xref: /openbmc/u-boot/fs/ext4/dev.c (revision 2e3f1ff63f50f36e74d46f939823241856ebf1bd)
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 <blk.h>
28  #include <config.h>
29  #include <memalign.h>
30  #include <ext4fs.h>
31  #include <ext_common.h>
32  #include "ext4_common.h"
33  
34  lbaint_t part_offset;
35  
36  static struct blk_desc *ext4fs_blk_desc;
37  static disk_partition_t *part_info;
38  
39  void ext4fs_set_blk_dev(struct blk_desc *rbdd, disk_partition_t *info)
40  {
41  	assert(rbdd->blksz == (1 << rbdd->log2blksz));
42  	ext4fs_blk_desc = rbdd;
43  	get_fs()->dev_desc = rbdd;
44  	part_info = info;
45  	part_offset = info->start;
46  	get_fs()->total_sect = ((uint64_t)info->size * info->blksz) >>
47  		get_fs()->dev_desc->log2blksz;
48  }
49  
50  int ext4fs_devread(lbaint_t sector, int byte_offset, int byte_len, char *buf)
51  {
52  	unsigned block_len;
53  	int log2blksz = ext4fs_blk_desc->log2blksz;
54  	ALLOC_CACHE_ALIGN_BUFFER(char, sec_buf, (ext4fs_blk_desc ?
55  						 ext4fs_blk_desc->blksz :
56  						 0));
57  	if (ext4fs_blk_desc == NULL) {
58  		printf("** Invalid Block Device Descriptor (NULL)\n");
59  		return 0;
60  	}
61  
62  	/* Check partition boundaries */
63  	if ((sector < 0) ||
64  	    ((sector + ((byte_offset + byte_len - 1) >> log2blksz))
65  	     >= part_info->size)) {
66  		printf("%s read outside partition " LBAFU "\n", __func__,
67  		       sector);
68  		return 0;
69  	}
70  
71  	/* Get the read to the beginning of a partition */
72  	sector += byte_offset >> log2blksz;
73  	byte_offset &= ext4fs_blk_desc->blksz - 1;
74  
75  	debug(" <" LBAFU ", %d, %d>\n", sector, byte_offset, byte_len);
76  
77  	if (byte_offset != 0) {
78  		int readlen;
79  		/* read first part which isn't aligned with start of sector */
80  		if (blk_dread(ext4fs_blk_desc, part_info->start + sector, 1,
81  			      (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  		blk_dread(ext4fs_blk_desc, part_info->start + sector, 1,
104  			  (void *)p);
105  		memcpy(buf, p, byte_len);
106  		return 1;
107  	}
108  
109  	if (blk_dread(ext4fs_blk_desc, part_info->start + sector,
110  		      block_len >> log2blksz, (void *)buf) !=
111  			block_len >> log2blksz) {
112  		printf(" ** %s read error - block\n", __func__);
113  		return 0;
114  	}
115  	block_len = byte_len & ~(ext4fs_blk_desc->blksz - 1);
116  	buf += block_len;
117  	byte_len -= block_len;
118  	sector += block_len / ext4fs_blk_desc->blksz;
119  
120  	if (byte_len != 0) {
121  		/* read rest of data which are not in whole sector */
122  		if (blk_dread(ext4fs_blk_desc, part_info->start + sector, 1,
123  			      (void *)sec_buf) != 1) {
124  			printf("* %s read error - last part\n", __func__);
125  			return 0;
126  		}
127  		memcpy(buf, sec_buf, byte_len);
128  	}
129  	return 1;
130  }
131  
132  int ext4_read_superblock(char *buffer)
133  {
134  	struct ext_filesystem *fs = get_fs();
135  	int sect = SUPERBLOCK_START >> fs->dev_desc->log2blksz;
136  	int off = SUPERBLOCK_START % fs->dev_desc->blksz;
137  
138  	return ext4fs_devread(sect, off, SUPERBLOCK_SIZE,
139  				buffer);
140  }
141