1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  PS3 flash memory os area.
4  *
5  *  Copyright (C) 2006 Sony Computer Entertainment Inc.
6  *  Copyright 2006 Sony Corp.
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/io.h>
11 #include <linux/workqueue.h>
12 #include <linux/fs.h>
13 #include <linux/syscalls.h>
14 #include <linux/export.h>
15 #include <linux/ctype.h>
16 #include <linux/memblock.h>
17 #include <linux/of.h>
18 #include <linux/slab.h>
19 
20 #include <asm/prom.h>
21 
22 #include "platform.h"
23 
24 enum {
25 	OS_AREA_SEGMENT_SIZE = 0X200,
26 };
27 
28 enum os_area_ldr_format {
29 	HEADER_LDR_FORMAT_RAW = 0,
30 	HEADER_LDR_FORMAT_GZIP = 1,
31 };
32 
33 #define OS_AREA_HEADER_MAGIC_NUM "cell_ext_os_area"
34 
35 /**
36  * struct os_area_header - os area header segment.
37  * @magic_num: Always 'cell_ext_os_area'.
38  * @hdr_version: Header format version number.
39  * @db_area_offset: Starting segment number of other os database area.
40  * @ldr_area_offset: Starting segment number of bootloader image area.
41  * @ldr_format: HEADER_LDR_FORMAT flag.
42  * @ldr_size: Size of bootloader image in bytes.
43  *
44  * Note that the docs refer to area offsets.  These are offsets in units of
45  * segments from the start of the os area (top of the header).  These are
46  * better thought of as segment numbers.  The os area of the os area is
47  * reserved for the os image.
48  */
49 
50 struct os_area_header {
51 	u8 magic_num[16];
52 	u32 hdr_version;
53 	u32 db_area_offset;
54 	u32 ldr_area_offset;
55 	u32 _reserved_1;
56 	u32 ldr_format;
57 	u32 ldr_size;
58 	u32 _reserved_2[6];
59 };
60 
61 enum os_area_boot_flag {
62 	PARAM_BOOT_FLAG_GAME_OS = 0,
63 	PARAM_BOOT_FLAG_OTHER_OS = 1,
64 };
65 
66 enum os_area_ctrl_button {
67 	PARAM_CTRL_BUTTON_O_IS_YES = 0,
68 	PARAM_CTRL_BUTTON_X_IS_YES = 1,
69 };
70 
71 /**
72  * struct os_area_params - os area params segment.
73  * @boot_flag: User preference of operating system, PARAM_BOOT_FLAG flag.
74  * @num_params: Number of params in this (params) segment.
75  * @rtc_diff: Difference in seconds between 1970 and the ps3 rtc value.
76  * @av_multi_out: User preference of AV output, PARAM_AV_MULTI_OUT flag.
77  * @ctrl_button: User preference of controller button config, PARAM_CTRL_BUTTON
78  *	flag.
79  * @static_ip_addr: User preference of static IP address.
80  * @network_mask: User preference of static network mask.
81  * @default_gateway: User preference of static default gateway.
82  * @dns_primary: User preference of static primary dns server.
83  * @dns_secondary: User preference of static secondary dns server.
84  *
85  * The ps3 rtc maintains a read-only value that approximates seconds since
86  * 2000-01-01 00:00:00 UTC.
87  *
88  * User preference of zero for static_ip_addr means use dhcp.
89  */
90 
91 struct os_area_params {
92 	u32 boot_flag;
93 	u32 _reserved_1[3];
94 	u32 num_params;
95 	u32 _reserved_2[3];
96 	/* param 0 */
97 	s64 rtc_diff;
98 	u8 av_multi_out;
99 	u8 ctrl_button;
100 	u8 _reserved_3[6];
101 	/* param 1 */
102 	u8 static_ip_addr[4];
103 	u8 network_mask[4];
104 	u8 default_gateway[4];
105 	u8 _reserved_4[4];
106 	/* param 2 */
107 	u8 dns_primary[4];
108 	u8 dns_secondary[4];
109 	u8 _reserved_5[8];
110 };
111 
112 #define OS_AREA_DB_MAGIC_NUM "-db-"
113 
114 /**
115  * struct os_area_db - Shared flash memory database.
116  * @magic_num: Always '-db-'.
117  * @version: os_area_db format version number.
118  * @index_64: byte offset of the database id index for 64 bit variables.
119  * @count_64: number of usable 64 bit index entries
120  * @index_32: byte offset of the database id index for 32 bit variables.
121  * @count_32: number of usable 32 bit index entries
122  * @index_16: byte offset of the database id index for 16 bit variables.
123  * @count_16: number of usable 16 bit index entries
124  *
125  * Flash rom storage for exclusive use by guests running in the other os lpar.
126  * The current system configuration allocates 1K (two segments) for other os
127  * use.
128  */
129 
130 struct os_area_db {
131 	u8 magic_num[4];
132 	u16 version;
133 	u16 _reserved_1;
134 	u16 index_64;
135 	u16 count_64;
136 	u16 index_32;
137 	u16 count_32;
138 	u16 index_16;
139 	u16 count_16;
140 	u32 _reserved_2;
141 	u8 _db_data[1000];
142 };
143 
144 /**
145  * enum os_area_db_owner - Data owners.
146  */
147 
148 enum os_area_db_owner {
149 	OS_AREA_DB_OWNER_ANY = -1,
150 	OS_AREA_DB_OWNER_NONE = 0,
151 	OS_AREA_DB_OWNER_PROTOTYPE = 1,
152 	OS_AREA_DB_OWNER_LINUX = 2,
153 	OS_AREA_DB_OWNER_PETITBOOT = 3,
154 	OS_AREA_DB_OWNER_MAX = 32,
155 };
156 
157 enum os_area_db_key {
158 	OS_AREA_DB_KEY_ANY = -1,
159 	OS_AREA_DB_KEY_NONE = 0,
160 	OS_AREA_DB_KEY_RTC_DIFF = 1,
161 	OS_AREA_DB_KEY_VIDEO_MODE = 2,
162 	OS_AREA_DB_KEY_MAX = 8,
163 };
164 
165 struct os_area_db_id {
166 	int owner;
167 	int key;
168 };
169 
170 static const struct os_area_db_id os_area_db_id_empty = {
171 	.owner = OS_AREA_DB_OWNER_NONE,
172 	.key = OS_AREA_DB_KEY_NONE
173 };
174 
175 static const struct os_area_db_id os_area_db_id_any = {
176 	.owner = OS_AREA_DB_OWNER_ANY,
177 	.key = OS_AREA_DB_KEY_ANY
178 };
179 
180 static const struct os_area_db_id os_area_db_id_rtc_diff = {
181 	.owner = OS_AREA_DB_OWNER_LINUX,
182 	.key = OS_AREA_DB_KEY_RTC_DIFF
183 };
184 
185 #define SECONDS_FROM_1970_TO_2000 946684800LL
186 
187 /**
188  * struct saved_params - Static working copies of data from the PS3 'os area'.
189  *
190  * The order of preference we use for the rtc_diff source:
191  *  1) The database value.
192  *  2) The game os value.
193  *  3) The number of seconds from 1970 to 2000.
194  */
195 
196 static struct saved_params {
197 	unsigned int valid;
198 	s64 rtc_diff;
199 	unsigned int av_multi_out;
200 } saved_params;
201 
202 static struct property property_rtc_diff = {
203 	.name = "linux,rtc_diff",
204 	.length = sizeof(saved_params.rtc_diff),
205 	.value = &saved_params.rtc_diff,
206 };
207 
208 static struct property property_av_multi_out = {
209 	.name = "linux,av_multi_out",
210 	.length = sizeof(saved_params.av_multi_out),
211 	.value = &saved_params.av_multi_out,
212 };
213 
214 
215 static DEFINE_MUTEX(os_area_flash_mutex);
216 
217 static const struct ps3_os_area_flash_ops *os_area_flash_ops;
218 
219 void ps3_os_area_flash_register(const struct ps3_os_area_flash_ops *ops)
220 {
221 	mutex_lock(&os_area_flash_mutex);
222 	os_area_flash_ops = ops;
223 	mutex_unlock(&os_area_flash_mutex);
224 }
225 EXPORT_SYMBOL_GPL(ps3_os_area_flash_register);
226 
227 static ssize_t os_area_flash_read(void *buf, size_t count, loff_t pos)
228 {
229 	ssize_t res = -ENODEV;
230 
231 	mutex_lock(&os_area_flash_mutex);
232 	if (os_area_flash_ops)
233 		res = os_area_flash_ops->read(buf, count, pos);
234 	mutex_unlock(&os_area_flash_mutex);
235 
236 	return res;
237 }
238 
239 static ssize_t os_area_flash_write(const void *buf, size_t count, loff_t pos)
240 {
241 	ssize_t res = -ENODEV;
242 
243 	mutex_lock(&os_area_flash_mutex);
244 	if (os_area_flash_ops)
245 		res = os_area_flash_ops->write(buf, count, pos);
246 	mutex_unlock(&os_area_flash_mutex);
247 
248 	return res;
249 }
250 
251 
252 /**
253  * os_area_set_property - Add or overwrite a saved_params value to the device tree.
254  *
255  * Overwrites an existing property.
256  */
257 
258 static void os_area_set_property(struct device_node *node,
259 	struct property *prop)
260 {
261 	int result;
262 	struct property *tmp = of_find_property(node, prop->name, NULL);
263 
264 	if (tmp) {
265 		pr_debug("%s:%d found %s\n", __func__, __LINE__, prop->name);
266 		of_remove_property(node, tmp);
267 	}
268 
269 	result = of_add_property(node, prop);
270 
271 	if (result)
272 		pr_debug("%s:%d of_set_property failed\n", __func__,
273 			__LINE__);
274 }
275 
276 /**
277  * os_area_get_property - Get a saved_params value from the device tree.
278  *
279  */
280 
281 static void __init os_area_get_property(struct device_node *node,
282 	struct property *prop)
283 {
284 	const struct property *tmp = of_find_property(node, prop->name, NULL);
285 
286 	if (tmp) {
287 		BUG_ON(prop->length != tmp->length);
288 		memcpy(prop->value, tmp->value, prop->length);
289 	} else
290 		pr_debug("%s:%d not found %s\n", __func__, __LINE__,
291 			prop->name);
292 }
293 
294 static void dump_field(char *s, const u8 *field, int size_of_field)
295 {
296 #if defined(DEBUG)
297 	int i;
298 
299 	for (i = 0; i < size_of_field; i++)
300 		s[i] = isprint(field[i]) ? field[i] : '.';
301 	s[i] = 0;
302 #endif
303 }
304 
305 #define dump_header(_a) _dump_header(_a, __func__, __LINE__)
306 static void _dump_header(const struct os_area_header *h, const char *func,
307 	int line)
308 {
309 	char str[sizeof(h->magic_num) + 1];
310 
311 	dump_field(str, h->magic_num, sizeof(h->magic_num));
312 	pr_debug("%s:%d: h.magic_num:       '%s'\n", func, line,
313 		str);
314 	pr_debug("%s:%d: h.hdr_version:     %u\n", func, line,
315 		h->hdr_version);
316 	pr_debug("%s:%d: h.db_area_offset:  %u\n", func, line,
317 		h->db_area_offset);
318 	pr_debug("%s:%d: h.ldr_area_offset: %u\n", func, line,
319 		h->ldr_area_offset);
320 	pr_debug("%s:%d: h.ldr_format:      %u\n", func, line,
321 		h->ldr_format);
322 	pr_debug("%s:%d: h.ldr_size:        %xh\n", func, line,
323 		h->ldr_size);
324 }
325 
326 #define dump_params(_a) _dump_params(_a, __func__, __LINE__)
327 static void _dump_params(const struct os_area_params *p, const char *func,
328 	int line)
329 {
330 	pr_debug("%s:%d: p.boot_flag:       %u\n", func, line, p->boot_flag);
331 	pr_debug("%s:%d: p.num_params:      %u\n", func, line, p->num_params);
332 	pr_debug("%s:%d: p.rtc_diff         %lld\n", func, line, p->rtc_diff);
333 	pr_debug("%s:%d: p.av_multi_out     %u\n", func, line, p->av_multi_out);
334 	pr_debug("%s:%d: p.ctrl_button:     %u\n", func, line, p->ctrl_button);
335 	pr_debug("%s:%d: p.static_ip_addr:  %u.%u.%u.%u\n", func, line,
336 		p->static_ip_addr[0], p->static_ip_addr[1],
337 		p->static_ip_addr[2], p->static_ip_addr[3]);
338 	pr_debug("%s:%d: p.network_mask:    %u.%u.%u.%u\n", func, line,
339 		p->network_mask[0], p->network_mask[1],
340 		p->network_mask[2], p->network_mask[3]);
341 	pr_debug("%s:%d: p.default_gateway: %u.%u.%u.%u\n", func, line,
342 		p->default_gateway[0], p->default_gateway[1],
343 		p->default_gateway[2], p->default_gateway[3]);
344 	pr_debug("%s:%d: p.dns_primary:     %u.%u.%u.%u\n", func, line,
345 		p->dns_primary[0], p->dns_primary[1],
346 		p->dns_primary[2], p->dns_primary[3]);
347 	pr_debug("%s:%d: p.dns_secondary:   %u.%u.%u.%u\n", func, line,
348 		p->dns_secondary[0], p->dns_secondary[1],
349 		p->dns_secondary[2], p->dns_secondary[3]);
350 }
351 
352 static int verify_header(const struct os_area_header *header)
353 {
354 	if (memcmp(header->magic_num, OS_AREA_HEADER_MAGIC_NUM,
355 		sizeof(header->magic_num))) {
356 		pr_debug("%s:%d magic_num failed\n", __func__, __LINE__);
357 		return -1;
358 	}
359 
360 	if (header->hdr_version < 1) {
361 		pr_debug("%s:%d hdr_version failed\n", __func__, __LINE__);
362 		return -1;
363 	}
364 
365 	if (header->db_area_offset > header->ldr_area_offset) {
366 		pr_debug("%s:%d offsets failed\n", __func__, __LINE__);
367 		return -1;
368 	}
369 
370 	return 0;
371 }
372 
373 static int db_verify(const struct os_area_db *db)
374 {
375 	if (memcmp(db->magic_num, OS_AREA_DB_MAGIC_NUM,
376 		sizeof(db->magic_num))) {
377 		pr_debug("%s:%d magic_num failed\n", __func__, __LINE__);
378 		return -EINVAL;
379 	}
380 
381 	if (db->version != 1) {
382 		pr_debug("%s:%d version failed\n", __func__, __LINE__);
383 		return -EINVAL;
384 	}
385 
386 	return 0;
387 }
388 
389 struct db_index {
390        uint8_t owner:5;
391        uint8_t key:3;
392 };
393 
394 struct db_iterator {
395 	const struct os_area_db *db;
396 	struct os_area_db_id match_id;
397 	struct db_index *idx;
398 	struct db_index *last_idx;
399 	union {
400 		uint64_t *value_64;
401 		uint32_t *value_32;
402 		uint16_t *value_16;
403 	};
404 };
405 
406 static unsigned int db_align_up(unsigned int val, unsigned int size)
407 {
408 	return (val + (size - 1)) & (~(size - 1));
409 }
410 
411 /**
412  * db_for_each_64 - Iterator for 64 bit entries.
413  *
414  * A NULL value for id can be used to match all entries.
415  * OS_AREA_DB_OWNER_ANY and OS_AREA_DB_KEY_ANY can be used to match all.
416  */
417 
418 static int db_for_each_64(const struct os_area_db *db,
419 	const struct os_area_db_id *match_id, struct db_iterator *i)
420 {
421 next:
422 	if (!i->db) {
423 		i->db = db;
424 		i->match_id = match_id ? *match_id : os_area_db_id_any;
425 		i->idx = (void *)db + db->index_64;
426 		i->last_idx = i->idx + db->count_64;
427 		i->value_64 = (void *)db + db->index_64
428 			+ db_align_up(db->count_64, 8);
429 	} else {
430 		i->idx++;
431 		i->value_64++;
432 	}
433 
434 	if (i->idx >= i->last_idx) {
435 		pr_debug("%s:%d: reached end\n", __func__, __LINE__);
436 		return 0;
437 	}
438 
439 	if (i->match_id.owner != OS_AREA_DB_OWNER_ANY
440 		&& i->match_id.owner != (int)i->idx->owner)
441 		goto next;
442 	if (i->match_id.key != OS_AREA_DB_KEY_ANY
443 		&& i->match_id.key != (int)i->idx->key)
444 		goto next;
445 
446 	return 1;
447 }
448 
449 static int db_delete_64(struct os_area_db *db, const struct os_area_db_id *id)
450 {
451 	struct db_iterator i;
452 
453 	for (i.db = NULL; db_for_each_64(db, id, &i); ) {
454 
455 		pr_debug("%s:%d: got (%d:%d) %llxh\n", __func__, __LINE__,
456 			i.idx->owner, i.idx->key,
457 			(unsigned long long)*i.value_64);
458 
459 		i.idx->owner = 0;
460 		i.idx->key = 0;
461 		*i.value_64 = 0;
462 	}
463 	return 0;
464 }
465 
466 static int db_set_64(struct os_area_db *db, const struct os_area_db_id *id,
467 	uint64_t value)
468 {
469 	struct db_iterator i;
470 
471 	pr_debug("%s:%d: (%d:%d) <= %llxh\n", __func__, __LINE__,
472 		id->owner, id->key, (unsigned long long)value);
473 
474 	if (!id->owner || id->owner == OS_AREA_DB_OWNER_ANY
475 		|| id->key == OS_AREA_DB_KEY_ANY) {
476 		pr_debug("%s:%d: bad id: (%d:%d)\n", __func__,
477 			__LINE__, id->owner, id->key);
478 		return -1;
479 	}
480 
481 	db_delete_64(db, id);
482 
483 	i.db = NULL;
484 	if (db_for_each_64(db, &os_area_db_id_empty, &i)) {
485 
486 		pr_debug("%s:%d: got (%d:%d) %llxh\n", __func__, __LINE__,
487 			i.idx->owner, i.idx->key,
488 			(unsigned long long)*i.value_64);
489 
490 		i.idx->owner = id->owner;
491 		i.idx->key = id->key;
492 		*i.value_64 = value;
493 
494 		pr_debug("%s:%d: set (%d:%d) <= %llxh\n", __func__, __LINE__,
495 			i.idx->owner, i.idx->key,
496 			(unsigned long long)*i.value_64);
497 		return 0;
498 	}
499 	pr_debug("%s:%d: database full.\n",
500 		__func__, __LINE__);
501 	return -1;
502 }
503 
504 static int db_get_64(const struct os_area_db *db,
505 	const struct os_area_db_id *id, uint64_t *value)
506 {
507 	struct db_iterator i;
508 
509 	i.db = NULL;
510 	if (db_for_each_64(db, id, &i)) {
511 		*value = *i.value_64;
512 		pr_debug("%s:%d: found %lld\n", __func__, __LINE__,
513 				(long long int)*i.value_64);
514 		return 0;
515 	}
516 	pr_debug("%s:%d: not found\n", __func__, __LINE__);
517 	return -1;
518 }
519 
520 static int db_get_rtc_diff(const struct os_area_db *db, int64_t *rtc_diff)
521 {
522 	return db_get_64(db, &os_area_db_id_rtc_diff, (uint64_t*)rtc_diff);
523 }
524 
525 #define dump_db(a) _dump_db(a, __func__, __LINE__)
526 static void _dump_db(const struct os_area_db *db, const char *func,
527 	int line)
528 {
529 	char str[sizeof(db->magic_num) + 1];
530 
531 	dump_field(str, db->magic_num, sizeof(db->magic_num));
532 	pr_debug("%s:%d: db.magic_num:      '%s'\n", func, line,
533 		str);
534 	pr_debug("%s:%d: db.version:         %u\n", func, line,
535 		db->version);
536 	pr_debug("%s:%d: db.index_64:        %u\n", func, line,
537 		db->index_64);
538 	pr_debug("%s:%d: db.count_64:        %u\n", func, line,
539 		db->count_64);
540 	pr_debug("%s:%d: db.index_32:        %u\n", func, line,
541 		db->index_32);
542 	pr_debug("%s:%d: db.count_32:        %u\n", func, line,
543 		db->count_32);
544 	pr_debug("%s:%d: db.index_16:        %u\n", func, line,
545 		db->index_16);
546 	pr_debug("%s:%d: db.count_16:        %u\n", func, line,
547 		db->count_16);
548 }
549 
550 static void os_area_db_init(struct os_area_db *db)
551 {
552 	enum {
553 		HEADER_SIZE = offsetof(struct os_area_db, _db_data),
554 		INDEX_64_COUNT = 64,
555 		VALUES_64_COUNT = 57,
556 		INDEX_32_COUNT = 64,
557 		VALUES_32_COUNT = 57,
558 		INDEX_16_COUNT = 64,
559 		VALUES_16_COUNT = 57,
560 	};
561 
562 	memset(db, 0, sizeof(struct os_area_db));
563 
564 	memcpy(db->magic_num, OS_AREA_DB_MAGIC_NUM, sizeof(db->magic_num));
565 	db->version = 1;
566 	db->index_64 = HEADER_SIZE;
567 	db->count_64 = VALUES_64_COUNT;
568 	db->index_32 = HEADER_SIZE
569 			+ INDEX_64_COUNT * sizeof(struct db_index)
570 			+ VALUES_64_COUNT * sizeof(u64);
571 	db->count_32 = VALUES_32_COUNT;
572 	db->index_16 = HEADER_SIZE
573 			+ INDEX_64_COUNT * sizeof(struct db_index)
574 			+ VALUES_64_COUNT * sizeof(u64)
575 			+ INDEX_32_COUNT * sizeof(struct db_index)
576 			+ VALUES_32_COUNT * sizeof(u32);
577 	db->count_16 = VALUES_16_COUNT;
578 
579 	/* Rules to check db layout. */
580 
581 	BUILD_BUG_ON(sizeof(struct db_index) != 1);
582 	BUILD_BUG_ON(sizeof(struct os_area_db) != 2 * OS_AREA_SEGMENT_SIZE);
583 	BUILD_BUG_ON(INDEX_64_COUNT & 0x7);
584 	BUILD_BUG_ON(VALUES_64_COUNT > INDEX_64_COUNT);
585 	BUILD_BUG_ON(INDEX_32_COUNT & 0x7);
586 	BUILD_BUG_ON(VALUES_32_COUNT > INDEX_32_COUNT);
587 	BUILD_BUG_ON(INDEX_16_COUNT & 0x7);
588 	BUILD_BUG_ON(VALUES_16_COUNT > INDEX_16_COUNT);
589 	BUILD_BUG_ON(HEADER_SIZE
590 			+ INDEX_64_COUNT * sizeof(struct db_index)
591 			+ VALUES_64_COUNT * sizeof(u64)
592 			+ INDEX_32_COUNT * sizeof(struct db_index)
593 			+ VALUES_32_COUNT * sizeof(u32)
594 			+ INDEX_16_COUNT * sizeof(struct db_index)
595 			+ VALUES_16_COUNT * sizeof(u16)
596 			> sizeof(struct os_area_db));
597 }
598 
599 /**
600  * update_flash_db - Helper for os_area_queue_work_handler.
601  *
602  */
603 
604 static int update_flash_db(void)
605 {
606 	const unsigned int buf_len = 8 * OS_AREA_SEGMENT_SIZE;
607 	struct os_area_header *header;
608 	ssize_t count;
609 	int error;
610 	loff_t pos;
611 	struct os_area_db* db;
612 
613 	/* Read in header and db from flash. */
614 
615 	header = kmalloc(buf_len, GFP_KERNEL);
616 	if (!header) {
617 		pr_debug("%s: kmalloc failed\n", __func__);
618 		return -ENOMEM;
619 	}
620 
621 	count = os_area_flash_read(header, buf_len, 0);
622 	if (count < 0) {
623 		pr_debug("%s: os_area_flash_read failed %zd\n", __func__,
624 			 count);
625 		error = count;
626 		goto fail;
627 	}
628 
629 	pos = header->db_area_offset * OS_AREA_SEGMENT_SIZE;
630 	if (count < OS_AREA_SEGMENT_SIZE || verify_header(header) ||
631 	    count < pos) {
632 		pr_debug("%s: verify_header failed\n", __func__);
633 		dump_header(header);
634 		error = -EINVAL;
635 		goto fail;
636 	}
637 
638 	/* Now got a good db offset and some maybe good db data. */
639 
640 	db = (void *)header + pos;
641 
642 	error = db_verify(db);
643 	if (error) {
644 		pr_notice("%s: Verify of flash database failed, formatting.\n",
645 			  __func__);
646 		dump_db(db);
647 		os_area_db_init(db);
648 	}
649 
650 	/* Now got good db data. */
651 
652 	db_set_64(db, &os_area_db_id_rtc_diff, saved_params.rtc_diff);
653 
654 	count = os_area_flash_write(db, sizeof(struct os_area_db), pos);
655 	if (count < 0 || count < sizeof(struct os_area_db)) {
656 		pr_debug("%s: os_area_flash_write failed %zd\n", __func__,
657 			 count);
658 		error = count < 0 ? count : -EIO;
659 	}
660 
661 fail:
662 	kfree(header);
663 	return error;
664 }
665 
666 /**
667  * os_area_queue_work_handler - Asynchronous write handler.
668  *
669  * An asynchronous write for flash memory and the device tree.  Do not
670  * call directly, use os_area_queue_work().
671  */
672 
673 static void os_area_queue_work_handler(struct work_struct *work)
674 {
675 	struct device_node *node;
676 	int error;
677 
678 	pr_debug(" -> %s:%d\n", __func__, __LINE__);
679 
680 	node = of_find_node_by_path("/");
681 	if (node) {
682 		os_area_set_property(node, &property_rtc_diff);
683 		of_node_put(node);
684 	} else
685 		pr_debug("%s:%d of_find_node_by_path failed\n",
686 			__func__, __LINE__);
687 
688 	error = update_flash_db();
689 	if (error)
690 		pr_warn("%s: Could not update FLASH ROM\n", __func__);
691 
692 	pr_debug(" <- %s:%d\n", __func__, __LINE__);
693 }
694 
695 static void os_area_queue_work(void)
696 {
697 	static DECLARE_WORK(q, os_area_queue_work_handler);
698 
699 	wmb();
700 	schedule_work(&q);
701 }
702 
703 /**
704  * ps3_os_area_save_params - Copy data from os area mirror to @saved_params.
705  *
706  * For the convenience of the guest the HV makes a copy of the os area in
707  * flash to a high address in the boot memory region and then puts that RAM
708  * address and the byte count into the repository for retrieval by the guest.
709  * We copy the data we want into a static variable and allow the memory setup
710  * by the HV to be claimed by the memblock manager.
711  *
712  * The os area mirror will not be available to a second stage kernel, and
713  * the header verify will fail.  In this case, the saved_params values will
714  * be set from flash memory or the passed in device tree in ps3_os_area_init().
715  */
716 
717 void __init ps3_os_area_save_params(void)
718 {
719 	int result;
720 	u64 lpar_addr;
721 	unsigned int size;
722 	struct os_area_header *header;
723 	struct os_area_params *params;
724 	struct os_area_db *db;
725 
726 	pr_debug(" -> %s:%d\n", __func__, __LINE__);
727 
728 	result = ps3_repository_read_boot_dat_info(&lpar_addr, &size);
729 
730 	if (result) {
731 		pr_debug("%s:%d ps3_repository_read_boot_dat_info failed\n",
732 			__func__, __LINE__);
733 		return;
734 	}
735 
736 	header = (struct os_area_header *)__va(lpar_addr);
737 	params = (struct os_area_params *)__va(lpar_addr
738 		+ OS_AREA_SEGMENT_SIZE);
739 
740 	result = verify_header(header);
741 
742 	if (result) {
743 		/* Second stage kernels exit here. */
744 		pr_debug("%s:%d verify_header failed\n", __func__, __LINE__);
745 		dump_header(header);
746 		return;
747 	}
748 
749 	db = (struct os_area_db *)__va(lpar_addr
750 		+ header->db_area_offset * OS_AREA_SEGMENT_SIZE);
751 
752 	dump_header(header);
753 	dump_params(params);
754 	dump_db(db);
755 
756 	result = db_verify(db) || db_get_rtc_diff(db, &saved_params.rtc_diff);
757 	if (result)
758 		saved_params.rtc_diff = params->rtc_diff ? params->rtc_diff
759 			: SECONDS_FROM_1970_TO_2000;
760 	saved_params.av_multi_out = params->av_multi_out;
761 	saved_params.valid = 1;
762 
763 	memset(header, 0, sizeof(*header));
764 
765 	pr_debug(" <- %s:%d\n", __func__, __LINE__);
766 }
767 
768 /**
769  * ps3_os_area_init - Setup os area device tree properties as needed.
770  */
771 
772 void __init ps3_os_area_init(void)
773 {
774 	struct device_node *node;
775 
776 	pr_debug(" -> %s:%d\n", __func__, __LINE__);
777 
778 	node = of_find_node_by_path("/");
779 
780 	if (!saved_params.valid && node) {
781 		/* Second stage kernels should have a dt entry. */
782 		os_area_get_property(node, &property_rtc_diff);
783 		os_area_get_property(node, &property_av_multi_out);
784 	}
785 
786 	if(!saved_params.rtc_diff)
787 		saved_params.rtc_diff = SECONDS_FROM_1970_TO_2000;
788 
789 	if (node) {
790 		os_area_set_property(node, &property_rtc_diff);
791 		os_area_set_property(node, &property_av_multi_out);
792 		of_node_put(node);
793 	} else
794 		pr_debug("%s:%d of_find_node_by_path failed\n",
795 			__func__, __LINE__);
796 
797 	pr_debug(" <- %s:%d\n", __func__, __LINE__);
798 }
799 
800 /**
801  * ps3_os_area_get_rtc_diff - Returns the rtc diff value.
802  */
803 
804 u64 ps3_os_area_get_rtc_diff(void)
805 {
806 	return saved_params.rtc_diff;
807 }
808 EXPORT_SYMBOL_GPL(ps3_os_area_get_rtc_diff);
809 
810 /**
811  * ps3_os_area_set_rtc_diff - Set the rtc diff value.
812  *
813  * An asynchronous write is needed to support writing updates from
814  * the timer interrupt context.
815  */
816 
817 void ps3_os_area_set_rtc_diff(u64 rtc_diff)
818 {
819 	if (saved_params.rtc_diff != rtc_diff) {
820 		saved_params.rtc_diff = rtc_diff;
821 		os_area_queue_work();
822 	}
823 }
824 EXPORT_SYMBOL_GPL(ps3_os_area_set_rtc_diff);
825 
826 /**
827  * ps3_os_area_get_av_multi_out - Returns the default video mode.
828  */
829 
830 enum ps3_param_av_multi_out ps3_os_area_get_av_multi_out(void)
831 {
832     return saved_params.av_multi_out;
833 }
834 EXPORT_SYMBOL_GPL(ps3_os_area_get_av_multi_out);
835