summaryrefslogtreecommitdiffstats
path: root/arch/riscv/kernel/setup.c
blob: de7db114c31531ba244cb45c765b3fb2e1c559eb (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
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
/*
 * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
 *  Chen Liqin <liqin.chen@sunplusct.com>
 *  Lennox Wu <lennox.wu@sunplusct.com>
 * Copyright (C) 2012 Regents of the University of California
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see the file COPYING, or write
 * to the Free Software Foundation, Inc.,
 */

#include <linux/init.h>
#include <linux/mm.h>
#include <linux/memblock.h>
#include <linux/sched.h>
#include <linux/initrd.h>
#include <linux/console.h>
#include <linux/screen_info.h>
#include <linux/of_fdt.h>
#include <linux/of_platform.h>
#include <linux/sched/task.h>

#include <asm/setup.h>
#include <asm/sections.h>
#include <asm/pgtable.h>
#include <asm/smp.h>
#include <asm/sbi.h>
#include <asm/tlbflush.h>
#include <asm/thread_info.h>

#ifdef CONFIG_HVC_RISCV_SBI
#include <asm/hvc_riscv_sbi.h>
#endif

#ifdef CONFIG_DUMMY_CONSOLE
struct screen_info screen_info = {
	.orig_video_lines	= 30,
	.orig_video_cols	= 80,
	.orig_video_mode	= 0,
	.orig_video_ega_bx	= 0,
	.orig_video_isVGA	= 1,
	.orig_video_points	= 8
};
#endif

#ifdef CONFIG_CMDLINE_BOOL
static char __initdata builtin_cmdline[COMMAND_LINE_SIZE] = CONFIG_CMDLINE;
#endif /* CONFIG_CMDLINE_BOOL */

unsigned long va_pa_offset;
unsigned long pfn_base;

/* The lucky hart to first increment this variable will boot the other cores */
atomic_t hart_lottery;

#ifdef CONFIG_BLK_DEV_INITRD
static void __init setup_initrd(void)
{
	extern char __initramfs_start[];
	extern unsigned long __initramfs_size;
	unsigned long size;

	if (__initramfs_size > 0) {
		initrd_start = (unsigned long)(&__initramfs_start);
		initrd_end = initrd_start + __initramfs_size;
	}

	if (initrd_start >= initrd_end) {
		printk(KERN_INFO "initrd not found or empty");
		goto disable;
	}
	if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
		printk(KERN_ERR "initrd extends beyond end of memory");
		goto disable;
	}

	size =  initrd_end - initrd_start;
	memblock_reserve(__pa(initrd_start), size);
	initrd_below_start_ok = 1;

	printk(KERN_INFO "Initial ramdisk at: 0x%p (%lu bytes)\n",
		(void *)(initrd_start), size);
	return;
disable:
	pr_cont(" - disabling initrd\n");
	initrd_start = 0;
	initrd_end = 0;
}
#endif /* CONFIG_BLK_DEV_INITRD */

pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);

#ifndef __PAGETABLE_PMD_FOLDED
#define NUM_SWAPPER_PMDS ((uintptr_t)-PAGE_OFFSET >> PGDIR_SHIFT)
pmd_t swapper_pmd[PTRS_PER_PMD*((-PAGE_OFFSET)/PGDIR_SIZE)] __page_aligned_bss;
pmd_t trampoline_pmd[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
#endif

asmlinkage void __init setup_vm(void)
{
	extern char _start;
	uintptr_t i;
	uintptr_t pa = (uintptr_t) &_start;
	pgprot_t prot = __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_EXEC);

	va_pa_offset = PAGE_OFFSET - pa;
	pfn_base = PFN_DOWN(pa);

	/* Sanity check alignment and size */
	BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
	BUG_ON((pa % (PAGE_SIZE * PTRS_PER_PTE)) != 0);

#ifndef __PAGETABLE_PMD_FOLDED
	trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
		pfn_pgd(PFN_DOWN((uintptr_t)trampoline_pmd),
			__pgprot(_PAGE_TABLE));
	trampoline_pmd[0] = pfn_pmd(PFN_DOWN(pa), prot);

	for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
		size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
		swapper_pg_dir[o] =
			pfn_pgd(PFN_DOWN((uintptr_t)swapper_pmd) + i,
				__pgprot(_PAGE_TABLE));
	}
	for (i = 0; i < ARRAY_SIZE(swapper_pmd); i++)
		swapper_pmd[i] = pfn_pmd(PFN_DOWN(pa + i * PMD_SIZE), prot);
#else
	trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
		pfn_pgd(PFN_DOWN(pa), prot);

	for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
		size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
		swapper_pg_dir[o] =
			pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot);
	}
#endif
}

void __init sbi_save(unsigned int hartid, void *dtb)
{
	early_init_dt_scan(__va(dtb));
}

/*
 * Allow the user to manually add a memory region (in case DTS is broken);
 * "mem_end=nn[KkMmGg]"
 */
static int __init mem_end_override(char *p)
{
	resource_size_t base, end;

	if (!p)
		return -EINVAL;
	base = (uintptr_t) __pa(PAGE_OFFSET);
	end = memparse(p, &p) & PMD_MASK;
	if (end == 0)
		return -EINVAL;
	memblock_add(base, end - base);
	return 0;
}
early_param("mem_end", mem_end_override);

static void __init setup_bootmem(void)
{
	struct memblock_region *reg;
	phys_addr_t mem_size = 0;

	/* Find the memory region containing the kernel */
	for_each_memblock(memory, reg) {
		phys_addr_t vmlinux_end = __pa(_end);
		phys_addr_t end = reg->base + reg->size;

		if (reg->base <= vmlinux_end && vmlinux_end <= end) {
			/*
			 * Reserve from the start of the region to the end of
			 * the kernel
			 */
			memblock_reserve(reg->base, vmlinux_end - reg->base);
			mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET);
		}
	}
	BUG_ON(mem_size == 0);

	set_max_mapnr(PFN_DOWN(mem_size));
	max_low_pfn = pfn_base + PFN_DOWN(mem_size);

#ifdef CONFIG_BLK_DEV_INITRD
	setup_initrd();
#endif /* CONFIG_BLK_DEV_INITRD */

	early_init_fdt_reserve_self();
	early_init_fdt_scan_reserved_mem();
	memblock_allow_resize();
	memblock_dump_all();
}

void __init setup_arch(char **cmdline_p)
{
#if defined(CONFIG_HVC_RISCV_SBI)
	if (likely(early_console == NULL)) {
		early_console = &riscv_sbi_early_console_dev;
		register_console(early_console);
	}
#endif

#ifdef CONFIG_CMDLINE_BOOL
#ifdef CONFIG_CMDLINE_OVERRIDE
	strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
#else
	if (builtin_cmdline[0] != '\0') {
		/* Append bootloader command line to built-in */
		strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);
		strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);
		strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
	}
#endif /* CONFIG_CMDLINE_OVERRIDE */
#endif /* CONFIG_CMDLINE_BOOL */
	*cmdline_p = boot_command_line;

	parse_early_param();

	init_mm.start_code = (unsigned long) _stext;
	init_mm.end_code   = (unsigned long) _etext;
	init_mm.end_data   = (unsigned long) _edata;
	init_mm.brk        = (unsigned long) _end;

	setup_bootmem();
	paging_init();
	unflatten_device_tree();

#ifdef CONFIG_SMP
	setup_smp();
#endif

#ifdef CONFIG_DUMMY_CONSOLE
	conswitchp = &dummy_con;
#endif

	riscv_fill_hwcap();
}

static int __init riscv_device_init(void)
{
	return of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
}
subsys_initcall_sync(riscv_device_init);