xref: /openbmc/u-boot/fs/ext4/dev.c (revision 0a61ee88)
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 block_dev_desc_t *ext4fs_block_dev_desc;
36 static disk_partition_t *part_info;
37 
38 void ext4fs_set_blk_dev(block_dev_desc_t *rbdd, disk_partition_t *info)
39 {
40 	assert(rbdd->blksz == (1 << rbdd->log2blksz));
41 	ext4fs_block_dev_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_block_dev_desc->log2blksz;
53 	ALLOC_CACHE_ALIGN_BUFFER(char, sec_buf, (ext4fs_block_dev_desc ?
54 						 ext4fs_block_dev_desc->blksz :
55 						 0));
56 	if (ext4fs_block_dev_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_block_dev_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_block_dev_desc->block_read(ext4fs_block_dev_desc,
80 						      part_info->start + sector,
81 						      1, (void *)sec_buf)
82 		    != 1) {
83 			printf(" ** ext2fs_devread() read error **\n");
84 			return 0;
85 		}
86 		readlen = min((int)ext4fs_block_dev_desc->blksz - byte_offset,
87 			      byte_len);
88 		memcpy(buf, sec_buf + byte_offset, readlen);
89 		buf += readlen;
90 		byte_len -= readlen;
91 		sector++;
92 	}
93 
94 	if (byte_len == 0)
95 		return 1;
96 
97 	/* read sector aligned part */
98 	block_len = byte_len & ~(ext4fs_block_dev_desc->blksz - 1);
99 
100 	if (block_len == 0) {
101 		ALLOC_CACHE_ALIGN_BUFFER(u8, p, ext4fs_block_dev_desc->blksz);
102 
103 		block_len = ext4fs_block_dev_desc->blksz;
104 		ext4fs_block_dev_desc->block_read(ext4fs_block_dev_desc,
105 						  part_info->start + sector,
106 						  1, (void *)p);
107 		memcpy(buf, p, byte_len);
108 		return 1;
109 	}
110 
111 	if (ext4fs_block_dev_desc->block_read(ext4fs_block_dev_desc,
112 					      part_info->start + sector,
113 					      block_len >> log2blksz,
114 					      (void *)buf) !=
115 					      block_len >> log2blksz) {
116 		printf(" ** %s read error - block\n", __func__);
117 		return 0;
118 	}
119 	block_len = byte_len & ~(ext4fs_block_dev_desc->blksz - 1);
120 	buf += block_len;
121 	byte_len -= block_len;
122 	sector += block_len / ext4fs_block_dev_desc->blksz;
123 
124 	if (byte_len != 0) {
125 		/* read rest of data which are not in whole sector */
126 		if (ext4fs_block_dev_desc->block_read(ext4fs_block_dev_desc,
127 						      part_info->start + sector,
128 						      1, (void *)sec_buf)
129 		    != 1) {
130 			printf("* %s read error - last part\n", __func__);
131 			return 0;
132 		}
133 		memcpy(buf, sec_buf, byte_len);
134 	}
135 	return 1;
136 }
137 
138 int ext4_read_superblock(char *buffer)
139 {
140 	struct ext_filesystem *fs = get_fs();
141 	int sect = SUPERBLOCK_START >> fs->dev_desc->log2blksz;
142 	int off = SUPERBLOCK_START % fs->dev_desc->blksz;
143 
144 	return ext4fs_devread(sect, off, SUPERBLOCK_SIZE,
145 				buffer);
146 }
147