xref: /openbmc/linux/arch/riscv/kernel/setup.c (revision 05911c5d)
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 #include <linux/crash_dump.h>
24 
25 #include <asm/cpu_ops.h>
26 #include <asm/early_ioremap.h>
27 #include <asm/pgtable.h>
28 #include <asm/setup.h>
29 #include <asm/set_memory.h>
30 #include <asm/sections.h>
31 #include <asm/sbi.h>
32 #include <asm/tlbflush.h>
33 #include <asm/thread_info.h>
34 #include <asm/kasan.h>
35 #include <asm/efi.h>
36 
37 #include "head.h"
38 
39 #if defined(CONFIG_DUMMY_CONSOLE) || defined(CONFIG_EFI)
40 struct screen_info screen_info __section(".data") = {
41 	.orig_video_lines	= 30,
42 	.orig_video_cols	= 80,
43 	.orig_video_mode	= 0,
44 	.orig_video_ega_bx	= 0,
45 	.orig_video_isVGA	= 1,
46 	.orig_video_points	= 8
47 };
48 #endif
49 
50 /*
51  * The lucky hart to first increment this variable will boot the other cores.
52  * This is used before the kernel initializes the BSS so it can't be in the
53  * BSS.
54  */
55 atomic_t hart_lottery __section(".sdata")
56 #ifdef CONFIG_XIP_KERNEL
57 = ATOMIC_INIT(0xC001BEEF)
58 #endif
59 ;
60 unsigned long boot_cpu_hartid;
61 static DEFINE_PER_CPU(struct cpu, cpu_devices);
62 
63 /*
64  * Place kernel memory regions on the resource tree so that
65  * kexec-tools can retrieve them from /proc/iomem. While there
66  * also add "System RAM" regions for compatibility with other
67  * archs, and the rest of the known regions for completeness.
68  */
69 static struct resource kimage_res = { .name = "Kernel image", };
70 static struct resource code_res = { .name = "Kernel code", };
71 static struct resource data_res = { .name = "Kernel data", };
72 static struct resource rodata_res = { .name = "Kernel rodata", };
73 static struct resource bss_res = { .name = "Kernel bss", };
74 #ifdef CONFIG_CRASH_DUMP
75 static struct resource elfcorehdr_res = { .name = "ELF Core hdr", };
76 #endif
77 
78 static int __init add_resource(struct resource *parent,
79 				struct resource *res)
80 {
81 	int ret = 0;
82 
83 	ret = insert_resource(parent, res);
84 	if (ret < 0) {
85 		pr_err("Failed to add a %s resource at %llx\n",
86 			res->name, (unsigned long long) res->start);
87 		return ret;
88 	}
89 
90 	return 1;
91 }
92 
93 static int __init add_kernel_resources(void)
94 {
95 	int ret = 0;
96 
97 	/*
98 	 * The memory region of the kernel image is continuous and
99 	 * was reserved on setup_bootmem, register it here as a
100 	 * resource, with the various segments of the image as
101 	 * child nodes.
102 	 */
103 
104 	code_res.start = __pa_symbol(_text);
105 	code_res.end = __pa_symbol(_etext) - 1;
106 	code_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
107 
108 	rodata_res.start = __pa_symbol(__start_rodata);
109 	rodata_res.end = __pa_symbol(__end_rodata) - 1;
110 	rodata_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
111 
112 	data_res.start = __pa_symbol(_data);
113 	data_res.end = __pa_symbol(_edata) - 1;
114 	data_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
115 
116 	bss_res.start = __pa_symbol(__bss_start);
117 	bss_res.end = __pa_symbol(__bss_stop) - 1;
118 	bss_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
119 
120 	kimage_res.start = code_res.start;
121 	kimage_res.end = bss_res.end;
122 	kimage_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
123 
124 	ret = add_resource(&iomem_resource, &kimage_res);
125 	if (ret < 0)
126 		return ret;
127 
128 	ret = add_resource(&kimage_res, &code_res);
129 	if (ret < 0)
130 		return ret;
131 
132 	ret = add_resource(&kimage_res, &rodata_res);
133 	if (ret < 0)
134 		return ret;
135 
136 	ret = add_resource(&kimage_res, &data_res);
137 	if (ret < 0)
138 		return ret;
139 
140 	ret = add_resource(&kimage_res, &bss_res);
141 
142 	return ret;
143 }
144 
145 static void __init init_resources(void)
146 {
147 	struct memblock_region *region = NULL;
148 	struct resource *res = NULL;
149 	struct resource *mem_res = NULL;
150 	size_t mem_res_sz = 0;
151 	int num_resources = 0, res_idx = 0;
152 	int ret = 0;
153 
154 	/* + 1 as memblock_alloc() might increase memblock.reserved.cnt */
155 	num_resources = memblock.memory.cnt + memblock.reserved.cnt + 1;
156 	res_idx = num_resources - 1;
157 
158 	mem_res_sz = num_resources * sizeof(*mem_res);
159 	mem_res = memblock_alloc(mem_res_sz, SMP_CACHE_BYTES);
160 	if (!mem_res)
161 		panic("%s: Failed to allocate %zu bytes\n", __func__, mem_res_sz);
162 
163 	/*
164 	 * Start by adding the reserved regions, if they overlap
165 	 * with /memory regions, insert_resource later on will take
166 	 * care of it.
167 	 */
168 	ret = add_kernel_resources();
169 	if (ret < 0)
170 		goto error;
171 
172 #ifdef CONFIG_KEXEC_CORE
173 	if (crashk_res.start != crashk_res.end) {
174 		ret = add_resource(&iomem_resource, &crashk_res);
175 		if (ret < 0)
176 			goto error;
177 	}
178 #endif
179 
180 #ifdef CONFIG_CRASH_DUMP
181 	if (elfcorehdr_size > 0) {
182 		elfcorehdr_res.start = elfcorehdr_addr;
183 		elfcorehdr_res.end = elfcorehdr_addr + elfcorehdr_size - 1;
184 		elfcorehdr_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
185 		add_resource(&iomem_resource, &elfcorehdr_res);
186 	}
187 #endif
188 
189 	for_each_reserved_mem_region(region) {
190 		res = &mem_res[res_idx--];
191 
192 		res->name = "Reserved";
193 		res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
194 		res->start = __pfn_to_phys(memblock_region_reserved_base_pfn(region));
195 		res->end = __pfn_to_phys(memblock_region_reserved_end_pfn(region)) - 1;
196 
197 		/*
198 		 * Ignore any other reserved regions within
199 		 * system memory.
200 		 */
201 		if (memblock_is_memory(res->start)) {
202 			/* Re-use this pre-allocated resource */
203 			res_idx++;
204 			continue;
205 		}
206 
207 		ret = add_resource(&iomem_resource, res);
208 		if (ret < 0)
209 			goto error;
210 	}
211 
212 	/* Add /memory regions to the resource tree */
213 	for_each_mem_region(region) {
214 		res = &mem_res[res_idx--];
215 
216 		if (unlikely(memblock_is_nomap(region))) {
217 			res->name = "Reserved";
218 			res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
219 		} else {
220 			res->name = "System RAM";
221 			res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
222 		}
223 
224 		res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
225 		res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
226 
227 		ret = add_resource(&iomem_resource, res);
228 		if (ret < 0)
229 			goto error;
230 	}
231 
232 	/* Clean-up any unused pre-allocated resources */
233 	mem_res_sz = (num_resources - res_idx + 1) * sizeof(*mem_res);
234 	memblock_free(__pa(mem_res), mem_res_sz);
235 	return;
236 
237  error:
238 	/* Better an empty resource tree than an inconsistent one */
239 	release_child_resources(&iomem_resource);
240 	memblock_free(__pa(mem_res), mem_res_sz);
241 }
242 
243 
244 static void __init parse_dtb(void)
245 {
246 	/* Early scan of device tree from init memory */
247 	if (early_init_dt_scan(dtb_early_va)) {
248 		const char *name = of_flat_dt_get_machine_name();
249 
250 		if (name) {
251 			pr_info("Machine model: %s\n", name);
252 			dump_stack_set_arch_desc("%s (DT)", name);
253 		}
254 		return;
255 	}
256 
257 	pr_err("No DTB passed to the kernel\n");
258 #ifdef CONFIG_CMDLINE_FORCE
259 	strlcpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
260 	pr_info("Forcing kernel command line to: %s\n", boot_command_line);
261 #endif
262 }
263 
264 void __init setup_arch(char **cmdline_p)
265 {
266 	parse_dtb();
267 	init_mm.start_code = (unsigned long) _stext;
268 	init_mm.end_code   = (unsigned long) _etext;
269 	init_mm.end_data   = (unsigned long) _edata;
270 	init_mm.brk        = (unsigned long) _end;
271 
272 	*cmdline_p = boot_command_line;
273 
274 	early_ioremap_setup();
275 	jump_label_init();
276 	parse_early_param();
277 
278 	efi_init();
279 	setup_bootmem();
280 	paging_init();
281 #if IS_ENABLED(CONFIG_BUILTIN_DTB)
282 	unflatten_and_copy_device_tree();
283 #else
284 	if (early_init_dt_verify(__va(XIP_FIXUP(dtb_early_pa))))
285 		unflatten_device_tree();
286 	else
287 		pr_err("No DTB found in kernel mappings\n");
288 #endif
289 	misc_mem_init();
290 
291 	init_resources();
292 	sbi_init();
293 
294 	if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) {
295 		protect_kernel_text_data();
296 		protect_kernel_linear_mapping_text_rodata();
297 	}
298 
299 #ifdef CONFIG_SWIOTLB
300 	swiotlb_init(1);
301 #endif
302 
303 #ifdef CONFIG_KASAN
304 	kasan_init();
305 #endif
306 
307 #ifdef CONFIG_SMP
308 	setup_smp();
309 #endif
310 
311 	riscv_fill_hwcap();
312 }
313 
314 static int __init topology_init(void)
315 {
316 	int i, ret;
317 
318 	for_each_online_node(i)
319 		register_one_node(i);
320 
321 	for_each_possible_cpu(i) {
322 		struct cpu *cpu = &per_cpu(cpu_devices, i);
323 
324 		cpu->hotpluggable = cpu_has_hotplug(i);
325 		ret = register_cpu(cpu, i);
326 		if (unlikely(ret))
327 			pr_warn("Warning: %s: register_cpu %d failed (%d)\n",
328 			       __func__, i, ret);
329 	}
330 
331 	return 0;
332 }
333 subsys_initcall(topology_init);
334 
335 void free_initmem(void)
336 {
337 	unsigned long init_begin = (unsigned long)__init_begin;
338 	unsigned long init_end = (unsigned long)__init_end;
339 
340 	if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
341 		set_memory_rw_nx(init_begin, (init_end - init_begin) >> PAGE_SHIFT);
342 
343 	free_initmem_default(POISON_FREE_INITMEM);
344 }
345