xref: /linux/arch/riscv/kernel/setup.c (revision af2d6148d2a159e1a0862bce5a2c88c1618a2b27) 
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 EXPORT_SYMBOL_GPL(boot_cpu_hartid);
54 
55 /*
56  * Place kernel memory regions on the resource tree so that
57  * kexec-tools can retrieve them from /proc/iomem. While there
58  * also add "System RAM" regions for compatibility with other
59  * archs, and the rest of the known regions for completeness.
60  */
61 static struct resource kimage_res = { .name = "Kernel image", };
62 static struct resource code_res = { .name = "Kernel code", };
63 static struct resource data_res = { .name = "Kernel data", };
64 static struct resource rodata_res = { .name = "Kernel rodata", };
65 static struct resource bss_res = { .name = "Kernel bss", };
66 #ifdef CONFIG_CRASH_DUMP
67 static struct resource elfcorehdr_res = { .name = "ELF Core hdr", };
68 #endif
69 
70 static int num_standard_resources;
71 static struct resource *standard_resources;
72 
73 static int __init add_resource(struct resource *parent,
74 				struct resource *res)
75 {
76 	int ret = 0;
77 
78 	ret = insert_resource(parent, res);
79 	if (ret < 0) {
80 		pr_err("Failed to add a %s resource at %llx\n",
81 			res->name, (unsigned long long) res->start);
82 		return ret;
83 	}
84 
85 	return 1;
86 }
87 
88 static int __init add_kernel_resources(void)
89 {
90 	int ret = 0;
91 
92 	/*
93 	 * The memory region of the kernel image is continuous and
94 	 * was reserved on setup_bootmem, register it here as a
95 	 * resource, with the various segments of the image as
96 	 * child nodes.
97 	 */
98 
99 	code_res.start = __pa_symbol(_text);
100 	code_res.end = __pa_symbol(_etext) - 1;
101 	code_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
102 
103 	rodata_res.start = __pa_symbol(__start_rodata);
104 	rodata_res.end = __pa_symbol(__end_rodata) - 1;
105 	rodata_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
106 
107 	data_res.start = __pa_symbol(_data);
108 	data_res.end = __pa_symbol(_edata) - 1;
109 	data_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
110 
111 	bss_res.start = __pa_symbol(__bss_start);
112 	bss_res.end = __pa_symbol(__bss_stop) - 1;
113 	bss_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
114 
115 	kimage_res.start = code_res.start;
116 	kimage_res.end = bss_res.end;
117 	kimage_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
118 
119 	ret = add_resource(&iomem_resource, &kimage_res);
120 	if (ret < 0)
121 		return ret;
122 
123 	ret = add_resource(&kimage_res, &code_res);
124 	if (ret < 0)
125 		return ret;
126 
127 	ret = add_resource(&kimage_res, &rodata_res);
128 	if (ret < 0)
129 		return ret;
130 
131 	ret = add_resource(&kimage_res, &data_res);
132 	if (ret < 0)
133 		return ret;
134 
135 	ret = add_resource(&kimage_res, &bss_res);
136 
137 	return ret;
138 }
139 
140 static void __init init_resources(void)
141 {
142 	struct memblock_region *region = NULL;
143 	struct resource *res = NULL;
144 	struct resource *mem_res = NULL;
145 	size_t mem_res_sz = 0;
146 	int num_resources = 0, res_idx = 0, non_resv_res = 0;
147 	int ret = 0;
148 
149 	/* + 1 as memblock_alloc() might increase memblock.reserved.cnt */
150 	num_resources = memblock.memory.cnt + memblock.reserved.cnt + 1;
151 	res_idx = num_resources - 1;
152 
153 	mem_res_sz = num_resources * sizeof(*mem_res);
154 	mem_res = memblock_alloc_or_panic(mem_res_sz, SMP_CACHE_BYTES);
155 
156 	/*
157 	 * Start by adding the reserved regions, if they overlap
158 	 * with /memory regions, insert_resource later on will take
159 	 * care of it.
160 	 */
161 	ret = add_kernel_resources();
162 	if (ret < 0)
163 		goto error;
164 
165 #ifdef CONFIG_CRASH_DUMP
166 	if (elfcorehdr_size > 0) {
167 		elfcorehdr_res.start = elfcorehdr_addr;
168 		elfcorehdr_res.end = elfcorehdr_addr + elfcorehdr_size - 1;
169 		elfcorehdr_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
170 		add_resource(&iomem_resource, &elfcorehdr_res);
171 	}
172 #endif
173 
174 	for_each_reserved_mem_region(region) {
175 		res = &mem_res[res_idx--];
176 
177 		res->name = "Reserved";
178 		res->flags = IORESOURCE_MEM | IORESOURCE_EXCLUSIVE;
179 		res->start = __pfn_to_phys(memblock_region_reserved_base_pfn(region));
180 		res->end = __pfn_to_phys(memblock_region_reserved_end_pfn(region)) - 1;
181 
182 		/*
183 		 * Ignore any other reserved regions within
184 		 * system memory.
185 		 */
186 		if (memblock_is_memory(res->start)) {
187 			/* Re-use this pre-allocated resource */
188 			res_idx++;
189 			continue;
190 		}
191 
192 		ret = add_resource(&iomem_resource, res);
193 		if (ret < 0)
194 			goto error;
195 	}
196 
197 	/* Add /memory regions to the resource tree */
198 	for_each_mem_region(region) {
199 		res = &mem_res[res_idx--];
200 		non_resv_res++;
201 
202 		if (unlikely(memblock_is_nomap(region))) {
203 			res->name = "Reserved";
204 			res->flags = IORESOURCE_MEM | IORESOURCE_EXCLUSIVE;
205 		} else {
206 			res->name = "System RAM";
207 			res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
208 		}
209 
210 		res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
211 		res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
212 
213 		ret = add_resource(&iomem_resource, res);
214 		if (ret < 0)
215 			goto error;
216 	}
217 
218 	num_standard_resources = non_resv_res;
219 	standard_resources = &mem_res[res_idx + 1];
220 
221 	/* Clean-up any unused pre-allocated resources */
222 	if (res_idx >= 0)
223 		memblock_free(mem_res, (res_idx + 1) * sizeof(*mem_res));
224 	return;
225 
226  error:
227 	/* Better an empty resource tree than an inconsistent one */
228 	release_child_resources(&iomem_resource);
229 	memblock_free(mem_res, mem_res_sz);
230 }
231 
232 static int __init reserve_memblock_reserved_regions(void)
233 {
234 	u64 i, j;
235 
236 	for (i = 0; i < num_standard_resources; i++) {
237 		struct resource *mem = &standard_resources[i];
238 		phys_addr_t r_start, r_end, mem_size = resource_size(mem);
239 
240 		if (!memblock_is_region_reserved(mem->start, mem_size))
241 			continue;
242 
243 		for_each_reserved_mem_range(j, &r_start, &r_end) {
244 			resource_size_t start, end;
245 
246 			start = max(PFN_PHYS(PFN_DOWN(r_start)), mem->start);
247 			end = min(PFN_PHYS(PFN_UP(r_end)) - 1, mem->end);
248 
249 			if (start > mem->end || end < mem->start)
250 				continue;
251 
252 			reserve_region_with_split(mem, start, end, "Reserved");
253 		}
254 	}
255 
256 	return 0;
257 }
258 arch_initcall(reserve_memblock_reserved_regions);
259 
260 static void __init parse_dtb(void)
261 {
262 	/* Early scan of device tree from init memory */
263 	if (early_init_dt_scan(dtb_early_va, dtb_early_pa)) {
264 		const char *name = of_flat_dt_get_machine_name();
265 
266 		if (name) {
267 			pr_info("Machine model: %s\n", name);
268 			dump_stack_set_arch_desc("%s (DT)", name);
269 		}
270 	} else {
271 		pr_err("No DTB passed to the kernel\n");
272 	}
273 }
274 
275 #if defined(CONFIG_RISCV_COMBO_SPINLOCKS)
276 DEFINE_STATIC_KEY_TRUE(qspinlock_key);
277 EXPORT_SYMBOL(qspinlock_key);
278 #endif
279 
280 static void __init riscv_spinlock_init(void)
281 {
282 	char *using_ext = NULL;
283 
284 	if (IS_ENABLED(CONFIG_RISCV_TICKET_SPINLOCKS)) {
285 		pr_info("Ticket spinlock: enabled\n");
286 		return;
287 	}
288 
289 	if (IS_ENABLED(CONFIG_RISCV_ISA_ZABHA) &&
290 	    IS_ENABLED(CONFIG_RISCV_ISA_ZACAS) &&
291 	    riscv_isa_extension_available(NULL, ZABHA) &&
292 	    riscv_isa_extension_available(NULL, ZACAS)) {
293 		using_ext = "using Zabha";
294 	} else if (riscv_isa_extension_available(NULL, ZICCRSE)) {
295 		using_ext = "using Ziccrse";
296 	}
297 #if defined(CONFIG_RISCV_COMBO_SPINLOCKS)
298 	else {
299 		static_branch_disable(&qspinlock_key);
300 		pr_info("Ticket spinlock: enabled\n");
301 		return;
302 	}
303 #endif
304 
305 	if (!using_ext)
306 		pr_err("Queued spinlock without Zabha or Ziccrse");
307 	else
308 		pr_info("Queued spinlock %s: enabled\n", using_ext);
309 }
310 
311 extern void __init init_rt_signal_env(void);
312 
313 void __init setup_arch(char **cmdline_p)
314 {
315 	parse_dtb();
316 	setup_initial_init_mm(_stext, _etext, _edata, _end);
317 
318 	*cmdline_p = boot_command_line;
319 
320 	early_ioremap_setup();
321 	sbi_init();
322 	jump_label_init();
323 	parse_early_param();
324 
325 	efi_init();
326 	paging_init();
327 
328 	/* Parse the ACPI tables for possible boot-time configuration */
329 	acpi_boot_table_init();
330 
331 #if IS_ENABLED(CONFIG_BUILTIN_DTB)
332 	unflatten_and_copy_device_tree();
333 #else
334 	unflatten_device_tree();
335 #endif
336 	misc_mem_init();
337 
338 	init_resources();
339 
340 #ifdef CONFIG_KASAN
341 	kasan_init();
342 #endif
343 
344 #ifdef CONFIG_SMP
345 	setup_smp();
346 #endif
347 
348 	if (!acpi_disabled) {
349 		acpi_init_rintc_map();
350 		acpi_map_cpus_to_nodes();
351 	}
352 
353 	riscv_init_cbo_blocksizes();
354 	riscv_fill_hwcap();
355 	apply_boot_alternatives();
356 	init_rt_signal_env();
357 
358 	if (IS_ENABLED(CONFIG_RISCV_ISA_ZICBOM) &&
359 	    riscv_isa_extension_available(NULL, ZICBOM))
360 		riscv_noncoherent_supported();
361 	riscv_set_dma_cache_alignment();
362 
363 	riscv_user_isa_enable();
364 	riscv_spinlock_init();
365 }
366 
367 bool arch_cpu_is_hotpluggable(int cpu)
368 {
369 	return cpu_has_hotplug(cpu);
370 }
371 
372 void free_initmem(void)
373 {
374 	if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) {
375 		set_kernel_memory(lm_alias(__init_begin), lm_alias(__init_end), set_memory_rw_nx);
376 		if (IS_ENABLED(CONFIG_64BIT))
377 			set_kernel_memory(__init_begin, __init_end, set_memory_nx);
378 	}
379 
380 	free_initmem_default(POISON_FREE_INITMEM);
381 }
382 
383 static int dump_kernel_offset(struct notifier_block *self,
384 			      unsigned long v, void *p)
385 {
386 	pr_emerg("Kernel Offset: 0x%lx from 0x%lx\n",
387 		 kernel_map.virt_offset,
388 		 KERNEL_LINK_ADDR);
389 
390 	return 0;
391 }
392 
393 static struct notifier_block kernel_offset_notifier = {
394 	.notifier_call = dump_kernel_offset
395 };
396 
397 static int __init register_kernel_offset_dumper(void)
398 {
399 	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE))
400 		atomic_notifier_chain_register(&panic_notifier_list,
401 					       &kernel_offset_notifier);
402 
403 	return 0;
404 }
405 device_initcall(register_kernel_offset_dumper);
406