xref: /linux/arch/s390/boot/decompressor.c (revision 1a2ac6d7ecdcde74a4e16f31de64124160fc7237)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Definitions and wrapper functions for kernel decompressor
4  *
5  * Copyright IBM Corp. 2010
6  *
7  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/string.h>
12 #include <asm/page.h>
13 #include "decompressor.h"
14 #include "boot.h"
15 
16 /*
17  * gzip declarations
18  */
19 #define STATIC static
20 
21 #undef memset
22 #undef memcpy
23 #undef memmove
24 #define memmove memmove
25 #define memzero(s, n) memset((s), 0, (n))
26 
27 #if defined(CONFIG_KERNEL_BZIP2)
28 #define BOOT_HEAP_SIZE	0x400000
29 #elif defined(CONFIG_KERNEL_ZSTD)
30 #define BOOT_HEAP_SIZE	0x30000
31 #else
32 #define BOOT_HEAP_SIZE	0x10000
33 #endif
34 
35 static unsigned long free_mem_ptr = (unsigned long) _end;
36 static unsigned long free_mem_end_ptr = (unsigned long) _end + BOOT_HEAP_SIZE;
37 
38 #ifdef CONFIG_KERNEL_GZIP
39 #include "../../../../lib/decompress_inflate.c"
40 #endif
41 
42 #ifdef CONFIG_KERNEL_BZIP2
43 #include "../../../../lib/decompress_bunzip2.c"
44 #endif
45 
46 #ifdef CONFIG_KERNEL_LZ4
47 #include "../../../../lib/decompress_unlz4.c"
48 #endif
49 
50 #ifdef CONFIG_KERNEL_LZMA
51 #include "../../../../lib/decompress_unlzma.c"
52 #endif
53 
54 #ifdef CONFIG_KERNEL_LZO
55 #include "../../../../lib/decompress_unlzo.c"
56 #endif
57 
58 #ifdef CONFIG_KERNEL_XZ
59 #include "../../../../lib/decompress_unxz.c"
60 #endif
61 
62 #ifdef CONFIG_KERNEL_ZSTD
63 #include "../../../../lib/decompress_unzstd.c"
64 #endif
65 
66 #define decompress_offset ALIGN((unsigned long)_end + BOOT_HEAP_SIZE, PAGE_SIZE)
67 
68 unsigned long mem_safe_offset(void)
69 {
70 	/*
71 	 * due to 4MB HEAD_SIZE for bzip2
72 	 * 'decompress_offset + vmlinux.image_size' could be larger than
73 	 * kernel at final position + its .bss, so take the larger of two
74 	 */
75 	return max(decompress_offset + vmlinux.image_size,
76 		   vmlinux.default_lma + vmlinux.image_size + vmlinux.bss_size);
77 }
78 
79 void *decompress_kernel(void)
80 {
81 	void *output = (void *)decompress_offset;
82 
83 	__decompress(_compressed_start, _compressed_end - _compressed_start,
84 		     NULL, NULL, output, vmlinux.image_size, NULL, error);
85 	return output;
86 }
87