summaryrefslogtreecommitdiffstats
path: root/arch/s390/boot/startup.c
blob: 7b0d05414618be9e992f96298b1b92b38fea898c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
// SPDX-License-Identifier: GPL-2.0
#include <linux/string.h>
#include <linux/elf.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/kexec.h>
#include <asm/sclp.h>
#include <asm/diag.h>
#include <asm/uv.h>
#include "compressed/decompressor.h"
#include "boot.h"

extern char __boot_data_start[], __boot_data_end[];
extern char __boot_data_preserved_start[], __boot_data_preserved_end[];
unsigned long __bootdata_preserved(__kaslr_offset);

/*
 * Some code and data needs to stay below 2 GB, even when the kernel would be
 * relocated above 2 GB, because it has to use 31 bit addresses.
 * Such code and data is part of the .dma section, and its location is passed
 * over to the decompressed / relocated kernel via the .boot.preserved.data
 * section.
 */
extern char _sdma[], _edma[];
extern char _stext_dma[], _etext_dma[];
extern struct exception_table_entry _start_dma_ex_table[];
extern struct exception_table_entry _stop_dma_ex_table[];
unsigned long __bootdata_preserved(__sdma) = __pa(&_sdma);
unsigned long __bootdata_preserved(__edma) = __pa(&_edma);
unsigned long __bootdata_preserved(__stext_dma) = __pa(&_stext_dma);
unsigned long __bootdata_preserved(__etext_dma) = __pa(&_etext_dma);
struct exception_table_entry *
	__bootdata_preserved(__start_dma_ex_table) = _start_dma_ex_table;
struct exception_table_entry *
	__bootdata_preserved(__stop_dma_ex_table) = _stop_dma_ex_table;

int _diag210_dma(struct diag210 *addr);
int _diag26c_dma(void *req, void *resp, enum diag26c_sc subcode);
int _diag14_dma(unsigned long rx, unsigned long ry1, unsigned long subcode);
void _diag0c_dma(struct hypfs_diag0c_entry *entry);
void _diag308_reset_dma(void);
struct diag_ops __bootdata_preserved(diag_dma_ops) = {
	.diag210 = _diag210_dma,
	.diag26c = _diag26c_dma,
	.diag14 = _diag14_dma,
	.diag0c = _diag0c_dma,
	.diag308_reset = _diag308_reset_dma
};
static struct diag210 _diag210_tmp_dma __section(".dma.data");
struct diag210 *__bootdata_preserved(__diag210_tmp_dma) = &_diag210_tmp_dma;
void _swsusp_reset_dma(void);
unsigned long __bootdata_preserved(__swsusp_reset_dma) = __pa(_swsusp_reset_dma);

void error(char *x)
{
	sclp_early_printk("\n\n");
	sclp_early_printk(x);
	sclp_early_printk("\n\n -- System halted");

	disabled_wait();
}

#ifdef CONFIG_KERNEL_UNCOMPRESSED
unsigned long mem_safe_offset(void)
{
	return vmlinux.default_lma + vmlinux.image_size + vmlinux.bss_size;
}
#endif

static void rescue_initrd(unsigned long addr)
{
	if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD))
		return;
	if (!INITRD_START || !INITRD_SIZE)
		return;
	if (addr <= INITRD_START)
		return;
	memmove((void *)addr, (void *)INITRD_START, INITRD_SIZE);
	INITRD_START = addr;
}

static void copy_bootdata(void)
{
	if (__boot_data_end - __boot_data_start != vmlinux.bootdata_size)
		error(".boot.data section size mismatch");
	memcpy((void *)vmlinux.bootdata_off, __boot_data_start, vmlinux.bootdata_size);
	if (__boot_data_preserved_end - __boot_data_preserved_start != vmlinux.bootdata_preserved_size)
		error(".boot.preserved.data section size mismatch");
	memcpy((void *)vmlinux.bootdata_preserved_off, __boot_data_preserved_start, vmlinux.bootdata_preserved_size);
}

static void handle_relocs(unsigned long offset)
{
	Elf64_Rela *rela_start, *rela_end, *rela;
	int r_type, r_sym, rc;
	Elf64_Addr loc, val;
	Elf64_Sym *dynsym;

	rela_start = (Elf64_Rela *) vmlinux.rela_dyn_start;
	rela_end = (Elf64_Rela *) vmlinux.rela_dyn_end;
	dynsym = (Elf64_Sym *) vmlinux.dynsym_start;
	for (rela = rela_start; rela < rela_end; rela++) {
		loc = rela->r_offset + offset;
		val = rela->r_addend + offset;
		r_sym = ELF64_R_SYM(rela->r_info);
		if (r_sym)
			val += dynsym[r_sym].st_value;
		r_type = ELF64_R_TYPE(rela->r_info);
		rc = arch_kexec_do_relocs(r_type, (void *) loc, val, 0);
		if (rc)
			error("Unknown relocation type");
	}
}

void startup_kernel(void)
{
	unsigned long random_lma;
	unsigned long safe_addr;
	void *img;

	store_ipl_parmblock();
	safe_addr = mem_safe_offset();
	safe_addr = read_ipl_report(safe_addr);
	uv_query_info();
	rescue_initrd(safe_addr);
	sclp_early_read_info();
	setup_boot_command_line();
	parse_boot_command_line();
	setup_memory_end();
	detect_memory();

	random_lma = __kaslr_offset = 0;
	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_enabled) {
		random_lma = get_random_base(safe_addr);
		if (random_lma) {
			__kaslr_offset = random_lma - vmlinux.default_lma;
			img = (void *)vmlinux.default_lma;
			vmlinux.default_lma += __kaslr_offset;
			vmlinux.entry += __kaslr_offset;
			vmlinux.bootdata_off += __kaslr_offset;
			vmlinux.bootdata_preserved_off += __kaslr_offset;
			vmlinux.rela_dyn_start += __kaslr_offset;
			vmlinux.rela_dyn_end += __kaslr_offset;
			vmlinux.dynsym_start += __kaslr_offset;
		}
	}

	if (!IS_ENABLED(CONFIG_KERNEL_UNCOMPRESSED)) {
		img = decompress_kernel();
		memmove((void *)vmlinux.default_lma, img, vmlinux.image_size);
	} else if (__kaslr_offset)
		memcpy((void *)vmlinux.default_lma, img, vmlinux.image_size);

	copy_bootdata();
	if (IS_ENABLED(CONFIG_RELOCATABLE))
		handle_relocs(__kaslr_offset);

	if (__kaslr_offset) {
		/* Clear non-relocated kernel */
		if (IS_ENABLED(CONFIG_KERNEL_UNCOMPRESSED))
			memset(img, 0, vmlinux.image_size);
	}
	vmlinux.entry();
}