| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (c) 2019 MediaTek Inc. |
| * Author: Guochun Mao <guochun.mao@mediatek.com> |
| * Xiaolei Li <xiaolei.li@mediatek.com> |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/mtd/mtd.h> |
| #include <linux/mtd/partitions.h> |
| #include <asm/div64.h> |
| |
| /* GPT Signature should be 0x5452415020494645 */ |
| #define GPT_SIGNATURE_1 0x54524150U |
| #define GPT_SIGNATURE_2 0x20494645U |
| |
| /* GPT Offsets */ |
| #define HEADER_SIZE_OFFSET 12 |
| #define HEADER_CRC_OFFSET 16 |
| #define PRIMARY_HEADER_OFFSET 24 |
| #define BACKUP_HEADER_OFFSET 32 |
| #define FIRST_USABLE_LBA_OFFSET 40 |
| #define LAST_USABLE_LBA_OFFSET 48 |
| #define PARTITION_ENTRIES_OFFSET 72 |
| #define PARTITION_COUNT_OFFSET 80 |
| #define PENTRY_SIZE_OFFSET 84 |
| #define PARTITION_CRC_OFFSET 88 |
| |
| #define ENTRY_SIZE 0x80 |
| |
| #define UNIQUE_GUID_OFFSET 16 |
| #define FIRST_LBA_OFFSET 32 |
| #define LAST_LBA_OFFSET 40 |
| #define ATTRIBUTE_FLAG_OFFSET 48 |
| #define PARTITION_NAME_OFFSET 56 |
| |
| #define MAX_GPT_NAME_SIZE 72 |
| #define PARTITION_TYPE_GUID_SIZE 16 |
| #define UNIQUE_PARTITION_GUID_SIZE 16 |
| #define NUM_PARTITIONS 128 |
| |
| #define GET_LWORD_FROM_BYTE(ptr) (*(uint32_t *)((unsigned long)(ptr))) |
| #define GET_LLWORD_FROM_BYTE(ptr) (*(uint64_t *)((unsigned long)(ptr))) |
| |
| struct chs { |
| uint8_t c; |
| uint8_t h; |
| uint8_t s; |
| }; |
| |
| struct mbr_part { |
| uint8_t status; |
| struct chs start; |
| uint8_t type; |
| struct chs end; |
| uint32_t lba_start; |
| uint32_t lba_length; |
| }; |
| |
| struct gpt_info { |
| uint64_t first_usable_lba; |
| uint64_t backup_header_lba; |
| uint32_t partition_entry_size; |
| uint32_t header_size; |
| uint32_t max_partition_count; |
| }; |
| |
| static int validate_mbr_partition(struct mtd_info *master, |
| const struct mbr_part *part) |
| { |
| u32 lba_size, lba_number; |
| uint64_t temp; |
| |
| if (mtd_type_is_nand(master) != 0) |
| lba_size = master->writesize; |
| else |
| lba_size = 512; |
| |
| /* check for invalid types */ |
| if ((int8_t)part->type == 0) |
| return -1; |
| /* check for invalid status */ |
| if (part->status != (uint8_t)0x80 && |
| part->status != (uint8_t)0x00) |
| return -1; |
| |
| /* make sure the range fits within the device */ |
| temp = (uint64_t)master->size; |
| do_div(temp, lba_size); |
| lba_number = temp; |
| if (part->lba_start >= lba_number) |
| return -1; |
| if ((part->lba_start + part->lba_length) > lba_number) |
| return -1; |
| |
| return 0; |
| } |
| |
| /* |
| * Parse the gpt header and get the required header fields |
| * Return 0 on valid signature |
| */ |
| static int partition_parse_gpt_header(unsigned char *buffer, |
| struct gpt_info *info) |
| { |
| /* Check GPT Signature */ |
| if (GET_LWORD_FROM_BYTE(&buffer[0]) != GPT_SIGNATURE_2 || |
| GET_LWORD_FROM_BYTE(&buffer[4]) != GPT_SIGNATURE_1) |
| return 1; |
| |
| info->header_size = GET_LWORD_FROM_BYTE(&buffer[HEADER_SIZE_OFFSET]); |
| info->backup_header_lba = |
| GET_LLWORD_FROM_BYTE(&buffer[BACKUP_HEADER_OFFSET]); |
| info->first_usable_lba = |
| GET_LLWORD_FROM_BYTE(&buffer[FIRST_USABLE_LBA_OFFSET]); |
| info->max_partition_count = |
| GET_LWORD_FROM_BYTE(&buffer[PARTITION_COUNT_OFFSET]); |
| info->partition_entry_size = |
| GET_LWORD_FROM_BYTE(&buffer[PENTRY_SIZE_OFFSET]); |
| |
| return 0; |
| } |
| |
| static void gpt_add_part(struct mtd_partition *part, char *name, |
| u64 offset, uint32_t mask_flags, uint64_t size) |
| { |
| part->name = name; |
| part->offset = offset; |
| part->mask_flags = mask_flags; |
| part->size = size; |
| } |
| |
| #define BBT_RESERVED_BLOCK 4 |
| #define SGPT_RESERVED_BLOCK 4 |
| #define PGPT_RESERVED_BLOCK 2 |
| /* |
| * @master: master mtd device description object pointer |
| * @ofs: the start address |
| */ |
| static int find_next_good_gpt_block(struct mtd_info *master, loff_t *ofs) |
| { |
| loff_t addr = *ofs; |
| u32 count; |
| /* the block search order. 0: forward; otherwise: backward */ |
| int order; |
| int i = 0; |
| |
| /* PGPT start from address 0 */ |
| if (addr < master->erasesize) { |
| count = PGPT_RESERVED_BLOCK; |
| order = 0; |
| } else { |
| count = SGPT_RESERVED_BLOCK; |
| order = 1; |
| } |
| while (i < count) { |
| if (!mtd_block_isbad(master, addr)) { |
| if (i) |
| dev_err(&master->dev, "GPT: map from 0x%llx to 0x%llx\n", |
| *ofs, addr); |
| *ofs = addr; |
| return 0; |
| } |
| addr = order ? (addr - master->erasesize) : |
| (addr + master->erasesize); |
| i++; |
| } |
| |
| dev_err(&master->dev, |
| "all bad blocks are bad, addr:0x%llx, count:%d\n", |
| addr, count); |
| |
| return -ENOMEM; |
| } |
| |
| static int mtd_read_gpt(struct mtd_info *master, loff_t from, size_t len, |
| size_t *retlen, u_char *buf) |
| { |
| loff_t addr = from; |
| int ret; |
| |
| if (mtd_type_is_nand(master) != 0) { |
| ret = find_next_good_gpt_block(master, &addr); |
| if (ret) |
| return ret; |
| } |
| |
| return mtd_read(master, addr, len, retlen, buf); |
| } |
| |
| static int gpt_parse(struct mtd_info *master, |
| const struct mtd_partition **pparts, |
| struct mtd_part_parser_data *data) |
| { |
| struct mtd_partition *parts; |
| int curr_part = 0; |
| int err; |
| u_char *buf, *temp_buf; |
| size_t bytes_read = 0; |
| int i, j, n, part_entry_cnt, gpt_entries; |
| int gpt_partitions_exist = 0; |
| struct mbr_part part[4]; |
| struct gpt_info gptinfo = {0, 0, 0, 0, 0}; |
| loff_t partition_0, sgpt_addr = master->size; |
| u32 lba_size; |
| int tmp; |
| |
| dev_dbg(&master->dev, "GPT: enter gpt parser...\n"); |
| |
| if (mtd_type_is_nand(master) != 0) { |
| lba_size = master->writesize; |
| sgpt_addr -= BBT_RESERVED_BLOCK * master->erasesize; |
| } else { |
| lba_size = 512; |
| sgpt_addr -= lba_size; |
| } |
| |
| buf = kzalloc(lba_size, GFP_KERNEL); |
| if (buf == NULL) |
| return -ENOMEM; |
| |
| err = mtd_read_gpt(master, 0, lba_size, &bytes_read, buf); |
| if (err < 0) |
| goto freebuf; |
| |
| /* look for the aa55 tag */ |
| if (buf[510] != (u_char)0x55 || buf[511] != (u_char)0xaa) { |
| dev_err(&master->dev, "GPT: not find aa55 @ 510,511\n"); |
| goto freebuf; |
| } |
| |
| /* see if a partition table makes sense here */ |
| temp_buf = (u_char *)&part[0]; |
| memcpy(temp_buf, &buf[446], sizeof(part)); |
| |
| /* validate each of the partition entries */ |
| for (i = 0; i < 4; i++) { |
| if (validate_mbr_partition(master, &part[i]) >= 0) { |
| /* |
| * Type 0xEE indicates end of MBR |
| * and GPT partitions exist |
| */ |
| if (part[i].type == (uint8_t)0xee) { |
| gpt_partitions_exist = 1; |
| break; |
| } |
| } |
| } |
| |
| if (gpt_partitions_exist == 0) { |
| dev_err(&master->dev, "GPT: not find GPT\n"); |
| goto freebuf; |
| } |
| |
| err = mtd_read_gpt(master, (loff_t)lba_size, lba_size, &bytes_read, |
| buf); |
| if (err < 0) |
| goto freebuf; |
| |
| err = partition_parse_gpt_header(buf, &gptinfo); |
| if (err != 0) { |
| dev_warn(&master->dev, "GPT: Read GPT header fail, try to check the backup gpt.\n"); |
| err = mtd_read(master, sgpt_addr - (loff_t)lba_size, |
| lba_size, &bytes_read, buf); |
| if (err < 0) { |
| dev_err(&master->dev, "GPT: Could not read backup gpt.\n"); |
| goto freebuf; |
| } |
| |
| err = partition_parse_gpt_header(buf, &gptinfo); |
| if (err != 0) { |
| dev_err(&master->dev, "GPT: Primary and backup signatures invalid.\n"); |
| goto freebuf; |
| } |
| } |
| |
| parts = kcalloc(gptinfo.max_partition_count, |
| sizeof(struct mtd_partition), GFP_KERNEL); |
| if (parts == NULL) |
| goto freebuf; |
| |
| part_entry_cnt = (int)lba_size / ENTRY_SIZE; |
| partition_0 = |
| (loff_t)GET_LLWORD_FROM_BYTE(&buf[PARTITION_ENTRIES_OFFSET]); |
| |
| /* Read GPT Entries */ |
| gpt_entries = roundup((int)gptinfo.max_partition_count, part_entry_cnt); |
| gpt_entries /= part_entry_cnt; |
| for (i = 0; i < gpt_entries; i++) { |
| err = mtd_read_gpt(master, |
| ((partition_0 + (loff_t)i) * (loff_t)lba_size), |
| lba_size, &bytes_read, buf); |
| if (err < 0) { |
| dev_err(&master->dev, "GPT: read failed reading partition entries.\n"); |
| goto freeparts; |
| } |
| |
| for (j = 0; j < part_entry_cnt; j++) { |
| int8_t type_guid[PARTITION_TYPE_GUID_SIZE]; |
| char *name = kzalloc(MAX_GPT_NAME_SIZE, |
| GFP_KERNEL); |
| char UTF16_name[MAX_GPT_NAME_SIZE]; |
| uint64_t first_lba, last_lba, size; |
| |
| temp_buf = (u_char *)&type_guid[0]; |
| memcpy(temp_buf, |
| &buf[(u32)j * gptinfo.partition_entry_size], |
| PARTITION_TYPE_GUID_SIZE); |
| if (type_guid[0] == 0 && type_guid[1] == 0) { |
| kfree(name); |
| goto parsedone; |
| } |
| |
| tmp = j * (int)gptinfo.partition_entry_size; |
| tmp += FIRST_LBA_OFFSET; |
| first_lba = GET_LLWORD_FROM_BYTE(&buf[tmp]); |
| tmp = j * (int)gptinfo.partition_entry_size; |
| tmp += LAST_LBA_OFFSET; |
| last_lba = GET_LLWORD_FROM_BYTE(&buf[tmp]); |
| size = last_lba - first_lba + 1ULL; |
| |
| memset(&UTF16_name[0], 0x00, MAX_GPT_NAME_SIZE); |
| temp_buf = (u_char *)&UTF16_name[0]; |
| memcpy(temp_buf, |
| &buf[(u32)j * gptinfo.partition_entry_size + |
| (uint32_t)PARTITION_NAME_OFFSET], |
| MAX_GPT_NAME_SIZE); |
| |
| /* |
| * Currently partition names in *.xml are UTF-8 and |
| * lowercase only supporting english for now so removing |
| * 2nd byte of UTF-16 |
| */ |
| for (n = 0; n < MAX_GPT_NAME_SIZE / 2; n++) |
| name[n] = UTF16_name[n * 2]; |
| |
| dev_dbg(&master->dev, "partition(%s) first_lba(%llu), last_lba(%llu), size(%llu)\n", |
| name, first_lba, last_lba, size); |
| |
| gpt_add_part(&parts[curr_part++], name, |
| first_lba * lba_size, 0, |
| (last_lba - first_lba + 1ULL) * lba_size); |
| |
| dev_dbg(&master->dev, "gpt there are <%d> parititons.\n", |
| curr_part); |
| } |
| } |
| |
| parsedone: |
| *pparts = parts; |
| kfree(buf); |
| return curr_part; |
| |
| freeparts: |
| kfree(parts); |
| freebuf: |
| kfree(buf); |
| return 0; |
| }; |
| |
| static struct mtd_part_parser gpt_parser = { |
| .owner = THIS_MODULE, |
| .parse_fn = gpt_parse, |
| .name = "gptpart", |
| }; |
| |
| static int __init gptpart_init(void) |
| { |
| return register_mtd_parser(&gpt_parser); |
| } |
| |
| static void __exit gptpart_exit(void) |
| { |
| deregister_mtd_parser(&gpt_parser); |
| } |
| |
| module_init(gptpart_init); |
| module_exit(gptpart_exit); |
| |
| MODULE_LICENSE("GPL v2"); |
| MODULE_DESCRIPTION("GPT partitioning for flash memories"); |