xref: /linux/arch/riscv/kernel/setup.c (revision 6c8c1406) 
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/smp.h>
21 #include <linux/efi.h>
22 #include <linux/crash_dump.h>
23 
24 #include <asm/alternative.h>
25 #include <asm/cacheflush.h>
26 #include <asm/cpu_ops.h>
27 #include <asm/early_ioremap.h>
28 #include <asm/pgtable.h>
29 #include <asm/setup.h>
30 #include <asm/set_memory.h>
31 #include <asm/sections.h>
32 #include <asm/sbi.h>
33 #include <asm/tlbflush.h>
34 #include <asm/thread_info.h>
35 #include <asm/kasan.h>
36 #include <asm/efi.h>
37 
38 #include "head.h"
39 
40 #if defined(CONFIG_DUMMY_CONSOLE) || defined(CONFIG_EFI)
41 struct screen_info screen_info __section(".data") = {
42 	.orig_video_lines	= 30,
43 	.orig_video_cols	= 80,
44 	.orig_video_mode	= 0,
45 	.orig_video_ega_bx	= 0,
46 	.orig_video_isVGA	= 1,
47 	.orig_video_points	= 8
48 };
49 #endif
50 
51 /*
52  * The lucky hart to first increment this variable will boot the other cores.
53  * This is used before the kernel initializes the BSS so it can't be in the
54  * BSS.
55  */
56 atomic_t hart_lottery __section(".sdata")
57 #ifdef CONFIG_XIP_KERNEL
58 = ATOMIC_INIT(0xC001BEEF)
59 #endif
60 ;
61 unsigned long boot_cpu_hartid;
62 static DEFINE_PER_CPU(struct cpu, cpu_devices);
63 
64 /*
65  * Place kernel memory regions on the resource tree so that
66  * kexec-tools can retrieve them from /proc/iomem. While there
67  * also add "System RAM" regions for compatibility with other
68  * archs, and the rest of the known regions for completeness.
69  */
70 static struct resource kimage_res = { .name = "Kernel image", };
71 static struct resource code_res = { .name = "Kernel code", };
72 static struct resource data_res = { .name = "Kernel data", };
73 static struct resource rodata_res = { .name = "Kernel rodata", };
74 static struct resource bss_res = { .name = "Kernel bss", };
75 #ifdef CONFIG_CRASH_DUMP
76 static struct resource elfcorehdr_res = { .name = "ELF Core hdr", };
77 #endif
78 
79 static int __init add_resource(struct resource *parent,
80 				struct resource *res)
81 {
82 	int ret = 0;
83 
84 	ret = insert_resource(parent, res);
85 	if (ret < 0) {
86 		pr_err("Failed to add a %s resource at %llx\n",
87 			res->name, (unsigned long long) res->start);
88 		return ret;
89 	}
90 
91 	return 1;
92 }
93 
94 static int __init add_kernel_resources(void)
95 {
96 	int ret = 0;
97 
98 	/*
99 	 * The memory region of the kernel image is continuous and
100 	 * was reserved on setup_bootmem, register it here as a
101 	 * resource, with the various segments of the image as
102 	 * child nodes.
103 	 */
104 
105 	code_res.start = __pa_symbol(_text);
106 	code_res.end = __pa_symbol(_etext) - 1;
107 	code_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
108 
109 	rodata_res.start = __pa_symbol(__start_rodata);
110 	rodata_res.end = __pa_symbol(__end_rodata) - 1;
111 	rodata_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
112 
113 	data_res.start = __pa_symbol(_data);
114 	data_res.end = __pa_symbol(_edata) - 1;
115 	data_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
116 
117 	bss_res.start = __pa_symbol(__bss_start);
118 	bss_res.end = __pa_symbol(__bss_stop) - 1;
119 	bss_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
120 
121 	kimage_res.start = code_res.start;
122 	kimage_res.end = bss_res.end;
123 	kimage_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
124 
125 	ret = add_resource(&iomem_resource, &kimage_res);
126 	if (ret < 0)
127 		return ret;
128 
129 	ret = add_resource(&kimage_res, &code_res);
130 	if (ret < 0)
131 		return ret;
132 
133 	ret = add_resource(&kimage_res, &rodata_res);
134 	if (ret < 0)
135 		return ret;
136 
137 	ret = add_resource(&kimage_res, &data_res);
138 	if (ret < 0)
139 		return ret;
140 
141 	ret = add_resource(&kimage_res, &bss_res);
142 
143 	return ret;
144 }
145 
146 static void __init init_resources(void)
147 {
148 	struct memblock_region *region = NULL;
149 	struct resource *res = NULL;
150 	struct resource *mem_res = NULL;
151 	size_t mem_res_sz = 0;
152 	int num_resources = 0, res_idx = 0;
153 	int ret = 0;
154 
155 	/* + 1 as memblock_alloc() might increase memblock.reserved.cnt */
156 	num_resources = memblock.memory.cnt + memblock.reserved.cnt + 1;
157 	res_idx = num_resources - 1;
158 
159 	mem_res_sz = num_resources * sizeof(*mem_res);
160 	mem_res = memblock_alloc(mem_res_sz, SMP_CACHE_BYTES);
161 	if (!mem_res)
162 		panic("%s: Failed to allocate %zu bytes\n", __func__, mem_res_sz);
163 
164 	/*
165 	 * Start by adding the reserved regions, if they overlap
166 	 * with /memory regions, insert_resource later on will take
167 	 * care of it.
168 	 */
169 	ret = add_kernel_resources();
170 	if (ret < 0)
171 		goto error;
172 
173 #ifdef CONFIG_KEXEC_CORE
174 	if (crashk_res.start != crashk_res.end) {
175 		ret = add_resource(&iomem_resource, &crashk_res);
176 		if (ret < 0)
177 			goto error;
178 	}
179 #endif
180 
181 #ifdef CONFIG_CRASH_DUMP
182 	if (elfcorehdr_size > 0) {
183 		elfcorehdr_res.start = elfcorehdr_addr;
184 		elfcorehdr_res.end = elfcorehdr_addr + elfcorehdr_size - 1;
185 		elfcorehdr_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
186 		add_resource(&iomem_resource, &elfcorehdr_res);
187 	}
188 #endif
189 
190 	for_each_reserved_mem_region(region) {
191 		res = &mem_res[res_idx--];
192 
193 		res->name = "Reserved";
194 		res->flags = IORESOURCE_MEM | IORESOURCE_EXCLUSIVE;
195 		res->start = __pfn_to_phys(memblock_region_reserved_base_pfn(region));
196 		res->end = __pfn_to_phys(memblock_region_reserved_end_pfn(region)) - 1;
197 
198 		/*
199 		 * Ignore any other reserved regions within
200 		 * system memory.
201 		 */
202 		if (memblock_is_memory(res->start)) {
203 			/* Re-use this pre-allocated resource */
204 			res_idx++;
205 			continue;
206 		}
207 
208 		ret = add_resource(&iomem_resource, res);
209 		if (ret < 0)
210 			goto error;
211 	}
212 
213 	/* Add /memory regions to the resource tree */
214 	for_each_mem_region(region) {
215 		res = &mem_res[res_idx--];
216 
217 		if (unlikely(memblock_is_nomap(region))) {
218 			res->name = "Reserved";
219 			res->flags = IORESOURCE_MEM | IORESOURCE_EXCLUSIVE;
220 		} else {
221 			res->name = "System RAM";
222 			res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
223 		}
224 
225 		res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
226 		res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
227 
228 		ret = add_resource(&iomem_resource, res);
229 		if (ret < 0)
230 			goto error;
231 	}
232 
233 	/* Clean-up any unused pre-allocated resources */
234 	if (res_idx >= 0)
235 		memblock_free(mem_res, (res_idx + 1) * sizeof(*mem_res));
236 	return;
237 
238  error:
239 	/* Better an empty resource tree than an inconsistent one */
240 	release_child_resources(&iomem_resource);
241 	memblock_free(mem_res, mem_res_sz);
242 }
243 
244 
245 static void __init parse_dtb(void)
246 {
247 	/* Early scan of device tree from init memory */
248 	if (early_init_dt_scan(dtb_early_va)) {
249 		const char *name = of_flat_dt_get_machine_name();
250 
251 		if (name) {
252 			pr_info("Machine model: %s\n", name);
253 			dump_stack_set_arch_desc("%s (DT)", name);
254 		}
255 	} else {
256 		pr_err("No DTB passed to the kernel\n");
257 	}
258 
259 #ifdef CONFIG_CMDLINE_FORCE
260 	strscpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
261 	pr_info("Forcing kernel command line to: %s\n", boot_command_line);
262 #endif
263 }
264 
265 void __init setup_arch(char **cmdline_p)
266 {
267 	parse_dtb();
268 	setup_initial_init_mm(_stext, _etext, _edata, _end);
269 
270 	*cmdline_p = boot_command_line;
271 
272 	early_ioremap_setup();
273 	jump_label_init();
274 	parse_early_param();
275 
276 	efi_init();
277 	paging_init();
278 #if IS_ENABLED(CONFIG_BUILTIN_DTB)
279 	unflatten_and_copy_device_tree();
280 #else
281 	if (early_init_dt_verify(__va(XIP_FIXUP(dtb_early_pa))))
282 		unflatten_device_tree();
283 	else
284 		pr_err("No DTB found in kernel mappings\n");
285 #endif
286 	early_init_fdt_scan_reserved_mem();
287 	misc_mem_init();
288 
289 	init_resources();
290 	sbi_init();
291 
292 #ifdef CONFIG_KASAN
293 	kasan_init();
294 #endif
295 
296 #ifdef CONFIG_SMP
297 	setup_smp();
298 #endif
299 
300 	riscv_init_cbom_blocksize();
301 	riscv_fill_hwcap();
302 	apply_boot_alternatives();
303 }
304 
305 static int __init topology_init(void)
306 {
307 	int i, ret;
308 
309 	for_each_possible_cpu(i) {
310 		struct cpu *cpu = &per_cpu(cpu_devices, i);
311 
312 		cpu->hotpluggable = cpu_has_hotplug(i);
313 		ret = register_cpu(cpu, i);
314 		if (unlikely(ret))
315 			pr_warn("Warning: %s: register_cpu %d failed (%d)\n",
316 			       __func__, i, ret);
317 	}
318 
319 	return 0;
320 }
321 subsys_initcall(topology_init);
322 
323 void free_initmem(void)
324 {
325 	if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
326 		set_kernel_memory(lm_alias(__init_begin), lm_alias(__init_end),
327 				  IS_ENABLED(CONFIG_64BIT) ?
328 					set_memory_rw : set_memory_rw_nx);
329 
330 	free_initmem_default(POISON_FREE_INITMEM);
331 }
332