xref: /openbmc/u-boot/fs/ext4/dev.c (revision 4101f687)
1 /*
2  * (C) Copyright 2011 - 2012 Samsung Electronics
3  * EXT4 filesystem implementation in Uboot by
4  * Uma Shankar <uma.shankar@samsung.com>
5  * Manjunatha C Achar <a.manjunatha@samsung.com>
6  *
7  * made from existing ext2/dev.c file of Uboot
8  * (C) Copyright 2004
9  * esd gmbh <www.esd-electronics.com>
10  * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
11  *
12  * based on code of fs/reiserfs/dev.c by
13  *
14  * (C) Copyright 2003 - 2004
15  * Sysgo AG, <www.elinos.com>, Pavel Bartusek <pba@sysgo.com>
16  *
17  * SPDX-License-Identifier:	GPL-2.0+
18  */
19 
20 /*
21  * Changelog:
22  *	0.1 - Newly created file for ext4fs support. Taken from
23  *		fs/ext2/dev.c file in uboot.
24  */
25 
26 #include <common.h>
27 #include <config.h>
28 #include <memalign.h>
29 #include <ext4fs.h>
30 #include <ext_common.h>
31 #include "ext4_common.h"
32 
33 lbaint_t part_offset;
34 
35 static struct blk_desc *ext4fs_blk_desc;
36 static disk_partition_t *part_info;
37 
38 void ext4fs_set_blk_dev(struct blk_desc *rbdd, disk_partition_t *info)
39 {
40 	assert(rbdd->blksz == (1 << rbdd->log2blksz));
41 	ext4fs_blk_desc = rbdd;
42 	get_fs()->dev_desc = rbdd;
43 	part_info = info;
44 	part_offset = info->start;
45 	get_fs()->total_sect = ((uint64_t)info->size * info->blksz) >>
46 		get_fs()->dev_desc->log2blksz;
47 }
48 
49 int ext4fs_devread(lbaint_t sector, int byte_offset, int byte_len, char *buf)
50 {
51 	unsigned block_len;
52 	int log2blksz = ext4fs_blk_desc->log2blksz;
53 	ALLOC_CACHE_ALIGN_BUFFER(char, sec_buf, (ext4fs_blk_desc ?
54 						 ext4fs_blk_desc->blksz :
55 						 0));
56 	if (ext4fs_blk_desc == NULL) {
57 		printf("** Invalid Block Device Descriptor (NULL)\n");
58 		return 0;
59 	}
60 
61 	/* Check partition boundaries */
62 	if ((sector < 0) ||
63 	    ((sector + ((byte_offset + byte_len - 1) >> log2blksz))
64 	     >= part_info->size)) {
65 		printf("%s read outside partition " LBAFU "\n", __func__,
66 		       sector);
67 		return 0;
68 	}
69 
70 	/* Get the read to the beginning of a partition */
71 	sector += byte_offset >> log2blksz;
72 	byte_offset &= ext4fs_blk_desc->blksz - 1;
73 
74 	debug(" <" LBAFU ", %d, %d>\n", sector, byte_offset, byte_len);
75 
76 	if (byte_offset != 0) {
77 		int readlen;
78 		/* read first part which isn't aligned with start of sector */
79 		if (ext4fs_blk_desc->block_read(ext4fs_blk_desc,
80 						part_info->start + sector,
81 						1, (void *)sec_buf) != 1) {
82 			printf(" ** ext2fs_devread() read error **\n");
83 			return 0;
84 		}
85 		readlen = min((int)ext4fs_blk_desc->blksz - byte_offset,
86 			      byte_len);
87 		memcpy(buf, sec_buf + byte_offset, readlen);
88 		buf += readlen;
89 		byte_len -= readlen;
90 		sector++;
91 	}
92 
93 	if (byte_len == 0)
94 		return 1;
95 
96 	/* read sector aligned part */
97 	block_len = byte_len & ~(ext4fs_blk_desc->blksz - 1);
98 
99 	if (block_len == 0) {
100 		ALLOC_CACHE_ALIGN_BUFFER(u8, p, ext4fs_blk_desc->blksz);
101 
102 		block_len = ext4fs_blk_desc->blksz;
103 		ext4fs_blk_desc->block_read(ext4fs_blk_desc,
104 						  part_info->start + sector,
105 						  1, (void *)p);
106 		memcpy(buf, p, byte_len);
107 		return 1;
108 	}
109 
110 	if (ext4fs_blk_desc->block_read(ext4fs_blk_desc,
111 					part_info->start + sector,
112 					block_len >> log2blksz, (void *)buf)
113 				!= block_len >> log2blksz) {
114 		printf(" ** %s read error - block\n", __func__);
115 		return 0;
116 	}
117 	block_len = byte_len & ~(ext4fs_blk_desc->blksz - 1);
118 	buf += block_len;
119 	byte_len -= block_len;
120 	sector += block_len / ext4fs_blk_desc->blksz;
121 
122 	if (byte_len != 0) {
123 		/* read rest of data which are not in whole sector */
124 		if (ext4fs_blk_desc->block_read(ext4fs_blk_desc,
125 						part_info->start + sector,
126 						1, (void *)sec_buf) != 1) {
127 			printf("* %s read error - last part\n", __func__);
128 			return 0;
129 		}
130 		memcpy(buf, sec_buf, byte_len);
131 	}
132 	return 1;
133 }
134 
135 int ext4_read_superblock(char *buffer)
136 {
137 	struct ext_filesystem *fs = get_fs();
138 	int sect = SUPERBLOCK_START >> fs->dev_desc->log2blksz;
139 	int off = SUPERBLOCK_START % fs->dev_desc->blksz;
140 
141 	return ext4fs_devread(sect, off, SUPERBLOCK_SIZE,
142 				buffer);
143 }
144