xref: /linux/arch/riscv/kernel/setup.c (revision c8b90d40d5bba8e6fba457b8a7c10d3c0d467e37) 
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/acpi.h>
12 #include <linux/cpu.h>
13 #include <linux/init.h>
14 #include <linux/mm.h>
15 #include <linux/memblock.h>
16 #include <linux/sched.h>
17 #include <linux/console.h>
18 #include <linux/of_fdt.h>
19 #include <linux/sched/task.h>
20 #include <linux/smp.h>
21 #include <linux/efi.h>
22 #include <linux/crash_dump.h>
23 #include <linux/panic_notifier.h>
24 
25 #include <asm/acpi.h>
26 #include <asm/alternative.h>
27 #include <asm/cacheflush.h>
28 #include <asm/cpufeature.h>
29 #include <asm/early_ioremap.h>
30 #include <asm/pgtable.h>
31 #include <asm/setup.h>
32 #include <asm/set_memory.h>
33 #include <asm/sections.h>
34 #include <asm/sbi.h>
35 #include <asm/tlbflush.h>
36 #include <asm/thread_info.h>
37 #include <asm/kasan.h>
38 #include <asm/efi.h>
39 
40 #include "head.h"
41 
42 /*
43  * The lucky hart to first increment this variable will boot the other cores.
44  * This is used before the kernel initializes the BSS so it can't be in the
45  * BSS.
46  */
47 atomic_t hart_lottery __section(".sdata")
48 #ifdef CONFIG_XIP_KERNEL
49 = ATOMIC_INIT(0xC001BEEF)
50 #endif
51 ;
52 unsigned long boot_cpu_hartid;
53 
54 /*
55  * Place kernel memory regions on the resource tree so that
56  * kexec-tools can retrieve them from /proc/iomem. While there
57  * also add "System RAM" regions for compatibility with other
58  * archs, and the rest of the known regions for completeness.
59  */
60 static struct resource kimage_res = { .name = "Kernel image", };
61 static struct resource code_res = { .name = "Kernel code", };
62 static struct resource data_res = { .name = "Kernel data", };
63 static struct resource rodata_res = { .name = "Kernel rodata", };
64 static struct resource bss_res = { .name = "Kernel bss", };
65 #ifdef CONFIG_CRASH_DUMP
66 static struct resource elfcorehdr_res = { .name = "ELF Core hdr", };
67 #endif
68 
69 static int __init add_resource(struct resource *parent,
70 				struct resource *res)
71 {
72 	int ret = 0;
73 
74 	ret = insert_resource(parent, res);
75 	if (ret < 0) {
76 		pr_err("Failed to add a %s resource at %llx\n",
77 			res->name, (unsigned long long) res->start);
78 		return ret;
79 	}
80 
81 	return 1;
82 }
83 
84 static int __init add_kernel_resources(void)
85 {
86 	int ret = 0;
87 
88 	/*
89 	 * The memory region of the kernel image is continuous and
90 	 * was reserved on setup_bootmem, register it here as a
91 	 * resource, with the various segments of the image as
92 	 * child nodes.
93 	 */
94 
95 	code_res.start = __pa_symbol(_text);
96 	code_res.end = __pa_symbol(_etext) - 1;
97 	code_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
98 
99 	rodata_res.start = __pa_symbol(__start_rodata);
100 	rodata_res.end = __pa_symbol(__end_rodata) - 1;
101 	rodata_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
102 
103 	data_res.start = __pa_symbol(_data);
104 	data_res.end = __pa_symbol(_edata) - 1;
105 	data_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
106 
107 	bss_res.start = __pa_symbol(__bss_start);
108 	bss_res.end = __pa_symbol(__bss_stop) - 1;
109 	bss_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
110 
111 	kimage_res.start = code_res.start;
112 	kimage_res.end = bss_res.end;
113 	kimage_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
114 
115 	ret = add_resource(&iomem_resource, &kimage_res);
116 	if (ret < 0)
117 		return ret;
118 
119 	ret = add_resource(&kimage_res, &code_res);
120 	if (ret < 0)
121 		return ret;
122 
123 	ret = add_resource(&kimage_res, &rodata_res);
124 	if (ret < 0)
125 		return ret;
126 
127 	ret = add_resource(&kimage_res, &data_res);
128 	if (ret < 0)
129 		return ret;
130 
131 	ret = add_resource(&kimage_res, &bss_res);
132 
133 	return ret;
134 }
135 
136 static void __init init_resources(void)
137 {
138 	struct memblock_region *region = NULL;
139 	struct resource *res = NULL;
140 	struct resource *mem_res = NULL;
141 	size_t mem_res_sz = 0;
142 	int num_resources = 0, res_idx = 0;
143 	int ret = 0;
144 
145 	/* + 1 as memblock_alloc() might increase memblock.reserved.cnt */
146 	num_resources = memblock.memory.cnt + memblock.reserved.cnt + 1;
147 	res_idx = num_resources - 1;
148 
149 	mem_res_sz = num_resources * sizeof(*mem_res);
150 	mem_res = memblock_alloc(mem_res_sz, SMP_CACHE_BYTES);
151 	if (!mem_res)
152 		panic("%s: Failed to allocate %zu bytes\n", __func__, mem_res_sz);
153 
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 	ret = add_kernel_resources();
160 	if (ret < 0)
161 		goto error;
162 
163 #ifdef CONFIG_CRASH_DUMP
164 	if (elfcorehdr_size > 0) {
165 		elfcorehdr_res.start = elfcorehdr_addr;
166 		elfcorehdr_res.end = elfcorehdr_addr + elfcorehdr_size - 1;
167 		elfcorehdr_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
168 		add_resource(&iomem_resource, &elfcorehdr_res);
169 	}
170 #endif
171 
172 	for_each_reserved_mem_region(region) {
173 		res = &mem_res[res_idx--];
174 
175 		res->name = "Reserved";
176 		res->flags = IORESOURCE_MEM | IORESOURCE_EXCLUSIVE;
177 		res->start = __pfn_to_phys(memblock_region_reserved_base_pfn(region));
178 		res->end = __pfn_to_phys(memblock_region_reserved_end_pfn(region)) - 1;
179 
180 		/*
181 		 * Ignore any other reserved regions within
182 		 * system memory.
183 		 */
184 		if (memblock_is_memory(res->start)) {
185 			/* Re-use this pre-allocated resource */
186 			res_idx++;
187 			continue;
188 		}
189 
190 		ret = add_resource(&iomem_resource, res);
191 		if (ret < 0)
192 			goto error;
193 	}
194 
195 	/* Add /memory regions to the resource tree */
196 	for_each_mem_region(region) {
197 		res = &mem_res[res_idx--];
198 
199 		if (unlikely(memblock_is_nomap(region))) {
200 			res->name = "Reserved";
201 			res->flags = IORESOURCE_MEM | IORESOURCE_EXCLUSIVE;
202 		} else {
203 			res->name = "System RAM";
204 			res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
205 		}
206 
207 		res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
208 		res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
209 
210 		ret = add_resource(&iomem_resource, res);
211 		if (ret < 0)
212 			goto error;
213 	}
214 
215 	/* Clean-up any unused pre-allocated resources */
216 	if (res_idx >= 0)
217 		memblock_free(mem_res, (res_idx + 1) * sizeof(*mem_res));
218 	return;
219 
220  error:
221 	/* Better an empty resource tree than an inconsistent one */
222 	release_child_resources(&iomem_resource);
223 	memblock_free(mem_res, mem_res_sz);
224 }
225 
226 
227 static void __init parse_dtb(void)
228 {
229 	/* Early scan of device tree from init memory */
230 	if (early_init_dt_scan(dtb_early_va, __pa(dtb_early_va))) {
231 		const char *name = of_flat_dt_get_machine_name();
232 
233 		if (name) {
234 			pr_info("Machine model: %s\n", name);
235 			dump_stack_set_arch_desc("%s (DT)", name);
236 		}
237 	} else {
238 		pr_err("No DTB passed to the kernel\n");
239 	}
240 
241 #ifdef CONFIG_CMDLINE_FORCE
242 	strscpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
243 	pr_info("Forcing kernel command line to: %s\n", boot_command_line);
244 #endif
245 }
246 
247 #if defined(CONFIG_RISCV_COMBO_SPINLOCKS)
248 DEFINE_STATIC_KEY_TRUE(qspinlock_key);
249 EXPORT_SYMBOL(qspinlock_key);
250 #endif
251 
252 static void __init riscv_spinlock_init(void)
253 {
254 	char *using_ext = NULL;
255 
256 	if (IS_ENABLED(CONFIG_RISCV_TICKET_SPINLOCKS)) {
257 		pr_info("Ticket spinlock: enabled\n");
258 		return;
259 	}
260 
261 	if (IS_ENABLED(CONFIG_RISCV_ISA_ZABHA) &&
262 	    IS_ENABLED(CONFIG_RISCV_ISA_ZACAS) &&
263 	    riscv_isa_extension_available(NULL, ZABHA) &&
264 	    riscv_isa_extension_available(NULL, ZACAS)) {
265 		using_ext = "using Zabha";
266 	} else if (riscv_isa_extension_available(NULL, ZICCRSE)) {
267 		using_ext = "using Ziccrse";
268 	}
269 #if defined(CONFIG_RISCV_COMBO_SPINLOCKS)
270 	else {
271 		static_branch_disable(&qspinlock_key);
272 		pr_info("Ticket spinlock: enabled\n");
273 		return;
274 	}
275 #endif
276 
277 	if (!using_ext)
278 		pr_err("Queued spinlock without Zabha or Ziccrse");
279 	else
280 		pr_info("Queued spinlock %s: enabled\n", using_ext);
281 }
282 
283 extern void __init init_rt_signal_env(void);
284 
285 void __init setup_arch(char **cmdline_p)
286 {
287 	parse_dtb();
288 	setup_initial_init_mm(_stext, _etext, _edata, _end);
289 
290 	*cmdline_p = boot_command_line;
291 
292 	early_ioremap_setup();
293 	sbi_init();
294 	jump_label_init();
295 	parse_early_param();
296 
297 	efi_init();
298 	paging_init();
299 
300 	/* Parse the ACPI tables for possible boot-time configuration */
301 	acpi_boot_table_init();
302 
303 #if IS_ENABLED(CONFIG_BUILTIN_DTB)
304 	unflatten_and_copy_device_tree();
305 #else
306 	unflatten_device_tree();
307 #endif
308 	misc_mem_init();
309 
310 	init_resources();
311 
312 #ifdef CONFIG_KASAN
313 	kasan_init();
314 #endif
315 
316 #ifdef CONFIG_SMP
317 	setup_smp();
318 #endif
319 
320 	if (!acpi_disabled) {
321 		acpi_init_rintc_map();
322 		acpi_map_cpus_to_nodes();
323 	}
324 
325 	riscv_init_cbo_blocksizes();
326 	riscv_fill_hwcap();
327 	init_rt_signal_env();
328 	apply_boot_alternatives();
329 
330 	if (IS_ENABLED(CONFIG_RISCV_ISA_ZICBOM) &&
331 	    riscv_isa_extension_available(NULL, ZICBOM))
332 		riscv_noncoherent_supported();
333 	riscv_set_dma_cache_alignment();
334 
335 	riscv_user_isa_enable();
336 	riscv_spinlock_init();
337 }
338 
339 bool arch_cpu_is_hotpluggable(int cpu)
340 {
341 	return cpu_has_hotplug(cpu);
342 }
343 
344 void free_initmem(void)
345 {
346 	if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) {
347 		set_kernel_memory(lm_alias(__init_begin), lm_alias(__init_end), set_memory_rw_nx);
348 		if (IS_ENABLED(CONFIG_64BIT))
349 			set_kernel_memory(__init_begin, __init_end, set_memory_nx);
350 	}
351 
352 	free_initmem_default(POISON_FREE_INITMEM);
353 }
354 
355 static int dump_kernel_offset(struct notifier_block *self,
356 			      unsigned long v, void *p)
357 {
358 	pr_emerg("Kernel Offset: 0x%lx from 0x%lx\n",
359 		 kernel_map.virt_offset,
360 		 KERNEL_LINK_ADDR);
361 
362 	return 0;
363 }
364 
365 static struct notifier_block kernel_offset_notifier = {
366 	.notifier_call = dump_kernel_offset
367 };
368 
369 static int __init register_kernel_offset_dumper(void)
370 {
371 	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE))
372 		atomic_notifier_chain_register(&panic_notifier_list,
373 					       &kernel_offset_notifier);
374 
375 	return 0;
376 }
377 device_initcall(register_kernel_offset_dumper);
378