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 | * pdc_module_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 | |
74 | MODULE_AUTHOR("Thibaut VARENE <varenet@parisc-linux.org>" ); |
75 | MODULE_DESCRIPTION("sysfs interface to HP PDC Stable Storage data" ); |
76 | MODULE_LICENSE("GPL" ); |
77 | MODULE_VERSION(PDCS_VERSION); |
78 | |
79 | /* holds Stable Storage size. Initialized once and for all, no lock needed */ |
80 | static unsigned long pdcs_size __read_mostly; |
81 | |
82 | /* holds OS ID. Initialized once and for all, hopefully to 0x0006 */ |
83 | static u16 pdcs_osid __read_mostly; |
84 | |
85 | /* This struct defines what we need to deal with a parisc pdc path entry */ |
86 | struct 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 pdc_module_path devpath; /* device path in parisc representation */ |
92 | struct device *dev; /* corresponding device */ |
93 | struct kobject kobj; |
94 | }; |
95 | |
96 | struct 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) \ |
103 | struct 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) \ |
110 | struct 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) \ |
117 | struct 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 | */ |
138 | static int |
139 | pdcspath_fetch(struct pdcspath_entry *entry) |
140 | { |
141 | struct pdc_module_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 pdc_module_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 | */ |
179 | static void |
180 | pdcspath_store(struct pdcspath_entry *entry) |
181 | { |
182 | struct pdc_module_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 | */ |
220 | static ssize_t |
221 | pdcspath_hwpath_read(struct pdcspath_entry *entry, char *buf) |
222 | { |
223 | char *out = buf; |
224 | struct pdc_module_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->path.bc[i] < 0) |
240 | continue; |
241 | out += sprintf(buf: out, fmt: "%d/" , devpath->path.bc[i]); |
242 | } |
243 | out += sprintf(buf: out, fmt: "%u\n" , (unsigned char)devpath->path.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 | */ |
263 | static ssize_t |
264 | pdcspath_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 | strscpy(p: in, q: buf, size: count + 1); |
278 | |
279 | /* Let's clean up the target. 0xff is a blank pattern */ |
280 | memset(&hwpath, 0xff, sizeof(hwpath)); |
281 | |
282 | /* First, pick the mod field (the last one of the input string) */ |
283 | if (!(temp = strrchr(in, '/'))) |
284 | return -EINVAL; |
285 | |
286 | hwpath.mod = simple_strtoul(temp+1, NULL, 10); |
287 | in[temp-in] = '\0'; /* truncate the remaining string. just precaution */ |
288 | DPRINTK("%s: mod: %d\n" , __func__, hwpath.mod); |
289 | |
290 | /* Then, loop for each delimiter, making sure we don't have too many. |
291 | we write the bc fields in a down-top way. No matter what, we stop |
292 | before writing the last field. If there are too many fields anyway, |
293 | then the user is a moron and it'll be caught up later when we'll |
294 | check the consistency of the given hwpath. */ |
295 | for (i=5; ((temp = strrchr(in, '/'))) && (temp-in > 0) && (likely(i)); i--) { |
296 | hwpath.bc[i] = simple_strtoul(temp+1, NULL, 10); |
297 | in[temp-in] = '\0'; |
298 | DPRINTK("%s: bc[%d]: %d\n" , __func__, i, hwpath.path.bc[i]); |
299 | } |
300 | |
301 | /* Store the final field */ |
302 | hwpath.bc[i] = simple_strtoul(in, NULL, 10); |
303 | DPRINTK("%s: bc[%d]: %d\n" , __func__, i, hwpath.path.bc[i]); |
304 | |
305 | /* Now we check that the user isn't trying to lure us */ |
306 | if (!(dev = hwpath_to_device((struct hardware_path *)&hwpath))) { |
307 | printk(KERN_WARNING "%s: attempt to set invalid \"%s\" " |
308 | "hardware path: %s\n" , __func__, entry->name, buf); |
309 | return -EINVAL; |
310 | } |
311 | |
312 | /* So far so good, let's get in deep */ |
313 | write_lock(&entry->rw_lock); |
314 | entry->ready = 0; |
315 | entry->dev = dev; |
316 | |
317 | /* Now, dive in. Write back to the hardware */ |
318 | pdcspath_store(entry); |
319 | |
320 | /* Update the symlink to the real device */ |
321 | sysfs_remove_link(kobj: &entry->kobj, name: "device" ); |
322 | write_unlock(&entry->rw_lock); |
323 | |
324 | ret = sysfs_create_link(kobj: &entry->kobj, target: &entry->dev->kobj, name: "device" ); |
325 | WARN_ON(ret); |
326 | |
327 | printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" path to \"%s\"\n" , |
328 | entry->name, buf); |
329 | |
330 | return count; |
331 | } |
332 | |
333 | /** |
334 | * pdcspath_layer_read - Extended layer (eg. SCSI ids) pretty printing. |
335 | * @entry: An allocated and populated pdscpath_entry struct. |
336 | * @buf: The output buffer to write to. |
337 | * |
338 | * We will call this function to format the output of the layer attribute file. |
339 | */ |
340 | static ssize_t |
341 | pdcspath_layer_read(struct pdcspath_entry *entry, char *buf) |
342 | { |
343 | char *out = buf; |
344 | struct pdc_module_path *devpath; |
345 | short i; |
346 | |
347 | if (!entry || !buf) |
348 | return -EINVAL; |
349 | |
350 | read_lock(&entry->rw_lock); |
351 | devpath = &entry->devpath; |
352 | i = entry->ready; |
353 | read_unlock(&entry->rw_lock); |
354 | |
355 | if (!i) /* entry is not ready */ |
356 | return -ENODATA; |
357 | |
358 | for (i = 0; i < 6 && devpath->layers[i]; i++) |
359 | out += sprintf(buf: out, fmt: "%u " , devpath->layers[i]); |
360 | |
361 | out += sprintf(buf: out, fmt: "\n" ); |
362 | |
363 | return out - buf; |
364 | } |
365 | |
366 | /** |
367 | * pdcspath_layer_write - This function handles extended layer modifying. |
368 | * @entry: An allocated and populated pdscpath_entry struct. |
369 | * @buf: The input buffer to read from. |
370 | * @count: The number of bytes to be read. |
371 | * |
372 | * We will call this function to change the current layer value. |
373 | * Layers are to be given '.'-delimited, without brackets. |
374 | * XXX beware we are far less checky WRT input data provided than for hwpath. |
375 | * Potential harm can be done, since there's no way to check the validity of |
376 | * the layer fields. |
377 | */ |
378 | static ssize_t |
379 | pdcspath_layer_write(struct pdcspath_entry *entry, const char *buf, size_t count) |
380 | { |
381 | unsigned int layers[6]; /* device-specific info (ctlr#, unit#, ...) */ |
382 | unsigned short i; |
383 | char in[64], *temp; |
384 | |
385 | if (!entry || !buf || !count) |
386 | return -EINVAL; |
387 | |
388 | /* We'll use a local copy of buf */ |
389 | count = min_t(size_t, count, sizeof(in)-1); |
390 | strscpy(p: in, q: buf, size: count + 1); |
391 | |
392 | /* Let's clean up the target. 0 is a blank pattern */ |
393 | memset(&layers, 0, sizeof(layers)); |
394 | |
395 | /* First, pick the first layer */ |
396 | if (unlikely(!isdigit(*in))) |
397 | return -EINVAL; |
398 | layers[0] = simple_strtoul(in, NULL, 10); |
399 | DPRINTK("%s: layer[0]: %d\n" , __func__, layers[0]); |
400 | |
401 | temp = in; |
402 | for (i=1; ((temp = strchr(temp, '.'))) && (likely(i<6)); i++) { |
403 | if (unlikely(!isdigit(*(++temp)))) |
404 | return -EINVAL; |
405 | layers[i] = simple_strtoul(temp, NULL, 10); |
406 | DPRINTK("%s: layer[%d]: %d\n" , __func__, i, layers[i]); |
407 | } |
408 | |
409 | /* So far so good, let's get in deep */ |
410 | write_lock(&entry->rw_lock); |
411 | |
412 | /* First, overwrite the current layers with the new ones, not touching |
413 | the hardware path. */ |
414 | memcpy(&entry->devpath.layers, &layers, sizeof(layers)); |
415 | |
416 | /* Now, dive in. Write back to the hardware */ |
417 | pdcspath_store(entry); |
418 | write_unlock(&entry->rw_lock); |
419 | |
420 | printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" layers to \"%s\"\n" , |
421 | entry->name, buf); |
422 | |
423 | return count; |
424 | } |
425 | |
426 | /** |
427 | * pdcspath_attr_show - Generic read function call wrapper. |
428 | * @kobj: The kobject to get info from. |
429 | * @attr: The attribute looked upon. |
430 | * @buf: The output buffer. |
431 | */ |
432 | static ssize_t |
433 | pdcspath_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) |
434 | { |
435 | struct pdcspath_entry *entry = to_pdcspath_entry(kobj); |
436 | struct pdcspath_attribute *pdcs_attr = to_pdcspath_attribute(attr); |
437 | ssize_t ret = 0; |
438 | |
439 | if (pdcs_attr->show) |
440 | ret = pdcs_attr->show(entry, buf); |
441 | |
442 | return ret; |
443 | } |
444 | |
445 | /** |
446 | * pdcspath_attr_store - Generic write function call wrapper. |
447 | * @kobj: The kobject to write info to. |
448 | * @attr: The attribute to be modified. |
449 | * @buf: The input buffer. |
450 | * @count: The size of the buffer. |
451 | */ |
452 | static ssize_t |
453 | pdcspath_attr_store(struct kobject *kobj, struct attribute *attr, |
454 | const char *buf, size_t count) |
455 | { |
456 | struct pdcspath_entry *entry = to_pdcspath_entry(kobj); |
457 | struct pdcspath_attribute *pdcs_attr = to_pdcspath_attribute(attr); |
458 | ssize_t ret = 0; |
459 | |
460 | if (!capable(CAP_SYS_ADMIN)) |
461 | return -EACCES; |
462 | |
463 | if (pdcs_attr->store) |
464 | ret = pdcs_attr->store(entry, buf, count); |
465 | |
466 | return ret; |
467 | } |
468 | |
469 | static const struct sysfs_ops pdcspath_attr_ops = { |
470 | .show = pdcspath_attr_show, |
471 | .store = pdcspath_attr_store, |
472 | }; |
473 | |
474 | /* These are the two attributes of any PDC path. */ |
475 | static PATHS_ATTR(hwpath, 0644, pdcspath_hwpath_read, pdcspath_hwpath_write); |
476 | static PATHS_ATTR(layer, 0644, pdcspath_layer_read, pdcspath_layer_write); |
477 | |
478 | static struct attribute *paths_subsys_attrs[] = { |
479 | &paths_attr_hwpath.attr, |
480 | &paths_attr_layer.attr, |
481 | NULL, |
482 | }; |
483 | ATTRIBUTE_GROUPS(paths_subsys); |
484 | |
485 | /* Specific kobject type for our PDC paths */ |
486 | static struct kobj_type ktype_pdcspath = { |
487 | .sysfs_ops = &pdcspath_attr_ops, |
488 | .default_groups = paths_subsys_groups, |
489 | }; |
490 | |
491 | /* We hard define the 4 types of path we expect to find */ |
492 | static PDCSPATH_ENTRY(PDCS_ADDR_PPRI, primary); |
493 | static PDCSPATH_ENTRY(PDCS_ADDR_PCON, console); |
494 | static PDCSPATH_ENTRY(PDCS_ADDR_PALT, alternative); |
495 | static PDCSPATH_ENTRY(PDCS_ADDR_PKBD, keyboard); |
496 | |
497 | /* An array containing all PDC paths we will deal with */ |
498 | static struct pdcspath_entry *pdcspath_entries[] = { |
499 | &pdcspath_entry_primary, |
500 | &pdcspath_entry_alternative, |
501 | &pdcspath_entry_console, |
502 | &pdcspath_entry_keyboard, |
503 | NULL, |
504 | }; |
505 | |
506 | |
507 | /* For more insight of what's going on here, refer to PDC Procedures doc, |
508 | * Section PDC_STABLE */ |
509 | |
510 | /** |
511 | * pdcs_size_read - Stable Storage size output. |
512 | * @kobj: The kobject used to share data with userspace. |
513 | * @attr: The kobject attributes. |
514 | * @buf: The output buffer to write to. |
515 | */ |
516 | static ssize_t pdcs_size_read(struct kobject *kobj, |
517 | struct kobj_attribute *attr, |
518 | char *buf) |
519 | { |
520 | char *out = buf; |
521 | |
522 | if (!buf) |
523 | return -EINVAL; |
524 | |
525 | /* show the size of the stable storage */ |
526 | out += sprintf(buf: out, fmt: "%ld\n" , pdcs_size); |
527 | |
528 | return out - buf; |
529 | } |
530 | |
531 | /** |
532 | * pdcs_auto_read - Stable Storage autoboot/search flag output. |
533 | * @kobj: The kobject used to share data with userspace. |
534 | * @attr: The kobject attributes. |
535 | * @buf: The output buffer to write to. |
536 | * @knob: The PF_AUTOBOOT or PF_AUTOSEARCH flag |
537 | */ |
538 | static ssize_t pdcs_auto_read(struct kobject *kobj, |
539 | struct kobj_attribute *attr, |
540 | char *buf, int knob) |
541 | { |
542 | char *out = buf; |
543 | struct pdcspath_entry *pathentry; |
544 | |
545 | if (!buf) |
546 | return -EINVAL; |
547 | |
548 | /* Current flags are stored in primary boot path entry */ |
549 | pathentry = &pdcspath_entry_primary; |
550 | |
551 | read_lock(&pathentry->rw_lock); |
552 | out += sprintf(buf: out, fmt: "%s\n" , (pathentry->devpath.path.flags & knob) ? |
553 | "On" : "Off" ); |
554 | read_unlock(&pathentry->rw_lock); |
555 | |
556 | return out - buf; |
557 | } |
558 | |
559 | /** |
560 | * pdcs_autoboot_read - Stable Storage autoboot flag output. |
561 | * @kobj: The kobject used to share data with userspace. |
562 | * @attr: The kobject attributes. |
563 | * @buf: The output buffer to write to. |
564 | */ |
565 | static ssize_t pdcs_autoboot_read(struct kobject *kobj, |
566 | struct kobj_attribute *attr, char *buf) |
567 | { |
568 | return pdcs_auto_read(kobj, attr, buf, knob: PF_AUTOBOOT); |
569 | } |
570 | |
571 | /** |
572 | * pdcs_autosearch_read - Stable Storage autoboot flag output. |
573 | * @kobj: The kobject used to share data with userspace. |
574 | * @attr: The kobject attributes. |
575 | * @buf: The output buffer to write to. |
576 | */ |
577 | static ssize_t pdcs_autosearch_read(struct kobject *kobj, |
578 | struct kobj_attribute *attr, char *buf) |
579 | { |
580 | return pdcs_auto_read(kobj, attr, buf, knob: PF_AUTOSEARCH); |
581 | } |
582 | |
583 | /** |
584 | * pdcs_timer_read - Stable Storage timer count output (in seconds). |
585 | * @kobj: The kobject used to share data with userspace. |
586 | * @attr: The kobject attributes. |
587 | * @buf: The output buffer to write to. |
588 | * |
589 | * The value of the timer field correponds to a number of seconds in powers of 2. |
590 | */ |
591 | static ssize_t pdcs_timer_read(struct kobject *kobj, |
592 | struct kobj_attribute *attr, char *buf) |
593 | { |
594 | char *out = buf; |
595 | struct pdcspath_entry *pathentry; |
596 | |
597 | if (!buf) |
598 | return -EINVAL; |
599 | |
600 | /* Current flags are stored in primary boot path entry */ |
601 | pathentry = &pdcspath_entry_primary; |
602 | |
603 | /* print the timer value in seconds */ |
604 | read_lock(&pathentry->rw_lock); |
605 | out += sprintf(buf: out, fmt: "%u\n" , (pathentry->devpath.path.flags & PF_TIMER) ? |
606 | (1 << (pathentry->devpath.path.flags & PF_TIMER)) : 0); |
607 | read_unlock(&pathentry->rw_lock); |
608 | |
609 | return out - buf; |
610 | } |
611 | |
612 | /** |
613 | * pdcs_osid_read - Stable Storage OS ID register output. |
614 | * @kobj: The kobject used to share data with userspace. |
615 | * @attr: The kobject attributes. |
616 | * @buf: The output buffer to write to. |
617 | */ |
618 | static ssize_t pdcs_osid_read(struct kobject *kobj, |
619 | struct kobj_attribute *attr, char *buf) |
620 | { |
621 | char *out = buf; |
622 | |
623 | if (!buf) |
624 | return -EINVAL; |
625 | |
626 | out += sprintf(buf: out, fmt: "%s dependent data (0x%.4x)\n" , |
627 | os_id_to_string(pdcs_osid), pdcs_osid); |
628 | |
629 | return out - buf; |
630 | } |
631 | |
632 | /** |
633 | * pdcs_osdep1_read - Stable Storage OS-Dependent data area 1 output. |
634 | * @kobj: The kobject used to share data with userspace. |
635 | * @attr: The kobject attributes. |
636 | * @buf: The output buffer to write to. |
637 | * |
638 | * This can hold 16 bytes of OS-Dependent data. |
639 | */ |
640 | static 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(buf: out, fmt: "0x%.8x\n" , result[0]); |
653 | out += sprintf(buf: out, fmt: "0x%.8x\n" , result[1]); |
654 | out += sprintf(buf: out, fmt: "0x%.8x\n" , result[2]); |
655 | out += sprintf(buf: out, fmt: "0x%.8x\n" , result[3]); |
656 | |
657 | return out - buf; |
658 | } |
659 | |
660 | /** |
661 | * pdcs_diagnostic_read - Stable Storage Diagnostic register output. |
662 | * @kobj: The kobject used to share data with userspace. |
663 | * @attr: The kobject attributes. |
664 | * @buf: The output buffer to write to. |
665 | * |
666 | * I have NFC how to interpret the content of that register ;-). |
667 | */ |
668 | static ssize_t pdcs_diagnostic_read(struct kobject *kobj, |
669 | struct kobj_attribute *attr, char *buf) |
670 | { |
671 | char *out = buf; |
672 | u32 result; |
673 | |
674 | if (!buf) |
675 | return -EINVAL; |
676 | |
677 | /* get diagnostic */ |
678 | if (pdc_stable_read(PDCS_ADDR_DIAG, &result, sizeof(result)) != PDC_OK) |
679 | return -EIO; |
680 | |
681 | out += sprintf(buf: out, fmt: "0x%.4x\n" , (result >> 16)); |
682 | |
683 | return out - buf; |
684 | } |
685 | |
686 | /** |
687 | * pdcs_fastsize_read - Stable Storage FastSize register output. |
688 | * @kobj: The kobject used to share data with userspace. |
689 | * @attr: The kobject attributes. |
690 | * @buf: The output buffer to write to. |
691 | * |
692 | * This register holds the amount of system RAM to be tested during boot sequence. |
693 | */ |
694 | static ssize_t pdcs_fastsize_read(struct kobject *kobj, |
695 | struct kobj_attribute *attr, char *buf) |
696 | { |
697 | char *out = buf; |
698 | u32 result; |
699 | |
700 | if (!buf) |
701 | return -EINVAL; |
702 | |
703 | /* get fast-size */ |
704 | if (pdc_stable_read(PDCS_ADDR_FSIZ, &result, sizeof(result)) != PDC_OK) |
705 | return -EIO; |
706 | |
707 | if ((result & 0x0F) < 0x0E) |
708 | out += sprintf(buf: out, fmt: "%d kB" , (1<<(result & 0x0F))*256); |
709 | else |
710 | out += sprintf(buf: out, fmt: "All" ); |
711 | out += sprintf(buf: out, fmt: "\n" ); |
712 | |
713 | return out - buf; |
714 | } |
715 | |
716 | /** |
717 | * pdcs_osdep2_read - Stable Storage OS-Dependent data area 2 output. |
718 | * @kobj: The kobject used to share data with userspace. |
719 | * @attr: The kobject attributes. |
720 | * @buf: The output buffer to write to. |
721 | * |
722 | * This can hold pdcs_size - 224 bytes of OS-Dependent data, when available. |
723 | */ |
724 | static ssize_t pdcs_osdep2_read(struct kobject *kobj, |
725 | struct kobj_attribute *attr, char *buf) |
726 | { |
727 | char *out = buf; |
728 | unsigned long size; |
729 | unsigned short i; |
730 | u32 result; |
731 | |
732 | if (unlikely(pdcs_size <= 224)) |
733 | return -ENODATA; |
734 | |
735 | size = pdcs_size - 224; |
736 | |
737 | if (!buf) |
738 | return -EINVAL; |
739 | |
740 | for (i=0; i<size; i+=4) { |
741 | if (unlikely(pdc_stable_read(PDCS_ADDR_OSD2 + i, &result, |
742 | sizeof(result)) != PDC_OK)) |
743 | return -EIO; |
744 | out += sprintf(buf: out, fmt: "0x%.8x\n" , result); |
745 | } |
746 | |
747 | return out - buf; |
748 | } |
749 | |
750 | /** |
751 | * pdcs_auto_write - This function handles autoboot/search flag modifying. |
752 | * @kobj: The kobject used to share data with userspace. |
753 | * @attr: The kobject attributes. |
754 | * @buf: The input buffer to read from. |
755 | * @count: The number of bytes to be read. |
756 | * @knob: The PF_AUTOBOOT or PF_AUTOSEARCH flag |
757 | * |
758 | * We will call this function to change the current autoboot flag. |
759 | * We expect a precise syntax: |
760 | * \"n\" (n == 0 or 1) to toggle AutoBoot Off or On |
761 | */ |
762 | static ssize_t pdcs_auto_write(struct kobject *kobj, |
763 | struct kobj_attribute *attr, const char *buf, |
764 | size_t count, int knob) |
765 | { |
766 | struct pdcspath_entry *pathentry; |
767 | unsigned char flags; |
768 | char in[8], *temp; |
769 | char c; |
770 | |
771 | if (!capable(CAP_SYS_ADMIN)) |
772 | return -EACCES; |
773 | |
774 | if (!buf || !count) |
775 | return -EINVAL; |
776 | |
777 | /* We'll use a local copy of buf */ |
778 | count = min_t(size_t, count, sizeof(in)-1); |
779 | strscpy(p: in, q: buf, size: count + 1); |
780 | |
781 | /* Current flags are stored in primary boot path entry */ |
782 | pathentry = &pdcspath_entry_primary; |
783 | |
784 | /* Be nice to the existing flag record */ |
785 | read_lock(&pathentry->rw_lock); |
786 | flags = pathentry->devpath.path.flags; |
787 | read_unlock(&pathentry->rw_lock); |
788 | |
789 | DPRINTK("%s: flags before: 0x%X\n" , __func__, flags); |
790 | |
791 | temp = skip_spaces(in); |
792 | |
793 | c = *temp++ - '0'; |
794 | if ((c != 0) && (c != 1)) |
795 | goto parse_error; |
796 | if (c == 0) |
797 | flags &= ~knob; |
798 | else |
799 | flags |= knob; |
800 | |
801 | DPRINTK("%s: flags after: 0x%X\n" , __func__, flags); |
802 | |
803 | /* So far so good, let's get in deep */ |
804 | write_lock(&pathentry->rw_lock); |
805 | |
806 | /* Change the path entry flags first */ |
807 | pathentry->devpath.path.flags = flags; |
808 | |
809 | /* Now, dive in. Write back to the hardware */ |
810 | pdcspath_store(entry: pathentry); |
811 | write_unlock(&pathentry->rw_lock); |
812 | |
813 | printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" to \"%s\"\n" , |
814 | (knob & PF_AUTOBOOT) ? "autoboot" : "autosearch" , |
815 | (flags & knob) ? "On" : "Off" ); |
816 | |
817 | return count; |
818 | |
819 | parse_error: |
820 | printk(KERN_WARNING "%s: Parse error: expect \"n\" (n == 0 or 1)\n" , __func__); |
821 | return -EINVAL; |
822 | } |
823 | |
824 | /** |
825 | * pdcs_autoboot_write - This function handles autoboot flag modifying. |
826 | * @kobj: The kobject used to share data with userspace. |
827 | * @attr: The kobject attributes. |
828 | * @buf: The input buffer to read from. |
829 | * @count: The number of bytes to be read. |
830 | * |
831 | * We will call this function to change the current boot flags. |
832 | * We expect a precise syntax: |
833 | * \"n\" (n == 0 or 1) to toggle AutoSearch Off or On |
834 | */ |
835 | static ssize_t pdcs_autoboot_write(struct kobject *kobj, |
836 | struct kobj_attribute *attr, |
837 | const char *buf, size_t count) |
838 | { |
839 | return pdcs_auto_write(kobj, attr, buf, count, knob: PF_AUTOBOOT); |
840 | } |
841 | |
842 | /** |
843 | * pdcs_autosearch_write - This function handles autosearch flag modifying. |
844 | * @kobj: The kobject used to share data with userspace. |
845 | * @attr: The kobject attributes. |
846 | * @buf: The input buffer to read from. |
847 | * @count: The number of bytes to be read. |
848 | * |
849 | * We will call this function to change the current boot flags. |
850 | * We expect a precise syntax: |
851 | * \"n\" (n == 0 or 1) to toggle AutoSearch Off or On |
852 | */ |
853 | static ssize_t pdcs_autosearch_write(struct kobject *kobj, |
854 | struct kobj_attribute *attr, |
855 | const char *buf, size_t count) |
856 | { |
857 | return pdcs_auto_write(kobj, attr, buf, count, knob: PF_AUTOSEARCH); |
858 | } |
859 | |
860 | /** |
861 | * pdcs_osdep1_write - Stable Storage OS-Dependent data area 1 input. |
862 | * @kobj: The kobject used to share data with userspace. |
863 | * @attr: The kobject attributes. |
864 | * @buf: The input buffer to read from. |
865 | * @count: The number of bytes to be read. |
866 | * |
867 | * This can store 16 bytes of OS-Dependent data. We use a byte-by-byte |
868 | * write approach. It's up to userspace to deal with it when constructing |
869 | * its input buffer. |
870 | */ |
871 | static ssize_t pdcs_osdep1_write(struct kobject *kobj, |
872 | struct kobj_attribute *attr, |
873 | const char *buf, size_t count) |
874 | { |
875 | u8 in[16]; |
876 | |
877 | if (!capable(CAP_SYS_ADMIN)) |
878 | return -EACCES; |
879 | |
880 | if (!buf || !count) |
881 | return -EINVAL; |
882 | |
883 | if (unlikely(pdcs_osid != OS_ID_LINUX)) |
884 | return -EPERM; |
885 | |
886 | if (count > 16) |
887 | return -EMSGSIZE; |
888 | |
889 | /* We'll use a local copy of buf */ |
890 | memset(in, 0, 16); |
891 | memcpy(in, buf, count); |
892 | |
893 | if (pdc_stable_write(PDCS_ADDR_OSD1, &in, sizeof(in)) != PDC_OK) |
894 | return -EIO; |
895 | |
896 | return count; |
897 | } |
898 | |
899 | /** |
900 | * pdcs_osdep2_write - Stable Storage OS-Dependent data area 2 input. |
901 | * @kobj: The kobject used to share data with userspace. |
902 | * @attr: The kobject attributes. |
903 | * @buf: The input buffer to read from. |
904 | * @count: The number of bytes to be read. |
905 | * |
906 | * This can store pdcs_size - 224 bytes of OS-Dependent data. We use a |
907 | * byte-by-byte write approach. It's up to userspace to deal with it when |
908 | * constructing its input buffer. |
909 | */ |
910 | static ssize_t pdcs_osdep2_write(struct kobject *kobj, |
911 | struct kobj_attribute *attr, |
912 | const char *buf, size_t count) |
913 | { |
914 | unsigned long size; |
915 | unsigned short i; |
916 | u8 in[4]; |
917 | |
918 | if (!capable(CAP_SYS_ADMIN)) |
919 | return -EACCES; |
920 | |
921 | if (!buf || !count) |
922 | return -EINVAL; |
923 | |
924 | if (unlikely(pdcs_size <= 224)) |
925 | return -ENOSYS; |
926 | |
927 | if (unlikely(pdcs_osid != OS_ID_LINUX)) |
928 | return -EPERM; |
929 | |
930 | size = pdcs_size - 224; |
931 | |
932 | if (count > size) |
933 | return -EMSGSIZE; |
934 | |
935 | /* We'll use a local copy of buf */ |
936 | |
937 | for (i=0; i<count; i+=4) { |
938 | memset(in, 0, 4); |
939 | memcpy(in, buf+i, (count-i < 4) ? count-i : 4); |
940 | if (unlikely(pdc_stable_write(PDCS_ADDR_OSD2 + i, &in, |
941 | sizeof(in)) != PDC_OK)) |
942 | return -EIO; |
943 | } |
944 | |
945 | return count; |
946 | } |
947 | |
948 | /* The remaining attributes. */ |
949 | static PDCS_ATTR(size, 0444, pdcs_size_read, NULL); |
950 | static PDCS_ATTR(autoboot, 0644, pdcs_autoboot_read, pdcs_autoboot_write); |
951 | static PDCS_ATTR(autosearch, 0644, pdcs_autosearch_read, pdcs_autosearch_write); |
952 | static PDCS_ATTR(timer, 0444, pdcs_timer_read, NULL); |
953 | static PDCS_ATTR(osid, 0444, pdcs_osid_read, NULL); |
954 | static PDCS_ATTR(osdep1, 0600, pdcs_osdep1_read, pdcs_osdep1_write); |
955 | static PDCS_ATTR(diagnostic, 0400, pdcs_diagnostic_read, NULL); |
956 | static PDCS_ATTR(fastsize, 0400, pdcs_fastsize_read, NULL); |
957 | static PDCS_ATTR(osdep2, 0600, pdcs_osdep2_read, pdcs_osdep2_write); |
958 | |
959 | static struct attribute *pdcs_subsys_attrs[] = { |
960 | &pdcs_attr_size.attr, |
961 | &pdcs_attr_autoboot.attr, |
962 | &pdcs_attr_autosearch.attr, |
963 | &pdcs_attr_timer.attr, |
964 | &pdcs_attr_osid.attr, |
965 | &pdcs_attr_osdep1.attr, |
966 | &pdcs_attr_diagnostic.attr, |
967 | &pdcs_attr_fastsize.attr, |
968 | &pdcs_attr_osdep2.attr, |
969 | NULL, |
970 | }; |
971 | |
972 | static const struct attribute_group pdcs_attr_group = { |
973 | .attrs = pdcs_subsys_attrs, |
974 | }; |
975 | |
976 | static struct kobject *stable_kobj; |
977 | static struct kset *paths_kset; |
978 | |
979 | /** |
980 | * pdcs_register_pathentries - Prepares path entries kobjects for sysfs usage. |
981 | * |
982 | * It creates kobjects corresponding to each path entry with nice sysfs |
983 | * links to the real device. This is where the magic takes place: when |
984 | * registering the subsystem attributes during module init, each kobject hereby |
985 | * created will show in the sysfs tree as a folder containing files as defined |
986 | * by path_subsys_attr[]. |
987 | */ |
988 | static inline int __init |
989 | pdcs_register_pathentries(void) |
990 | { |
991 | unsigned short i; |
992 | struct pdcspath_entry *entry; |
993 | int err; |
994 | |
995 | /* Initialize the entries rw_lock before anything else */ |
996 | for (i = 0; (entry = pdcspath_entries[i]); i++) |
997 | rwlock_init(&entry->rw_lock); |
998 | |
999 | for (i = 0; (entry = pdcspath_entries[i]); i++) { |
1000 | write_lock(&entry->rw_lock); |
1001 | err = pdcspath_fetch(entry); |
1002 | write_unlock(&entry->rw_lock); |
1003 | |
1004 | if (err < 0) |
1005 | continue; |
1006 | |
1007 | entry->kobj.kset = paths_kset; |
1008 | err = kobject_init_and_add(kobj: &entry->kobj, ktype: &ktype_pdcspath, NULL, |
1009 | fmt: "%s" , entry->name); |
1010 | if (err) { |
1011 | kobject_put(kobj: &entry->kobj); |
1012 | return err; |
1013 | } |
1014 | |
1015 | /* kobject is now registered */ |
1016 | write_lock(&entry->rw_lock); |
1017 | entry->ready = 2; |
1018 | write_unlock(&entry->rw_lock); |
1019 | |
1020 | /* Add a nice symlink to the real device */ |
1021 | if (entry->dev) { |
1022 | err = sysfs_create_link(kobj: &entry->kobj, target: &entry->dev->kobj, name: "device" ); |
1023 | WARN_ON(err); |
1024 | } |
1025 | |
1026 | kobject_uevent(kobj: &entry->kobj, action: KOBJ_ADD); |
1027 | } |
1028 | |
1029 | return 0; |
1030 | } |
1031 | |
1032 | /** |
1033 | * pdcs_unregister_pathentries - Routine called when unregistering the module. |
1034 | */ |
1035 | static inline void |
1036 | pdcs_unregister_pathentries(void) |
1037 | { |
1038 | unsigned short i; |
1039 | struct pdcspath_entry *entry; |
1040 | |
1041 | for (i = 0; (entry = pdcspath_entries[i]); i++) { |
1042 | read_lock(&entry->rw_lock); |
1043 | if (entry->ready >= 2) |
1044 | kobject_put(kobj: &entry->kobj); |
1045 | read_unlock(&entry->rw_lock); |
1046 | } |
1047 | } |
1048 | |
1049 | /* |
1050 | * For now we register the stable subsystem with the firmware subsystem |
1051 | * and the paths subsystem with the stable subsystem |
1052 | */ |
1053 | static int __init |
1054 | pdc_stable_init(void) |
1055 | { |
1056 | int rc = 0, error; |
1057 | u32 result; |
1058 | |
1059 | /* find the size of the stable storage */ |
1060 | if (pdc_stable_get_size(&pdcs_size) != PDC_OK) |
1061 | return -ENODEV; |
1062 | |
1063 | /* make sure we have enough data */ |
1064 | if (pdcs_size < 96) |
1065 | return -ENODATA; |
1066 | |
1067 | printk(KERN_INFO PDCS_PREFIX " facility v%s\n" , PDCS_VERSION); |
1068 | |
1069 | /* get OSID */ |
1070 | if (pdc_stable_read(PDCS_ADDR_OSID, &result, sizeof(result)) != PDC_OK) |
1071 | return -EIO; |
1072 | |
1073 | /* the actual result is 16 bits away */ |
1074 | pdcs_osid = (u16)(result >> 16); |
1075 | |
1076 | /* For now we'll register the directory at /sys/firmware/stable */ |
1077 | stable_kobj = kobject_create_and_add(name: "stable" , parent: firmware_kobj); |
1078 | if (!stable_kobj) { |
1079 | rc = -ENOMEM; |
1080 | goto fail_firmreg; |
1081 | } |
1082 | |
1083 | /* Don't forget the root entries */ |
1084 | error = sysfs_create_group(kobj: stable_kobj, grp: &pdcs_attr_group); |
1085 | if (error) { |
1086 | rc = -ENOMEM; |
1087 | goto fail_ksetreg; |
1088 | } |
1089 | |
1090 | /* register the paths kset as a child of the stable kset */ |
1091 | paths_kset = kset_create_and_add(name: "paths" , NULL, parent_kobj: stable_kobj); |
1092 | if (!paths_kset) { |
1093 | rc = -ENOMEM; |
1094 | goto fail_ksetreg; |
1095 | } |
1096 | |
1097 | /* now we create all "files" for the paths kset */ |
1098 | if ((rc = pdcs_register_pathentries())) |
1099 | goto fail_pdcsreg; |
1100 | |
1101 | return rc; |
1102 | |
1103 | fail_pdcsreg: |
1104 | pdcs_unregister_pathentries(); |
1105 | kset_unregister(kset: paths_kset); |
1106 | |
1107 | fail_ksetreg: |
1108 | kobject_put(kobj: stable_kobj); |
1109 | |
1110 | fail_firmreg: |
1111 | printk(KERN_INFO PDCS_PREFIX " bailing out\n" ); |
1112 | return rc; |
1113 | } |
1114 | |
1115 | static void __exit |
1116 | pdc_stable_exit(void) |
1117 | { |
1118 | pdcs_unregister_pathentries(); |
1119 | kset_unregister(kset: paths_kset); |
1120 | kobject_put(kobj: stable_kobj); |
1121 | } |
1122 | |
1123 | |
1124 | module_init(pdc_stable_init); |
1125 | module_exit(pdc_stable_exit); |
1126 | |