errno.h>
67#include <linux/spinlock.h>
68
69#include <asm/pdc.h>
70#include <asm/page.h>
71#include <asm/uaccess.h>
72#include <asm/hardware.h>
73
74#define PDCS_VERSION "0.30"
75#define PDCS_PREFIX "PDC Stable Storage"
76
77#define PDCS_ADDR_PPRI 0x00
78#define PDCS_ADDR_OSID 0x40
79#define PDCS_ADDR_OSD1 0x48
80#define PDCS_ADDR_DIAG 0x58
81#define PDCS_ADDR_FSIZ 0x5C
82#define PDCS_ADDR_PCON 0x60
83#define PDCS_ADDR_PALT 0x80
84#define PDCS_ADDR_PKBD 0xA0
85#define PDCS_ADDR_OSD2 0xE0
86
87MODULE_AUTHOR("Thibaut VARENE <varenet@parisc-linux.org>");
88MODULE_DESCRIPTION("sysfs interface to HP PDC Stable Storage data");
89MODULE_LICENSE("GPL");
90MODULE_VERSION(PDCS_VERSION);
91
92/* holds Stable Storage size. Initialized once and for all, no lock needed */
93static unsigned long pdcs_size __read_mostly;
94
95/* holds OS ID. Initialized once and for all, hopefully to 0x0006 */
96static u16 pdcs_osid __read_mostly;
97
98/* This struct defines what we need to deal with a parisc pdc path entry */
99struct pdcspath_entry {
100 rwlock_t rw_lock; /* to protect path entry access */
101 short ready; /* entry record is valid if != 0 */
102 unsigned long addr; /* entry address in stable storage */
103 char *name; /* entry name */
104 struct device_path devpath; /* device path in parisc representation */
105 struct device *dev; /* corresponding device */
106 struct kobject kobj;
107};
108
109struct pdcspath_attribute {
110 struct attribute attr;
111 ssize_t (*show)(struct pdcspath_entry *entry, char *buf);
112 ssize_t (*store)(struct pdcspath_entry *entry, const char *buf, size_t count);
113};
114
115#define PDCSPATH_ENTRY(_addr, _name) \
116struct pdcspath_entry pdcspath_entry_##_name = { \
117 .ready = 0, \
118 .addr = _addr, \
119 .name = __stringify(_name), \
120};
121
122#define PDCS_ATTR(_name, _mode, _show, _store) \
123struct kobj_attribute pdcs_attr_##_name = { \
124 .attr = {.name = __stringify(_name), .mode = _mode}, \
125 .show = _show, \
126 .store = _store, \
127};
128
129#define PATHS_ATTR(_name, _mode, _show, _store) \
130struct pdcspath_attribute paths_attr_##_name = { \
131 .attr = {.name = __stringify(_name), .mode = _mode}, \
132 .show = _show, \
133 .store = _store, \
134};
135
136#define to_pdcspath_attribute(_attr) container_of(_attr, struct pdcspath_attribute, attr)
137#define to_pdcspath_entry(obj) container_of(obj, struct pdcspath_entry, kobj)
138
139/**
140 * pdcspath_fetch - This function populates the path entry structs.
141 * @entry: A pointer to an allocated pdcspath_entry.
142 *
143 * The general idea is that you don't read from the Stable Storage every time
144 * you access the files provided by the facilities. We store a copy of the
145 * content of the stable storage WRT various paths in these structs. We read
146 * these structs when reading the files, and we will write to these structs when
147 * writing to the files, and only then write them back to the Stable Storage.
148 *
149 * This function expects to be called with @entry->rw_lock write-hold.
150 */
151static int
152pdcspath_fetch(struct pdcspath_entry *entry)
153{
154 struct device_path *devpath;
155
156 if (!entry)
157 return -EINVAL;
158
159 devpath = &entry->devpath;
160
161 DPRINTK("%s: fetch: 0x%p, 0x%p, addr: 0x%lx\n", __func__,
162 entry, devpath, entry->addr);
163
164 /* addr, devpath and count must be word aligned */
165 if (pdc_stable_read(entry->addr, devpath, sizeof(*devpath)) != PDC_OK)
166 return -EIO;
167
168 /* Find the matching device.
169 NOTE: hardware_path overlays with device_path, so the nice cast can
170 be used */
171 entry->dev = hwpath_to_device((struct hardware_path *)devpath);
172
173 entry->ready = 1;
174
175 DPRINTK("%s: device: 0x%p\n", __func__, entry->dev);
176
177 return 0;
178}
179
180/**
181 * pdcspath_store - This function writes a path to stable storage.
182 * @entry: A pointer to an allocated pdcspath_entry.
183 *
184 * It can be used in two ways: either by passing it a preset devpath struct
185 * containing an already computed hardware path, or by passing it a device
186 * pointer, from which it'll find out the corresponding hardware path.
187 * For now we do not handle the case where there's an error in writing to the
188 * Stable Storage area, so you'd better not mess up the data :P
189 *
190 * This function expects to be called with @entry->rw_lock write-hold.
191 */
192static void
193pdcspath_store(struct pdcspath_entry *entry)
194{
195 struct device_path *devpath;
196
197 BUG_ON(!entry);
198
199 devpath = &entry->devpath;
200
201 /* We expect the caller to set the ready flag to 0 if the hardware
202 path struct provided is invalid, so that we know we have to fill it.
203 First case, we don't have a preset hwpath... */
204 if (!entry->ready) {
205 /* ...but we have a device, map it */
206 BUG_ON(!entry->dev);
207 device_to_hwpath(entry->dev, (struct hardware_path *)devpath);
208 }
209 /* else, we expect the provided hwpath to be valid. */
210
211 DPRINTK("%s: store: 0x%p, 0x%p, addr: 0x%lx\n", __func__,
212 entry, devpath, entry->addr);
213
214 /* addr, devpath and count must be word aligned */
215 if (pdc_stable_write(entry->addr, devpath, sizeof(*devpath)) != PDC_OK) {
216 printk(KERN_ERR "%s: an error occurred when writing to PDC.\n"
217 "It is likely that the Stable Storage data has been corrupted.\n"
218 "Please check it carefully upon next reboot.\n", __func__);
219 WARN_ON(1);
220 }
221
222 /* kobject is already registered */
223 entry->ready = 2;
224
225 DPRINTK("%s: device: 0x%p\n", __func__, entry->dev);
226}
227
228/**
229 * pdcspath_hwpath_read - This function handles hardware path pretty printing.
230 * @entry: An allocated and populated pdscpath_entry struct.
231 * @buf: The output buffer to write to.
232 *
233 * We will call this function to format the output of the hwpath attribute file.
234 */
235static ssize_t
236pdcspath_hwpath_read(struct pdcspath_entry *entry, char *buf)
237{
238 char *out = buf;
239 struct device_path *devpath;
240 short i;
241
242 if (!entry || !buf)
243 return -EINVAL;
244
245 read_lock(&entry->rw_lock);
246 devpath = &entry->devpath;
247 i = entry->ready;
248 read_unlock(&entry->rw_lock);
249
250 if (!i) /* entry is not ready */
251 return -ENODATA;
252
253 for (i = 0; i < 6; i++) {
254 if (devpath->bc[i] >= 128)
255 continue;
256 out += sprintf(out, "%u/", (unsigned char)devpath->bc[i]);
257 }
258 out += sprintf(out, "%u\n", (unsigned char)devpath->mod);
259
260 return out - buf;
261}
262
263/**
264 * pdcspath_hwpath_write - This function handles hardware path modifying.
265 * @entry: An allocated and populated pdscpath_entry struct.
266 * @buf: The input buffer to read from.
267 * @count: The number of bytes to be read.
268 *
269 * We will call this function to change the current hardware path.
270 * Hardware paths are to be given '/'-delimited, without brackets.
271 * We make sure that the provided path actually maps to an existing
272 * device, BUT nothing would prevent some foolish user to set the path to some
273 * PCI bridge or even a CPU...
274 * A better work around would be to make sure we are at the end of a device tree
275 * for instance, but it would be IMHO beyond the simple scope of that driver.
276 * The aim is to provide a facility. Data correctness is left to userland.
277 */
278static ssize_t
279pdcspath_hwpath_write(struct pdcspath_entry *entry, const char *buf, size_t count)
280{
281 struct hardware_path hwpath;
282 unsigned short i;
283 char in[count+1], *temp;
284 struct device *dev;
285 int ret;
286
287 if (!entry || !buf || !count)
288 return -EINVAL;
289
290 /* We'll use a local copy of buf */
291 memset(in, 0, count+1);
292 strncpy(in, buf, count);
293
294 /* Let's clean up the target. 0xff is a blank pattern */
295 memset(&hwpath, 0xff, sizeof(hwpath));
296
297 /* First, pick the mod field (the last one of the input string) */
298 if (!(temp = strrchr(in, '/')))
299 return -EINVAL;
300
301 hwpath.mod = simple_strtoul(temp+1, NULL, 10);
302 in[temp-in] = '\0'; /* truncate the remaining string. just precaution */
303 DPRINTK("%s: mod: %d\n", __func__, hwpath.mod);
304
305 /* Then, loop for each delimiter, making sure we don't have too many.
306 we write the bc fields in a down-top way. No matter what, we stop
307 before writing the last field. If there are too many fields anyway,
308 then the user is a moron and it'll be caught up later when we'll
309 check the consistency of the given hwpath. */
310 for (i=5; ((temp = strrchr(in, '/'))) && (temp-in > 0) && (likely(i)); i--) {
311 hwpath.bc[i] = simple_strtoul(temp+1, NULL, 10);
312 in[temp-in] = '\0';
313 DPRINTK("%s: bc[%d]: %d\n", __func__, i, hwpath.bc[i]);
314 }
315
316 /* Store the final field */
317 hwpath.bc[i] = simple_strtoul(in, NULL, 10);
318 DPRINTK("%s: bc[%d]: %d\n", __func__, i, hwpath.bc[i]);
319
320 /* Now we check that the user isn't trying to lure us */
321 if (!(dev = hwpath_to_device((struct hardware_path *)&hwpath))) {
322 printk(KERN_WARNING "%s: attempt to set invalid \"%s\" "
323 "hardware path: %s\n", __func__, entry->name, buf);
324 return -EINVAL;
325 }
326
327 /* So far so good, let's get in deep */
328 write_lock(&entry->rw_lock);
329 entry->ready = 0;
330 entry->dev = dev;
331
332 /* Now, dive in. Write back to the hardware */
333 pdcspath_store(entry);
334
335 /* Update the symlink to the real device */
336 sysfs_remove_link(&entry->kobj, "device");
337 ret = sysfs_create_link(&entry->kobj, &entry->dev->kobj, "device");
338 WARN_ON(ret);
339
340 write_unlock(&entry->rw_lock);
341
342 printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" path to \"%s\"\n",
343 entry->name, buf);
344
345 return count;
346}
347
348/**
349 * pdcspath_layer_read - Extended layer (eg. SCSI ids) pretty printing.
350 * @entry: An allocated and populated pdscpath_entry struct.
351 * @buf: The output buffer to write to.
352 *
353 * We will call this function to format the output of the layer attribute file.
354 */
355static ssize_t
356pdcspath_layer_read(struct pdcspath_entry *entry, char *buf)
357{
358 char *out = buf;
359 struct device_path *devpath;
360 short i;
361
362 if (!entry || !buf)
363 return -EINVAL;
364
365 read_lock(&entry->rw_lock);
366 devpath = &entry->devpath;
367 i = entry->ready;
368 read_unlock(&entry->rw_lock);
369
370 if (!i) /* entry is not ready */
371 return -ENODATA;
372
373 for (i = 0; i < 6 && devpath->layers[i]; i++)
374 out += sprintf(out, "%u ", devpath->layers[i]);
375
376 out += sprintf(out, "\n");
377
378 return out - buf;
379}
380
381/**
382 * pdcspath_layer_write - This function handles extended layer modifying.
383 * @entry: An allocated and populated pdscpath_entry struct.
384 * @buf: The input buffer to read from.
385 * @count: The number of bytes to be read.
386 *
387 * We will call this function to change the current layer value.
388 * Layers are to be given '.'-delimited, without brackets.
389 * XXX beware we are far less checky WRT input data provided than for hwpath.
390 * Potential harm can be done, since there's no way to check the validity of
391 * the layer fields.
392 */
393static ssize_t
394pdcspath_layer_write(struct pdcspath_entry *entry, const char *buf, size_t count)
395{
396 unsigned int layers[6]; /* device-specific info (ctlr#, unit#, ...) */
397 unsigned short i;
398 char in[count+1], *temp;
399
400 if (!entry || !buf || !count)
401 return -EINVAL;
402
403 /* We'll use a local copy of buf */
404 memset(in, 0, count+1);
405 strncpy(in, buf, count);
406
407 /* Let's clean up the target. 0 is a blank pattern */
408 memset(&layers, 0, sizeof(layers));
409
410 /* First, pick the first layer */
411 if (unlikely(!isdigit(*in)))
412 return -EINVAL;
413 layers[0] = simple_strtoul(in, NULL, 10);
414 DPRINTK("%s: layer[0]: %d\n", __func__, layers[0]);
415
416 temp = in;
417 for (i=1; ((temp = strchr(temp, '.'))) && (likely(i<6)); i++) {
418 if (unlikely(!isdigit(*(++temp))))
419 return -EINVAL;
420 layers[i] = simple_strtoul(temp, NULL, 10);
421 DPRINTK("%s: layer[%d]: %d\n", __func__, i, layers[i]);
422 }
423
424 /* So far so good, let's get in deep */
425 write_lock(&entry->rw_lock);
426
427 /* First, overwrite the current layers with the new ones, not touching
428 the hardware path. */
429 memcpy(&entry->devpath.layers, &layers, sizeof(layers));
430
431 /* Now, dive in. Write back to the hardware */
432 pdcspath_store(entry);
433 write_unlock(&entry->rw_lock);
434
435 printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" layers to \"%s\"\n",
436 entry->name, buf);
437
438 return count;
439}
440
441/**
442 * pdcspath_attr_show - Generic read function call wrapper.
443 * @kobj: The kobject to get info from.
444 * @attr: The attribute looked upon.
445 * @buf: The output buffer.
446 */
447static ssize_t
448pdcspath_attr_show(struct kobject *kobj, struct attribute *attr, char *buf)
449{
450 struct pdcspath_entry *entry = to_pdcspath_entry(kobj);
451 struct pdcspath_attribute *pdcs_attr = to_pdcspath_attribute(attr);
452 ssize_t ret = 0;
453
454 if (pdcs_attr->show)
455 ret = pdcs_attr->show(entry, buf);
456
457 return ret;
458}
459
460/**
461 * pdcspath_attr_store - Generic write function call wrapper.
462 * @kobj: The kobject to write info to.
463 * @attr: The attribute to be modified.
464 * @buf: The input buffer.
465 * @count: The size of the buffer.
466 */
467static ssize_t
468pdcspath_attr_store(struct kobject *kobj, struct attribute *attr,
469 const char *buf, size_t count)
470{
471 struct pdcspath_entry *entry = to_pdcspath_entry(kobj);
472 struct pdcspath_attribute *pdcs_attr = to_pdcspath_attribute(attr);
473 ssize_t ret = 0;
474
475 if (!capable(CAP_SYS_ADMIN))
476 return -EACCES;
477
478 if (pdcs_attr->store)
479 ret = pdcs_attr->store(entry, buf, count);
480
481 return ret;
482}
483
484static const struct sysfs_ops pdcspath_attr_ops = {
485 .show = pdcspath_attr_show,
486 .store = pdcspath_attr_store,
487};
488
489/* These are the two attributes of any PDC path. */
490static PATHS_ATTR(hwpath, 0644, pdcspath_hwpath_read, pdcspath_hwpath_write);
491static PATHS_ATTR(layer, 0644, pdcspath_layer_read, pdcspath_layer_write);
492
493static struct attribute *paths_subsys_attrs[] = {
494 &paths_attr_hwpath.attr,
495 &paths_attr_layer.attr,
496 NULL,
497};
498
499/* Specific kobject type for our PDC paths */
500static struct kobj_type ktype_pdcspath = {
501 .sysfs_ops = &pdcspath_attr_ops,
502 .default_attrs = paths_subsys_attrs,
503};
504
505/* We hard define the 4 types of path we expect to find */
506static PDCSPATH_ENTRY(PDCS_ADDR_PPRI, primary);
507static PDCSPATH_ENTRY(PDCS_ADDR_PCON, console);
508static PDCSPATH_ENTRY(PDCS_ADDR_PALT, alternative);
509static PDCSPATH_ENTRY(PDCS_ADDR_PKBD, keyboard);
510
511/* An array containing all PDC paths we will deal with */
512static struct pdcspath_entry *pdcspath_entries[] = {
513 &pdcspath_entry_primary,
514 &pdcspath_entry_alternative,
515 &pdcspath_entry_console,
516 &pdcspath_entry_keyboard,
517 NULL,
518};
519
520
521/* For more insight of what's going on here, refer to PDC Procedures doc,
522 * Section PDC_STABLE */
523
524/**
525 * pdcs_size_read - Stable Storage size output.
526 * @buf: The output buffer to write to.
527 */
528static ssize_t pdcs_size_read(struct kobject *kobj,
529 struct kobj_attribute *attr,
530 char *buf)
531{
532 char *out = buf;
533
534 if (!buf)
535 return -EINVAL;
536
537 /* show the size of the stable storage */
538 out += sprintf(out, "%ld\n", pdcs_size);
539
540 return out - buf;
541}
542
543/**
544 * pdcs_auto_read - Stable Storage autoboot/search flag output.
545 * @buf: The output buffer to write to.
546 * @knob: The PF_AUTOBOOT or PF_AUTOSEARCH flag
547 */
548static ssize_t pdcs_auto_read(struct kobject *kobj,
549 struct kobj_attribute *attr,
550 char *buf, int knob)
551{
552 char *out = buf;
553 struct pdcspath_entry *pathentry;
554
555 if (!buf)
556 return -EINVAL;
557
558 /* Current flags are stored in primary boot path entry */
559 pathentry = &pdcspath_entry_primary;
560
561 read_lock(&pathentry->rw_lock);
562 out += sprintf(out, "%s\n", (pathentry->devpath.flags & knob) ?
563 "On" : "Off");
564 read_unlock(&pathentry->rw_lock);
565
566 return out - buf;
567}
568
569/**
570 * pdcs_autoboot_read - Stable Storage autoboot flag output.
571 * @buf: The output buffer to write to.
572 */
573static ssize_t pdcs_autoboot_read(struct kobject *kobj,
574 struct kobj_attribute *attr, char *buf)
575{
576 return pdcs_auto_read(kobj, attr, buf, PF_AUTOBOOT);
577}
578
579/**
580 * pdcs_autosearch_read - Stable Storage autoboot flag output.
581 * @buf: The output buffer to write to.
582 */
583static ssize_t pdcs_autosearch_read(struct kobject *kobj,
584 struct kobj_attribute *attr, char *buf)
585{
586 return pdcs_auto_read(kobj, attr, buf, PF_AUTOSEARCH);
587}
588
589/**
590 * pdcs_timer_read - Stable Storage timer count output (in seconds).
591 * @buf: The output buffer to write to.
592 *
593 * The value of the timer field correponds to a number of seconds in powers of 2.
594 */
595static ssize_t pdcs_timer_read(struct kobject *kobj,
596 struct kobj_attribute *attr, char *buf)
597{
598 char *out = buf;
599 struct pdcspath_entry *pathentry;
600
601 if (!buf)
602 return -EINVAL;
603
604 /* Current flags are stored in primary boot path entry */
605 pathentry = &pdcspath_entry_primary;
606
607 /* print the timer value in seconds */
608 read_lock(&pathentry->rw_lock);
609 out += sprintf(out, "%u\n", (pathentry->devpath.flags & PF_TIMER) ?
610 (1 << (pathentry->devpath.flags & PF_TIMER)) : 0);
611 read_unlock(&pathentry->rw_lock);
612
613 return out - buf;
614}
615
616/**
617 * pdcs_osid_read - Stable Storage OS ID register output.
618 * @buf: The output buffer to write to.
619 */
620static ssize_t pdcs_osid_read(struct kobject *kobj,
621 struct kobj_attribute *attr, char *buf)
622{
623 char *out = buf;
624
625 if (!buf)
626 return -EINVAL;
627
628 out += sprintf(out, "%s dependent data (0x%.4x)\n",
629 os_id_to_string(pdcs_osid), pdcs_osid);
630
631 return out - buf;
632}
633
634/**
635 * pdcs_osdep1_read - Stable Storage OS-Dependent data area 1 output.
636 * @buf: The output buffer to write to.
637 *
638 * This can hold 16 bytes of OS-Dependent data.
639 */
640static ssize_t pdcs_osdep1_read(struct kobject *kobj,
641 struct kobj_attribute *attr, char *buf)
642{
643 char *out = buf;
644 u32 result[4];
645
646 if (!buf)
647 return -EINVAL;
648
649 if (pdc_stable_read(PDCS_ADDR_OSD1, &result, sizeof(result)) != PDC_OK)
650 return -EIO;
651
652 out += sprintf(out, "0x%.8x\n", result[0]);
653 out += sprintf(out, "0x%.8x\n", result[1]);
654 out += sprintf(out, "0x%.8x\n", result[2]);
655 out += sprintf(out, "0x%.8x\n", result[3]);
656
657 return out - buf;
658}
659
660/**
661 * pdcs_diagnostic_read - Stable Storage Diagnostic register output.
662 * @buf: The output buffer to write to.
663 *
664 * I have NFC how to interpret the content of that register ;-).
665 */
666static ssize_t pdcs_diagnostic_read(struct kobject *kobj,
667 struct kobj_attribute *attr, char *buf)
668{
669 char *out = buf;
670 u32 result;
671
672 if (!buf)
673 return -EINVAL;
674
675 /* get diagnostic */
676 if (pdc_stable_read(PDCS_ADDR_DIAG, &result, sizeof(result)) != PDC_OK)
677 return -EIO;
678
679 out += sprintf(out, "0x%.4x\n", (result >> 16));
680
681 return out - buf;
682}
683
684/**
685 * pdcs_fastsize_read - Stable Storage FastSize register output.
686 * @buf: The output buffer to write to.
687 *
688 * This register holds the amount of system RAM to be tested during boot sequence.
689 */
690static ssize_t pdcs_fastsize_read(struct kobject *kobj,
691 struct kobj_attribute *attr, char *buf)
692{
693 char *out = buf;
694 u32 result;
695
696 if (!buf)
697 return -EINVAL;
698
699 /* get fast-size */
700 if (pdc_stable_read(PDCS_ADDR_FSIZ, &result, sizeof(result)) != PDC_OK)
701 return -EIO;
702
703 if ((result & 0x0F) < 0x0E)
704 out += sprintf(out, "%d kB", (1<<(result & 0x0F))*256);
705 else
706 out += sprintf(out, "All");
707 out += sprintf(out, "\n");
708
709 return out - buf;
710}
711
712/**
713 * pdcs_osdep2_read - Stable Storage OS-Dependent data area 2 output.
714 * @buf: The output buffer to write to.
715 *
716 * This can hold pdcs_size - 224 bytes of OS-Dependent data, when available.
717 */
718static ssize_t pdcs_osdep2_read(struct kobject *kobj,
719 struct kobj_attribute *attr, char *buf)
720{
721 char *out = buf;
722 unsigned long size;
723 unsigned short i;
724 u32 result;
725
726 if (unlikely(pdcs_size <= 224))
727 return -ENODATA;
728
729 size = pdcs_size - 224;
730
731 if (!buf)
732 return -EINVAL;
733
734 for (i=0; i<size; i+=4) {
735 if (unlikely(pdc_stable_read(PDCS_ADDR_OSD2 + i, &result,
736 sizeof(result)) != PDC_OK))
737 return -EIO;
738 out += sprintf(out, "0x%.8x\n", result);
739 }
740
741 return out - buf;
742}
743
744/**
745 * pdcs_auto_write - This function handles autoboot/search flag modifying.
746 * @buf: The input buffer to read from.
747 * @count: The number of bytes to be read.
748 * @knob: The PF_AUTOBOOT or PF_AUTOSEARCH flag
749 *
750 * We will call this function to change the current autoboot flag.
751 * We expect a precise syntax:
752 * \"n\" (n == 0 or 1) to toggle AutoBoot Off or On
753 */
754static ssize_t pdcs_auto_write(struct kobject *kobj,
755 struct kobj_attribute *attr, const char *buf,
756 size_t count, int knob)
757{
758 struct pdcspath_entry *pathentry;
759 unsigned char flags;
760 char in[count+1], *temp;
761 char c;
762
763 if (!capable(CAP_SYS_ADMIN))
764 return -EACCES;
765
766 if (!buf || !count)
767 return -EINVAL;
768
769 /* We'll use a local copy of buf */
770 memset(in, 0, count+1);
771 strncpy(in, buf, count);
772
773 /* Current flags are stored in primary boot path entry */
774 pathentry = &pdcspath_entry_primary;
775
776 /* Be nice to the existing flag record */
777 read_lock(&pathentry->rw_lock);
778 flags = pathentry->devpath.flags;
779 read_unlock(&pathentry->rw_lock);
780
781 DPRINTK("%s: flags before: 0x%X\n", __func__, flags);
782
783 temp = skip_spaces(in);
784
785 c = *temp++ - '0';
786 if ((c != 0) && (c != 1))
787 goto parse_error;
788 if (c == 0)
789 flags &= ~knob;
790 else
791 flags |= knob;
792
793 DPRINTK("%s: flags after: 0x%X\n", __func__, flags);
794
795 /* So far so good, let's get in deep */
796 write_lock(&pathentry->rw_lock);
797
798 /* Change the path entry flags first */
799 pathentry->devpath.flags = flags;
800
801 /* Now, dive in. Write back to the hardware */
802 pdcspath_store(pathentry);
803 write_unlock(&pathentry->rw_lock);
804
805 printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" to \"%s\"\n",
806 (knob & PF_AUTOBOOT) ? "autoboot" : "autosearch",
807 (flags & knob) ? "On" : "Off");
808
809 return count;
810
811parse_error:
812 printk(KERN_WARNING "%s: Parse error: expect \"n\" (n == 0 or 1)\n", __func__);
813 return -EINVAL;
814}
815
816/**
817 * pdcs_autoboot_write - This function handles autoboot flag modifying.
818 * @buf: The input buffer to read from.
819 * @count: The number of bytes to be read.
820 *
821 * We will call this function to change the current boot flags.
822 * We expect a precise syntax:
823 * \"n\" (n == 0 or 1) to toggle AutoSearch Off or On
824 */
825static ssize_t pdcs_autoboot_write(struct kobject *kobj,
826 struct kobj_attribute *attr,
827 const char *buf, size_t count)
828{
829 return pdcs_auto_write(kobj, attr, buf, count, PF_AUTOBOOT);
830}
831
832/**
833 * pdcs_autosearch_write - This function handles autosearch flag modifying.
834 * @buf: The input buffer to read from.
835 * @count: The number of bytes to be read.
836 *
837 * We will call this function to change the current boot flags.
838 * We expect a precise syntax:
839 * \"n\" (n == 0 or 1) to toggle AutoSearch Off or On
840 */
841static ssize_t pdcs_autosearch_write(struct kobject *kobj,
842 struct kobj_attribute *attr,
843 const char *buf, size_t count)
844{
845 return pdcs_auto_write(kobj, attr, buf, count, PF_AUTOSEARCH);
846}
847
848/**
849 * pdcs_osdep1_write - Stable Storage OS-Dependent data area 1 input.
850 * @buf: The input buffer to read from.
851 * @count: The number of bytes to be read.
852 *
853 * This can store 16 bytes of OS-Dependent data. We use a byte-by-byte
854 * write approach. It's up to userspace to deal with it when constructing
855 * its input buffer.
856 */
857static ssize_t pdcs_osdep1_write(struct kobject *kobj,
858 struct kobj_attribute *attr,
859 const char *buf, size_t count)
860{
861 u8 in[16];
862
863 if (!capable(CAP_SYS_ADMIN))
864 return -EACCES;
865
866 if (!buf || !count)
867 return -EINVAL;
868
869 if (unlikely(pdcs_osid != OS_ID_LINUX))
870 return -EPERM;
871
872 if (count > 16)
873 return -EMSGSIZE;
874
875 /* We'll use a local copy of buf */
876 memset(in, 0, 16);
877 memcpy(in, buf, count);
878
879 if (pdc_stable_write(PDCS_ADDR_OSD1, &in, sizeof(in)) != PDC_OK)
880 return -EIO;
881
882 return count;
883}
884
885/**
886 * pdcs_osdep2_write - Stable Storage OS-Dependent data area 2 input.
887 * @buf: The input buffer to read from.
888 * @count: The number of bytes to be read.
889 *
890 * This can store pdcs_size - 224 bytes of OS-Dependent data. We use a
891 * byte-by-byte write approach. It's up to userspace to deal with it when
892 * constructing its input buffer.
893 */
894static ssize_t pdcs_osdep2_write(struct kobject *kobj,
895 struct kobj_attribute *attr,
896 const char *buf, size_t count)
897{
898 unsigned long size;
899 unsigned short i;
900 u8 in[4];
901
902 if (!capable(CAP_SYS_ADMIN))
903 return -EACCES;
904
905 if (!buf || !count)
906 return -EINVAL;
907
908 if (unlikely(pdcs_size <= 224))
909 return -ENOSYS;
910
911 if (unlikely(pdcs_osid != OS_ID_LINUX))
912 return -EPERM;
913
914 size = pdcs_size - 224;
915
916 if (count > size)
917 return -EMSGSIZE;
918
919 /* We'll use a local copy of buf */
920
921 for (i=0; i<count; i+=4) {
922 memset(in, 0, 4);
923 memcpy(in, buf+i, (count-i < 4) ? count-i : 4);
924 if (unlikely(pdc_stable_write(PDCS_ADDR_OSD2 + i, &in,
925 sizeof(in)) != PDC_OK))
926 return -EIO;
927 }
928
929 return count;
930}
931
932/* The remaining attributes. */
933static PDCS_ATTR(size, 0444, pdcs_size_read, NULL);
934static PDCS_ATTR(autoboot, 0644, pdcs_autoboot_read, pdcs_autoboot_write);
935static PDCS_ATTR(autosearch, 0644, pdcs_autosearch_read, pdcs_autosearch_write);
936static PDCS_ATTR(timer, 0444, pdcs_timer_read, NULL);
937static PDCS_ATTR(osid, 0444, pdcs_osid_read, NULL);
938static PDCS_ATTR(osdep1, 0600, pdcs_osdep1_read, pdcs_osdep1_write);
939static PDCS_ATTR(diagnostic, 0400, pdcs_diagnostic_read, NULL);
940static PDCS_ATTR(fastsize, 0400, pdcs_fastsize_read, NULL);
941static PDCS_ATTR(osdep2, 0600, pdcs_osdep2_read, pdcs_osdep2_write);
942
943static struct attribute *pdcs_subsys_attrs[] = {
944 &pdcs_attr_size.attr,
945 &pdcs_attr_autoboot.attr,
946 &pdcs_attr_autosearch.attr,
947 &pdcs_attr_timer.attr,
948 &pdcs_attr_osid.attr,
949 &pdcs_attr_osdep1.attr,
950 &pdcs_attr_diagnostic.attr,
951 &pdcs_attr_fastsize.attr,
952 &pdcs_attr_osdep2.attr,
953 NULL,
954};
955
956static struct attribute_group pdcs_attr_group = {
957 .attrs = pdcs_subsys_attrs,
958};
959
960static struct kobject *stable_kobj;
961static struct kset *paths_kset;
962
963/**
964 * pdcs_register_pathentries - Prepares path entries kobjects for sysfs usage.
965 *
966 * It creates kobjects corresponding to each path entry with nice sysfs
967 * links to the real device. This is where the magic takes place: when
968 * registering the subsystem attributes during module init, each kobject hereby
969 * created will show in the sysfs tree as a folder containing files as defined
970 * by path_subsys_attr[].
971 */
972static inline int __init
973pdcs_register_pathentries(void)
974{
975 unsigned short i;
976 struct pdcspath_entry *entry;
977 int err;
978
979 /* Initialize the entries rw_lock before anything else */
980 for (i = 0; (entry = pdcspath_entries[i]); i++)
981 rwlock_init(&entry->rw_lock);
982
983 for (i = 0; (entry = pdcspath_entries[i]); i++) {
984 write_lock(&entry->rw_lock);
985 err = pdcspath_fetch(entry);
986 write_unlock(&entry->rw_lock);
987
988 if (err < 0)
989 continue;
990
991 entry->kobj.kset = paths_kset;
992 err = kobject_init_and_add(&entry->kobj, &ktype_pdcspath, NULL,
993 "%s", entry->name);
994 if (err)
995 return err;
996
997 /* kobject is now registered */
998 write_lock(&entry->rw_lock);
999 entry->ready = 2;
1000
1001 /* Add a nice symlink to the real device */
1002 if (entry->dev) {
1003 err = sysfs_create_link(&entry->kobj, &entry->dev->kobj, "device");
1004 WARN_ON(err);
1005 }
1006
1007 write_unlock(&entry->rw_lock);
1008 kobject_uevent(&entry->kobj, KOBJ_ADD);
1009 }
1010
1011 return 0;
1012}
1013
1014/**
1015 * pdcs_unregister_pathentries - Routine called when unregistering the module.
1016 */
1017static inline void
1018pdcs_unregister_pathentries(void)
1019{
1020 unsigned short i;
1021 struct pdcspath_entry *entry;
1022
1023 for (i = 0; (entry = pdcspath_entries[i]); i++) {
1024 read_lock(&entry->rw_lock);
1025 if (entry->ready >= 2)
1026 kobject_put(&entry->kobj);
1027 read_unlock(&entry->rw_lock);
1028 }
1029}
1030
1031/*
1032 * For now we register the stable subsystem with the firmware subsystem
1033 * and the paths subsystem with the stable subsystem
1034 */
1035static int __init
1036pdc_stable_init(void)
1037{
1038 int rc = 0, error = 0;
1039 u32 result;
1040
1041 /* find the size of the stable storage */
1042 if (pdc_stable_get_size(&pdcs_size) != PDC_OK)
1043 return -ENODEV;
1044
1045 /* make sure we have enough data */
1046 if (pdcs_size < 96)
1047 return -ENODATA;
1048
1049 printk(KERN_INFO PDCS_PREFIX " facility v%s\n", PDCS_VERSION);
1050
1051 /* get OSID */
1052 if (pdc_stable_read(PDCS_ADDR_OSID, &result, sizeof(result)) != PDC_OK)
1053 return -EIO;
1054
1055 /* the actual result is 16 bits away */
1056 pdcs_osid = (u16)(result >> 16);
1057
1058 /* For now we'll register the directory at /sys/firmware/stable */
1059 stable_kobj = kobject_create_and_add("stable", firmware_kobj);
1060 if (!stable_kobj) {
1061 rc = -ENOMEM;
1062 goto fail_firmreg;
1063 }
1064
1065 /* Don't forget the root entries */
1066 error = sysfs_create_group(stable_kobj, &pdcs_attr_group);
1067
1068 /* register the paths kset as a child of the stable kset */
1069 paths_kset = kset_create_and_add("paths", NULL, stable_kobj);
1070 if (!paths_kset) {
1071 rc = -ENOMEM;
1072 goto fail_ksetreg;
1073 }
1074
1075 /* now we create all "files" for the paths kset */
1076 if ((rc = pdcs_register_pathentries()))
1077 goto fail_pdcsreg;
1078
1079 return rc;
1080
1081fail_pdcsreg:
1082 pdcs_unregister_pathentries();
1083 kset_unregister(paths_kset);
1084
1085fail_ksetreg:
1086 kobject_put(stable_kobj);
1087
1088fail_firmreg:
1089 printk(KERN_INFO PDCS_PREFIX " bailing out\n");
1090 return rc;
1091}
1092
1093static void __exit
1094pdc_stable_exit(void)
1095{
1096 pdcs_unregister_pathentries();
1097 kset_unregister(paths_kset);
1098 kobject_put(stable_kobj);
1099}
1100
1101
1102module_init(pdc_stable_init);
1103module_exit(pdc_stable_exit);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Interfaces to retrieve and set PDC Stable options (firmware)
4 *
5 * Copyright (C) 2005-2006 Thibaut VARENE <varenet@parisc-linux.org>
6 *
7 * DEV NOTE: the PDC Procedures reference states that:
8 * "A minimum of 96 bytes of Stable Storage is required. Providing more than
9 * 96 bytes of Stable Storage is optional [...]. Failure to provide the
10 * optional locations from 96 to 192 results in the loss of certain
11 * functionality during boot."
12 *
13 * Since locations between 96 and 192 are the various paths, most (if not
14 * all) PA-RISC machines should have them. Anyway, for safety reasons, the
15 * following code can deal with just 96 bytes of Stable Storage, and all
16 * sizes between 96 and 192 bytes (provided they are multiple of struct
17 * device_path size, eg: 128, 160 and 192) to provide full information.
18 * One last word: there's one path we can always count on: the primary path.
19 * Anything above 224 bytes is used for 'osdep2' OS-dependent storage area.
20 *
21 * The first OS-dependent area should always be available. Obviously, this is
22 * not true for the other one. Also bear in mind that reading/writing from/to
23 * osdep2 is much more expensive than from/to osdep1.
24 * NOTE: We do not handle the 2 bytes OS-dep area at 0x5D, nor the first
25 * 2 bytes of storage available right after OSID. That's a total of 4 bytes
26 * sacrificed: -ETOOLAZY :P
27 *
28 * The current policy wrt file permissions is:
29 * - write: root only
30 * - read: (reading triggers PDC calls) ? root only : everyone
31 * The rationale is that PDC calls could hog (DoS) the machine.
32 *
33 * TODO:
34 * - timer/fastsize write calls
35 */
36
37#undef PDCS_DEBUG
38#ifdef PDCS_DEBUG
39#define DPRINTK(fmt, args...) printk(KERN_DEBUG fmt, ## args)
40#else
41#define DPRINTK(fmt, args...)
42#endif
43
44#include <linux/module.h>
45#include <linux/init.h>
46#include <linux/kernel.h>
47#include <linux/string.h>
48#include <linux/capability.h>
49#include <linux/ctype.h>
50#include <linux/sysfs.h>
51#include <linux/kobject.h>
52#include <linux/device.h>
53#include <linux/errno.h>
54#include <linux/spinlock.h>
55
56#include <asm/pdc.h>
57#include <asm/page.h>
58#include <linux/uaccess.h>
59#include <asm/hardware.h>
60
61#define PDCS_VERSION "0.30"
62#define PDCS_PREFIX "PDC Stable Storage"
63
64#define PDCS_ADDR_PPRI 0x00
65#define PDCS_ADDR_OSID 0x40
66#define PDCS_ADDR_OSD1 0x48
67#define PDCS_ADDR_DIAG 0x58
68#define PDCS_ADDR_FSIZ 0x5C
69#define PDCS_ADDR_PCON 0x60
70#define PDCS_ADDR_PALT 0x80
71#define PDCS_ADDR_PKBD 0xA0
72#define PDCS_ADDR_OSD2 0xE0
73
74MODULE_AUTHOR("Thibaut VARENE <varenet@parisc-linux.org>");
75MODULE_DESCRIPTION("sysfs interface to HP PDC Stable Storage data");
76MODULE_LICENSE("GPL");
77MODULE_VERSION(PDCS_VERSION);
78
79/* holds Stable Storage size. Initialized once and for all, no lock needed */
80static unsigned long pdcs_size __read_mostly;
81
82/* holds OS ID. Initialized once and for all, hopefully to 0x0006 */
83static u16 pdcs_osid __read_mostly;
84
85/* This struct defines what we need to deal with a parisc pdc path entry */
86struct pdcspath_entry {
87 rwlock_t rw_lock; /* to protect path entry access */
88 short ready; /* entry record is valid if != 0 */
89 unsigned long addr; /* entry address in stable storage */
90 char *name; /* entry name */
91 struct device_path devpath; /* device path in parisc representation */
92 struct device *dev; /* corresponding device */
93 struct kobject kobj;
94};
95
96struct pdcspath_attribute {
97 struct attribute attr;
98 ssize_t (*show)(struct pdcspath_entry *entry, char *buf);
99 ssize_t (*store)(struct pdcspath_entry *entry, const char *buf, size_t count);
100};
101
102#define PDCSPATH_ENTRY(_addr, _name) \
103struct pdcspath_entry pdcspath_entry_##_name = { \
104 .ready = 0, \
105 .addr = _addr, \
106 .name = __stringify(_name), \
107};
108
109#define PDCS_ATTR(_name, _mode, _show, _store) \
110struct kobj_attribute pdcs_attr_##_name = { \
111 .attr = {.name = __stringify(_name), .mode = _mode}, \
112 .show = _show, \
113 .store = _store, \
114};
115
116#define PATHS_ATTR(_name, _mode, _show, _store) \
117struct pdcspath_attribute paths_attr_##_name = { \
118 .attr = {.name = __stringify(_name), .mode = _mode}, \
119 .show = _show, \
120 .store = _store, \
121};
122
123#define to_pdcspath_attribute(_attr) container_of(_attr, struct pdcspath_attribute, attr)
124#define to_pdcspath_entry(obj) container_of(obj, struct pdcspath_entry, kobj)
125
126/**
127 * pdcspath_fetch - This function populates the path entry structs.
128 * @entry: A pointer to an allocated pdcspath_entry.
129 *
130 * The general idea is that you don't read from the Stable Storage every time
131 * you access the files provided by the facilities. We store a copy of the
132 * content of the stable storage WRT various paths in these structs. We read
133 * these structs when reading the files, and we will write to these structs when
134 * writing to the files, and only then write them back to the Stable Storage.
135 *
136 * This function expects to be called with @entry->rw_lock write-hold.
137 */
138static int
139pdcspath_fetch(struct pdcspath_entry *entry)
140{
141 struct device_path *devpath;
142
143 if (!entry)
144 return -EINVAL;
145
146 devpath = &entry->devpath;
147
148 DPRINTK("%s: fetch: 0x%p, 0x%p, addr: 0x%lx\n", __func__,
149 entry, devpath, entry->addr);
150
151 /* addr, devpath and count must be word aligned */
152 if (pdc_stable_read(entry->addr, devpath, sizeof(*devpath)) != PDC_OK)
153 return -EIO;
154
155 /* Find the matching device.
156 NOTE: hardware_path overlays with device_path, so the nice cast can
157 be used */
158 entry->dev = hwpath_to_device((struct hardware_path *)devpath);
159
160 entry->ready = 1;
161
162 DPRINTK("%s: device: 0x%p\n", __func__, entry->dev);
163
164 return 0;
165}
166
167/**
168 * pdcspath_store - This function writes a path to stable storage.
169 * @entry: A pointer to an allocated pdcspath_entry.
170 *
171 * It can be used in two ways: either by passing it a preset devpath struct
172 * containing an already computed hardware path, or by passing it a device
173 * pointer, from which it'll find out the corresponding hardware path.
174 * For now we do not handle the case where there's an error in writing to the
175 * Stable Storage area, so you'd better not mess up the data :P
176 *
177 * This function expects to be called with @entry->rw_lock write-hold.
178 */
179static void
180pdcspath_store(struct pdcspath_entry *entry)
181{
182 struct device_path *devpath;
183
184 BUG_ON(!entry);
185
186 devpath = &entry->devpath;
187
188 /* We expect the caller to set the ready flag to 0 if the hardware
189 path struct provided is invalid, so that we know we have to fill it.
190 First case, we don't have a preset hwpath... */
191 if (!entry->ready) {
192 /* ...but we have a device, map it */
193 BUG_ON(!entry->dev);
194 device_to_hwpath(entry->dev, (struct hardware_path *)devpath);
195 }
196 /* else, we expect the provided hwpath to be valid. */
197
198 DPRINTK("%s: store: 0x%p, 0x%p, addr: 0x%lx\n", __func__,
199 entry, devpath, entry->addr);
200
201 /* addr, devpath and count must be word aligned */
202 if (pdc_stable_write(entry->addr, devpath, sizeof(*devpath)) != PDC_OK)
203 WARN(1, KERN_ERR "%s: an error occurred when writing to PDC.\n"
204 "It is likely that the Stable Storage data has been corrupted.\n"
205 "Please check it carefully upon next reboot.\n", __func__);
206
207 /* kobject is already registered */
208 entry->ready = 2;
209
210 DPRINTK("%s: device: 0x%p\n", __func__, entry->dev);
211}
212
213/**
214 * pdcspath_hwpath_read - This function handles hardware path pretty printing.
215 * @entry: An allocated and populated pdscpath_entry struct.
216 * @buf: The output buffer to write to.
217 *
218 * We will call this function to format the output of the hwpath attribute file.
219 */
220static ssize_t
221pdcspath_hwpath_read(struct pdcspath_entry *entry, char *buf)
222{
223 char *out = buf;
224 struct device_path *devpath;
225 short i;
226
227 if (!entry || !buf)
228 return -EINVAL;
229
230 read_lock(&entry->rw_lock);
231 devpath = &entry->devpath;
232 i = entry->ready;
233 read_unlock(&entry->rw_lock);
234
235 if (!i) /* entry is not ready */
236 return -ENODATA;
237
238 for (i = 0; i < 6; i++) {
239 if (devpath->bc[i] >= 128)
240 continue;
241 out += sprintf(out, "%u/", (unsigned char)devpath->bc[i]);
242 }
243 out += sprintf(out, "%u\n", (unsigned char)devpath->mod);
244
245 return out - buf;
246}
247
248/**
249 * pdcspath_hwpath_write - This function handles hardware path modifying.
250 * @entry: An allocated and populated pdscpath_entry struct.
251 * @buf: The input buffer to read from.
252 * @count: The number of bytes to be read.
253 *
254 * We will call this function to change the current hardware path.
255 * Hardware paths are to be given '/'-delimited, without brackets.
256 * We make sure that the provided path actually maps to an existing
257 * device, BUT nothing would prevent some foolish user to set the path to some
258 * PCI bridge or even a CPU...
259 * A better work around would be to make sure we are at the end of a device tree
260 * for instance, but it would be IMHO beyond the simple scope of that driver.
261 * The aim is to provide a facility. Data correctness is left to userland.
262 */
263static ssize_t
264pdcspath_hwpath_write(struct pdcspath_entry *entry, const char *buf, size_t count)
265{
266 struct hardware_path hwpath;
267 unsigned short i;
268 char in[64], *temp;
269 struct device *dev;
270 int ret;
271
272 if (!entry || !buf || !count)
273 return -EINVAL;
274
275 /* We'll use a local copy of buf */
276 count = min_t(size_t, count, sizeof(in)-1);
277 strncpy(in, buf, count);
278 in[count] = '\0';
279
280 /* Let's clean up the target. 0xff is a blank pattern */
281 memset(&hwpath, 0xff, sizeof(hwpath));
282
283 /* First, pick the mod field (the last one of the input string) */
284 if (!(temp = strrchr(in, '/')))
285 return -EINVAL;
286
287 hwpath.mod = simple_strtoul(temp+1, NULL, 10);
288 in[temp-in] = '\0'; /* truncate the remaining string. just precaution */
289 DPRINTK("%s: mod: %d\n", __func__, hwpath.mod);
290
291 /* Then, loop for each delimiter, making sure we don't have too many.
292 we write the bc fields in a down-top way. No matter what, we stop
293 before writing the last field. If there are too many fields anyway,
294 then the user is a moron and it'll be caught up later when we'll
295 check the consistency of the given hwpath. */
296 for (i=5; ((temp = strrchr(in, '/'))) && (temp-in > 0) && (likely(i)); i--) {
297 hwpath.bc[i] = simple_strtoul(temp+1, NULL, 10);
298 in[temp-in] = '\0';
299 DPRINTK("%s: bc[%d]: %d\n", __func__, i, hwpath.bc[i]);
300 }
301
302 /* Store the final field */
303 hwpath.bc[i] = simple_strtoul(in, NULL, 10);
304 DPRINTK("%s: bc[%d]: %d\n", __func__, i, hwpath.bc[i]);
305
306 /* Now we check that the user isn't trying to lure us */
307 if (!(dev = hwpath_to_device((struct hardware_path *)&hwpath))) {
308 printk(KERN_WARNING "%s: attempt to set invalid \"%s\" "
309 "hardware path: %s\n", __func__, entry->name, buf);
310 return -EINVAL;
311 }
312
313 /* So far so good, let's get in deep */
314 write_lock(&entry->rw_lock);
315 entry->ready = 0;
316 entry->dev = dev;
317
318 /* Now, dive in. Write back to the hardware */
319 pdcspath_store(entry);
320
321 /* Update the symlink to the real device */
322 sysfs_remove_link(&entry->kobj, "device");
323 write_unlock(&entry->rw_lock);
324
325 ret = sysfs_create_link(&entry->kobj, &entry->dev->kobj, "device");
326 WARN_ON(ret);
327
328 printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" path to \"%s\"\n",
329 entry->name, buf);
330
331 return count;
332}
333
334/**
335 * pdcspath_layer_read - Extended layer (eg. SCSI ids) pretty printing.
336 * @entry: An allocated and populated pdscpath_entry struct.
337 * @buf: The output buffer to write to.
338 *
339 * We will call this function to format the output of the layer attribute file.
340 */
341static ssize_t
342pdcspath_layer_read(struct pdcspath_entry *entry, char *buf)
343{
344 char *out = buf;
345 struct device_path *devpath;
346 short i;
347
348 if (!entry || !buf)
349 return -EINVAL;
350
351 read_lock(&entry->rw_lock);
352 devpath = &entry->devpath;
353 i = entry->ready;
354 read_unlock(&entry->rw_lock);
355
356 if (!i) /* entry is not ready */
357 return -ENODATA;
358
359 for (i = 0; i < 6 && devpath->layers[i]; i++)
360 out += sprintf(out, "%u ", devpath->layers[i]);
361
362 out += sprintf(out, "\n");
363
364 return out - buf;
365}
366
367/**
368 * pdcspath_layer_write - This function handles extended layer modifying.
369 * @entry: An allocated and populated pdscpath_entry struct.
370 * @buf: The input buffer to read from.
371 * @count: The number of bytes to be read.
372 *
373 * We will call this function to change the current layer value.
374 * Layers are to be given '.'-delimited, without brackets.
375 * XXX beware we are far less checky WRT input data provided than for hwpath.
376 * Potential harm can be done, since there's no way to check the validity of
377 * the layer fields.
378 */
379static ssize_t
380pdcspath_layer_write(struct pdcspath_entry *entry, const char *buf, size_t count)
381{
382 unsigned int layers[6]; /* device-specific info (ctlr#, unit#, ...) */
383 unsigned short i;
384 char in[64], *temp;
385
386 if (!entry || !buf || !count)
387 return -EINVAL;
388
389 /* We'll use a local copy of buf */
390 count = min_t(size_t, count, sizeof(in)-1);
391 strncpy(in, buf, count);
392 in[count] = '\0';
393
394 /* Let's clean up the target. 0 is a blank pattern */
395 memset(&layers, 0, sizeof(layers));
396
397 /* First, pick the first layer */
398 if (unlikely(!isdigit(*in)))
399 return -EINVAL;
400 layers[0] = simple_strtoul(in, NULL, 10);
401 DPRINTK("%s: layer[0]: %d\n", __func__, layers[0]);
402
403 temp = in;
404 for (i=1; ((temp = strchr(temp, '.'))) && (likely(i<6)); i++) {
405 if (unlikely(!isdigit(*(++temp))))
406 return -EINVAL;
407 layers[i] = simple_strtoul(temp, NULL, 10);
408 DPRINTK("%s: layer[%d]: %d\n", __func__, i, layers[i]);
409 }
410
411 /* So far so good, let's get in deep */
412 write_lock(&entry->rw_lock);
413
414 /* First, overwrite the current layers with the new ones, not touching
415 the hardware path. */
416 memcpy(&entry->devpath.layers, &layers, sizeof(layers));
417
418 /* Now, dive in. Write back to the hardware */
419 pdcspath_store(entry);
420 write_unlock(&entry->rw_lock);
421
422 printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" layers to \"%s\"\n",
423 entry->name, buf);
424
425 return count;
426}
427
428/**
429 * pdcspath_attr_show - Generic read function call wrapper.
430 * @kobj: The kobject to get info from.
431 * @attr: The attribute looked upon.
432 * @buf: The output buffer.
433 */
434static ssize_t
435pdcspath_attr_show(struct kobject *kobj, struct attribute *attr, char *buf)
436{
437 struct pdcspath_entry *entry = to_pdcspath_entry(kobj);
438 struct pdcspath_attribute *pdcs_attr = to_pdcspath_attribute(attr);
439 ssize_t ret = 0;
440
441 if (pdcs_attr->show)
442 ret = pdcs_attr->show(entry, buf);
443
444 return ret;
445}
446
447/**
448 * pdcspath_attr_store - Generic write function call wrapper.
449 * @kobj: The kobject to write info to.
450 * @attr: The attribute to be modified.
451 * @buf: The input buffer.
452 * @count: The size of the buffer.
453 */
454static ssize_t
455pdcspath_attr_store(struct kobject *kobj, struct attribute *attr,
456 const char *buf, size_t count)
457{
458 struct pdcspath_entry *entry = to_pdcspath_entry(kobj);
459 struct pdcspath_attribute *pdcs_attr = to_pdcspath_attribute(attr);
460 ssize_t ret = 0;
461
462 if (!capable(CAP_SYS_ADMIN))
463 return -EACCES;
464
465 if (pdcs_attr->store)
466 ret = pdcs_attr->store(entry, buf, count);
467
468 return ret;
469}
470
471static const struct sysfs_ops pdcspath_attr_ops = {
472 .show = pdcspath_attr_show,
473 .store = pdcspath_attr_store,
474};
475
476/* These are the two attributes of any PDC path. */
477static PATHS_ATTR(hwpath, 0644, pdcspath_hwpath_read, pdcspath_hwpath_write);
478static PATHS_ATTR(layer, 0644, pdcspath_layer_read, pdcspath_layer_write);
479
480static struct attribute *paths_subsys_attrs[] = {
481 &paths_attr_hwpath.attr,
482 &paths_attr_layer.attr,
483 NULL,
484};
485
486/* Specific kobject type for our PDC paths */
487static struct kobj_type ktype_pdcspath = {
488 .sysfs_ops = &pdcspath_attr_ops,
489 .default_attrs = paths_subsys_attrs,
490};
491
492/* We hard define the 4 types of path we expect to find */
493static PDCSPATH_ENTRY(PDCS_ADDR_PPRI, primary);
494static PDCSPATH_ENTRY(PDCS_ADDR_PCON, console);
495static PDCSPATH_ENTRY(PDCS_ADDR_PALT, alternative);
496static PDCSPATH_ENTRY(PDCS_ADDR_PKBD, keyboard);
497
498/* An array containing all PDC paths we will deal with */
499static struct pdcspath_entry *pdcspath_entries[] = {
500 &pdcspath_entry_primary,
501 &pdcspath_entry_alternative,
502 &pdcspath_entry_console,
503 &pdcspath_entry_keyboard,
504 NULL,
505};
506
507
508/* For more insight of what's going on here, refer to PDC Procedures doc,
509 * Section PDC_STABLE */
510
511/**
512 * pdcs_size_read - Stable Storage size output.
513 * @buf: The output buffer to write to.
514 */
515static ssize_t pdcs_size_read(struct kobject *kobj,
516 struct kobj_attribute *attr,
517 char *buf)
518{
519 char *out = buf;
520
521 if (!buf)
522 return -EINVAL;
523
524 /* show the size of the stable storage */
525 out += sprintf(out, "%ld\n", pdcs_size);
526
527 return out - buf;
528}
529
530/**
531 * pdcs_auto_read - Stable Storage autoboot/search flag output.
532 * @buf: The output buffer to write to.
533 * @knob: The PF_AUTOBOOT or PF_AUTOSEARCH flag
534 */
535static ssize_t pdcs_auto_read(struct kobject *kobj,
536 struct kobj_attribute *attr,
537 char *buf, int knob)
538{
539 char *out = buf;
540 struct pdcspath_entry *pathentry;
541
542 if (!buf)
543 return -EINVAL;
544
545 /* Current flags are stored in primary boot path entry */
546 pathentry = &pdcspath_entry_primary;
547
548 read_lock(&pathentry->rw_lock);
549 out += sprintf(out, "%s\n", (pathentry->devpath.flags & knob) ?
550 "On" : "Off");
551 read_unlock(&pathentry->rw_lock);
552
553 return out - buf;
554}
555
556/**
557 * pdcs_autoboot_read - Stable Storage autoboot flag output.
558 * @buf: The output buffer to write to.
559 */
560static ssize_t pdcs_autoboot_read(struct kobject *kobj,
561 struct kobj_attribute *attr, char *buf)
562{
563 return pdcs_auto_read(kobj, attr, buf, PF_AUTOBOOT);
564}
565
566/**
567 * pdcs_autosearch_read - Stable Storage autoboot flag output.
568 * @buf: The output buffer to write to.
569 */
570static ssize_t pdcs_autosearch_read(struct kobject *kobj,
571 struct kobj_attribute *attr, char *buf)
572{
573 return pdcs_auto_read(kobj, attr, buf, PF_AUTOSEARCH);
574}
575
576/**
577 * pdcs_timer_read - Stable Storage timer count output (in seconds).
578 * @buf: The output buffer to write to.
579 *
580 * The value of the timer field correponds to a number of seconds in powers of 2.
581 */
582static ssize_t pdcs_timer_read(struct kobject *kobj,
583 struct kobj_attribute *attr, char *buf)
584{
585 char *out = buf;
586 struct pdcspath_entry *pathentry;
587
588 if (!buf)
589 return -EINVAL;
590
591 /* Current flags are stored in primary boot path entry */
592 pathentry = &pdcspath_entry_primary;
593
594 /* print the timer value in seconds */
595 read_lock(&pathentry->rw_lock);
596 out += sprintf(out, "%u\n", (pathentry->devpath.flags & PF_TIMER) ?
597 (1 << (pathentry->devpath.flags & PF_TIMER)) : 0);
598 read_unlock(&pathentry->rw_lock);
599
600 return out - buf;
601}
602
603/**
604 * pdcs_osid_read - Stable Storage OS ID register output.
605 * @buf: The output buffer to write to.
606 */
607static ssize_t pdcs_osid_read(struct kobject *kobj,
608 struct kobj_attribute *attr, char *buf)
609{
610 char *out = buf;
611
612 if (!buf)
613 return -EINVAL;
614
615 out += sprintf(out, "%s dependent data (0x%.4x)\n",
616 os_id_to_string(pdcs_osid), pdcs_osid);
617
618 return out - buf;
619}
620
621/**
622 * pdcs_osdep1_read - Stable Storage OS-Dependent data area 1 output.
623 * @buf: The output buffer to write to.
624 *
625 * This can hold 16 bytes of OS-Dependent data.
626 */
627static ssize_t pdcs_osdep1_read(struct kobject *kobj,
628 struct kobj_attribute *attr, char *buf)
629{
630 char *out = buf;
631 u32 result[4];
632
633 if (!buf)
634 return -EINVAL;
635
636 if (pdc_stable_read(PDCS_ADDR_OSD1, &result, sizeof(result)) != PDC_OK)
637 return -EIO;
638
639 out += sprintf(out, "0x%.8x\n", result[0]);
640 out += sprintf(out, "0x%.8x\n", result[1]);
641 out += sprintf(out, "0x%.8x\n", result[2]);
642 out += sprintf(out, "0x%.8x\n", result[3]);
643
644 return out - buf;
645}
646
647/**
648 * pdcs_diagnostic_read - Stable Storage Diagnostic register output.
649 * @buf: The output buffer to write to.
650 *
651 * I have NFC how to interpret the content of that register ;-).
652 */
653static ssize_t pdcs_diagnostic_read(struct kobject *kobj,
654 struct kobj_attribute *attr, char *buf)
655{
656 char *out = buf;
657 u32 result;
658
659 if (!buf)
660 return -EINVAL;
661
662 /* get diagnostic */
663 if (pdc_stable_read(PDCS_ADDR_DIAG, &result, sizeof(result)) != PDC_OK)
664 return -EIO;
665
666 out += sprintf(out, "0x%.4x\n", (result >> 16));
667
668 return out - buf;
669}
670
671/**
672 * pdcs_fastsize_read - Stable Storage FastSize register output.
673 * @buf: The output buffer to write to.
674 *
675 * This register holds the amount of system RAM to be tested during boot sequence.
676 */
677static ssize_t pdcs_fastsize_read(struct kobject *kobj,
678 struct kobj_attribute *attr, char *buf)
679{
680 char *out = buf;
681 u32 result;
682
683 if (!buf)
684 return -EINVAL;
685
686 /* get fast-size */
687 if (pdc_stable_read(PDCS_ADDR_FSIZ, &result, sizeof(result)) != PDC_OK)
688 return -EIO;
689
690 if ((result & 0x0F) < 0x0E)
691 out += sprintf(out, "%d kB", (1<<(result & 0x0F))*256);
692 else
693 out += sprintf(out, "All");
694 out += sprintf(out, "\n");
695
696 return out - buf;
697}
698
699/**
700 * pdcs_osdep2_read - Stable Storage OS-Dependent data area 2 output.
701 * @buf: The output buffer to write to.
702 *
703 * This can hold pdcs_size - 224 bytes of OS-Dependent data, when available.
704 */
705static ssize_t pdcs_osdep2_read(struct kobject *kobj,
706 struct kobj_attribute *attr, char *buf)
707{
708 char *out = buf;
709 unsigned long size;
710 unsigned short i;
711 u32 result;
712
713 if (unlikely(pdcs_size <= 224))
714 return -ENODATA;
715
716 size = pdcs_size - 224;
717
718 if (!buf)
719 return -EINVAL;
720
721 for (i=0; i<size; i+=4) {
722 if (unlikely(pdc_stable_read(PDCS_ADDR_OSD2 + i, &result,
723 sizeof(result)) != PDC_OK))
724 return -EIO;
725 out += sprintf(out, "0x%.8x\n", result);
726 }
727
728 return out - buf;
729}
730
731/**
732 * pdcs_auto_write - This function handles autoboot/search flag modifying.
733 * @buf: The input buffer to read from.
734 * @count: The number of bytes to be read.
735 * @knob: The PF_AUTOBOOT or PF_AUTOSEARCH flag
736 *
737 * We will call this function to change the current autoboot flag.
738 * We expect a precise syntax:
739 * \"n\" (n == 0 or 1) to toggle AutoBoot Off or On
740 */
741static ssize_t pdcs_auto_write(struct kobject *kobj,
742 struct kobj_attribute *attr, const char *buf,
743 size_t count, int knob)
744{
745 struct pdcspath_entry *pathentry;
746 unsigned char flags;
747 char in[8], *temp;
748 char c;
749
750 if (!capable(CAP_SYS_ADMIN))
751 return -EACCES;
752
753 if (!buf || !count)
754 return -EINVAL;
755
756 /* We'll use a local copy of buf */
757 count = min_t(size_t, count, sizeof(in)-1);
758 strncpy(in, buf, count);
759 in[count] = '\0';
760
761 /* Current flags are stored in primary boot path entry */
762 pathentry = &pdcspath_entry_primary;
763
764 /* Be nice to the existing flag record */
765 read_lock(&pathentry->rw_lock);
766 flags = pathentry->devpath.flags;
767 read_unlock(&pathentry->rw_lock);
768
769 DPRINTK("%s: flags before: 0x%X\n", __func__, flags);
770
771 temp = skip_spaces(in);
772
773 c = *temp++ - '0';
774 if ((c != 0) && (c != 1))
775 goto parse_error;
776 if (c == 0)
777 flags &= ~knob;
778 else
779 flags |= knob;
780
781 DPRINTK("%s: flags after: 0x%X\n", __func__, flags);
782
783 /* So far so good, let's get in deep */
784 write_lock(&pathentry->rw_lock);
785
786 /* Change the path entry flags first */
787 pathentry->devpath.flags = flags;
788
789 /* Now, dive in. Write back to the hardware */
790 pdcspath_store(pathentry);
791 write_unlock(&pathentry->rw_lock);
792
793 printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" to \"%s\"\n",
794 (knob & PF_AUTOBOOT) ? "autoboot" : "autosearch",
795 (flags & knob) ? "On" : "Off");
796
797 return count;
798
799parse_error:
800 printk(KERN_WARNING "%s: Parse error: expect \"n\" (n == 0 or 1)\n", __func__);
801 return -EINVAL;
802}
803
804/**
805 * pdcs_autoboot_write - This function handles autoboot flag modifying.
806 * @buf: The input buffer to read from.
807 * @count: The number of bytes to be read.
808 *
809 * We will call this function to change the current boot flags.
810 * We expect a precise syntax:
811 * \"n\" (n == 0 or 1) to toggle AutoSearch Off or On
812 */
813static ssize_t pdcs_autoboot_write(struct kobject *kobj,
814 struct kobj_attribute *attr,
815 const char *buf, size_t count)
816{
817 return pdcs_auto_write(kobj, attr, buf, count, PF_AUTOBOOT);
818}
819
820/**
821 * pdcs_autosearch_write - This function handles autosearch flag modifying.
822 * @buf: The input buffer to read from.
823 * @count: The number of bytes to be read.
824 *
825 * We will call this function to change the current boot flags.
826 * We expect a precise syntax:
827 * \"n\" (n == 0 or 1) to toggle AutoSearch Off or On
828 */
829static ssize_t pdcs_autosearch_write(struct kobject *kobj,
830 struct kobj_attribute *attr,
831 const char *buf, size_t count)
832{
833 return pdcs_auto_write(kobj, attr, buf, count, PF_AUTOSEARCH);
834}
835
836/**
837 * pdcs_osdep1_write - Stable Storage OS-Dependent data area 1 input.
838 * @buf: The input buffer to read from.
839 * @count: The number of bytes to be read.
840 *
841 * This can store 16 bytes of OS-Dependent data. We use a byte-by-byte
842 * write approach. It's up to userspace to deal with it when constructing
843 * its input buffer.
844 */
845static ssize_t pdcs_osdep1_write(struct kobject *kobj,
846 struct kobj_attribute *attr,
847 const char *buf, size_t count)
848{
849 u8 in[16];
850
851 if (!capable(CAP_SYS_ADMIN))
852 return -EACCES;
853
854 if (!buf || !count)
855 return -EINVAL;
856
857 if (unlikely(pdcs_osid != OS_ID_LINUX))
858 return -EPERM;
859
860 if (count > 16)
861 return -EMSGSIZE;
862
863 /* We'll use a local copy of buf */
864 memset(in, 0, 16);
865 memcpy(in, buf, count);
866
867 if (pdc_stable_write(PDCS_ADDR_OSD1, &in, sizeof(in)) != PDC_OK)
868 return -EIO;
869
870 return count;
871}
872
873/**
874 * pdcs_osdep2_write - Stable Storage OS-Dependent data area 2 input.
875 * @buf: The input buffer to read from.
876 * @count: The number of bytes to be read.
877 *
878 * This can store pdcs_size - 224 bytes of OS-Dependent data. We use a
879 * byte-by-byte write approach. It's up to userspace to deal with it when
880 * constructing its input buffer.
881 */
882static ssize_t pdcs_osdep2_write(struct kobject *kobj,
883 struct kobj_attribute *attr,
884 const char *buf, size_t count)
885{
886 unsigned long size;
887 unsigned short i;
888 u8 in[4];
889
890 if (!capable(CAP_SYS_ADMIN))
891 return -EACCES;
892
893 if (!buf || !count)
894 return -EINVAL;
895
896 if (unlikely(pdcs_size <= 224))
897 return -ENOSYS;
898
899 if (unlikely(pdcs_osid != OS_ID_LINUX))
900 return -EPERM;
901
902 size = pdcs_size - 224;
903
904 if (count > size)
905 return -EMSGSIZE;
906
907 /* We'll use a local copy of buf */
908
909 for (i=0; i<count; i+=4) {
910 memset(in, 0, 4);
911 memcpy(in, buf+i, (count-i < 4) ? count-i : 4);
912 if (unlikely(pdc_stable_write(PDCS_ADDR_OSD2 + i, &in,
913 sizeof(in)) != PDC_OK))
914 return -EIO;
915 }
916
917 return count;
918}
919
920/* The remaining attributes. */
921static PDCS_ATTR(size, 0444, pdcs_size_read, NULL);
922static PDCS_ATTR(autoboot, 0644, pdcs_autoboot_read, pdcs_autoboot_write);
923static PDCS_ATTR(autosearch, 0644, pdcs_autosearch_read, pdcs_autosearch_write);
924static PDCS_ATTR(timer, 0444, pdcs_timer_read, NULL);
925static PDCS_ATTR(osid, 0444, pdcs_osid_read, NULL);
926static PDCS_ATTR(osdep1, 0600, pdcs_osdep1_read, pdcs_osdep1_write);
927static PDCS_ATTR(diagnostic, 0400, pdcs_diagnostic_read, NULL);
928static PDCS_ATTR(fastsize, 0400, pdcs_fastsize_read, NULL);
929static PDCS_ATTR(osdep2, 0600, pdcs_osdep2_read, pdcs_osdep2_write);
930
931static struct attribute *pdcs_subsys_attrs[] = {
932 &pdcs_attr_size.attr,
933 &pdcs_attr_autoboot.attr,
934 &pdcs_attr_autosearch.attr,
935 &pdcs_attr_timer.attr,
936 &pdcs_attr_osid.attr,
937 &pdcs_attr_osdep1.attr,
938 &pdcs_attr_diagnostic.attr,
939 &pdcs_attr_fastsize.attr,
940 &pdcs_attr_osdep2.attr,
941 NULL,
942};
943
944static const struct attribute_group pdcs_attr_group = {
945 .attrs = pdcs_subsys_attrs,
946};
947
948static struct kobject *stable_kobj;
949static struct kset *paths_kset;
950
951/**
952 * pdcs_register_pathentries - Prepares path entries kobjects for sysfs usage.
953 *
954 * It creates kobjects corresponding to each path entry with nice sysfs
955 * links to the real device. This is where the magic takes place: when
956 * registering the subsystem attributes during module init, each kobject hereby
957 * created will show in the sysfs tree as a folder containing files as defined
958 * by path_subsys_attr[].
959 */
960static inline int __init
961pdcs_register_pathentries(void)
962{
963 unsigned short i;
964 struct pdcspath_entry *entry;
965 int err;
966
967 /* Initialize the entries rw_lock before anything else */
968 for (i = 0; (entry = pdcspath_entries[i]); i++)
969 rwlock_init(&entry->rw_lock);
970
971 for (i = 0; (entry = pdcspath_entries[i]); i++) {
972 write_lock(&entry->rw_lock);
973 err = pdcspath_fetch(entry);
974 write_unlock(&entry->rw_lock);
975
976 if (err < 0)
977 continue;
978
979 entry->kobj.kset = paths_kset;
980 err = kobject_init_and_add(&entry->kobj, &ktype_pdcspath, NULL,
981 "%s", entry->name);
982 if (err)
983 return err;
984
985 /* kobject is now registered */
986 write_lock(&entry->rw_lock);
987 entry->ready = 2;
988 write_unlock(&entry->rw_lock);
989
990 /* Add a nice symlink to the real device */
991 if (entry->dev) {
992 err = sysfs_create_link(&entry->kobj, &entry->dev->kobj, "device");
993 WARN_ON(err);
994 }
995
996 kobject_uevent(&entry->kobj, KOBJ_ADD);
997 }
998
999 return 0;
1000}
1001
1002/**
1003 * pdcs_unregister_pathentries - Routine called when unregistering the module.
1004 */
1005static inline void
1006pdcs_unregister_pathentries(void)
1007{
1008 unsigned short i;
1009 struct pdcspath_entry *entry;
1010
1011 for (i = 0; (entry = pdcspath_entries[i]); i++) {
1012 read_lock(&entry->rw_lock);
1013 if (entry->ready >= 2)
1014 kobject_put(&entry->kobj);
1015 read_unlock(&entry->rw_lock);
1016 }
1017}
1018
1019/*
1020 * For now we register the stable subsystem with the firmware subsystem
1021 * and the paths subsystem with the stable subsystem
1022 */
1023static int __init
1024pdc_stable_init(void)
1025{
1026 int rc = 0, error = 0;
1027 u32 result;
1028
1029 /* find the size of the stable storage */
1030 if (pdc_stable_get_size(&pdcs_size) != PDC_OK)
1031 return -ENODEV;
1032
1033 /* make sure we have enough data */
1034 if (pdcs_size < 96)
1035 return -ENODATA;
1036
1037 printk(KERN_INFO PDCS_PREFIX " facility v%s\n", PDCS_VERSION);
1038
1039 /* get OSID */
1040 if (pdc_stable_read(PDCS_ADDR_OSID, &result, sizeof(result)) != PDC_OK)
1041 return -EIO;
1042
1043 /* the actual result is 16 bits away */
1044 pdcs_osid = (u16)(result >> 16);
1045
1046 /* For now we'll register the directory at /sys/firmware/stable */
1047 stable_kobj = kobject_create_and_add("stable", firmware_kobj);
1048 if (!stable_kobj) {
1049 rc = -ENOMEM;
1050 goto fail_firmreg;
1051 }
1052
1053 /* Don't forget the root entries */
1054 error = sysfs_create_group(stable_kobj, &pdcs_attr_group);
1055
1056 /* register the paths kset as a child of the stable kset */
1057 paths_kset = kset_create_and_add("paths", NULL, stable_kobj);
1058 if (!paths_kset) {
1059 rc = -ENOMEM;
1060 goto fail_ksetreg;
1061 }
1062
1063 /* now we create all "files" for the paths kset */
1064 if ((rc = pdcs_register_pathentries()))
1065 goto fail_pdcsreg;
1066
1067 return rc;
1068
1069fail_pdcsreg:
1070 pdcs_unregister_pathentries();
1071 kset_unregister(paths_kset);
1072
1073fail_ksetreg:
1074 kobject_put(stable_kobj);
1075
1076fail_firmreg:
1077 printk(KERN_INFO PDCS_PREFIX " bailing out\n");
1078 return rc;
1079}
1080
1081static void __exit
1082pdc_stable_exit(void)
1083{
1084 pdcs_unregister_pathentries();
1085 kset_unregister(paths_kset);
1086 kobject_put(stable_kobj);
1087}
1088
1089
1090module_init(pdc_stable_init);
1091module_exit(pdc_stable_exit);