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1da177e4 LT |
1 | /* |
2 | * Interfaces to retrieve and set PDC Stable options (firmware) | |
3 | * | |
c7428422 | 4 | * Copyright (C) 2005-2006 Thibaut VARENE <varenet@parisc-linux.org> |
1da177e4 LT |
5 | * |
6 | * This program is free software; you can redistribute it and/or modify | |
a81dd18e TV |
7 | * it under the terms of the GNU General Public License, version 2, as |
8 | * published by the Free Software Foundation. | |
1da177e4 LT |
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 | |
c7428422 | 28 | * following code can deal with just 96 bytes of Stable Storage, and all |
1da177e4 LT |
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 | * The code makes no use of data above 192 bytes. One last word: there's one | |
32 | * path we can always count on: the primary path. | |
c7428422 TV |
33 | * |
34 | * The current policy wrt file permissions is: | |
35 | * - write: root only | |
36 | * - read: (reading triggers PDC calls) ? root only : everyone | |
37 | * The rationale is that PDC calls could hog (DoS) the machine. | |
38 | * | |
39 | * TODO: | |
40 | * - timer/fastsize write calls | |
1da177e4 LT |
41 | */ |
42 | ||
43 | #undef PDCS_DEBUG | |
44 | #ifdef PDCS_DEBUG | |
45 | #define DPRINTK(fmt, args...) printk(KERN_DEBUG fmt, ## args) | |
46 | #else | |
47 | #define DPRINTK(fmt, args...) | |
48 | #endif | |
49 | ||
50 | #include <linux/module.h> | |
51 | #include <linux/init.h> | |
1da177e4 LT |
52 | #include <linux/kernel.h> |
53 | #include <linux/string.h> | |
c59ede7b | 54 | #include <linux/capability.h> |
1da177e4 LT |
55 | #include <linux/ctype.h> |
56 | #include <linux/sysfs.h> | |
57 | #include <linux/kobject.h> | |
58 | #include <linux/device.h> | |
59 | #include <linux/errno.h> | |
c7428422 | 60 | #include <linux/spinlock.h> |
1da177e4 LT |
61 | |
62 | #include <asm/pdc.h> | |
63 | #include <asm/page.h> | |
64 | #include <asm/uaccess.h> | |
65 | #include <asm/hardware.h> | |
66 | ||
c7428422 TV |
67 | #define PDCS_VERSION "0.22" |
68 | #define PDCS_PREFIX "PDC Stable Storage" | |
1da177e4 LT |
69 | |
70 | #define PDCS_ADDR_PPRI 0x00 | |
71 | #define PDCS_ADDR_OSID 0x40 | |
72 | #define PDCS_ADDR_FSIZ 0x5C | |
73 | #define PDCS_ADDR_PCON 0x60 | |
74 | #define PDCS_ADDR_PALT 0x80 | |
75 | #define PDCS_ADDR_PKBD 0xA0 | |
76 | ||
77 | MODULE_AUTHOR("Thibaut VARENE <varenet@parisc-linux.org>"); | |
78 | MODULE_DESCRIPTION("sysfs interface to HP PDC Stable Storage data"); | |
79 | MODULE_LICENSE("GPL"); | |
80 | MODULE_VERSION(PDCS_VERSION); | |
81 | ||
c7428422 | 82 | /* holds Stable Storage size. Initialized once and for all, no lock needed */ |
8039de10 | 83 | static unsigned long pdcs_size __read_mostly; |
1da177e4 LT |
84 | |
85 | /* This struct defines what we need to deal with a parisc pdc path entry */ | |
86 | struct pdcspath_entry { | |
c7428422 | 87 | rwlock_t rw_lock; /* to protect path entry access */ |
1da177e4 LT |
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 | ||
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 subsys_attribute pdcs_attr_##_name = { \ | |
111 | .attr = {.name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE}, \ | |
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, .owner = THIS_MODULE}, \ | |
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 facilites. 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. | |
c7428422 TV |
135 | * |
136 | * This function expects to be called with @entry->rw_lock write-hold. | |
1da177e4 LT |
137 | */ |
138 | static int | |
139 | pdcspath_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 | |
c7428422 TV |
176 | * |
177 | * This function expects to be called with @entry->rw_lock write-hold. | |
1da177e4 | 178 | */ |
c7428422 | 179 | static void |
1da177e4 LT |
180 | pdcspath_store(struct pdcspath_entry *entry) |
181 | { | |
182 | struct device_path *devpath; | |
183 | ||
c7428422 | 184 | BUG_ON(!entry); |
1da177e4 LT |
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 */ | |
c7428422 TV |
193 | BUG_ON(!entry->dev); |
194 | device_to_hwpath(entry->dev, (struct hardware_path *)devpath); | |
1da177e4 LT |
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 | printk(KERN_ERR "%s: an error occured 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__); | |
c7428422 | 206 | WARN_ON(1); |
1da177e4 LT |
207 | } |
208 | ||
4b991da7 TV |
209 | /* kobject is already registered */ |
210 | entry->ready = 2; | |
1da177e4 LT |
211 | |
212 | DPRINTK("%s: device: 0x%p\n", __func__, entry->dev); | |
1da177e4 LT |
213 | } |
214 | ||
215 | /** | |
216 | * pdcspath_hwpath_read - This function handles hardware path pretty printing. | |
217 | * @entry: An allocated and populated pdscpath_entry struct. | |
218 | * @buf: The output buffer to write to. | |
219 | * | |
220 | * We will call this function to format the output of the hwpath attribute file. | |
221 | */ | |
222 | static ssize_t | |
223 | pdcspath_hwpath_read(struct pdcspath_entry *entry, char *buf) | |
224 | { | |
225 | char *out = buf; | |
226 | struct device_path *devpath; | |
c7428422 | 227 | short i; |
1da177e4 LT |
228 | |
229 | if (!entry || !buf) | |
230 | return -EINVAL; | |
231 | ||
c7428422 | 232 | read_lock(&entry->rw_lock); |
1da177e4 | 233 | devpath = &entry->devpath; |
c7428422 TV |
234 | i = entry->ready; |
235 | read_unlock(&entry->rw_lock); | |
1da177e4 | 236 | |
c7428422 | 237 | if (!i) /* entry is not ready */ |
1da177e4 LT |
238 | return -ENODATA; |
239 | ||
240 | for (i = 0; i < 6; i++) { | |
241 | if (devpath->bc[i] >= 128) | |
242 | continue; | |
243 | out += sprintf(out, "%u/", (unsigned char)devpath->bc[i]); | |
244 | } | |
245 | out += sprintf(out, "%u\n", (unsigned char)devpath->mod); | |
246 | ||
247 | return out - buf; | |
248 | } | |
249 | ||
250 | /** | |
251 | * pdcspath_hwpath_write - This function handles hardware path modifying. | |
252 | * @entry: An allocated and populated pdscpath_entry struct. | |
253 | * @buf: The input buffer to read from. | |
254 | * @count: The number of bytes to be read. | |
255 | * | |
256 | * We will call this function to change the current hardware path. | |
257 | * Hardware paths are to be given '/'-delimited, without brackets. | |
c7428422 | 258 | * We make sure that the provided path actually maps to an existing |
1da177e4 LT |
259 | * device, BUT nothing would prevent some foolish user to set the path to some |
260 | * PCI bridge or even a CPU... | |
261 | * A better work around would be to make sure we are at the end of a device tree | |
262 | * for instance, but it would be IMHO beyond the simple scope of that driver. | |
263 | * The aim is to provide a facility. Data correctness is left to userland. | |
264 | */ | |
265 | static ssize_t | |
266 | pdcspath_hwpath_write(struct pdcspath_entry *entry, const char *buf, size_t count) | |
267 | { | |
268 | struct hardware_path hwpath; | |
269 | unsigned short i; | |
270 | char in[count+1], *temp; | |
271 | struct device *dev; | |
272 | ||
273 | if (!entry || !buf || !count) | |
274 | return -EINVAL; | |
275 | ||
276 | /* We'll use a local copy of buf */ | |
277 | memset(in, 0, count+1); | |
278 | strncpy(in, buf, count); | |
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 */ | |
c7428422 | 314 | write_lock(&entry->rw_lock); |
1da177e4 LT |
315 | entry->ready = 0; |
316 | entry->dev = dev; | |
317 | ||
318 | /* Now, dive in. Write back to the hardware */ | |
c7428422 | 319 | pdcspath_store(entry); |
1da177e4 LT |
320 | |
321 | /* Update the symlink to the real device */ | |
322 | sysfs_remove_link(&entry->kobj, "device"); | |
323 | sysfs_create_link(&entry->kobj, &entry->dev->kobj, "device"); | |
c7428422 | 324 | write_unlock(&entry->rw_lock); |
1da177e4 | 325 | |
c7428422 | 326 | printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" path to \"%s\"\n", |
1da177e4 LT |
327 | entry->name, buf); |
328 | ||
329 | return count; | |
330 | } | |
331 | ||
332 | /** | |
333 | * pdcspath_layer_read - Extended layer (eg. SCSI ids) pretty printing. | |
334 | * @entry: An allocated and populated pdscpath_entry struct. | |
335 | * @buf: The output buffer to write to. | |
336 | * | |
337 | * We will call this function to format the output of the layer attribute file. | |
338 | */ | |
339 | static ssize_t | |
340 | pdcspath_layer_read(struct pdcspath_entry *entry, char *buf) | |
341 | { | |
342 | char *out = buf; | |
343 | struct device_path *devpath; | |
c7428422 | 344 | short i; |
1da177e4 LT |
345 | |
346 | if (!entry || !buf) | |
347 | return -EINVAL; | |
348 | ||
c7428422 | 349 | read_lock(&entry->rw_lock); |
1da177e4 | 350 | devpath = &entry->devpath; |
c7428422 TV |
351 | i = entry->ready; |
352 | read_unlock(&entry->rw_lock); | |
1da177e4 | 353 | |
c7428422 | 354 | if (!i) /* entry is not ready */ |
1da177e4 LT |
355 | return -ENODATA; |
356 | ||
357 | for (i = 0; devpath->layers[i] && (likely(i < 6)); i++) | |
358 | out += sprintf(out, "%u ", devpath->layers[i]); | |
359 | ||
360 | out += sprintf(out, "\n"); | |
361 | ||
362 | return out - buf; | |
363 | } | |
364 | ||
365 | /** | |
366 | * pdcspath_layer_write - This function handles extended layer modifying. | |
367 | * @entry: An allocated and populated pdscpath_entry struct. | |
368 | * @buf: The input buffer to read from. | |
369 | * @count: The number of bytes to be read. | |
370 | * | |
371 | * We will call this function to change the current layer value. | |
372 | * Layers are to be given '.'-delimited, without brackets. | |
373 | * XXX beware we are far less checky WRT input data provided than for hwpath. | |
374 | * Potential harm can be done, since there's no way to check the validity of | |
375 | * the layer fields. | |
376 | */ | |
377 | static ssize_t | |
378 | pdcspath_layer_write(struct pdcspath_entry *entry, const char *buf, size_t count) | |
379 | { | |
380 | unsigned int layers[6]; /* device-specific info (ctlr#, unit#, ...) */ | |
381 | unsigned short i; | |
382 | char in[count+1], *temp; | |
383 | ||
384 | if (!entry || !buf || !count) | |
385 | return -EINVAL; | |
386 | ||
387 | /* We'll use a local copy of buf */ | |
388 | memset(in, 0, count+1); | |
389 | strncpy(in, buf, count); | |
390 | ||
391 | /* Let's clean up the target. 0 is a blank pattern */ | |
392 | memset(&layers, 0, sizeof(layers)); | |
393 | ||
394 | /* First, pick the first layer */ | |
395 | if (unlikely(!isdigit(*in))) | |
396 | return -EINVAL; | |
397 | layers[0] = simple_strtoul(in, NULL, 10); | |
398 | DPRINTK("%s: layer[0]: %d\n", __func__, layers[0]); | |
399 | ||
400 | temp = in; | |
401 | for (i=1; ((temp = strchr(temp, '.'))) && (likely(i<6)); i++) { | |
402 | if (unlikely(!isdigit(*(++temp)))) | |
403 | return -EINVAL; | |
404 | layers[i] = simple_strtoul(temp, NULL, 10); | |
405 | DPRINTK("%s: layer[%d]: %d\n", __func__, i, layers[i]); | |
406 | } | |
407 | ||
408 | /* So far so good, let's get in deep */ | |
c7428422 | 409 | write_lock(&entry->rw_lock); |
1da177e4 LT |
410 | |
411 | /* First, overwrite the current layers with the new ones, not touching | |
412 | the hardware path. */ | |
413 | memcpy(&entry->devpath.layers, &layers, sizeof(layers)); | |
414 | ||
415 | /* Now, dive in. Write back to the hardware */ | |
c7428422 TV |
416 | pdcspath_store(entry); |
417 | write_unlock(&entry->rw_lock); | |
1da177e4 | 418 | |
c7428422 | 419 | printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" layers to \"%s\"\n", |
1da177e4 LT |
420 | entry->name, buf); |
421 | ||
422 | return count; | |
423 | } | |
424 | ||
425 | /** | |
426 | * pdcspath_attr_show - Generic read function call wrapper. | |
427 | * @kobj: The kobject to get info from. | |
428 | * @attr: The attribute looked upon. | |
429 | * @buf: The output buffer. | |
430 | */ | |
431 | static ssize_t | |
432 | pdcspath_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) | |
433 | { | |
434 | struct pdcspath_entry *entry = to_pdcspath_entry(kobj); | |
435 | struct pdcspath_attribute *pdcs_attr = to_pdcspath_attribute(attr); | |
436 | ssize_t ret = 0; | |
437 | ||
1da177e4 LT |
438 | if (pdcs_attr->show) |
439 | ret = pdcs_attr->show(entry, buf); | |
440 | ||
441 | return ret; | |
442 | } | |
443 | ||
444 | /** | |
445 | * pdcspath_attr_store - Generic write function call wrapper. | |
446 | * @kobj: The kobject to write info to. | |
447 | * @attr: The attribute to be modified. | |
448 | * @buf: The input buffer. | |
449 | * @count: The size of the buffer. | |
450 | */ | |
451 | static ssize_t | |
452 | pdcspath_attr_store(struct kobject *kobj, struct attribute *attr, | |
453 | const char *buf, size_t count) | |
454 | { | |
455 | struct pdcspath_entry *entry = to_pdcspath_entry(kobj); | |
456 | struct pdcspath_attribute *pdcs_attr = to_pdcspath_attribute(attr); | |
457 | ssize_t ret = 0; | |
458 | ||
459 | if (!capable(CAP_SYS_ADMIN)) | |
460 | return -EACCES; | |
461 | ||
462 | if (pdcs_attr->store) | |
463 | ret = pdcs_attr->store(entry, buf, count); | |
464 | ||
465 | return ret; | |
466 | } | |
467 | ||
468 | static struct sysfs_ops pdcspath_attr_ops = { | |
469 | .show = pdcspath_attr_show, | |
470 | .store = pdcspath_attr_store, | |
471 | }; | |
472 | ||
473 | /* These are the two attributes of any PDC path. */ | |
c7428422 TV |
474 | static PATHS_ATTR(hwpath, 0644, pdcspath_hwpath_read, pdcspath_hwpath_write); |
475 | static PATHS_ATTR(layer, 0644, pdcspath_layer_read, pdcspath_layer_write); | |
1da177e4 LT |
476 | |
477 | static struct attribute *paths_subsys_attrs[] = { | |
478 | &paths_attr_hwpath.attr, | |
479 | &paths_attr_layer.attr, | |
480 | NULL, | |
481 | }; | |
482 | ||
483 | /* Specific kobject type for our PDC paths */ | |
484 | static struct kobj_type ktype_pdcspath = { | |
485 | .sysfs_ops = &pdcspath_attr_ops, | |
486 | .default_attrs = paths_subsys_attrs, | |
487 | }; | |
488 | ||
489 | /* We hard define the 4 types of path we expect to find */ | |
490 | static PDCSPATH_ENTRY(PDCS_ADDR_PPRI, primary); | |
491 | static PDCSPATH_ENTRY(PDCS_ADDR_PCON, console); | |
492 | static PDCSPATH_ENTRY(PDCS_ADDR_PALT, alternative); | |
493 | static PDCSPATH_ENTRY(PDCS_ADDR_PKBD, keyboard); | |
494 | ||
495 | /* An array containing all PDC paths we will deal with */ | |
496 | static struct pdcspath_entry *pdcspath_entries[] = { | |
497 | &pdcspath_entry_primary, | |
498 | &pdcspath_entry_alternative, | |
499 | &pdcspath_entry_console, | |
500 | &pdcspath_entry_keyboard, | |
501 | NULL, | |
502 | }; | |
503 | ||
c7428422 TV |
504 | |
505 | /* For more insight of what's going on here, refer to PDC Procedures doc, | |
506 | * Section PDC_STABLE */ | |
507 | ||
1da177e4 | 508 | /** |
c7428422 | 509 | * pdcs_size_read - Stable Storage size output. |
1da177e4 LT |
510 | * @entry: An allocated and populated subsytem struct. We don't use it tho. |
511 | * @buf: The output buffer to write to. | |
1da177e4 LT |
512 | */ |
513 | static ssize_t | |
c7428422 | 514 | pdcs_size_read(struct subsystem *entry, char *buf) |
1da177e4 LT |
515 | { |
516 | char *out = buf; | |
1da177e4 LT |
517 | |
518 | if (!entry || !buf) | |
519 | return -EINVAL; | |
520 | ||
521 | /* show the size of the stable storage */ | |
c7428422 | 522 | out += sprintf(out, "%ld\n", pdcs_size); |
1da177e4 | 523 | |
c7428422 TV |
524 | return out - buf; |
525 | } | |
526 | ||
527 | /** | |
528 | * pdcs_auto_read - Stable Storage autoboot/search flag output. | |
529 | * @entry: An allocated and populated subsytem struct. We don't use it tho. | |
530 | * @buf: The output buffer to write to. | |
531 | * @knob: The PF_AUTOBOOT or PF_AUTOSEARCH flag | |
532 | */ | |
533 | static ssize_t | |
534 | pdcs_auto_read(struct subsystem *entry, char *buf, int knob) | |
535 | { | |
536 | char *out = buf; | |
537 | struct pdcspath_entry *pathentry; | |
1da177e4 | 538 | |
c7428422 TV |
539 | if (!entry || !buf) |
540 | return -EINVAL; | |
541 | ||
542 | /* Current flags are stored in primary boot path entry */ | |
543 | pathentry = &pdcspath_entry_primary; | |
544 | ||
545 | read_lock(&pathentry->rw_lock); | |
546 | out += sprintf(out, "%s\n", (pathentry->devpath.flags & knob) ? | |
547 | "On" : "Off"); | |
548 | read_unlock(&pathentry->rw_lock); | |
549 | ||
550 | return out - buf; | |
551 | } | |
552 | ||
553 | /** | |
554 | * pdcs_autoboot_read - Stable Storage autoboot flag output. | |
555 | * @entry: An allocated and populated subsytem struct. We don't use it tho. | |
556 | * @buf: The output buffer to write to. | |
557 | */ | |
558 | static inline ssize_t | |
559 | pdcs_autoboot_read(struct subsystem *entry, char *buf) | |
560 | { | |
561 | return pdcs_auto_read(entry, buf, PF_AUTOBOOT); | |
562 | } | |
563 | ||
564 | /** | |
565 | * pdcs_autosearch_read - Stable Storage autoboot flag output. | |
566 | * @entry: An allocated and populated subsytem struct. We don't use it tho. | |
567 | * @buf: The output buffer to write to. | |
568 | */ | |
569 | static inline ssize_t | |
570 | pdcs_autosearch_read(struct subsystem *entry, char *buf) | |
571 | { | |
572 | return pdcs_auto_read(entry, buf, PF_AUTOSEARCH); | |
573 | } | |
574 | ||
575 | /** | |
576 | * pdcs_timer_read - Stable Storage timer count output (in seconds). | |
577 | * @entry: An allocated and populated subsytem struct. We don't use it tho. | |
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 | */ | |
582 | static ssize_t | |
583 | pdcs_timer_read(struct subsystem *entry, char *buf) | |
584 | { | |
585 | char *out = buf; | |
586 | struct pdcspath_entry *pathentry; | |
587 | ||
588 | if (!entry || !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 | * @entry: An allocated and populated subsytem struct. We don't use it tho. | |
606 | * @buf: The output buffer to write to. | |
607 | */ | |
608 | static ssize_t | |
609 | pdcs_osid_read(struct subsystem *entry, char *buf) | |
610 | { | |
611 | char *out = buf; | |
612 | __u32 result; | |
613 | char *tmpstr = NULL; | |
614 | ||
615 | if (!entry || !buf) | |
616 | return -EINVAL; | |
1da177e4 LT |
617 | |
618 | /* get OSID */ | |
619 | if (pdc_stable_read(PDCS_ADDR_OSID, &result, sizeof(result)) != PDC_OK) | |
620 | return -EIO; | |
621 | ||
622 | /* the actual result is 16 bits away */ | |
623 | switch (result >> 16) { | |
624 | case 0x0000: tmpstr = "No OS-dependent data"; break; | |
625 | case 0x0001: tmpstr = "HP-UX dependent data"; break; | |
626 | case 0x0002: tmpstr = "MPE-iX dependent data"; break; | |
627 | case 0x0003: tmpstr = "OSF dependent data"; break; | |
628 | case 0x0004: tmpstr = "HP-RT dependent data"; break; | |
629 | case 0x0005: tmpstr = "Novell Netware dependent data"; break; | |
630 | default: tmpstr = "Unknown"; break; | |
631 | } | |
c7428422 TV |
632 | out += sprintf(out, "%s (0x%.4x)\n", tmpstr, (result >> 16)); |
633 | ||
634 | return out - buf; | |
635 | } | |
636 | ||
637 | /** | |
638 | * pdcs_fastsize_read - Stable Storage FastSize register output. | |
639 | * @entry: An allocated and populated subsytem struct. We don't use it tho. | |
640 | * @buf: The output buffer to write to. | |
641 | * | |
642 | * This register holds the amount of system RAM to be tested during boot sequence. | |
643 | */ | |
644 | static ssize_t | |
645 | pdcs_fastsize_read(struct subsystem *entry, char *buf) | |
646 | { | |
647 | char *out = buf; | |
648 | __u32 result; | |
649 | ||
650 | if (!entry || !buf) | |
651 | return -EINVAL; | |
1da177e4 LT |
652 | |
653 | /* get fast-size */ | |
654 | if (pdc_stable_read(PDCS_ADDR_FSIZ, &result, sizeof(result)) != PDC_OK) | |
655 | return -EIO; | |
656 | ||
1da177e4 | 657 | if ((result & 0x0F) < 0x0E) |
abff7543 | 658 | out += sprintf(out, "%d kB", (1<<(result & 0x0F))*256); |
1da177e4 LT |
659 | else |
660 | out += sprintf(out, "All"); | |
661 | out += sprintf(out, "\n"); | |
662 | ||
663 | return out - buf; | |
664 | } | |
665 | ||
666 | /** | |
c7428422 | 667 | * pdcs_auto_write - This function handles autoboot/search flag modifying. |
1da177e4 LT |
668 | * @entry: An allocated and populated subsytem struct. We don't use it tho. |
669 | * @buf: The input buffer to read from. | |
670 | * @count: The number of bytes to be read. | |
c7428422 | 671 | * @knob: The PF_AUTOBOOT or PF_AUTOSEARCH flag |
1da177e4 | 672 | * |
c7428422 | 673 | * We will call this function to change the current autoboot flag. |
1da177e4 | 674 | * We expect a precise syntax: |
c7428422 | 675 | * \"n\" (n == 0 or 1) to toggle AutoBoot Off or On |
1da177e4 LT |
676 | */ |
677 | static ssize_t | |
c7428422 | 678 | pdcs_auto_write(struct subsystem *entry, const char *buf, size_t count, int knob) |
1da177e4 LT |
679 | { |
680 | struct pdcspath_entry *pathentry; | |
681 | unsigned char flags; | |
682 | char in[count+1], *temp; | |
683 | char c; | |
684 | ||
685 | if (!capable(CAP_SYS_ADMIN)) | |
686 | return -EACCES; | |
687 | ||
688 | if (!entry || !buf || !count) | |
689 | return -EINVAL; | |
690 | ||
691 | /* We'll use a local copy of buf */ | |
692 | memset(in, 0, count+1); | |
693 | strncpy(in, buf, count); | |
694 | ||
695 | /* Current flags are stored in primary boot path entry */ | |
696 | pathentry = &pdcspath_entry_primary; | |
697 | ||
698 | /* Be nice to the existing flag record */ | |
c7428422 | 699 | read_lock(&pathentry->rw_lock); |
1da177e4 | 700 | flags = pathentry->devpath.flags; |
c7428422 | 701 | read_unlock(&pathentry->rw_lock); |
1da177e4 LT |
702 | |
703 | DPRINTK("%s: flags before: 0x%X\n", __func__, flags); | |
704 | ||
705 | temp = in; | |
706 | ||
707 | while (*temp && isspace(*temp)) | |
708 | temp++; | |
709 | ||
710 | c = *temp++ - '0'; | |
711 | if ((c != 0) && (c != 1)) | |
712 | goto parse_error; | |
713 | if (c == 0) | |
c7428422 | 714 | flags &= ~knob; |
1da177e4 | 715 | else |
c7428422 | 716 | flags |= knob; |
1da177e4 LT |
717 | |
718 | DPRINTK("%s: flags after: 0x%X\n", __func__, flags); | |
719 | ||
720 | /* So far so good, let's get in deep */ | |
c7428422 | 721 | write_lock(&pathentry->rw_lock); |
1da177e4 LT |
722 | |
723 | /* Change the path entry flags first */ | |
724 | pathentry->devpath.flags = flags; | |
725 | ||
726 | /* Now, dive in. Write back to the hardware */ | |
c7428422 TV |
727 | pdcspath_store(pathentry); |
728 | write_unlock(&pathentry->rw_lock); | |
1da177e4 | 729 | |
c7428422 TV |
730 | printk(KERN_INFO PDCS_PREFIX ": changed \"%s\" to \"%s\"\n", |
731 | (knob & PF_AUTOBOOT) ? "autoboot" : "autosearch", | |
732 | (flags & knob) ? "On" : "Off"); | |
1da177e4 LT |
733 | |
734 | return count; | |
735 | ||
736 | parse_error: | |
c7428422 | 737 | printk(KERN_WARNING "%s: Parse error: expect \"n\" (n == 0 or 1)\n", __func__); |
1da177e4 LT |
738 | return -EINVAL; |
739 | } | |
740 | ||
c7428422 TV |
741 | /** |
742 | * pdcs_autoboot_write - This function handles autoboot flag modifying. | |
743 | * @entry: An allocated and populated subsytem struct. We don't use it tho. | |
744 | * @buf: The input buffer to read from. | |
745 | * @count: The number of bytes to be read. | |
746 | * | |
747 | * We will call this function to change the current boot flags. | |
748 | * We expect a precise syntax: | |
749 | * \"n\" (n == 0 or 1) to toggle AutoSearch Off or On | |
750 | */ | |
751 | static inline ssize_t | |
752 | pdcs_autoboot_write(struct subsystem *entry, const char *buf, size_t count) | |
753 | { | |
754 | return pdcs_auto_write(entry, buf, count, PF_AUTOBOOT); | |
755 | } | |
756 | ||
757 | /** | |
758 | * pdcs_autosearch_write - This function handles autosearch flag modifying. | |
759 | * @entry: An allocated and populated subsytem struct. We don't use it tho. | |
760 | * @buf: The input buffer to read from. | |
761 | * @count: The number of bytes to be read. | |
762 | * | |
763 | * We will call this function to change the current boot flags. | |
764 | * We expect a precise syntax: | |
765 | * \"n\" (n == 0 or 1) to toggle AutoSearch Off or On | |
766 | */ | |
767 | static inline ssize_t | |
768 | pdcs_autosearch_write(struct subsystem *entry, const char *buf, size_t count) | |
769 | { | |
770 | return pdcs_auto_write(entry, buf, count, PF_AUTOSEARCH); | |
771 | } | |
772 | ||
773 | /* The remaining attributes. */ | |
774 | static PDCS_ATTR(size, 0444, pdcs_size_read, NULL); | |
775 | static PDCS_ATTR(autoboot, 0644, pdcs_autoboot_read, pdcs_autoboot_write); | |
776 | static PDCS_ATTR(autosearch, 0644, pdcs_autosearch_read, pdcs_autosearch_write); | |
777 | static PDCS_ATTR(timer, 0444, pdcs_timer_read, NULL); | |
778 | static PDCS_ATTR(osid, 0400, pdcs_osid_read, NULL); | |
779 | static PDCS_ATTR(fastsize, 0400, pdcs_fastsize_read, NULL); | |
1da177e4 LT |
780 | |
781 | static struct subsys_attribute *pdcs_subsys_attrs[] = { | |
c7428422 TV |
782 | &pdcs_attr_size, |
783 | &pdcs_attr_autoboot, | |
784 | &pdcs_attr_autosearch, | |
785 | &pdcs_attr_timer, | |
786 | &pdcs_attr_osid, | |
787 | &pdcs_attr_fastsize, | |
788 | NULL, | |
1da177e4 LT |
789 | }; |
790 | ||
791 | static decl_subsys(paths, &ktype_pdcspath, NULL); | |
c7428422 | 792 | static decl_subsys(stable, NULL, NULL); |
1da177e4 LT |
793 | |
794 | /** | |
795 | * pdcs_register_pathentries - Prepares path entries kobjects for sysfs usage. | |
796 | * | |
797 | * It creates kobjects corresponding to each path entry with nice sysfs | |
798 | * links to the real device. This is where the magic takes place: when | |
799 | * registering the subsystem attributes during module init, each kobject hereby | |
800 | * created will show in the sysfs tree as a folder containing files as defined | |
801 | * by path_subsys_attr[]. | |
802 | */ | |
803 | static inline int __init | |
804 | pdcs_register_pathentries(void) | |
805 | { | |
806 | unsigned short i; | |
807 | struct pdcspath_entry *entry; | |
4b991da7 | 808 | int err; |
1da177e4 | 809 | |
c7428422 TV |
810 | /* Initialize the entries rw_lock before anything else */ |
811 | for (i = 0; (entry = pdcspath_entries[i]); i++) | |
812 | rwlock_init(&entry->rw_lock); | |
813 | ||
1da177e4 | 814 | for (i = 0; (entry = pdcspath_entries[i]); i++) { |
c7428422 TV |
815 | write_lock(&entry->rw_lock); |
816 | err = pdcspath_fetch(entry); | |
817 | write_unlock(&entry->rw_lock); | |
818 | ||
819 | if (err < 0) | |
1da177e4 LT |
820 | continue; |
821 | ||
4b991da7 TV |
822 | if ((err = kobject_set_name(&entry->kobj, "%s", entry->name))) |
823 | return err; | |
1da177e4 | 824 | kobj_set_kset_s(entry, paths_subsys); |
4b991da7 TV |
825 | if ((err = kobject_register(&entry->kobj))) |
826 | return err; | |
827 | ||
828 | /* kobject is now registered */ | |
c7428422 | 829 | write_lock(&entry->rw_lock); |
4b991da7 TV |
830 | entry->ready = 2; |
831 | ||
1da177e4 | 832 | /* Add a nice symlink to the real device */ |
c7428422 TV |
833 | if (entry->dev) |
834 | sysfs_create_link(&entry->kobj, &entry->dev->kobj, "device"); | |
835 | ||
836 | write_unlock(&entry->rw_lock); | |
1da177e4 LT |
837 | } |
838 | ||
839 | return 0; | |
840 | } | |
841 | ||
842 | /** | |
843 | * pdcs_unregister_pathentries - Routine called when unregistering the module. | |
844 | */ | |
4b991da7 | 845 | static inline void |
1da177e4 LT |
846 | pdcs_unregister_pathentries(void) |
847 | { | |
848 | unsigned short i; | |
849 | struct pdcspath_entry *entry; | |
850 | ||
c7428422 TV |
851 | for (i = 0; (entry = pdcspath_entries[i]); i++) { |
852 | read_lock(&entry->rw_lock); | |
4b991da7 | 853 | if (entry->ready >= 2) |
c7428422 TV |
854 | kobject_unregister(&entry->kobj); |
855 | read_unlock(&entry->rw_lock); | |
856 | } | |
1da177e4 LT |
857 | } |
858 | ||
859 | /* | |
c7428422 TV |
860 | * For now we register the stable subsystem with the firmware subsystem |
861 | * and the paths subsystem with the stable subsystem | |
1da177e4 LT |
862 | */ |
863 | static int __init | |
864 | pdc_stable_init(void) | |
865 | { | |
866 | struct subsys_attribute *attr; | |
867 | int i, rc = 0, error = 0; | |
868 | ||
869 | /* find the size of the stable storage */ | |
870 | if (pdc_stable_get_size(&pdcs_size) != PDC_OK) | |
871 | return -ENODEV; | |
872 | ||
c7428422 TV |
873 | /* make sure we have enough data */ |
874 | if (pdcs_size < 96) | |
875 | return -ENODATA; | |
876 | ||
877 | printk(KERN_INFO PDCS_PREFIX " facility v%s\n", PDCS_VERSION); | |
1da177e4 | 878 | |
c7428422 TV |
879 | /* For now we'll register the stable subsys within this driver */ |
880 | if ((rc = firmware_register(&stable_subsys))) | |
4b991da7 | 881 | goto fail_firmreg; |
1da177e4 | 882 | |
c7428422 | 883 | /* Don't forget the root entries */ |
1da177e4 LT |
884 | for (i = 0; (attr = pdcs_subsys_attrs[i]) && !error; i++) |
885 | if (attr->show) | |
c7428422 | 886 | error = subsys_create_file(&stable_subsys, attr); |
1da177e4 | 887 | |
c7428422 TV |
888 | /* register the paths subsys as a subsystem of stable subsys */ |
889 | kset_set_kset_s(&paths_subsys, stable_subsys); | |
4b991da7 TV |
890 | if ((rc= subsystem_register(&paths_subsys))) |
891 | goto fail_subsysreg; | |
1da177e4 LT |
892 | |
893 | /* now we create all "files" for the paths subsys */ | |
4b991da7 TV |
894 | if ((rc = pdcs_register_pathentries())) |
895 | goto fail_pdcsreg; | |
896 | ||
897 | return rc; | |
1da177e4 | 898 | |
4b991da7 TV |
899 | fail_pdcsreg: |
900 | pdcs_unregister_pathentries(); | |
901 | subsystem_unregister(&paths_subsys); | |
902 | ||
903 | fail_subsysreg: | |
c7428422 | 904 | firmware_unregister(&stable_subsys); |
4b991da7 TV |
905 | |
906 | fail_firmreg: | |
c7428422 | 907 | printk(KERN_INFO PDCS_PREFIX " bailing out\n"); |
4b991da7 | 908 | return rc; |
1da177e4 LT |
909 | } |
910 | ||
911 | static void __exit | |
912 | pdc_stable_exit(void) | |
913 | { | |
914 | pdcs_unregister_pathentries(); | |
915 | subsystem_unregister(&paths_subsys); | |
916 | ||
c7428422 | 917 | firmware_unregister(&stable_subsys); |
1da177e4 LT |
918 | } |
919 | ||
920 | ||
921 | module_init(pdc_stable_init); | |
922 | module_exit(pdc_stable_exit); |