xref: /linux/arch/riscv/kernel/setup.c (revision ca853314e78b0a65c20b6a889a23c31f918d4aa2)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
4  *  Chen Liqin <liqin.chen@sunplusct.com>
5  *  Lennox Wu <lennox.wu@sunplusct.com>
6  * Copyright (C) 2012 Regents of the University of California
7  * Copyright (C) 2020 FORTH-ICS/CARV
8  *  Nick Kossifidis <mick@ics.forth.gr>
9  */
10 
11 #include <linux/init.h>
12 #include <linux/mm.h>
13 #include <linux/memblock.h>
14 #include <linux/sched.h>
15 #include <linux/console.h>
16 #include <linux/screen_info.h>
17 #include <linux/of_fdt.h>
18 #include <linux/of_platform.h>
19 #include <linux/sched/task.h>
20 #include <linux/swiotlb.h>
21 #include <linux/smp.h>
22 #include <linux/efi.h>
23 
24 #include <asm/cpu_ops.h>
25 #include <asm/early_ioremap.h>
26 #include <asm/setup.h>
27 #include <asm/set_memory.h>
28 #include <asm/sections.h>
29 #include <asm/sbi.h>
30 #include <asm/tlbflush.h>
31 #include <asm/thread_info.h>
32 #include <asm/kasan.h>
33 #include <asm/efi.h>
34 
35 #include "head.h"
36 
37 #if defined(CONFIG_DUMMY_CONSOLE) || defined(CONFIG_EFI)
38 struct screen_info screen_info __section(".data") = {
39 	.orig_video_lines	= 30,
40 	.orig_video_cols	= 80,
41 	.orig_video_mode	= 0,
42 	.orig_video_ega_bx	= 0,
43 	.orig_video_isVGA	= 1,
44 	.orig_video_points	= 8
45 };
46 #endif
47 
48 /*
49  * The lucky hart to first increment this variable will boot the other cores.
50  * This is used before the kernel initializes the BSS so it can't be in the
51  * BSS.
52  */
53 atomic_t hart_lottery __section(".sdata");
54 unsigned long boot_cpu_hartid;
55 static DEFINE_PER_CPU(struct cpu, cpu_devices);
56 
57 /*
58  * Place kernel memory regions on the resource tree so that
59  * kexec-tools can retrieve them from /proc/iomem. While there
60  * also add "System RAM" regions for compatibility with other
61  * archs, and the rest of the known regions for completeness.
62  */
63 static struct resource code_res = { .name = "Kernel code", };
64 static struct resource data_res = { .name = "Kernel data", };
65 static struct resource rodata_res = { .name = "Kernel rodata", };
66 static struct resource bss_res = { .name = "Kernel bss", };
67 
68 static int __init add_resource(struct resource *parent,
69 				struct resource *res)
70 {
71 	int ret = 0;
72 
73 	ret = insert_resource(parent, res);
74 	if (ret < 0) {
75 		pr_err("Failed to add a %s resource at %llx\n",
76 			res->name, (unsigned long long) res->start);
77 		return ret;
78 	}
79 
80 	return 1;
81 }
82 
83 static int __init add_kernel_resources(struct resource *res)
84 {
85 	int ret = 0;
86 
87 	/*
88 	 * The memory region of the kernel image is continuous and
89 	 * was reserved on setup_bootmem, find it here and register
90 	 * it as a resource, then register the various segments of
91 	 * the image as child nodes
92 	 */
93 	if (!(res->start <= code_res.start && res->end >= data_res.end))
94 		return 0;
95 
96 	res->name = "Kernel image";
97 	res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
98 
99 	/*
100 	 * We removed a part of this region on setup_bootmem so
101 	 * we need to expand the resource for the bss to fit in.
102 	 */
103 	res->end = bss_res.end;
104 
105 	ret = add_resource(&iomem_resource, res);
106 	if (ret < 0)
107 		return ret;
108 
109 	ret = add_resource(res, &code_res);
110 	if (ret < 0)
111 		return ret;
112 
113 	ret = add_resource(res, &rodata_res);
114 	if (ret < 0)
115 		return ret;
116 
117 	ret = add_resource(res, &data_res);
118 	if (ret < 0)
119 		return ret;
120 
121 	ret = add_resource(res, &bss_res);
122 
123 	return ret;
124 }
125 
126 static void __init init_resources(void)
127 {
128 	struct memblock_region *region = NULL;
129 	struct resource *res = NULL;
130 	struct resource *mem_res = NULL;
131 	size_t mem_res_sz = 0;
132 	int ret = 0, i = 0;
133 
134 	code_res.start = __pa_symbol(_text);
135 	code_res.end = __pa_symbol(_etext) - 1;
136 	code_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
137 
138 	rodata_res.start = __pa_symbol(__start_rodata);
139 	rodata_res.end = __pa_symbol(__end_rodata) - 1;
140 	rodata_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
141 
142 	data_res.start = __pa_symbol(_data);
143 	data_res.end = __pa_symbol(_edata) - 1;
144 	data_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
145 
146 	bss_res.start = __pa_symbol(__bss_start);
147 	bss_res.end = __pa_symbol(__bss_stop) - 1;
148 	bss_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
149 
150 	mem_res_sz = (memblock.memory.cnt + memblock.reserved.cnt) * sizeof(*mem_res);
151 	mem_res = memblock_alloc(mem_res_sz, SMP_CACHE_BYTES);
152 	if (!mem_res)
153 		panic("%s: Failed to allocate %zu bytes\n", __func__, mem_res_sz);
154 	/*
155 	 * Start by adding the reserved regions, if they overlap
156 	 * with /memory regions, insert_resource later on will take
157 	 * care of it.
158 	 */
159 	for_each_reserved_mem_region(region) {
160 		res = &mem_res[i++];
161 
162 		res->name = "Reserved";
163 		res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
164 		res->start = __pfn_to_phys(memblock_region_reserved_base_pfn(region));
165 		res->end = __pfn_to_phys(memblock_region_reserved_end_pfn(region)) - 1;
166 
167 		ret = add_kernel_resources(res);
168 		if (ret < 0)
169 			goto error;
170 		else if (ret)
171 			continue;
172 
173 		/*
174 		 * Ignore any other reserved regions within
175 		 * system memory.
176 		 */
177 		if (memblock_is_memory(res->start)) {
178 			memblock_free((phys_addr_t) res, sizeof(struct resource));
179 			continue;
180 		}
181 
182 		ret = add_resource(&iomem_resource, res);
183 		if (ret < 0)
184 			goto error;
185 	}
186 
187 	/* Add /memory regions to the resource tree */
188 	for_each_mem_region(region) {
189 		res = &mem_res[i++];
190 
191 		if (unlikely(memblock_is_nomap(region))) {
192 			res->name = "Reserved";
193 			res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
194 		} else {
195 			res->name = "System RAM";
196 			res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
197 		}
198 
199 		res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
200 		res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
201 
202 		ret = add_resource(&iomem_resource, res);
203 		if (ret < 0)
204 			goto error;
205 	}
206 
207 	return;
208 
209  error:
210 	/* Better an empty resource tree than an inconsistent one */
211 	release_child_resources(&iomem_resource);
212 	memblock_free((phys_addr_t) mem_res, mem_res_sz);
213 }
214 
215 
216 static void __init parse_dtb(void)
217 {
218 	/* Early scan of device tree from init memory */
219 	if (early_init_dt_scan(dtb_early_va))
220 		return;
221 
222 	pr_err("No DTB passed to the kernel\n");
223 #ifdef CONFIG_CMDLINE_FORCE
224 	strlcpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
225 	pr_info("Forcing kernel command line to: %s\n", boot_command_line);
226 #endif
227 }
228 
229 void __init setup_arch(char **cmdline_p)
230 {
231 	parse_dtb();
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 	*cmdline_p = boot_command_line;
238 
239 	early_ioremap_setup();
240 	jump_label_init();
241 	parse_early_param();
242 
243 	efi_init();
244 	setup_bootmem();
245 	paging_init();
246 	init_resources();
247 #if IS_ENABLED(CONFIG_BUILTIN_DTB)
248 	unflatten_and_copy_device_tree();
249 #else
250 	if (early_init_dt_verify(__va(dtb_early_pa)))
251 		unflatten_device_tree();
252 	else
253 		pr_err("No DTB found in kernel mappings\n");
254 #endif
255 
256 	if (IS_ENABLED(CONFIG_RISCV_SBI))
257 		sbi_init();
258 
259 	if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
260 		protect_kernel_text_data();
261 #ifdef CONFIG_SWIOTLB
262 	swiotlb_init(1);
263 #endif
264 
265 #ifdef CONFIG_KASAN
266 	kasan_init();
267 #endif
268 
269 #ifdef CONFIG_SMP
270 	setup_smp();
271 #endif
272 
273 	riscv_fill_hwcap();
274 }
275 
276 static int __init topology_init(void)
277 {
278 	int i;
279 
280 	for_each_possible_cpu(i) {
281 		struct cpu *cpu = &per_cpu(cpu_devices, i);
282 
283 		cpu->hotpluggable = cpu_has_hotplug(i);
284 		register_cpu(cpu, i);
285 	}
286 
287 	return 0;
288 }
289 subsys_initcall(topology_init);
290 
291 void free_initmem(void)
292 {
293 	unsigned long init_begin = (unsigned long)__init_begin;
294 	unsigned long init_end = (unsigned long)__init_end;
295 
296 	set_memory_rw_nx(init_begin, (init_end - init_begin) >> PAGE_SHIFT);
297 	free_initmem_default(POISON_FREE_INITMEM);
298 }
299