xref: /openbmc/linux/arch/riscv/kernel/setup.c (revision 36acd5e2)
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 	int ret = 0;
131 
132 	code_res.start = __pa_symbol(_text);
133 	code_res.end = __pa_symbol(_etext) - 1;
134 	code_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
135 
136 	rodata_res.start = __pa_symbol(__start_rodata);
137 	rodata_res.end = __pa_symbol(__end_rodata) - 1;
138 	rodata_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
139 
140 	data_res.start = __pa_symbol(_data);
141 	data_res.end = __pa_symbol(_edata) - 1;
142 	data_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
143 
144 	bss_res.start = __pa_symbol(__bss_start);
145 	bss_res.end = __pa_symbol(__bss_stop) - 1;
146 	bss_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
147 
148 	/*
149 	 * Start by adding the reserved regions, if they overlap
150 	 * with /memory regions, insert_resource later on will take
151 	 * care of it.
152 	 */
153 	for_each_reserved_mem_region(region) {
154 		res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES);
155 		if (!res)
156 			panic("%s: Failed to allocate %zu bytes\n", __func__,
157 			      sizeof(struct resource));
158 
159 		res->name = "Reserved";
160 		res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
161 		res->start = __pfn_to_phys(memblock_region_reserved_base_pfn(region));
162 		res->end = __pfn_to_phys(memblock_region_reserved_end_pfn(region)) - 1;
163 
164 		ret = add_kernel_resources(res);
165 		if (ret < 0)
166 			goto error;
167 		else if (ret)
168 			continue;
169 
170 		/*
171 		 * Ignore any other reserved regions within
172 		 * system memory.
173 		 */
174 		if (memblock_is_memory(res->start))
175 			continue;
176 
177 		ret = add_resource(&iomem_resource, res);
178 		if (ret < 0)
179 			goto error;
180 	}
181 
182 	/* Add /memory regions to the resource tree */
183 	for_each_mem_region(region) {
184 		res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES);
185 		if (!res)
186 			panic("%s: Failed to allocate %zu bytes\n", __func__,
187 			      sizeof(struct resource));
188 
189 		if (unlikely(memblock_is_nomap(region))) {
190 			res->name = "Reserved";
191 			res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
192 		} else {
193 			res->name = "System RAM";
194 			res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
195 		}
196 
197 		res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
198 		res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
199 
200 		ret = add_resource(&iomem_resource, res);
201 		if (ret < 0)
202 			goto error;
203 	}
204 
205 	return;
206 
207  error:
208 	memblock_free((phys_addr_t) res, sizeof(struct resource));
209 	/* Better an empty resource tree than an inconsistent one */
210 	release_child_resources(&iomem_resource);
211 }
212 
213 
214 static void __init parse_dtb(void)
215 {
216 	/* Early scan of device tree from init memory */
217 	if (early_init_dt_scan(dtb_early_va))
218 		return;
219 
220 	pr_err("No DTB passed to the kernel\n");
221 #ifdef CONFIG_CMDLINE_FORCE
222 	strlcpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
223 	pr_info("Forcing kernel command line to: %s\n", boot_command_line);
224 #endif
225 }
226 
227 void __init setup_arch(char **cmdline_p)
228 {
229 	parse_dtb();
230 	init_mm.start_code = (unsigned long) _stext;
231 	init_mm.end_code   = (unsigned long) _etext;
232 	init_mm.end_data   = (unsigned long) _edata;
233 	init_mm.brk        = (unsigned long) _end;
234 
235 	*cmdline_p = boot_command_line;
236 
237 	early_ioremap_setup();
238 	jump_label_init();
239 	parse_early_param();
240 
241 	efi_init();
242 	setup_bootmem();
243 	paging_init();
244 	init_resources();
245 #if IS_ENABLED(CONFIG_BUILTIN_DTB)
246 	unflatten_and_copy_device_tree();
247 #else
248 	if (early_init_dt_verify(__va(dtb_early_pa)))
249 		unflatten_device_tree();
250 	else
251 		pr_err("No DTB found in kernel mappings\n");
252 #endif
253 
254 	if (IS_ENABLED(CONFIG_RISCV_SBI))
255 		sbi_init();
256 
257 	if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
258 		protect_kernel_text_data();
259 #ifdef CONFIG_SWIOTLB
260 	swiotlb_init(1);
261 #endif
262 
263 #ifdef CONFIG_KASAN
264 	kasan_init();
265 #endif
266 
267 #ifdef CONFIG_SMP
268 	setup_smp();
269 #endif
270 
271 	riscv_fill_hwcap();
272 }
273 
274 static int __init topology_init(void)
275 {
276 	int i;
277 
278 	for_each_possible_cpu(i) {
279 		struct cpu *cpu = &per_cpu(cpu_devices, i);
280 
281 		cpu->hotpluggable = cpu_has_hotplug(i);
282 		register_cpu(cpu, i);
283 	}
284 
285 	return 0;
286 }
287 subsys_initcall(topology_init);
288 
289 void free_initmem(void)
290 {
291 	unsigned long init_begin = (unsigned long)__init_begin;
292 	unsigned long init_end = (unsigned long)__init_end;
293 
294 	set_memory_rw_nx(init_begin, (init_end - init_begin) >> PAGE_SHIFT);
295 	free_initmem_default(POISON_FREE_INITMEM);
296 }
297