cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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os-area.c (21403B)


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