xref: /openbmc/u-boot/fs/ext4/dev.c (revision 3765b3e7)
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 <ext4fs.h>
29 #include <ext_common.h>
30 #include "ext4_common.h"
31 
32 lbaint_t part_offset;
33 
34 static block_dev_desc_t *ext4fs_block_dev_desc;
35 static disk_partition_t *part_info;
36 
37 void ext4fs_set_blk_dev(block_dev_desc_t *rbdd, disk_partition_t *info)
38 {
39 	assert(rbdd->blksz == (1 << rbdd->log2blksz));
40 	ext4fs_block_dev_desc = rbdd;
41 	get_fs()->dev_desc = rbdd;
42 	part_info = info;
43 	part_offset = info->start;
44 	get_fs()->total_sect = (info->size * info->blksz) >>
45 		get_fs()->dev_desc->log2blksz;
46 }
47 
48 int ext4fs_devread(lbaint_t sector, int byte_offset, int byte_len, char *buf)
49 {
50 	unsigned block_len;
51 	int log2blksz = ext4fs_block_dev_desc->log2blksz;
52 	ALLOC_CACHE_ALIGN_BUFFER(char, sec_buf, (ext4fs_block_dev_desc ?
53 						 ext4fs_block_dev_desc->blksz :
54 						 0));
55 	if (ext4fs_block_dev_desc == NULL) {
56 		printf("** Invalid Block Device Descriptor (NULL)\n");
57 		return 0;
58 	}
59 
60 	/* Check partition boundaries */
61 	if ((sector < 0) ||
62 	    ((sector + ((byte_offset + byte_len - 1) >> log2blksz))
63 	     >= part_info->size)) {
64 		printf("%s read outside partition " LBAFU "\n", __func__,
65 		       sector);
66 		return 0;
67 	}
68 
69 	/* Get the read to the beginning of a partition */
70 	sector += byte_offset >> log2blksz;
71 	byte_offset &= ext4fs_block_dev_desc->blksz - 1;
72 
73 	debug(" <" LBAFU ", %d, %d>\n", sector, byte_offset, byte_len);
74 
75 	if (byte_offset != 0) {
76 		/* read first part which isn't aligned with start of sector */
77 		if (ext4fs_block_dev_desc->
78 		    block_read(ext4fs_block_dev_desc->dev,
79 				part_info->start + sector, 1,
80 				(unsigned long *) sec_buf) != 1) {
81 			printf(" ** ext2fs_devread() read error **\n");
82 			return 0;
83 		}
84 		memcpy(buf, sec_buf + byte_offset,
85 			min(ext4fs_block_dev_desc->blksz
86 			    - byte_offset, byte_len));
87 		buf += min(ext4fs_block_dev_desc->blksz
88 			   - byte_offset, byte_len);
89 		byte_len -= min(ext4fs_block_dev_desc->blksz
90 				- byte_offset, byte_len);
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->dev,
105 						  part_info->start + sector,
106 						  1, (unsigned long *)p);
107 		memcpy(buf, p, byte_len);
108 		return 1;
109 	}
110 
111 	if (ext4fs_block_dev_desc->block_read(ext4fs_block_dev_desc->dev,
112 					       part_info->start + sector,
113 					       block_len >> log2blksz,
114 					       (unsigned long *) 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->
127 		    block_read(ext4fs_block_dev_desc->dev,
128 				part_info->start + sector, 1,
129 				(unsigned long *) sec_buf) != 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