xref: /openbmc/linux/arch/riscv/kernel/setup.c (revision 5d331b7f)
1 /*
2  * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
3  *  Chen Liqin <liqin.chen@sunplusct.com>
4  *  Lennox Wu <lennox.wu@sunplusct.com>
5  * Copyright (C) 2012 Regents of the University of California
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, see the file COPYING, or write
19  * to the Free Software Foundation, Inc.,
20  */
21 
22 #include <linux/init.h>
23 #include <linux/mm.h>
24 #include <linux/memblock.h>
25 #include <linux/sched.h>
26 #include <linux/initrd.h>
27 #include <linux/console.h>
28 #include <linux/screen_info.h>
29 #include <linux/of_fdt.h>
30 #include <linux/of_platform.h>
31 #include <linux/sched/task.h>
32 #include <linux/swiotlb.h>
33 
34 #include <asm/setup.h>
35 #include <asm/sections.h>
36 #include <asm/pgtable.h>
37 #include <asm/smp.h>
38 #include <asm/sbi.h>
39 #include <asm/tlbflush.h>
40 #include <asm/thread_info.h>
41 
42 #ifdef CONFIG_EARLY_PRINTK
43 static void sbi_console_write(struct console *co, const char *buf,
44 			      unsigned int n)
45 {
46 	int i;
47 
48 	for (i = 0; i < n; ++i) {
49 		if (buf[i] == '\n')
50 			sbi_console_putchar('\r');
51 		sbi_console_putchar(buf[i]);
52 	}
53 }
54 
55 struct console riscv_sbi_early_console_dev __initdata = {
56 	.name	= "early",
57 	.write	= sbi_console_write,
58 	.flags	= CON_PRINTBUFFER | CON_BOOT | CON_ANYTIME,
59 	.index	= -1
60 };
61 #endif
62 
63 #ifdef CONFIG_DUMMY_CONSOLE
64 struct screen_info screen_info = {
65 	.orig_video_lines	= 30,
66 	.orig_video_cols	= 80,
67 	.orig_video_mode	= 0,
68 	.orig_video_ega_bx	= 0,
69 	.orig_video_isVGA	= 1,
70 	.orig_video_points	= 8
71 };
72 #endif
73 
74 unsigned long va_pa_offset;
75 EXPORT_SYMBOL(va_pa_offset);
76 unsigned long pfn_base;
77 EXPORT_SYMBOL(pfn_base);
78 
79 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
80 EXPORT_SYMBOL(empty_zero_page);
81 
82 /* The lucky hart to first increment this variable will boot the other cores */
83 atomic_t hart_lottery;
84 unsigned long boot_cpu_hartid;
85 
86 unsigned long __cpuid_to_hartid_map[NR_CPUS] = {
87 	[0 ... NR_CPUS-1] = INVALID_HARTID
88 };
89 
90 void __init smp_setup_processor_id(void)
91 {
92 	cpuid_to_hartid_map(0) = boot_cpu_hartid;
93 }
94 
95 #ifdef CONFIG_BLK_DEV_INITRD
96 static void __init setup_initrd(void)
97 {
98 	unsigned long size;
99 
100 	if (initrd_start >= initrd_end) {
101 		printk(KERN_INFO "initrd not found or empty");
102 		goto disable;
103 	}
104 	if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
105 		printk(KERN_ERR "initrd extends beyond end of memory");
106 		goto disable;
107 	}
108 
109 	size =  initrd_end - initrd_start;
110 	memblock_reserve(__pa(initrd_start), size);
111 	initrd_below_start_ok = 1;
112 
113 	printk(KERN_INFO "Initial ramdisk at: 0x%p (%lu bytes)\n",
114 		(void *)(initrd_start), size);
115 	return;
116 disable:
117 	pr_cont(" - disabling initrd\n");
118 	initrd_start = 0;
119 	initrd_end = 0;
120 }
121 #endif /* CONFIG_BLK_DEV_INITRD */
122 
123 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
124 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
125 
126 #ifndef __PAGETABLE_PMD_FOLDED
127 #define NUM_SWAPPER_PMDS ((uintptr_t)-PAGE_OFFSET >> PGDIR_SHIFT)
128 pmd_t swapper_pmd[PTRS_PER_PMD*((-PAGE_OFFSET)/PGDIR_SIZE)] __page_aligned_bss;
129 pmd_t trampoline_pmd[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
130 #endif
131 
132 asmlinkage void __init setup_vm(void)
133 {
134 	extern char _start;
135 	uintptr_t i;
136 	uintptr_t pa = (uintptr_t) &_start;
137 	pgprot_t prot = __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_EXEC);
138 
139 	va_pa_offset = PAGE_OFFSET - pa;
140 	pfn_base = PFN_DOWN(pa);
141 
142 	/* Sanity check alignment and size */
143 	BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
144 	BUG_ON((pa % (PAGE_SIZE * PTRS_PER_PTE)) != 0);
145 
146 #ifndef __PAGETABLE_PMD_FOLDED
147 	trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
148 		pfn_pgd(PFN_DOWN((uintptr_t)trampoline_pmd),
149 			__pgprot(_PAGE_TABLE));
150 	trampoline_pmd[0] = pfn_pmd(PFN_DOWN(pa), prot);
151 
152 	for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
153 		size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
154 		swapper_pg_dir[o] =
155 			pfn_pgd(PFN_DOWN((uintptr_t)swapper_pmd) + i,
156 				__pgprot(_PAGE_TABLE));
157 	}
158 	for (i = 0; i < ARRAY_SIZE(swapper_pmd); i++)
159 		swapper_pmd[i] = pfn_pmd(PFN_DOWN(pa + i * PMD_SIZE), prot);
160 #else
161 	trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
162 		pfn_pgd(PFN_DOWN(pa), prot);
163 
164 	for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
165 		size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
166 		swapper_pg_dir[o] =
167 			pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot);
168 	}
169 #endif
170 }
171 
172 void __init parse_dtb(unsigned int hartid, void *dtb)
173 {
174 	early_init_dt_scan(__va(dtb));
175 }
176 
177 static void __init setup_bootmem(void)
178 {
179 	struct memblock_region *reg;
180 	phys_addr_t mem_size = 0;
181 
182 	/* Find the memory region containing the kernel */
183 	for_each_memblock(memory, reg) {
184 		phys_addr_t vmlinux_end = __pa(_end);
185 		phys_addr_t end = reg->base + reg->size;
186 
187 		if (reg->base <= vmlinux_end && vmlinux_end <= end) {
188 			/*
189 			 * Reserve from the start of the region to the end of
190 			 * the kernel
191 			 */
192 			memblock_reserve(reg->base, vmlinux_end - reg->base);
193 			mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET);
194 		}
195 	}
196 	BUG_ON(mem_size == 0);
197 
198 	set_max_mapnr(PFN_DOWN(mem_size));
199 	max_low_pfn = memblock_end_of_DRAM();
200 
201 #ifdef CONFIG_BLK_DEV_INITRD
202 	setup_initrd();
203 #endif /* CONFIG_BLK_DEV_INITRD */
204 
205 	early_init_fdt_reserve_self();
206 	early_init_fdt_scan_reserved_mem();
207 	memblock_allow_resize();
208 	memblock_dump_all();
209 
210 	for_each_memblock(memory, reg) {
211 		unsigned long start_pfn = memblock_region_memory_base_pfn(reg);
212 		unsigned long end_pfn = memblock_region_memory_end_pfn(reg);
213 
214 		memblock_set_node(PFN_PHYS(start_pfn),
215 		                  PFN_PHYS(end_pfn - start_pfn),
216 		                  &memblock.memory, 0);
217 	}
218 }
219 
220 void __init setup_arch(char **cmdline_p)
221 {
222 #if defined(CONFIG_EARLY_PRINTK)
223        if (likely(early_console == NULL)) {
224                early_console = &riscv_sbi_early_console_dev;
225                register_console(early_console);
226        }
227 #endif
228 	*cmdline_p = boot_command_line;
229 
230 	parse_early_param();
231 
232 	init_mm.start_code = (unsigned long) _stext;
233 	init_mm.end_code   = (unsigned long) _etext;
234 	init_mm.end_data   = (unsigned long) _edata;
235 	init_mm.brk        = (unsigned long) _end;
236 
237 	setup_bootmem();
238 	paging_init();
239 	unflatten_device_tree();
240 
241 #ifdef CONFIG_SWIOTLB
242 	swiotlb_init(1);
243 #endif
244 
245 #ifdef CONFIG_SMP
246 	setup_smp();
247 #endif
248 
249 #ifdef CONFIG_DUMMY_CONSOLE
250 	conswitchp = &dummy_con;
251 #endif
252 
253 	riscv_fill_hwcap();
254 }
255 
256