xref: /linux/arch/riscv/kernel/setup.c (revision bbcd53c960713507ae764bf81970651b5577b95a)
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 	/* + 1 as memblock_alloc() might increase memblock.reserved.cnt */
151 	mem_res_sz = (memblock.memory.cnt + memblock.reserved.cnt + 1) * sizeof(*mem_res);
152 	mem_res = memblock_alloc(mem_res_sz, SMP_CACHE_BYTES);
153 	if (!mem_res)
154 		panic("%s: Failed to allocate %zu bytes\n", __func__, mem_res_sz);
155 	/*
156 	 * Start by adding the reserved regions, if they overlap
157 	 * with /memory regions, insert_resource later on will take
158 	 * care of it.
159 	 */
160 	for_each_reserved_mem_region(region) {
161 		res = &mem_res[i++];
162 
163 		res->name = "Reserved";
164 		res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
165 		res->start = __pfn_to_phys(memblock_region_reserved_base_pfn(region));
166 		res->end = __pfn_to_phys(memblock_region_reserved_end_pfn(region)) - 1;
167 
168 		ret = add_kernel_resources(res);
169 		if (ret < 0)
170 			goto error;
171 		else if (ret)
172 			continue;
173 
174 		/*
175 		 * Ignore any other reserved regions within
176 		 * system memory.
177 		 */
178 		if (memblock_is_memory(res->start)) {
179 			memblock_free((phys_addr_t) res, sizeof(struct resource));
180 			continue;
181 		}
182 
183 		ret = add_resource(&iomem_resource, res);
184 		if (ret < 0)
185 			goto error;
186 	}
187 
188 	/* Add /memory regions to the resource tree */
189 	for_each_mem_region(region) {
190 		res = &mem_res[i++];
191 
192 		if (unlikely(memblock_is_nomap(region))) {
193 			res->name = "Reserved";
194 			res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
195 		} else {
196 			res->name = "System RAM";
197 			res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
198 		}
199 
200 		res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
201 		res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
202 
203 		ret = add_resource(&iomem_resource, res);
204 		if (ret < 0)
205 			goto error;
206 	}
207 
208 	return;
209 
210  error:
211 	/* Better an empty resource tree than an inconsistent one */
212 	release_child_resources(&iomem_resource);
213 	memblock_free((phys_addr_t) mem_res, mem_res_sz);
214 }
215 
216 
217 static void __init parse_dtb(void)
218 {
219 	/* Early scan of device tree from init memory */
220 	if (early_init_dt_scan(dtb_early_va)) {
221 		const char *name = of_flat_dt_get_machine_name();
222 
223 		if (name) {
224 			pr_info("Machine model: %s\n", name);
225 			dump_stack_set_arch_desc("%s (DT)", name);
226 		}
227 		return;
228 	}
229 
230 	pr_err("No DTB passed to the kernel\n");
231 #ifdef CONFIG_CMDLINE_FORCE
232 	strlcpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
233 	pr_info("Forcing kernel command line to: %s\n", boot_command_line);
234 #endif
235 }
236 
237 void __init setup_arch(char **cmdline_p)
238 {
239 	parse_dtb();
240 	init_mm.start_code = (unsigned long) _stext;
241 	init_mm.end_code   = (unsigned long) _etext;
242 	init_mm.end_data   = (unsigned long) _edata;
243 	init_mm.brk        = (unsigned long) _end;
244 
245 	*cmdline_p = boot_command_line;
246 
247 	early_ioremap_setup();
248 	jump_label_init();
249 	parse_early_param();
250 
251 	efi_init();
252 	setup_bootmem();
253 	paging_init();
254 	init_resources();
255 #if IS_ENABLED(CONFIG_BUILTIN_DTB)
256 	unflatten_and_copy_device_tree();
257 #else
258 	if (early_init_dt_verify(__va(dtb_early_pa)))
259 		unflatten_device_tree();
260 	else
261 		pr_err("No DTB found in kernel mappings\n");
262 #endif
263 	misc_mem_init();
264 
265 	sbi_init();
266 
267 	if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
268 		protect_kernel_text_data();
269 #ifdef CONFIG_SWIOTLB
270 	swiotlb_init(1);
271 #endif
272 
273 #ifdef CONFIG_KASAN
274 	kasan_init();
275 #endif
276 
277 #ifdef CONFIG_SMP
278 	setup_smp();
279 #endif
280 
281 	riscv_fill_hwcap();
282 }
283 
284 static int __init topology_init(void)
285 {
286 	int i, ret;
287 
288 	for_each_online_node(i)
289 		register_one_node(i);
290 
291 	for_each_possible_cpu(i) {
292 		struct cpu *cpu = &per_cpu(cpu_devices, i);
293 
294 		cpu->hotpluggable = cpu_has_hotplug(i);
295 		ret = register_cpu(cpu, i);
296 		if (unlikely(ret))
297 			pr_warn("Warning: %s: register_cpu %d failed (%d)\n",
298 			       __func__, i, ret);
299 	}
300 
301 	return 0;
302 }
303 subsys_initcall(topology_init);
304 
305 void free_initmem(void)
306 {
307 	unsigned long init_begin = (unsigned long)__init_begin;
308 	unsigned long init_end = (unsigned long)__init_end;
309 
310 	if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
311 		set_memory_rw_nx(init_begin, (init_end - init_begin) >> PAGE_SHIFT);
312 
313 	free_initmem_default(POISON_FREE_INITMEM);
314 }
315