xref: /linux/arch/riscv/kernel/setup.c (revision 7a5f1cd22d47f8ca4b760b6334378ae42c1bd24b) 
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 #include <linux/jump_label.h>
25 #include <linux/gcd.h>
26 
27 #include <asm/acpi.h>
28 #include <asm/alternative.h>
29 #include <asm/cacheflush.h>
30 #include <asm/cpufeature.h>
31 #include <asm/early_ioremap.h>
32 #include <asm/pgtable.h>
33 #include <asm/setup.h>
34 #include <asm/set_memory.h>
35 #include <asm/sections.h>
36 #include <asm/sbi.h>
37 #include <asm/tlbflush.h>
38 #include <asm/thread_info.h>
39 #include <asm/kasan.h>
40 #include <asm/efi.h>
41 
42 #include "head.h"
43 
44 /*
45  * The lucky hart to first increment this variable will boot the other cores.
46  * This is used before the kernel initializes the BSS so it can't be in the
47  * BSS.
48  */
49 atomic_t hart_lottery __section(".sdata");
50 unsigned long boot_cpu_hartid;
51 EXPORT_SYMBOL_GPL(boot_cpu_hartid);
52 
53 /*
54  * Place kernel memory regions on the resource tree so that
55  * kexec-tools can retrieve them from /proc/iomem. While there
56  * also add "System RAM" regions for compatibility with other
57  * archs, and the rest of the known regions for completeness.
58  */
59 static struct resource kimage_res = { .name = "Kernel image", };
60 static struct resource code_res = { .name = "Kernel code", };
61 static struct resource data_res = { .name = "Kernel data", };
62 static struct resource rodata_res = { .name = "Kernel rodata", };
63 static struct resource bss_res = { .name = "Kernel bss", };
64 #ifdef CONFIG_CRASH_DUMP
65 static struct resource elfcorehdr_res = { .name = "ELF Core hdr", };
66 #endif
67 
68 static int num_standard_resources;
69 static struct resource *standard_resources;
70 
71 static int __init add_resource(struct resource *parent,
72 				struct resource *res)
73 {
74 	int ret = 0;
75 
76 	ret = insert_resource(parent, res);
77 	if (ret < 0) {
78 		pr_err("Failed to add a %s resource at %llx\n",
79 			res->name, (unsigned long long) res->start);
80 		return ret;
81 	}
82 
83 	return 1;
84 }
85 
86 static int __init add_kernel_resources(void)
87 {
88 	int ret = 0;
89 
90 	/*
91 	 * The memory region of the kernel image is continuous and
92 	 * was reserved on setup_bootmem, register it here as a
93 	 * resource, with the various segments of the image as
94 	 * child nodes.
95 	 */
96 
97 	code_res.start = __pa_symbol(_text);
98 	code_res.end = __pa_symbol(_etext) - 1;
99 	code_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
100 
101 	rodata_res.start = __pa_symbol(__start_rodata);
102 	rodata_res.end = __pa_symbol(__end_rodata) - 1;
103 	rodata_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
104 
105 	data_res.start = __pa_symbol(_data);
106 	data_res.end = __pa_symbol(_edata) - 1;
107 	data_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
108 
109 	bss_res.start = __pa_symbol(__bss_start);
110 	bss_res.end = __pa_symbol(__bss_stop) - 1;
111 	bss_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
112 
113 	kimage_res.start = code_res.start;
114 	kimage_res.end = bss_res.end;
115 	kimage_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
116 
117 	ret = add_resource(&iomem_resource, &kimage_res);
118 	if (ret < 0)
119 		return ret;
120 
121 	ret = add_resource(&kimage_res, &code_res);
122 	if (ret < 0)
123 		return ret;
124 
125 	ret = add_resource(&kimage_res, &rodata_res);
126 	if (ret < 0)
127 		return ret;
128 
129 	ret = add_resource(&kimage_res, &data_res);
130 	if (ret < 0)
131 		return ret;
132 
133 	ret = add_resource(&kimage_res, &bss_res);
134 
135 	return ret;
136 }
137 
138 static void __init init_resources(void)
139 {
140 	struct memblock_region *region = NULL;
141 	struct resource *res = NULL;
142 	struct resource *mem_res = NULL;
143 	size_t mem_res_sz = 0;
144 	int num_resources = 0, res_idx = 0, non_resv_res = 0;
145 	int ret = 0;
146 
147 	/* + 1 as memblock_alloc() might increase memblock.reserved.cnt */
148 	num_resources = memblock.memory.cnt + memblock.reserved.cnt + 1;
149 	res_idx = num_resources - 1;
150 
151 	mem_res_sz = num_resources * sizeof(*mem_res);
152 	mem_res = memblock_alloc_or_panic(mem_res_sz, SMP_CACHE_BYTES);
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 		non_resv_res++;
199 
200 		if (unlikely(memblock_is_nomap(region))) {
201 			res->name = "Reserved";
202 			res->flags = IORESOURCE_MEM | IORESOURCE_EXCLUSIVE;
203 		} else {
204 			res->name = "System RAM";
205 			res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
206 		}
207 
208 		res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
209 		res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
210 
211 		ret = add_resource(&iomem_resource, res);
212 		if (ret < 0)
213 			goto error;
214 	}
215 
216 	num_standard_resources = non_resv_res;
217 	standard_resources = &mem_res[res_idx + 1];
218 
219 	/* Clean-up any unused pre-allocated resources */
220 	if (res_idx >= 0)
221 		memblock_free(mem_res, (res_idx + 1) * sizeof(*mem_res));
222 	return;
223 
224  error:
225 	/* Better an empty resource tree than an inconsistent one */
226 	release_child_resources(&iomem_resource);
227 	memblock_free(mem_res, mem_res_sz);
228 }
229 
230 static int __init reserve_memblock_reserved_regions(void)
231 {
232 	u64 i, j;
233 
234 	for (i = 0; i < num_standard_resources; i++) {
235 		struct resource *mem = &standard_resources[i];
236 		phys_addr_t r_start, r_end, mem_size = resource_size(mem);
237 
238 		if (!memblock_is_region_reserved(mem->start, mem_size))
239 			continue;
240 
241 		for_each_reserved_mem_range(j, &r_start, &r_end) {
242 			resource_size_t start, end;
243 
244 			start = max(PFN_PHYS(PFN_DOWN(r_start)), mem->start);
245 			end = min(PFN_PHYS(PFN_UP(r_end)) - 1, mem->end);
246 
247 			if (start > mem->end || end < mem->start)
248 				continue;
249 
250 			reserve_region_with_split(mem, start, end, "Reserved");
251 		}
252 	}
253 
254 	return 0;
255 }
256 arch_initcall(reserve_memblock_reserved_regions);
257 
258 static void __init parse_dtb(void)
259 {
260 	/* Early scan of device tree from init memory */
261 	if (early_init_dt_scan(dtb_early_va, dtb_early_pa)) {
262 		const char *name = of_flat_dt_get_machine_name();
263 
264 		if (name) {
265 			pr_info("Machine model: %s\n", name);
266 			dump_stack_set_arch_desc("%s (DT)", name);
267 		}
268 	} else {
269 		pr_err("No DTB passed to the kernel\n");
270 	}
271 }
272 
273 #if defined(CONFIG_RISCV_COMBO_SPINLOCKS)
274 DEFINE_STATIC_KEY_TRUE(qspinlock_key);
275 EXPORT_SYMBOL(qspinlock_key);
276 #endif
277 
278 static void __init riscv_spinlock_init(void)
279 {
280 	char *using_ext = NULL;
281 
282 	if (IS_ENABLED(CONFIG_RISCV_TICKET_SPINLOCKS)) {
283 		pr_info("Ticket spinlock: enabled\n");
284 		return;
285 	}
286 
287 	if (IS_ENABLED(CONFIG_RISCV_ISA_ZABHA) &&
288 	    IS_ENABLED(CONFIG_RISCV_ISA_ZACAS) &&
289 	    IS_ENABLED(CONFIG_TOOLCHAIN_HAS_ZACAS) &&
290 	    riscv_isa_extension_available(NULL, ZABHA) &&
291 	    riscv_isa_extension_available(NULL, ZACAS)) {
292 		using_ext = "using Zabha";
293 	} else if (riscv_isa_extension_available(NULL, ZICCRSE)) {
294 		using_ext = "using Ziccrse";
295 	}
296 #if defined(CONFIG_RISCV_COMBO_SPINLOCKS)
297 	else {
298 		static_branch_disable(&qspinlock_key);
299 		pr_info("Ticket spinlock: enabled\n");
300 		return;
301 	}
302 #endif
303 
304 	if (!using_ext)
305 		pr_err("Queued spinlock without Zabha or Ziccrse");
306 	else
307 		pr_info("Queued spinlock %s: enabled\n", using_ext);
308 }
309 
310 extern void __init init_rt_signal_env(void);
311 
312 void __init setup_arch(char **cmdline_p)
313 {
314 	parse_dtb();
315 	setup_initial_init_mm(_stext, _etext, _edata, _end);
316 
317 	*cmdline_p = boot_command_line;
318 
319 	early_ioremap_setup();
320 	sbi_init();
321 	jump_label_init();
322 	parse_early_param();
323 
324 	efi_init();
325 	paging_init();
326 
327 	/* Parse the ACPI tables for possible boot-time configuration */
328 	acpi_boot_table_init();
329 
330 	if (acpi_disabled) {
331 #if IS_ENABLED(CONFIG_BUILTIN_DTB)
332 		unflatten_and_copy_device_tree();
333 #else
334 		unflatten_device_tree();
335 #endif
336 	}
337 
338 	misc_mem_init();
339 
340 	init_resources();
341 
342 #ifdef CONFIG_KASAN
343 	kasan_init();
344 #endif
345 
346 #ifdef CONFIG_SMP
347 	setup_smp();
348 #endif
349 
350 	if (!acpi_disabled) {
351 		acpi_init_rintc_map();
352 		acpi_map_cpus_to_nodes();
353 	}
354 
355 	riscv_init_cbo_blocksizes();
356 	riscv_fill_hwcap();
357 	apply_boot_alternatives();
358 	init_rt_signal_env();
359 
360 	if (IS_ENABLED(CONFIG_RISCV_ISA_ZICBOM) &&
361 	    riscv_isa_extension_available(NULL, ZICBOM))
362 		riscv_noncoherent_supported();
363 	riscv_set_dma_cache_alignment();
364 
365 	riscv_user_isa_enable();
366 	riscv_spinlock_init();
367 
368 	if (!IS_ENABLED(CONFIG_RISCV_ISA_ZBB) || !riscv_isa_extension_available(NULL, ZBB))
369 		static_branch_disable(&efficient_ffs_key);
370 }
371 
372 bool arch_cpu_is_hotpluggable(int cpu)
373 {
374 	return cpu_has_hotplug(cpu);
375 }
376 
377 void free_initmem(void)
378 {
379 	if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) {
380 		set_kernel_memory(lm_alias(__init_begin), lm_alias(__init_end), set_memory_rw_nx);
381 		if (IS_ENABLED(CONFIG_64BIT))
382 			set_kernel_memory(__init_begin, __init_end, set_memory_nx);
383 	}
384 
385 	free_initmem_default(POISON_FREE_INITMEM);
386 }
387 
388 static int dump_kernel_offset(struct notifier_block *self,
389 			      unsigned long v, void *p)
390 {
391 	pr_emerg("Kernel Offset: 0x%lx from 0x%lx\n",
392 		 kernel_map.virt_offset,
393 		 KERNEL_LINK_ADDR);
394 
395 	return 0;
396 }
397 
398 static struct notifier_block kernel_offset_notifier = {
399 	.notifier_call = dump_kernel_offset
400 };
401 
402 static int __init register_kernel_offset_dumper(void)
403 {
404 	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE))
405 		atomic_notifier_chain_register(&panic_notifier_list,
406 					       &kernel_offset_notifier);
407 
408 	return 0;
409 }
410 device_initcall(register_kernel_offset_dumper);
411